tag:blogger.com,1999:blog-1193838235528858822024-03-13T08:38:56.085+01:00The Science Fiction Writers' Guide to SpaceTsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.comBlogger79125tag:blogger.com,1999:blog-119383823552885882.post-10493822618398263012015-04-14T02:49:00.000+02:002015-04-14T02:49:09.204+02:00Want to get your science checked?Those of you who follow this blog will have undoubtedly noticed that I don't post much any more. The number one reason for that is I've been in the throes of a PhD with very little desire to write about science/astronomy/astrophysics outside of work. Basically, blogging here stopped feeling like something fun to do and started to feel like more work, which is not what I wanted.<br />
<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQzKZCbgX9p1QNYtw6b1k_3n7fON7gBe5ILIo-aKI27iX6PqAFusEY-jFjUh8cGbLCCqjw_tr1BtrO0EpNvGpmrpUnVsgwVDhQyPvSo05sh6GGOzIEc04vEaiumf5e4w0hg48j3ejlc5IA/s1600/DefyingDoomsdaycampaigncover.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQzKZCbgX9p1QNYtw6b1k_3n7fON7gBe5ILIo-aKI27iX6PqAFusEY-jFjUh8cGbLCCqjw_tr1BtrO0EpNvGpmrpUnVsgwVDhQyPvSo05sh6GGOzIEc04vEaiumf5e4w0hg48j3ejlc5IA/s1600/DefyingDoomsdaycampaigncover.jpg" height="196" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><i>Defying Doomsday</i>, an upcoming anthology</td></tr>
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If you've been paying close attention, you may have seen my book blog, which I have been maintaining because talking about books is entirely unlike talking about science, even if they are science fiction and fantasy books. If you haven't already checked it out, you can do so <a href="http://tsanasreads.blogspot.se/" target="_blank">here</a>. I'm also editing an anthology, <i>Defying Doomsday</i>, which is currently being <a href="http://www.pozible.com/project/188146" target="_blank">crowdfunded</a>. You can read more about it <a href="http://defyingdoomsday.twelfthplanetpress.com/" target="_blank">here</a>.<br />
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However, I still feel strongly about getting the science right (or at least, not horribly wrong) in fiction. To that end, I am selling five science checks as part of the crowdfunding for <i>Defying Doomsday</i>. If you've always wanted a professional astrophysicist to look over your story and tell you which sciencey bits are done well and which aren't so good, now's your chance! Here's what it says on <a href="http://www.pozible.com/project/188146" target="_blank">our Pozible page</a>:<br />
<br />
<blockquote class="tr_bq">
<div class="right_conp" style="margin-bottom: 5px;">
<span style="font-weight: bold;">Story Science Check</span>
</div>
Tsana Dolichva, whose day job is astrophysics, will provide a
professional science check of your work, assessing and critiquing the
scientific validity of a piece of your fiction (up to 10,000 words) PLUS
a limited edition hardcover copy of Defying Doomsday (exclusive to
Pozible backers) PLUS the ebook edition of Defying Doomsday (all
formats) AND your name in the book with our thanks<br />
<br />
(For longer pieces please contact us and we can sort something out!) </blockquote>
<br />
I am more than happy to make arrangements to look at longer work if that's what you would prefer. It's a pretty good deal; not only do you get to have your science checked, you also get to support an awesome anthology! And if you're wondering, I have done some science checking before, including for professional authors.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFN3kypQNhxw-JM5nesRs6PEG5p712CN8gJWfCveIdTfIn5GgSd8Ij6AkECND8oMnn4nKflSybfQ6pDoCwA2I4lVnC8TSN_ZK0eOvopWOgj_Kv9o_Hy3Xk938gh2XXn6jLz7SlvYoEFAuc/s1600/DDavatar1.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFN3kypQNhxw-JM5nesRs6PEG5p712CN8gJWfCveIdTfIn5GgSd8Ij6AkECND8oMnn4nKflSybfQ6pDoCwA2I4lVnC8TSN_ZK0eOvopWOgj_Kv9o_Hy3Xk938gh2XXn6jLz7SlvYoEFAuc/s1600/DDavatar1.jpg" height="200" width="200" /></a>Here's a bit more about <i>Defying Doomsday</i>: <br />
<br />
<blockquote class="tr_bq">
<em>Defying Doomsday</em> is an anthology of apocalypse-survival
fiction with a focus on disabled characters, which will be edited by
Tsana Dolichva and Holly Kench, and published by Twelfth Planet Press in
mid 2016.<br /><br />
Apocalypse fiction rarely includes characters with disability,
chronic illness and other impairments. When these characters do appear,
they usually die early on, or are secondary characters undeveloped into
anything more than a burden to the protagonist. <em>Defying Doomsday</em>
will be an anthology showing that disabled characters have far more
interesting stories to tell in post-apocalyptic/dystopian fiction.<br /><br />
The anthology will be varied, with characters experiencing all kinds
of disability from physical impairments, chronic illnesses, mental
illnesses and/or neurodiverse characters. There will also be a variety
of stories, including those that are fun, sad, adventurous and horrific.<br /><br />
The stories in <em>Defying Doomsday</em> will look at periods of
upheaval from new and interesting perspectives. The anthology will share
narratives about characters with disability, characters with chronic
illnesses and other impairments, surviving the apocalypse and contending
with the collapse of life as they know it.</blockquote>
Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-23796076279847723282014-09-21T22:12:00.000+02:002014-09-21T22:12:31.972+02:00An infographicI am a great believer in science for the sake of science. But a lot of <strike>politicians</strike> people aren't and need to be convinced of the merits of things like space travel and telescopes. To that end, here is an info graphic you can throw at the next person who tells you science is a waste of money. It's probably safer than throwing a punch.<br />
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<div style="text-align: center;">
<a href="http://www.greatbusinessschools.org/nasa/"><img alt="NASA" border="0" src="http://www.greatbusinessschools.org/wp-content/uploads/2014/08/NASA.jpg" width="500" /></a></div>
Source: <a href="http://www.greatbusinessschools.org/">GreatBusinessSchools.org</a>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-55103513883626496942013-07-12T02:22:00.001+02:002013-07-12T02:22:02.635+02:00The Colours of Space (and Currents)I recently read (well, listened to) <i>The Colours of Space</i> by Marion Zimmer Bradley. You can read my proper review <a href="http://tsanasreads.blogspot.com/2013/07/the-colours-of-space-by-marion-zimmer.html" target="_blank">over at my book blog</a>, but here I wanted to discuss some of the science that popped up in the book.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXAn6TfIug0XGBXzbo7z3jFcd9m98RyEDC4ES-S4wP0mQjuiuh4IhbLrOC4_scdwqAERN81KuNFuU_x2ZLEsAfibf1Q-2R7xGrXjgTvBrV-AqbzI3mhBEly_hylcmvHAGoMtd6GDM9IevN/s1600/958447922_8a051655a5_o.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXAn6TfIug0XGBXzbo7z3jFcd9m98RyEDC4ES-S4wP0mQjuiuh4IhbLrOC4_scdwqAERN81KuNFuU_x2ZLEsAfibf1Q-2R7xGrXjgTvBrV-AqbzI3mhBEly_hylcmvHAGoMtd6GDM9IevN/s320/958447922_8a051655a5_o.jpg" width="256" /></a></div>
The title of the novel — <i>The Colours of Space</i> — refers to the stars
being much more brightly coloured when seen in space, as compared with
when seen from inside the Earth's atmosphere. (There's another reference
there to plot elements as well, which I won't spoil, but I read the
main reference as being to the multi-coloured stars.) The thing is, the
phenomenon, as described in the story, is not entirely real. Yes, stars
come in different colours, but those colours range from red to yellow,
white and blue. There are no green stars. <br />
<br />
Interestingly enough, this isn't the first time I've encountered the
idea of green stars in old science fiction. I understand where the
misconception comes from — wanting to move through the optical spectrum
with increasing temperature — but that's not quite how it works. Have
you ever seen something glow "green-hot"? No. That's because green is in
the middle of the visible spectrum and when it's the peak wavelength of
a black body, the object is still emitting strongly in the neighbouring
red and blue wavelengths which, when they're all combined, appear
white. Similarly, blue stars (and red stars) aren't blue like the sky;
they look pretty white because the star is still emitting strongly in
the other visible wavelengths.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://upload.wikimedia.org/wikipedia/commons/f/f3/Orion_Nebula_-_Hubble_2006_mosaic_18000.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://upload.wikimedia.org/wikipedia/commons/f/f3/Orion_Nebula_-_Hubble_2006_mosaic_18000.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Orion Nebula. Image credit: NASA/ESA</td></tr>
</tbody></table>
On the other hand, it's not unreasonable to think that Earth's atmosphere would bleach out the "real" colours of objects in space. After all, hills and whatnot in the distance often look paler than up close (because of water and often pollution in the atmosphere). But we can still see distinct colours of stars even from Earth and even, if you have binoculars or a good camera, the colours of nebulae (which are entirely prettier than mere stars). The constellation of Orion is a good example. Betelgeuse is a red giant (down the bottom of Orion if you're in the <strike>Good</strike> Southern Hemisphere), the Orion Nebula looks purplish (on the "handle" of the bit that looks like a saucepan from the south), the Horsehead Nebula (in Orion's Belt) is on the pink side, and the rest of the stars are yellow, white and blue but all look fairly white (from Earth AND space).<br />
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<a href="http://3.bp.blogspot.com/-N2D6FAVfSo0/T0qlDthkOdI/AAAAAAAAHDg/VYm35qVB7jc/s1600/The+Currents+Of+Space.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/-N2D6FAVfSo0/T0qlDthkOdI/AAAAAAAAHDg/VYm35qVB7jc/s320/The+Currents+Of+Space.jpg" width="197" /></a></div>
This reminds of another old book in which the underlying premise is based on now-outdated and hilariously erroneous science: <i>The Currents of Space</i> by Isaac Asimov. In that book a rather important plot element is that supernovae are caused by clouds of gas (the titular currents) drifting around space and every now and then changing the elemental makeup of stars enough to make them explode. (I think specifically it was clouds of carbon, but I don't have the book nearby to check.) We now know that this is mostly nothing like what causes supernovae.<br />
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There are two types of supernovae: core-collapse and Type Ia. Core-collapse supernovae occur when a massive star (more than around ten times the mass of our sun) runs out of fuel in its core and can no longer maintain its size and collapses in on itself and explodes. To put it very simply. Type Ia supernovae occur when a white dwarf (the corpse of a star originally like our sun) has another star nearby feeding it matter. When the white dwarf gets too massive to maintain its fundamental (proton and electron) structure, it will collapse in on itself and explode (and become a neutron star).<br />
<br />
Just because these books are based on science we now know not to be true, doesn't mean they're not worth reading (although I suspect it contributes to them being out of print). Have you read any other books with science that was reasonable when they were written, but doesn't stand up to the test of time and progress?Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-56595449908749025892013-04-28T12:42:00.000+02:002013-04-28T13:18:46.582+02:00Friction in space and on EarthThis post is in response to a comment I got on my previous post <a href="http://tsanad.blogspot.se/2013/03/more-thoughts-on-importance-of-science.html" target="_blank">"More thoughts on the importance of science in science fiction"</a> where <cite class="user"><a href="http://www.giraffedays.com/" rel="nofollow">Shannon</a></cite> <a href="http://tsanad.blogspot.com/2013/03/more-thoughts-on-importance-of-science.html?showComment=1367101473712#c6865706765479498260" target="_blank">commented/asked</a> (I'm only quoting the question-y part of her comment):<br />
<blockquote class="tr_bq">
It really is a hard concept to grasp, the no-friction-in-space thing. I
don't think I really get it - I'm not sure how to visualise it, for a
start - but I don't understand how a space ship - of the super-advanced,
sci-fi kind - can't slow down. I mean, it's mechanical and computerised
and runs on fuel; on Earth anything we build for transportation will
slow down especially if there's a mechanical failure etc. I know in
space you can't "stop", you'd only drift, right? I'm hoping you can
explain this a bit more to me because I really do want to understand! <br />
<br />
(The more time I have to let this concept dwell in my brain, the more
I'm starting to get it. So what does happen when you, in sci-fi, go from
"warp speed" or whatever they like to call it, to, well, not?)</blockquote>
<br />
On Earth (or really, anywhere that isn't the empty vacuum of space) moving objects slow down because they lose energy through friction — rubbing against other objects. Commonly on Earth, the source of friction would be land, water and/or air.<br />
<br />
Some examples: <br />
<ul>
<li>The motor of a boat needs to stay on to keep the boat moving, because if the motor is turned off, the boat will be slowed down by the water pushing back against it.</li>
<li>If you ski straight down a hill (let's say a small hill for safety reasons) you will accelerate (get faster) while you're going down hill, but once you reach the flat bit at the bottom you will eventually slow down and stop without having to stop yourself. This is because of the friction between the snow and your skis. Generally, skiing works because there's much less friction between snow and skis than, say, between shoes and dirt, but there isn't zero friction. When you were going down the hill and getting faster, there was still friction, but at that point gravity pulling you downwards was stronger.</li>
<li>If you drop something from a great height (tall building, aeroplane), gravity will make it accelerate as it falls down. However, the air pushes back on it, upwards (or more generally, in the opposite direction to the movement) and eventually will prevent the object falling any faster. (With air, the friction is directly related to the size and shape of the object and how fast it's going, but I won't get into the maths.) The maximum speed the object can reach while falling is called terminal velocity.</li>
<li>On the other hand, if there is no air — for example on the moon — there will of course be no friction from air and things like feathers which normally fall very slowly (because of all the little fuzzy bits catching on the air) will fall at the same speed and acceleration as a lead ball (or whatever). This will also work in a vacuum chamber where all the air has been removed. Here is a video of an astronaut on the last Apollo mission dropping a hammer and a feather at the same time:<br /><div class="separator" style="clear: both; text-align: center;">
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And a gif of the same if you can't be bothered watching and listening to the 47 second clip:<br />
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</li>
<li>Brakes on cars and whatnot work by intentionally increasing the friction on the axle to slow down the spinning speed of the wheels</li>
</ul>
Now let's talk about how spaceships slow down in space. I want to emphasis that my complaint with <i>Across the Universe</i> wasn't that the spaceship was slowing down, but that it was slowing down <i>by itself</i>. Things can only slow down by themselves if there is friction around (so really they're not slowing down by themselves but because of friction, but we don't usually think about or notice friction so it seems like its happening by itself).<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggNjSPfapUVzX1IQBeWhcc7BfSgBLnZbPZeD1CJDAKpqqbhDL0nEKuxvI-_myILjJH5q3MMzF228BX5rdUCtsFgs9fsPrzq09DR-hW0110T00Ym8snK8VcmSJA8yMAB3i_imR3EQALLrLD/s1600/robinson_sts114_big.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="217" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggNjSPfapUVzX1IQBeWhcc7BfSgBLnZbPZeD1CJDAKpqqbhDL0nEKuxvI-_myILjJH5q3MMzF228BX5rdUCtsFgs9fsPrzq09DR-hW0110T00Ym8snK8VcmSJA8yMAB3i_imR3EQALLrLD/s320/robinson_sts114_big.jpg" width="320" /></a></div>
In real life, spaceships slow down (and manoeuvre) by firing their engines in the other direction. It might be a bit easier to picture on a smaller scale. Consider an astronaut on a spacewalk. Let's pretend they're not tethered to their ship and that the ship is out in deep space away from the gravitational influence of any planets. To be able to move around, the astronaut will have a gas tank (or similar) that will allow them to press a button to move forward. The gas will shoot out backwards for a couple of seconds, and the astronaut will move forwards. At this point, if the astronaut does nothing, they will continue moving in a straight line indefinitely. Basically until they run into something. The same thing happens with a spaceship: gravity and obstacles not withstanding, after it fires its engines for a bit to accelerate, it will keep going in a straight line at the same speed until something else happens to stop it. <a href="http://www.youtube.com/watch?v=hHXx8AmBwXg" target="_blank">This clip</a> from WALL-E is a good example (thanks to <a href="http://speconspecfic.com/" target="_blank">Shaheen</a> for the suggestion). Also note that once they start spinning, things will continue spinning until something else makes them change, which you can see a bit of in that clip.<br />
<br />
That doesn't mean things can't stop or slow down in space. Our astronaut — assuming they're not unconscious — can fire their gas in the opposite direction (to manoeuvre properly they'd have to have several directional options, six for complete manoeuvrability) to slow down. The spaceship can also fire thrusters in the opposite direction to slow down (either by having two sets or by rotating the main ones). Coming to an absolute complete stop is a bit tricky because a) you would have to balance forces very exactly and b) there's not much to use as a reference for how fast you're going out in space, but matching speeds with another ship is doable. And the astronaut slowing down enough to not break a wrist colliding with his ship is also useful. <a href="http://tsanad.blogspot.se/2012/10/turning-around-in-space.html" target="_blank">My older post about turning around in space</a> addresses some issues with why just stopping and going in the opposite direction isn't the most efficient way of doing it.<br />
<br />
The very last part of the question was:<br />
<blockquote class="tr_bq">
So what does happen when you, in sci-fi, go from
"warp speed" or whatever they like to call it, to, well, not?</blockquote>
<br />
The short answer to this is, whatever you want. Warp speed and hyperspace and other "let's cheat to go faster than the speed of light devices" aren't real. They're generally not based on real physics, or if they are, it's very extrapolated and speculative and could well turn out to be just as implausible. That said, faster than light travel is a staple of science fiction and I'm not suggesting we should eliminate it because it's implausible. If <i>all</i> science fiction stories used only slow or relativistic (which means close to the speed of light, when weird things happen. <a href="http://tsanad.blogspot.se/2012/01/rapid-slow-space-travel.html" target="_blank">My post about it</a>) then there'd be a lot of very slow stories which would get boring. Variety is nice.<br />
<br />
As long as the rest of the science is plausible, then I don't have a problem with a bit of faster than light travel and faster than light communication. If the writer doesn't feel up to making up a semi-plausible sciencey explanation, then my personal preference is not to try explaining how the FTL works at all. Because they usually stuff up some minor point which annoys me disproportionately.<br />
<ul>
</ul>
Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com4tag:blogger.com,1999:blog-119383823552885882.post-86739550135831659882013-03-25T10:52:00.001+01:002013-03-25T10:52:37.833+01:00More thoughts on the importance of science in science fictionToday I was directed to a <a href="http://misabuckley.com/index.php/does-the-science-in-science-fiction-matter/" target="_blank">blog post</a> about how important science is in science fiction using the <strike>hideous crime against science</strike> example of Beth Revis's <i>Across the Universe</i>, which I blogged about <a href="http://tsanad.blogspot.se/2012/03/sciencefail-rant-across-universe-by.html" target="_blank">here</a>. (From the sound of it, the blog author may have read my post or someone else's similar reaction to the book.) The blog author asks how important is accurate science <i>really</i>, and is there a line? The rest of this post is based on <a href="http://misabuckley.com/index.php/does-the-science-in-science-fiction-matter/#comment-2399" target="_blank">my comment</a> over there.<br />
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I think there is definitely a line. Stuff like faster than light travel, teleportation, artificial gravity (in some circumstances) are fair game to use in fiction with no or only hand-wavey explanations. (In fact, sometimes trying to be too specific with them can be detrimental.) Everyone either knows that stuff isn't real or can very easily google it to find out. And it has a distinct plot-based purpose: if everyone wrote relativistically accurate science fiction (no faster than light travel), it would be very boring. When getting from A to B isn't the point of the story, using an accepted trope to speed things up is totally fine. Same with power sources for spaceships. That's an area where there will definitely be heaps of progress in the future that we can't necessarily predict and so hand-waving is fine.<br />
<br />
What isn't fine is getting basic and fundamental concepts wrong like the ship slowing down in space that Revis did. Note that she also had a hand-wavey power source in said spaceship and THAT is fine. But thinking there's friction in space? No. It's a popular book for teens and it's actively confounding a concept that's actually quite difficult to teach. Pretty much no one (and certainly no teen) has been in space and so books and movies are all most of us have to base our intuition on when it comes to how stuff in space works. For things on Earth, it's easy to think about our everyday experiences and predict (from a basic physics point of view) what will happen. On Earth, stuff DOES gradually slow down. In space it doesn't and that's a concept that some kids, when learning physics for the first time, find difficult to grasp. It's a disservice to further confuse the issue.<br />
<br />
And for the record, usually if an author tries to do their research, it's obvious in the writing.<br />
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Now, when I was searching for a link to something Revis said in an interview about her research for this book (or lack there of), I came across the <a href="http://www.bethrevis.com/frequently-asked-questions/" target="_blank">FAQ on her website</a>. One of the questions and responses is:<br />
<blockquote class="tr_bq">
<b>Q: WAIT A MINUTE. I think I found a scientific error in Across the Universe.</b><br />
<i>A: Well–there’s a chance I messed up. BUT if you’re one of the ones who noticed the REALLY BIG scientific error…well, I’ll just say that there IS a sequel, and it DOES address this, and maybe it’s not that the book is wrong, but that the characters have the wrong idea…</i></blockquote>
I can only assume the "REALLY BIG" scientific error is the friction in space thing that's made me so angry. I'm not 100% convinced that it and associated sciencefails are properly addressed. I can think of one scenario that would make it "the characters are wrong but the science isn't", and from the plot of book one and the hints I've seen around the web for the events in books two and three, it doesn't seem likely.<br />
<br />
Have any of my readers actually read the second book? Is it worth my time (and money) reading it just so I can blog about the problems in it? So far the answer to the second question has been "no" and picking up the second book in a shop and flicking through it didn't exactly fill be with the desire to jump back into that world.Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com7tag:blogger.com,1999:blog-119383823552885882.post-13631146375053748622012-12-15T17:35:00.001+01:002012-12-15T17:35:15.702+01:00Review: Blue Silence by Michelle Marquardt<em>This review is posted as part of my <a href="http://tsanad.blogspot.nl/p/aussie-women-writers-challenge.html" target="_blank">Australian Women Writers Challenge</a>. I have cross-posted it from my <a href="http://tsanasreads.blogspot.com/" target="_blank">review blog</a>. I have now completed the Australian Women Writers Challenge for 2012, and you can read my de-brief <a href="http://tsanasreads.blogspot.com/2012/12/aussie-women-writers-science-fiction.html" target="_blank">here</a>.</em><br />
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<i>Blue Silence</i> by Michelle Marquardt was originally published in 2002 and is sadly now out of print. Although I see it's <a href="http://www.infinitas.com.au/Product.php?bar=9781863252515" target="_blank">in stock at Infinitas</a> as of this writing. It was a winner of the George Turner Prize (as my edition proclaims on the cover).<br />
<br />
The story opens when a mysterious ship docks with one of the space
stations in orbit around Earth. The ship is, on the outside, an exact
replica of one that was sent out into deep space 180 years ago, and then
never heard from again. The difference? This ship has new drive
technology which was only invented a couple of years ago. And instead of
the seven original crew members, it's full of stasis pods and five
hundred creatures, half of whom look human, half of whom look almost
human.<br />
<br />
None of the aliens know where they came from or why — they have no
memories before waking up docked with the space station — and the
authorities on the space station don't really know what to do with them
either.<br />
<br />
Senator Maya Russini is the leader of the group of people who first
board the ship. A mission which one of the group does not return from
alive. Are the aliens dangerous? What do they mean for the various
political machinations happening within the space station's government
and between them and other governments?<br />
<br />
I liked Maya. She was an excellent example of a female character that
doesn't need to run around kicking people in the head to gain power.
She's also secretly a telepath (secret because she didn't register when
she turned 21), but in a nice twist, she's the weakest kind of telepath,
only able to read emotions, not thoughts. I think Marquardt has done a
good job of portraying a society in which women are equal without making
a big deal of it. (There are, in the end, more male characters, but
that's mostly because the two main aliens are male.)<br />
<br />
Her friend Ienne, the Minister for Foreign Affairs, also gets involved
with the aliens. Unlike Maya who mostly regards them as suspicious and
dangerous, Ienne is always looking for a way to use them to his
advantage (there's a treaty they and another space station are wrestling
over). He also goes out of his way to be rude to everyone with the
occasional exception of Maya.<br />
<br />
As I noticed when I was past half-way, <i>Blue Silence</i> is a very
character driven story, unusually so for science fiction. The world does
not need saving, nor does any war break out. Instead the action comes
directly from the interactions between the characters, including two of
the aliens who I don't think I can say much about without spoiling key
elements. There is excitement and there's no missing the climax, but
it's not like a plot driven story where all the action was building up
to an inevitable climax and world-saving event. In the end, we know more
about the aliens, but we don't know everything. Some answers are only
hinted at or presented as speculation. In a way, this was slightly
annoying because I like to know all the answers (arguably why I'm a
scientist in real life), but it worked for the book. The story wasn't
about the people trying to study the aliens, it was about people whose
paths happened to cross theirs.<br />
<br />
Also, the science, which I feel obliged to comment on, was well done. It
wasn't a technology-oriented story, but having been published ten years
ago, there was a risk the technology would feel a bit dated now. It
didn't. They didn't have smart phones, but they did have pagers which
were functionally mobile phones and received the equivalent of email on
ubiquitous computers. There was also a discussion on the merits of different kinds of space stations (mimicking Earth versus giant building floating in space) which was interesting.<br />
<br />
I highly recommend <i>Blue Silence</i> to anyone looking for something a
bit different in their science fiction. It also emphasises the variety
we have in the Australian science fiction field, something you might
miss if you only looked at the most recent few releases.<br />
<br />
4.5 / 5 stars
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Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-67234457691297428252012-12-07T08:47:00.000+01:002012-12-07T08:47:05.666+01:00Year-long days and living in them<i>This blog post was inspired by an email conversation with someone regarding the possibility of a planet having year-long (or half-year long) day/night cycles. The original question was whether this is even possible and whether such a planet would be habitable.</i><br />
<br />
From a purely astronomical point of view, this is definitely possible. There's no reason why you couldn't have a slowly rotating planet at around the same distance from it's sun as Earth is (well any reasons that do exist are fairly theoretical so we can ignore them). That said, if the planet is similar to Earth and its sun is similar to ours, then you kind of have to have the same length year because the length of the year (ie how long it takes to orbit the star) depends only on the mass of the star and the distance from it. This is due to Kepler's Laws, which I have <a href="http://tsanad.blogspot.se/2011/04/introduction-to-gravity.html" target="_blank">previously discussed here</a>. If you made no changes to star/planet distance, the year length would have to be the same.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjIKgxzsMGSsGCHcasIV1-65Oy_foPVoGcpI-Og7smAcaVaXV-K_jAL-fgYtU_hXB2mofuqbNzys4OS19I4GgKmLJ280SzCtJcsNjoh2oJyOr2yCmNf1mqodMM5Y8EKno2yo-MmEZKoFa3l/s1600/400px-Mercury's_orbital_resonance.svg.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjIKgxzsMGSsGCHcasIV1-65Oy_foPVoGcpI-Og7smAcaVaXV-K_jAL-fgYtU_hXB2mofuqbNzys4OS19I4GgKmLJ280SzCtJcsNjoh2oJyOr2yCmNf1mqodMM5Y8EKno2yo-MmEZKoFa3l/s320/400px-Mercury's_orbital_resonance.svg.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Image nicked from Wiki <a href="http://en.wikipedia.org/wiki/File:Mercury%27s_orbital_resonance.svg" target="_blank">here</a>. The little red line <br />represents the same point on the surface of <br />Mercury. The numbers are the order in which <br />the positions happen: 6, 1, 2 are night for <br />the red line and 3, 4, 5 are day, roughly.</td><td class="tr-caption" style="text-align: center;"><br /></td>
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You could also have something similar to Mercury which has three rotations (called "sidereal days" which are measured relative to the stars, not the sun) to two years. Because it rotates so slowly, weird stuff happens with its solar days (the light/dark periods, completely ignoring the positions of stars) so that in one year it experiences half a solar day. Mercury is like this because it's so close to the sun. It could have been tidally locked (the same side always facing the sun – discussed further, including for Mercury in particular, <a href="http://tsanad.blogspot.se/2011/05/tides-and-their-locks.html" target="_blank">here</a>) but the gravitational effects of the other planets in the solar system caused this more unusual resonance.<br />
<br />
However, if we're talking a planet as distant from the sun as Earth is, there's no danger of it becoming tidally locked in the sort of cosmological time frame we're currently living in. The time taken for the angular momentum between planet and star to be distributed into the tidally locked configuration takes longer the further apart they are (and the less massive when they're close enough). The Earth-moon system will eventually become more tidally locked: the moon already faces the same side towards us all the time, and eventually the same side of Earth will always point towards the moon.<br />
<br />
But that's a bit of a tangent, back to planets with long days and nights. You could have a planet rotating as slowly/quickly as you like, but you should be mindful that the people living there would almost certainly have a way of distinguishing between sidereal and solar days. Ancient people on Earth already had this worked out (the difference between sidereal and solar days is why the stars move across the sky with the seasons).<br />
<br />
<b>Living there</b><br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3iqU06QtHV8rP8CcXuwnROeKtp2VjN1bwEnglUCv31vu3Trc4VVM_8uGjM0vpM1fUD6zVVJX3Ez27vw07zOyUsDKTcTTQOZ_HFTGeISAHQa0HkSIykmrwNAW9mSvS4qY99yOUTKyZLXc9/s1600/uranus_keck_full.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3iqU06QtHV8rP8CcXuwnROeKtp2VjN1bwEnglUCv31vu3Trc4VVM_8uGjM0vpM1fUD6zVVJX3Ez27vw07zOyUsDKTcTTQOZ_HFTGeISAHQa0HkSIykmrwNAW9mSvS4qY99yOUTKyZLXc9/s400/uranus_keck_full.jpg" width="241" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Uranus: almost completely sideways.</td></tr>
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If you did have a planet with a year-long day, the periods of day and night would be roughly equal in the same way they are on Earth, just scaled up. It could vary a bit depending on the planet's axial tilt (how much the line between the poles is tilted relative to the plane of it's orbit — Earth's is around 23º and changes slightly when earthquakes occur) so the more inclined the axis, the more extreme the seasons. If there was no or very little axial tilt, there wouldn't be seasons. The other variable in day/night lengths is the latitude. Further away from the equator sunrise and sunset would last longer and the shortness of winter days and length of summer days would be more extreme (as on Earth, but a different axial tilt could make this more so). If there was no axial tilt, the poles would be in a state of twilight permanently. The other extreme is something like Uranus which has a 90º-ish axial tilt so that during a southern summer the south pole points towards the sun and during a southern winter the south pole gets no sun at all. Spring and Autumn are the transition period. The equator is in twilight during summer and winter and has more "normal" days, like what we're used to, during spring and autumn.<br />
<br />
Also, astronomical plausibility aside, I'm not convinced complicated life could naturally arise on a planet with a super-long day/night cycle, due to the long periods of boiling (day) and freezing (night). In terms of temperature-stability, probably only the twilight areas would be habitable. I suppose you could have migrating species (but that also has problems because in staying in permanent twilight they'd need sufficient landmasses connecting the two poles). Also, you'd probably get some sort of storms around the twilight zone, since the temperature would be in in a state of flux. I'm not an expert on atmospheres or meteorology, though, so that's a (-n educated) guess and I can't be too specific. But in short: our 24 hour days are what keeps Earth's temperature relatively temperate and suitable for life.<br />
<br />
There's be fewer issues for microbial life to arise but I don't know that anything larger would be viable. Maybe at the poles: if the planet was slightly closer to its star than Earth is, there could be non-migratory life living near the poles and with a stable orbit and rotational period, it should survive. Since the non-polar regions wouldn't have naturally arising complex life, there could be with completely different ecosystems/forms of life at either pole with only something like microbial ancestors connecting them.Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-1640841232415476062012-10-21T21:24:00.002+02:002012-10-21T21:24:36.331+02:00Atmospherically SpeakingToday I have another <a href="http://tsanad.blogspot.se/p/ask-tsana.html" target="_blank">Ask Tsana</a> post.<br />
<br />
<cite class="user"><a href="http://brainoplasty.com/" rel="nofollow">Brookelin</a></cite><span class="icon user"></span><span class="datetime secondary-text"></span> asked:<br />
<blockquote class="tr_bq">
<i>Hi again, Tsana.<br /><br />I was wondering - in an alternate universe, what would it take for a species to survive on Mars?<br /><br />I
know that it has some atmosphere, but not a whole lot. With the
pressure being below the Armstrong limit, could there feasibly be large
creatures (between collie and bear size) that could survive would have
higher thresholds and what would they need to do so?<br /><br />If the water on a human's tongue boils in space, would an alien creature in these environments be able to have eyes and mouths?<br /><br />What might these species' need to overcome the intense radiation caused by Mars' weak magnetosphere?<br /><br />Could
bio-genetically enhanced humans ever survive these conditions outside a
space suit for periods of time upwards of an hour, but less than a day?
<br /><br />Are these too many questions? Do you know the answers to any of them, or is this more of a medical thing?</i></blockquote>
I don't have answers to all of these questions because, as Brookelin said, some are more medical/biological and that's not my area of expertise. I will say that what we generally know a lot about is life on Earth. There are some constraints that exist for life on other planets but there is nothing to say that it has to resemble Earth life. They could have eating and seeing organs completely different to what we're used to. Even on Earth there's a pretty wide variety. I'm not sure that merely genetically enhancing a human would be enough to let them walk around on Mars. Science fictions stories have gone there, but I'm not sure genetics is up to it. I could be wrong, I'm just guessing. Hopefully my comments below on atmospheres and life on smaller planets such as Mars will answer the rest of the questions, though.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Mars_and_Syrtis_Major_-_GPN-2000-000923.jpg/600px-Mars_and_Syrtis_Major_-_GPN-2000-000923.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Mars_and_Syrtis_Major_-_GPN-2000-000923.jpg/600px-Mars_and_Syrtis_Major_-_GPN-2000-000923.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Mars. Credit: NASA, ESA, and The Hubble Heritage Team <br />
(STScI/AURA)</td></tr>
</tbody></table>
It's true that Mars has a very thin atmosphere; it's about 0.6% as dense as Earth's at their respective surfaces. Part of the reason for this is Mars's lower gravity. In general, gases will expand to evenly fill the container they're in. When the container is a planet's gravitational field, we get denser air closer to the ground and less dense air higher up. This is because the air higher up is pushing down on the lower air while having less air above it to push it down. More or less.<br />
<br />
Air is made up of particles (atoms and molecules) which move around very quickly and bounce off each other. That's why a gas is a gas and not a liquid or solid: the particles in a liquid don't move quickly enough to completely overcome the forces attracting them to each other and the particles in a solid can't move more than vibrating on the spot because the forces holding them in place are so strong. The energy that makes the particles move, for all states of matter, depends on the temperature: the hotter, the faster. The other important consideration is particle mass. At the same temperature, oxygen and hydrogen molecules (O<sub>2</sub> and H<sub>2</sub>) have the same energy. However, oxygen weighs sixteen times as much as hydrogen (because the atoms are larger and heavier) so it takes more energy to move oxygen molecules at the same speed as hydrogen molecules. The result is that at the same temperature, oxygen molecules move more slowly than hydrogen molecules. And it takes less energy for hydrogen molecules to reach escape velocity (the speed required to escape the gravitational pull of Earth/whatever planet) than oxygen. And that's why there is very little hydrogen in Earth's atmosphere despite it being the most abundant element on a cosmic scale — it escapes into space. It's also the reason only the gas giants, notably Jupiter and Saturn, have any significant about of hydrogen in their atmospheres — they have the strongest gravitational fields.<br />
<br />
So, Mars. Mars is smaller than Earth, with about a third the acceleration due to gravity at its surface. Mars is made up of <a href="http://en.wikipedia.org/wiki/Composition_of_Mars" target="_blank">similar elements</a> to Earth, most likely because they formed so closely together, so it's likely that the same sort of lighter elements could have made up Mars's atmosphere. However, due to the lower gravity, not only hydrogen but oxygen and nitrogen would also have escaped or never been captured by the planet. I would guess the main reason there's so much frozen carbon dioxide at the poles is because it has a relatively high melting point of -78ºC rather than the much colder melting points of oxygen (-219º C) and nitrogen (-210º C). For comparison, Mars's surface temperatures vary between -143º and +35º C. So basically, even if you imported or mined enough gas to raise the air pressure to human survivable levels, it would all be lost into space and would need constant replenishing which would get tedious and be difficult to sustain. You'd also, ideally, raise the surface temperature to more consistently human survivable levels — probably using some sort of greenhouse effect to trap more of the sun's energy — but that would just hasten the atmosphere's escape.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/b/b7/Titan-Complex_%27Anti-greenhouse%27.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://upload.wikimedia.org/wikipedia/commons/b/b7/Titan-Complex_'Anti-greenhouse'.jpg" width="309" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Titan's atmosphere as seen by Cassini. Credit: NASA</td></tr>
</tbody></table>
But all is not lost. Heavier molecules exist, particularly those made out of carbon. Titan, one of Saturn's moons, is smaller than Mars but has an atmospheric pressure <i>greater than Earth's</i> by about 45%. It's colder than Mars, which allows its atmosphere to condense a bit, but it's only got a surface gravity of around a seventh that of Earth's (less than half of Mars's). <a href="http://en.wikipedia.org/wiki/Titan_%28moon%29" target="_blank">According to Wiki</a>, its atmosphere is composed mainly of nitrogen (as is Earth's) and methane with some traces of heavier carbon molecules. It's a combination of the temperature, the distance from the sun, Saturn's magnetic field and some form of replenishing methane that keeps Titan's atmosphere thick and, well, full of methane. Distance from the sun is significant by itself because Titan is far enough that the ionising solar wind is weak enough to not completely ionise and destroy the top layers of its atmosphere. The same strategy probably wouldn't work on Mars to increase the atmospheric pressure permanently unless you could find some magically resistant to solar radiation molecule to populate the atmosphere with. There are two interesting theories for what keeps replenishing the methane on Titan (which should be destroyed even by the lowered energy it receives from the sun): cryovolcanoes — volcanoes shooting icy hydrocarbons instead of lava — or biological processes using/generating methane in place of water.<br />
<br />
The high levels of ionising radiation on Mars are as much due to its lack of atmosphere as its lack of magnetic field. (Side note: there's evidence that there was a magnetic field on Mars in the past, though I don't think we know why it went away.) Earth's atmosphere absorbs a lot of the ionising and UV radiation the sun throws at us (part of the reason the ozone layer is important). Not <i>all</i> of it is deflected — and things like X-rays and gamma rays can't be deflected because they don't have an electric charge — especially near the magnetic poles where the aurorae are caused by charged particles, mostly from the sun, interacting with the atmosphere. However, giving Mars a magnetic field would definitely help. Earth's is generated by molten iron in its core so it's not outside the realm of over-dramatic science fiction to drill a hole into the centre and start the core spinning. Come to think of it, <a href="http://www.imdb.com/title/tt0298814/" target="_blank">Hollywood's already done that</a>, just with Earth not Mars. (For the record, the ridiculous issues with that movie include the structural integrity of the hole and the failure to correctly represent <a href="http://tsanad.blogspot.se/2011/07/gravity-inside-solid-and-hollow-bodies.html" target="_blank">changes in gravity</a>.) A more feasible way to avoid radiation on Mars would be to live underground so that the ground above you did the work of absorbing harmful radiation. The reason too much radiation is bad for all forms of life is that it destroys and changes molecules. In humans this is one of the causes of cancer. In microbial life, which might only have a few cells to begin with, it's more deadly. It's why sterilising things with UV light works.<br />
<br />
So basically, the easiest way to get people living and wandering around on Mars is to have them live in airtight structures and give them suits for walking around outside it. The suits wouldn't have to be as extreme as space suits though, so that's something. I'm not saying it's completely impossible to walk around on the surface with less protection, just very difficult. And because someone will mention it in the comments if I don't, I've heard that Kim Stanley Robinson's Mars books, starting with <i>Red Mars</i>, do a good job of talking about the terraforming process, although I haven't read them. <a href="http://www.goodreads.com/series/51185-the-grand-tour" target="_blank">Ben Bova's Grand Tour of the solar system books</a> (eg <i>Mars</i> or <i>Saturn</i> and <i>Titan</i>) explore alternative forms of life all over the solar system. If you can stomach a bit of sexism, some of them are worth a read.<br />
<br />
<br />Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-225534312539560112012-10-01T20:10:00.000+02:002012-10-01T20:12:34.476+02:00Turning around in space<br />
Another ask Tsana question today. (And a relatively shortish response, sort of. Gasp!) Keep 'em coming, guys :-)<br />
<br />
Anon asked:<br />
<br />
<blockquote class="tr_bq">
<i>How hard would it be to turn around in space... Say for some reason,
Curiosity needed to turn around midflight and return to earth. Would
BURNING fuel on some sort of reverse thruster work or would it have to
make the trip to Mars, orbit the planet and break orbit to return</i><span id="bc_0_20b+seedCh2-D" kind="d"></span> </blockquote>
<blockquote class="tr_bq">
<i><span id="bc_0_20b+seedCh2-D" kind="d">This is for a picture book that I feel impelled to be at least somewhat based in reality... which may be dumb.</span></i> </blockquote>
<br />
Hi Anon,<br />
<br />
It's absolutely NOT dumb to try to make picture books or any sort of books for kids plausible or semi-plausible. Especially when it comes to these sorts of areas where they can't possibly have any hands-on experience. Hollywood bombards them (and all of us) with so much inaccuracy that any little bit of truth helps. If they remember your book when they come to learn about these things later on, it will help the science stick. If all they have to go on are poorly researched movies which have given them wrong "intuition" about these things, it makes it a lot harder for them since they have to unlearn the rubbish first.<br />
<br />
On to the actual question part! <br />
<br />
It's pretty tricky to turn around in space. Because there's no friction, you have to use the same amount of energy it took to speed up to slow down by the same amount (so to come to a stop, say). This is a huge waste of fuel. Changing course more subtly isn't as difficult, however.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/en/9/9e/Apollo_thirteen_movie.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/en/9/9e/Apollo_thirteen_movie.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Apollo 13 Movie poster. (Nabbed from Wiki)</td></tr>
</tbody></table>
For something specifically like Curiosity: an unmanned probe sent to another planet, I can't think of a reason they'd try to get it back to Earth (unless a sample return was specifically part of the mission plan, but I don't think that's what you're asking). If something went wrong, they'd be more likely to cut their losses and abandon it. Also, almost all of that kind of probe's fuel is used up during take off, leaving only enough for minor course corrections and landing. In that case, plausibility would dictate that attempting a gravitational slingshot around Mars would be the only way to maybe get it back. You'd also have the issue of how to collect it from Earth's orbit since a) Earth would have moved a lot while it was travelling and b) if you were lucky enough to get it to pass close to Earth, it would be travelling quite fast and probably wouldn't have enough fuel to go into orbit around Earth for collection. It would definitely be tricky.<br />
<br />
A very good example of a scenario relating to your question is the movie Apollo 13. If you haven't seen it, I recommend that you do. As far as I can remember (and I freely admit it's been many years since I watched it, so don't hold me to this), the physics in it was pretty accurate. In that, things go wrong with the (real life) 70s moon mission and, among other fixes, the astronauts have to slingshot around the moon to get safely back to Earth.<br />
<br />
In the end, I'd say it depends on the nature of your mission as to what would be done. If it was a manned mission to Mars, for example, they might try harder to bring them back early, but physics would not be on their side.<br />
<br />
Hope that answers your question!Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-75949003972861974182012-09-21T21:55:00.000+02:002012-10-01T20:10:29.332+02:00Gravity and atmospheric pressureI have another response to an "Ask Tsana" question today.<br />
<br />
<cite class="user"><a href="http://brainoplasty.com/" rel="nofollow">Brookelin</a> asked:</cite> <br />
<blockquote class="tr_bq">
<b>I was wondering... with planets like Europa and possibly Ganymede, who
possible have oceans, if humans made future settlements under said
oceans, would the pressure from the water above counteract the effects
of reduced gravity on the human body?</b></blockquote>
<br />
Interesting question. A preliminary point: it's Jupiter's moons Europa and Callisto that probably have sub-surface oceans (especially Europa), not Ganymede which is a solid rocky moon.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://apod.nasa.gov/apod/image/1101/europa_galileo_900.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="227" src="http://apod.nasa.gov/apod/image/1101/europa_galileo_900.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Europa, one of Jupiter's moons, has a vast ocean beneath <br />
its surface. Credit: Galileo Project, JPL, NASA; <br />
reprocessed by Ted Stryk</td></tr>
</tbody></table>
So, how do pressure and gravity work? In this context, gravity is the force that holds a planet/moon/star together and which attracts other objects to it. So we're all being pressed into the surface of Earth due to Earth's gravity. Pressure is the force a surrounding fluid (air, water, etc) exerts on something. So the atmospheric pressure we feel on Earth is pushing at us from all sides (well, OK, not out from the ground) and is due to all the air in Earth's atmosphere.<br />
<br />
When you go swimming, the further you dive down, the higher the water pressure around you gets. This is because the deeper you are, the more water is above you to press down on you and the more water is above the bits of water on either side of you, also pressing into you. If you've ever been snorkelling (or scuba diving, I suppose but I can't vouch for that due to lack of experience) you might have noticed that it gets harder to breath the deeper you go (assuming a long enough snorkel). This is due to the water pressing down on your chest. Air does the same thing, but we're used to it, so we don't notice. The other thing that happens under water is that the water underneath you pushes up on you: this is called the buoyancy force and it's why things (people, tennis balls, icebergs, etc) float.<br />
<br />
The higher up you go from sea level on Earth, the thinner the atmosphere gets (basically, the less atmosphere left above you). To halve the atmospheric pressure you experience, you need to go 5 km above sea level. (On the other hand, to double the pressure, you only need to be about 10 metres under water.) At that height, gravity is still pretty much the same as at sea level (the difference is about an eighth of a percent) and your main problems are getting enough oxygen (not a huge problem if your lung capacity is OK) and possibly altitude sickness (potentially a problem).<br />
<br />
We need some amount of air pressure around us to survive which is part of the reason astronauts wear space suits. However, there is a range at which we can still function and that range increases if we have extra oxygen (and don't get altitude sickness). People have climbed Mt Everest (8.8 km above sea level) which has an atmospheric pressure of about a third that at sea level at it's peak without oxygen, but even doing it with oxygen requires training and acclimatisation and isn't something anyone can just decide to do one morning (well, unless they also decide to put in all the training). <br />
<br />
On the surface of Europa or Callisto, there is no atmosphere and hence no atmospheric pressure. The ground is frozen water (probably not pure water, if only due to meteorite bombardment, but that's beside the point), but let's suppose we somehow got under the surface and set up a habitat. Since we're human and breathe air (a particular mix of mostly nitrogen, with some oxygen, carbon dioxide and misc) we'd have to have some sort of bubble habitat under the sea. But it's not just the air part that we need, we also need it to be around one (Earth) atmosphere of pressure. So we build a habitat with solid walls and fill it with the right amount of air... and then we're inside an air bubble and the water outside the bubble is having no effect on our bodies directly. The only way it would is if we went out into the water without pressure suits. Which probably wouldn't be the best idea in the world for a variety of health and safety reasons that don't necessarily have to do with the water pressure.<br />
<br />
Now let's talk about gravity. The main way we detect small changes in pressure is though our ears, for example when they pop on taking off and landing in aeroplanes. The main way we detect changes in apparent gravity (which is the same as changes in acceleration) is when we feel lighter or heavier. If you're standing, this might manifest as extra strain on your legs, if the apparent gravity has increased, or a feeling like your stomach is moving upwards (possibly accompanied by nausea), if the apparent gravity has decreased. You don't experience the same feeling underwater or up a tall mountain because the gravity doesn't change in those places although the pressure does.<br />
<br />
So what I'm ultimately trying to say is that the effects of gravity and atmospheric pressure are different. You can't compensate for a decrease in gravity by increasing pressure. Pressure is a force applied from all directions simultaneously, while gravity acts in just one direction. We know about the effects of Earth gravity, high gravity (from fighter pilots for example) and zero/microgravity (like on the space station) on people but much less about the effects of gravitational fields less than Earth's and more than zero. Europa's and Callisto's accelerations due gravity at the surface are about 13% Earth's and for comparison, the moon's is about 17% Earth's) so while we have had some experience with the moon landings during the Apollo missions, we don't really know how serious the health problems associated with spending prolonged periods at such low accelerations would be. There almost certainly would be some, but they probably wouldn't be as severe as zero gees. So while we can't use water pressure to compensate for gravity, it's not impossible for people to live on one of the moon's of Jupiter. We just don't know enough about what long term problems might arise.<br />
<br />
<br />Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com6tag:blogger.com,1999:blog-119383823552885882.post-32453711125787937212012-07-25T12:10:00.005+02:002012-07-25T12:10:54.481+02:00Quick note on terraforming Galilean moons<div dir="ltr" style="text-align: left;" trbidi="on">
This post comes from an "Ask Tsana" comment.<div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<a href="http://www.blogger.com/blogger.g?blogID=119383823552885882&pli=1" rel="nofollow">Sam Keola</a> asked:</div>
<blockquote class="tr_bq">
<div class="comment-content" id="bc_0_13MC">
<i>Aloha
from Hawai'i again Tsana! I have a hypothetical question. If in the
very distant future we had the technology to terraform, would it be best
to terraform Callisto and Ganymede or set up domed bases? Ganymede is
suppose to have an ocean similar to Europa, but I'm not sure if that's
"world wide". Your thoughts on terraforming!</i></div>
</blockquote>
The main problem with terraforming either of those moons is their gravity isn't large enough to keep any atmospheric gases for long after they're introduced. Ganymede, which is larger, has a surface gravity of close to a seventh of Earth's which is less than half of Mars's and Mars has difficulty keeping much of an atmosphere itself. Purely from that point of view, domes or something else sealed would be better.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://apod.nasa.gov/apod/image/0201/callisto3_gal_big.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://apod.nasa.gov/apod/image/0201/callisto3_gal_big.jpg" width="313" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Callisto. <br />Credit:
<a href="http://www.jpl.nasa.gov/galileo/index.html">Galileo Project</a>,
<a href="http://vraptor.jpl.nasa.gov/voyager/voyager.html">Voyager Project</a>,
<a href="http://www.jpl.nasa.gov/">JPL</a>,
<a href="http://www.nasa.gov/">NASA</a></td></tr>
</tbody></table>
<br />
Once you've decided to build something sealed, then it would be better for colonists to build on Ganymede, as opposed to the other Galilean moons, for a few reasons:<br />
<ul style="text-align: left;">
<li>It has the highest surface gravity, not by much but every little bit would prevent colonist's bodies from degrading. Actually, because the Galilean moons are less dense than Earth's moon, they have a lower surface gravity, despite being larger in volume. You're going to have low gravity-related heath problems in any case, however.</li>
<li>It's not as close to Jupiter as Europa (and Io!) is. The phenomenon responsible for keeping Europa's interior liquid is tidal friction thanks to its proximity to Jupiter. It's the sort of thing that also makes the surface more unstable (prone to volcanoes -- not as much as Io, of course -- and quakes) and less hospitable to people. You can read more about it <a href="http://tsanad.blogspot.se/2011/05/tides-and-their-locks.html" target="_blank">here</a>.</li>
</ul>
On the other hand, if what you're doing is mining and the minerals etc you're interested in are found on both Ganymede and Callisto, then Callisto is the place to put your colony. It's gravity slightly lower and, more importantly, it's further from Jupiter, meaning that when you're exporting your rocks, there's less gravitational pull from Jupiter to overcome.<br />
<br />
In terms of finding water to mine, all three moons in question (ie, not Io) have water on them, so that shouldn't be too much of a problem, especially if you're already planning to mine other things.<br />
<br />
Of course, there are also reasons why Europa would be a desirable place for a colony, especially for scientific reasons, exploring it's subsurface ocean primary among them. There's a good chance there's microbial life there.<br />
<br />
So there you have it, if you're going to colonise the larger Galilean moons, it's better to build a close structure on them rather than try to impart an atmosphere. It would be even harder than giving Earth's moon a permanent atmosphere.</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com1tag:blogger.com,1999:blog-119383823552885882.post-59970024473771975342012-06-07T10:00:00.000+02:002012-06-07T10:00:00.797+02:00Review: Polymer by Sally Rogers-Davidson<div dir="ltr" style="text-align: left;" trbidi="on">
<em>This review is posted as part of my <a href="http://tsanad.blogspot.nl/p/aussie-women-writers-challenge.html" target="_blank">Australian Women Writers Challenge</a>. I have cross-posted it on my <a href="http://tsanasreads.tumblr.com/" target="_blank">review blog</a>.</em><br />
<br />
<a href="http://media.tumblr.com/tumblr_m541ffQ2Cx1r42d1t.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img align="right" border="0" data-mce-src="http://media.tumblr.com/tumblr_m541ffQ2Cx1r42d1t.jpg" height="400" src="http://media.tumblr.com/tumblr_m541ffQ2Cx1r42d1t.jpg" width="264" /></a><em>Polymer</em>
by Sally Rogers-Davidson is a science fiction story which I would
categorise as adventure. Apart from being in first person, it reminded
me of pulpy SF adventure stories from way back when. Except with a
female protagonist and, like, more female issues than would ever have
come up in those books.<br />
<br />
The main story takes place within the
pages of a long-lost journal written by Polly Meridian (aka Polymer). On
the night of her graduation ceremony, her space station home is invaded
by aliens. (Aliens, in this book, pretty much means "people not from
the same place as me who might be human or could be blue aliens".) She
almost dies in the invasion but is "lucky" enough to be taken prisoner
and enslaved instead.<br />
<br />
Without spoiling any plot, a lot of things
happen to her. Some of them are externally driven (like being taken
prisoner) and some are on her own initiative. Either way, the book is
full of action (although I thought there was a bit of a slump shortly
after the invasion, it definitely picked up later on).<br />
<br />
<img align="right" data-mce-src="http://media.tumblr.com/tumblr_m54362vAgM1r42d1t.jpg" src="http://media.tumblr.com/tumblr_m54362vAgM1r42d1t.jpg" />Unlike <a data-mce-href="http://tsanad.blogspot.com/2012/01/review-spare-parts-by-sally-rogers.html" href="http://tsanad.blogspot.com/2012/01/review-spare-parts-by-sally-rogers.html"><em>Spare Parts</em></a>,
the other Sally Rogers-Davidson book I've read, I wouldn't call this
one YA. Sometimes the writing felt like it could be and the main
character is horribly naïve as isn't uncommon in YA, but ultimately the
book dealt with more grown-us issues. I wouldn't stop a teenager reading
it — it's not very M rated (there's sex and a bit of rape but it's
mostly off screen or not described in detail) — but I wouldn't call it
YA. Also, I think the main character is right on the cusp of the YA
protagonist age range.<br />
<br />
There were some problematic elements in the
book. I don't want to spoil anything, but I felt a bit uncomfortable by
Polly's shifting attitudes towards one of her captors. Given earlier
events, it just didn't sit well with me, even though I could understand
it from her point of view.<br />
<br />
I would recommend <em>Polymer</em> to anyone who enjoys a SF adventure story. I think Rogers-Davidson's writing style improved in <em>Spare Parts</em>, but that's understandable since <em>Polymer</em> was published four years earlier <img align="right" data-mce-src="http://media.tumblr.com/tumblr_m5436oSW9i1r42d1t.jpg" src="http://media.tumblr.com/tumblr_m5436oSW9i1r42d1t.jpg" />and I <em>think</em> it was her debut novel. If you enjoyed <em>Spare Parts</em>, give <em>Polymer</em> a go. It's a very different setting, but there are some similarities in outlook (relatively cheery). From a science point of view, it's fairly soft. There's hyperspace and FTL comms but it's not trying to be realistic, so the lack of rigour is in no way abrasive.<br />
<br />
If
you're wondering about the different covers, the top is the recently
released ebook cover (which is the version I have), the middle is the
original paperback cover, now out of print, and the bottom is the
re-released paperback. I think the bottom is my favourite.<br />
<br />
You can currently purchase <em>Polymer</em> from Lulu in <a data-mce-href="http://www.lulu.com/shop/sally-rogers-davidson/polymer/paperback/product-20028980.html" href="http://www.lulu.com/shop/sally-rogers-davidson/polymer/paperback/product-20028980.html">paper</a> or <a data-mce-href="http://www.lulu.com/shop/sally-rogers-davidson/polymer/ebook/product-20063083.html" href="http://www.lulu.com/shop/sally-rogers-davidson/polymer/ebook/product-20063083.html">ebook</a> formats. Hopefully the ebook will be coming to Smashwords and other retailers soon.<br />
<br />
3.5 / 5 stars</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-19615432855137174312012-06-02T15:57:00.001+02:002012-10-01T20:15:36.321+02:00Other Foreign Skies<div dir="ltr" style="text-align: left;" trbidi="on">
This post is a response to a question I got on my <a href="http://tsanad.blogspot.se/p/ask-tsana.html" target="_blank">Ask Tsana</a> page. <br />
<br />
<a href="http://www.blogger.com/profile/11254077078488701308" rel="nofollow">Sam Keola</a> asked:<br />
<blockquote class="tr_bq">
<i>Love the views of Jupiter from Ganymede and Io. How large would it appear from Europa or Callisto? And how large exactly would the sun appear? (I know tiny as hell, but another lovely picture would be amazing.)</i> </blockquote>
The mathematical answer to that is explained in <a href="http://tsanad.blogspot.se/2011/02/foreign-skies.html" target="_blank">this old post</a>. And my first set of Jupiter images (Io and Ganymede's skies) can be found <a href="http://tsanad.blogspot.se/2011/05/foreign-skies-daytime.html" target="_blank">here</a>.<br />
<br />
<b>Jupiter</b><br />
<br />
This time around, I used a different image of Jupiter so if you're wondering why it's rotated relative to the old pictures, that's why. For the Jovian images, I've used the same starting image because in the year since I last did this, I haven't managed to take a more suitable photo. Such is life.<br />
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisdhMvgoFm6__Sv55qAtFCjM1NlmzeMMAFkLA6BOh6HNwJ2DI4-lW_3KUBnRNpVND4eYkK-LG9O5ct7XqMkLOoHiXiwhGKL42S02Uw0Pkrya9PoDpexlTcZ7uW2Lm-uWv6wSVZMGZiWMD3/s1600/moon+day.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="297" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisdhMvgoFm6__Sv55qAtFCjM1NlmzeMMAFkLA6BOh6HNwJ2DI4-lW_3KUBnRNpVND4eYkK-LG9O5ct7XqMkLOoHiXiwhGKL42S02Uw0Pkrya9PoDpexlTcZ7uW2Lm-uWv6wSVZMGZiWMD3/s400/moon+day.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The original photo with a full moon in Earth's sky.</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"></td></tr>
<tr><td class="tr-caption" style="text-align: center;"></td></tr>
</tbody></table>
So. Europa is the second Galilean moon out from Jupiter. It's made mostly of ice, is the smallest of the Galilean moons and might harbour life in its subsurface liquid ocean. The diameter of Jupiter as it would appear in the Europan sky is almost 24 full moons across. Remember that Europa's sky wouldn't actually look blue either since it doesn't have an atmosphere but I don't have a decent night skyline to work with. I'll do a night version eventually.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0pU6-zUrDlGGKc0i0KCw8h9oK9z3iJroMxtd7fs6MLoFFdlVE2_48v_GZ0t6vifQkAmwuTZijzCvcGSHU4IlyqFd7-dZ_uEziVPgKOnmP1GSYO3XWXvLLfxal8eMicc_kuOM3PBVSPG7V/s1600/jove+Europa.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="298" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0pU6-zUrDlGGKc0i0KCw8h9oK9z3iJroMxtd7fs6MLoFFdlVE2_48v_GZ0t6vifQkAmwuTZijzCvcGSHU4IlyqFd7-dZ_uEziVPgKOnmP1GSYO3XWXvLLfxal8eMicc_kuOM3PBVSPG7V/s400/jove+Europa.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The size Jupiter would appear in Europa's sky. Or in Earth's sky if you swapped it with Europa.</td></tr>
</tbody></table>
<br />
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</div>
<div class="separator" style="clear: both; text-align: center;">
</div>
You might be wondering whether Jupiter would actually be oriented the way it appears in these images. Well it depends. The direction the bands run relative to the moon's horizon would depend on where on the moon you were. Close to the equator, the bands would be vertical (although if Jupiter was high in the sky, it would be pretty difficult to tell. Perhaps better to say east-west). If you were near a pole, they'd be horizontal as in these images. And remember, the Galilean moons are all tidally locked, so Jupiter would never <i>move</i>, just change how much of it was illuminated by the sun.<br />
<br />
And Callisto, the most distant of the Galilean moons. Callisto's Jupiter would appear "only" about 8.5 full moons across.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnLJIIvB4VNcPEWo19FriUk3c_iAOT3c9afPcb36_E-OSqpTULI4XhhRyxKKCd_gJF4OAKwhL2dv6gk0B_A3bxDxqSAJsBlbLyWlSEO5Othm25pJcpFGit_WELEEKyvlRuK8GXKGlGxXC3/s1600/jove+Callisto.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="298" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnLJIIvB4VNcPEWo19FriUk3c_iAOT3c9afPcb36_E-OSqpTULI4XhhRyxKKCd_gJF4OAKwhL2dv6gk0B_A3bxDxqSAJsBlbLyWlSEO5Othm25pJcpFGit_WELEEKyvlRuK8GXKGlGxXC3/s400/jove+Callisto.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The size Jupiter would appear from Callisto. If Callisto had an Earth-like atmosphere and gum trees.</td></tr>
</tbody></table>
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</div>
<br />
<b>The Sun</b><br />
<b> </b> <br />
The second part of Sam's question was how large would the sun appear from Jupiter. Well, on Earth, the sun and the moon appear to be approximately the same size (there's a little bit of a difference when the sun is at its closest and the moon at its furthest and vice versa). So the sun from Earth is about one full moon in diameter.<br />
<br />
From Jupiter (or its moons) the sun would appear about 0.4 full moons across which is a little bit less than a sixth of the <i>area</i> of the sun as seen from Earth (remember, the moon and sun seen from Earth are on average the same size).<br />
<br />
I cheated a little bit with these next two sun photos. They're actually two separate photos and I made the sun smaller in one of them. The reason the rest of the photo looks darker for the Jovian sun is because I was fiddling with settings on my camera. And if you're wondering why I chose sunsets, it's because those (and sunrises) are pretty much the only kinds of photos where the disc of the sun is properly visible.<br />
<br />
Ordinary sunset on Earth:<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbZDv1CrKN9s4hgUizMjCuKA1-kadRNZ-FFhaXuNtvkIJYehlritBMfmZU4PHuUX-AqVYLINT0cvZLm0WSWRcybDmbs_bdNNM7WlML5IELRXMOKZi4Jjh6scYcJGWBhz0FpdO_Nv7FmHtD/s1600/sunset.JPG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="265" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbZDv1CrKN9s4hgUizMjCuKA1-kadRNZ-FFhaXuNtvkIJYehlritBMfmZU4PHuUX-AqVYLINT0cvZLm0WSWRcybDmbs_bdNNM7WlML5IELRXMOKZi4Jjh6scYcJGWBhz0FpdO_Nv7FmHtD/s400/sunset.JPG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Sunset. A little bit more than half the sun is below the horizon.</td></tr>
</tbody></table>
Sunset if Earth was at the same distance as Jupiter (but yet still warm enough to have liquid water. And plants. By the way, with these two, it's probably clearer if you click on the images to enlarge and compare the sun side by side.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwPzd_hg-XXlJWADR3t-t_tbIAauKdIsiUBrYKvAPVKG7gx4LVE0j56njSI1DzWBX8D_-vUcjKJIpGdIWqP_Nxv3uqa0w2Gj-_rBYJQTwBhRCA5r7lW1XbeP7LpvBrykQ50jqml_NmiMIs/s1600/sunset+jupiter.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="265" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwPzd_hg-XXlJWADR3t-t_tbIAauKdIsiUBrYKvAPVKG7gx4LVE0j56njSI1DzWBX8D_-vUcjKJIpGdIWqP_Nxv3uqa0w2Gj-_rBYJQTwBhRCA5r7lW1XbeP7LpvBrykQ50jqml_NmiMIs/s400/sunset+jupiter.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A more diminutive sun, less than a sixth of the area of Earth's.</td></tr>
</tbody></table>
And there you have it. Photoshopped images (well, actually, I used Pixelmator) depicting the sizes of Jupiter and the sun from the Galilean moons and the Jovian system, respectively.</div>
Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com4tag:blogger.com,1999:blog-119383823552885882.post-27130388886386903522012-05-21T22:33:00.002+02:002012-05-21T22:33:42.892+02:00Cool article<div dir="ltr" style="text-align: left;" trbidi="on">
Browsing the internets, I came across this rather neat article about Earth's final solar eclipse (many, many years hence). Check it out <a href="http://astrobob.areavoices.com/2012/05/20/561667292-a-d-date-of-earths-last-solar-eclipse/" target="_blank">here</a>. It talks about the moon moving away from the Earth until one day it will be too small to completely cover the sun in our sky.<br />
<br />
If that sounds familiar, it might be because of <a href="http://tsanad.blogspot.se/2011/10/eureaka-terra-nova-pilots-sciencefail.html" target="_blank">this post</a> I wrote about the moon being closer to the Earth in the (now cancelled) TV show Terra Nova. (Hint: not for the reasons they said in the show.)</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-64269975219696124742012-05-14T13:55:00.004+02:002012-05-14T14:01:51.849+02:00Review: When We Have Wings by Claire Corbett<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-1A6XgDJMbJqbDOwqzgjQ6jKsLjmWcCjEs7OGS2vTnz8-pS2RLiWiQoud7wH2PEjF7y3ORGv2qa6ggrfVtYgDCf6kwVOQ7wcc_OtD7LanPethdcRWvDv0D6I2Bj1iobN_bl3ZnD2VNkND/s1600/clairecover.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-1A6XgDJMbJqbDOwqzgjQ6jKsLjmWcCjEs7OGS2vTnz8-pS2RLiWiQoud7wH2PEjF7y3ORGv2qa6ggrfVtYgDCf6kwVOQ7wcc_OtD7LanPethdcRWvDv0D6I2Bj1iobN_bl3ZnD2VNkND/s400/clairecover.jpg" width="260" /></a></div>
<i>This review is part of my Science Fiction Australian Women Writers Challenge. You can check my progress <a href="http://tsanad.blogspot.se/p/aussie-women-writers-challenge.html" target="_blank">here</a> and about the challenge in general <a href="http://www.australianwomenwriters.com/p/australian-women-writers-book-challenge_25.html" target="_blank">here</a>. Since starting the challenge, I have started a review-only blog and <a href="http://tsanasreads.tumblr.com/post/23034191981/when-we-have-wings-by-claire-corbette" target="_blank">this review is cross-posted</a> <a href="http://tsanasreads.tumblr.com/" target="_blank">there</a>.</i><br />
<br />
<i>When We Have Wings</i> by Claire Corbett is set in a vaguely
near future Sydney where the rich can fly thanks to having wings
implanted on their backs.<br />
<br />
Before I get into talking about the story, I want to point out that,
from a physics point of view, Corbett has described a very plausible
situation. The wings people get are quite large (the impression I got
was comparable to the height of the person) and they also get treatments
to change the physiology to make their bones lighter (carbon fibre was
involved) and their muscles stronger. And, of course, to grow the new
muscles needed to control their wings. (For the record, the fictional
wings were larger and more interestingly-coloured than on the cover,
although it’s a nice cover despite that.)<br />
<br />
I have little idea of how plausible the biology was, but assuming
those biological modifications were possible, the physics seemed to
check out (y’know, without actually writing out equations or anything).
The descriptions of flight and weather patterns were also quite rigorous
and I commend Corbett on her dedicated research. Those details made the
book all the more realistic and helped with the suspension of disbelief
so we could focus on the social issues surrounding flight.<br />
<br />
The story follows two characters: Zeke, a PI investigating a nanny
kidnapping the child of a flyer couple, and Peri, the nanny on the run.
The mystery of why and where the nanny took the baby is not the real
mystery, however — especially since about half the story is told from
her point of view. The real mysteries become apparent when Zeke digs a
little deeper and when events get away from everyone.<br />
<br />
The setting isn’t a dystopia. Similar to what I said about <a href="http://tsanad.blogspot.com/2012/01/review-spare-parts-by-sally-rogers.html">Spare Parts</a>,
just because there is a widening gap between haves and have nots,
doesn’t make it a dystopia. Especially when, other than the size of the
gap, there aren’t many social or political differences to our world.
It’s a commentary on where our world could go, given enough scientific
progress. And it doesn’t make the assumption that the medical
developments are inherently a bad thing, either. Partly, this is
explored through Zeke having to make a choice as to whether to give his
toddler son wings from an early age (it’s easier when they’re children)
or whether to deprive him of flight and bar entrance into the elite
flyer society.<br />
<br />
In many ways, flight is a metaphor in <i>When We Have Wings</i>. However, it’s not <i>just</i>
a metaphor, as evidenced by the rigorous world building and the real
exploration of social issues surrounding flight. What makes us human?
How much of a disadvantage is not being able to afford wings? Is being
an ordinary human (in their world), without modification, edging towards
being a disability since they can’t fly? There was a lot of background
political discussion about equality and quotas (of non-modified humans)
and equal access. In a world where everyone is expected to choose the
most favourable characteristics for their unborn children and concerns
like baldness are trivial to “fix” where do you draw the line? If you
want an unadulterated genome, where does that leave you (other than as a
member of the conservative anti-modification cult)?<br />
<br />
Progress marches on.<br />
<br />
<i>When We Have Wings</i> was an excellent read. I highly recommend
it to fans of science fiction, fantasy and anything in between. I
suspect it’s being at least partially marketed as main stream, so hey,
all readers of fiction, go out and buy it!<br />
<br />
4.5 / 5 stars</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-13950158257713549842012-04-26T20:11:00.001+02:002012-04-26T20:14:25.932+02:00Review: Black Glass by Meg Mundell<div dir="ltr" style="text-align: left;" trbidi="on">
This review is part of my Australian Women Writers Challenge (see banner at side). Since starting the challenge, I've started a dedicated review blog (with fantasy as well as SF books reviewed) <a href="http://tsanasreads.tumblr.com/" target="_blank">here</a>. This post is cross posted from said other blog.<br />
<br />
<i>Black Glass</i>, debut novel by Meg Mundell, caught my eye
because it was shortlisted for Aurealis Awards in both the SF and YA
categories. (And being written by a woman, hence counting towards my SF
Aussie Women Writers Challenge also helped.)<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEDk4yaPdIvUimPOrxLPCs2mMOLwBySXPkn7Q25ugclHkRSv_5ARH5RpKwQwYnC7lJknAq9_bFKje-xTCMmoCdetCviUliB8FtOBAh8LGSO3z4SpnytF1fjtLoKf1ZLgr6bXdiGCewYe68/s1600/10367686.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEDk4yaPdIvUimPOrxLPCs2mMOLwBySXPkn7Q25ugclHkRSv_5ARH5RpKwQwYnC7lJknAq9_bFKje-xTCMmoCdetCviUliB8FtOBAh8LGSO3z4SpnytF1fjtLoKf1ZLgr6bXdiGCewYe68/s320/10367686.jpg" width="207" /></a></div>
The narrative style and presentation of the story and characters is
exactly the sort I usually dislike. The scenes, as well as presenting
the two most central characters in a reasonably conventional narrative,
alternate scenic mood scenes (sometimes with a temporary character as a
focus), often (always?) in present tense, and dialogue without any
framing.<br />
<br />
I’ve stopped reading books written like this in the past because they annoyed me. But you know what? Mundell pulls it off <i>really well</i>. I was captivated from the start, never bored and the ending packed an unexpected punch.<br />
<br />
The setting is Melbourne, a depressing near future. A dystopia but a
plausible one, scarily close to our world now. Just a little bit more
technology, regulation and surveillance than today. Unlike certain other
YA dystopias I could mention like <i>The Hunger Games</i>, <a href="http://tsanasreads.tumblr.com/post/20896303714/uglies-by-scott-westerfeld"><i>Uglies</i></a> or <i>Divergent</i>, there is no bizarre disconnect between our world and the world of <i>Black Glass</i>. (Infinitely so when you compare with <i>Divergent</i>
— good book, but I found the back story mind-bogglingly implausible.
You’re unsatisfied with the world so you sort yourselves into factions
resembling Hogwarts houses? <i>REALLY?</i>) Also, it’s set in Australia, so it gets bonus setting points for not being doomed-US.<br />
<br />
The most science fictiony element, and my second favourite part of
the world building (my favourite being that it was set in Melbourne and I
enjoy visiting home vicariously), was the side story of Milk the mood
engineer. He uses scents and subtle changes in lighting to evoke moods
and emotions in whoever is in range of his devices. His mission is to
artistically make the spaces he works with more harmonious and the
people in them happier. I thought it was a fascinating concept and
explored with surprising depth in the relatively short novel.<br />
<br />
The central-most characters, Tally 13 and Grace 16, are sisters who,
up until the first chapter or so, have spent their lives following their
deadbeat father around small Australian towns, often leaving town at a
moment’s notice. The story starts when an accident kills their father
and separates the sisters. They had been planning to run away to the
city (Melbourne) “soon” but now they are forced to make their way there
separately.<br />
<br />
We follow the girls, the city and a few miscellaneous characters,
sometimes obliquely, as they make ends meet, get by and wonder where
their lives are going. By the time I was reading the climax, I was
sceptical of a satisfactory ending but by golly, I was not disappointed.
On the other hand, without spoilers, I can understand other people not
feeling the same way.<br />
<br />
I’m not sure I’d call <i>Black Glass</i> YA. The other characters
are mostly adults and a lot of the concepts explored are things you
don’t necessarily want kids to have to worry about. Of course, the
reality is that many kids today do worry about similar things to Tally
and Grace. I wouldn’t stop a twelve year old from reading it, but I
would also encourage them to wait a few years. I could see it as the
sort of book that might be studied in year 11 or 12, though.<br />
<br />
In any case, it’s an excellent piece of writing. I highly recommend <i>Back Glass</i>
to not only science fiction fans but everyone. Even if you think you
don’t like science fiction, science fictional element in Black Glass is
so minor you’ll barely notice.<br />
<br />
4.5 / 5 stars</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-60903679688212655092012-03-22T00:38:00.000+01:002012-03-22T00:48:16.172+01:00Destroying the Earth<div dir="ltr" style="text-align: left;" trbidi="on">
This post is inspired by a question I got on my <a href="http://tsanad.blogspot.se/p/ask-tsana.html">Ask Tsana</a> page. Katrina asked:<br />
<blockquote class="tr_bq">
<i>I'm trying to come up with a simple (haha) and plausible way to destroy a
planet to kick things off for a story but am having trouble getting the
science right.</i><br />
<br />
<i>One of the first sites I visited to figure this out was this Geocide site: http://qntm.org/geocide</i><br />
<br />
<i>Under the Geocide in fiction page (http://qntm.org/fictional), the author says, "The Sun Crusher is a relatively small ship which carries a small number of missiles, each of which is tough enough to shoot into the centre of a star and cause it to go nova, which would certainly annihilate any nearby Earthlike planet."</i><br />
<br />
<i>My question is, don't stars that get massive enough to go nova have brief lives and thus not live long enough for a habitable planet to develop? I'm just basing that on Wikipedia (http://en.wikipedia.org/wiki/Planetary_habitability#Massive_stars), though, so I was wondering if you could tell me more. Can the habitable zones of massive stars ever actually be inhabited (and then later die in a supernova)?</i></blockquote>
Excellent question!<br />
<br />
The answer depends a bit on to what extent you want to destroy your planet. <a href="http://qntm.org/destroy">Geocide</a> pretty much defines "destroy the Earth" as "annihilate in the particle physics sense, or dismantle/tear apart on either a macroscopic (large) or microscopic scale". He doesn't count Earth as destroyed if there's still a planet-like object there. However, for many narrative purposes, rendering the Earth entirely uninhabitable will do the trick.<br />
<br />
So, leaving the dismantling and annihilation to Geocide (the website is amusing, although be warned that some of the details of physics are slightly off, but close enough), what are some ways of rendering Earth unfit for life?<br />
<br />
<b>Destroy all humans</b><br />
<br />
So maybe what you want is not so much to destroy the planet as to destroy all the people on it. That's not really that hard. Or, at least, destroying <i>most</i> of the people isn't that hard. Some methods, which generally don't require elaboration:<br />
<ul style="text-align: left;">
<li>Widespread nuclear holocaust</li>
<li>Some sort of plague</li>
<li>Climate change. No, really, melt the icecaps and raise the temperature enough so that it is too hot and humid to survive without air-conditioning and eventually you'll run out of people. Or throw in some crazy weather disasters too. <i>The Rhesus Factor</i> by Sonny Whitelaw touches on this a bit (see my review <a href="http://tsanad.blogspot.se/2012/03/review-rhesus-factor-by-sonny-whitelaw.html">here</a>), also on the plague scenario.</li>
<li>Very large volcano eruption. This is one of the things thought to have caused at least one of the prehistoric dinosaur(ish)-era extinctions. A less epically large volcano (actually, <a href="http://en.wikipedia.org/wiki/Year_Without_a_Summer">a few of them probably contributed</a>) in 1816 caused the Northern Hemisphere (or Europe and America at least, not sure that Asia was affected as strongly, but google it if you're interested) to not thaw out in the summer. This was "the year without a summer". (And now I have <a href="http://www.youtube.com/watch?v=iKFSQ7KzP9A">that Rasputina song</a> stuck in my head. Click the link and you will too.)</li>
<li>Asteroid -- this one's a toss up between destroying all (most) humans and destroying all life. Ultimately, I suppose it's a matter of scale. Let's say this asteroid kills human life but not necessarily all the microbes. It would be somewhat similar to the volcano in the throwing dust and rubbish into the atmosphere, blocking out light and generalised doom.</li>
<li>Magnetic field of the Earth turning off in the process of flipping. This is something that happens spontaneously every so often. It's bad because a whole bunch of ionising radiation (miscellaneous charged particles) from space is kept at bay thanks to our nifty magnetic field. Taking it away would give us a lot more cancer and sterility and could wipe out a large chunk of humanity. Microbes and probably a lot of (some?) sea life would be OK. Good luck artificially killing the magnetic field, though.</li>
</ul>
All of those methods probably won't wipe out all life and, frankly, it's possible/likely that some tenacious dregs of humanity will hold on. Generally, evacuation is the surest way to avoid these apocalypses. Or prevention, but that's only really applicable in two or three of those scenarios.<br />
<br />
<b>Destroy all life</b><br />
<br />
Why aim low? Bugger humanity <i>and</i> everything else with one of these sterilising scenarios:<br />
<ul style="text-align: left;">
<li>Self-replicating nanobots (von Neumann machines) which consume all the
[insert important chemical here -- carbon is popular]. This is also know
as the grey goo scenario. Depending on the nanobots, this is likely to render the Earth inhospitable to life while they're still doing their thing.</li>
<li>Large asteroid/comet or small moon colliding with Earth. Where a small impact would cause natural disasters (earthquakes, tsunamis) and potentially block out the sun with dust, a large impact could do many detrimental things. It could change the Earth's rotation, knock it into a slightly different orbit (or send it spiralling into the sun, but that would require a particularly large body), it could smash the Earth into chucks (which, thanks to gravity, would probably later re-collide to form Earth 2.0), render an appreciable fraction of the surface molten... Actually, I now have a brilliant mental picture of two or six asteroids hitting the Earth simultaneously from opposite sides and sort of turning it into molten goop... Not actually sure that would work with two, but six seems faintly plausible in a hand-waving way. Anyway, point is, hit Earth with something big enough and bye-bye life. Depending on conditions, it's possible life could spontaneously arise again, depending on how reliably life arises and how long it takes (before, for example, the sun goes red giant).</li>
<li>Supernova/nearby gamma ray burst. The main problem with this notion is the lack of suitable supernovaing stars nearby, as Geocide mentions. However, you mentioned destroying <i>a</i> planet, not specifically Earth. A planet orbiting a star when it went supernova would be toast. Probably, it would be fairly inhospitable before the actual explosion, if <a href="http://en.wikipedia.org/wiki/Eta_Carinae">Eta Carinae</a> is anything to go by. A planet orbiting a non-explosive star <i>near</i> another star that went supernova could well end up sterilised, which is what I talked about in my <a href="http://tsanad.blogspot.se/2011/07/galactic-habitable-zone.html">post about the galactic habitable zone</a> (and near in the astronomical sense isn't that close by). And, actually, if we're talking about Type Ia (which is to say not core-collapse supernovae; not the death throes of a large star) supernovae, which involve white dwarfs and (probably) ordinary stars going through their red giant stage, we might not even see the supernova coming. That's a slightly unsettling thought.</li>
<li>Some sort of implausible doomsday device. Really, you can make up whatever rubbish you want for this one if you're so inclined. (But if you do, I don't promise not to tear your science apart if I read/see/whatever it.)</li>
</ul>
<br />
<b>A few words on supernovae and novae</b><br />
<br />
Supernovae are how stars bigger than about 8 solar masses end their lives. Novae are not small supernovae. I know, that's what I originally learnt as a child/teenager by osmosis from SF novels. I think the connection between the words nova and supernova are primarily historic; a star suddenly appeared or became much brighter and acquired the label (nova meaning new), but the different causes weren't understood until much more recently.<br />
<br />
Stars smaller than around 8 solar masses don't explode. They expand relatively slowly (well, y'know, compared with a supernova explosion) when they run out of hydrogen to fuse in their cores, then contract then expand again when they run out of helium. At this point, a large star going through the stages much more rapidly would collapse again under its own gravity and then <i>kaboom</i> supernova. Smaller stars aren't massive enough to collapse again under their own gravity. Instead, after the helium is used up, leaving either carbon or oxygen (or a combination) in the star's core, what was once the stellar atmosphere will keep expanding indefinitely. Initially, it forms a <a href="http://en.wikipedia.org/wiki/Planetary_nebula">planetary nebula</a> (not actually anything to do with planets), but eventually it will all dissipate and be undetectable. What's left behind is a <a href="http://en.wikipedia.org/wiki/White_dwarf">white dwarf</a>; basically a small, hot star which was once the core of the red giant star.<br />
<br />
Suppose there were two stars near each other, and one went through the red giant to white dwarf steps before the other. When the companion star undergoes its red giant phase, maybe it expands enough that some of it's outer atmosphere is close enough to the white dwarf to accrete onto it. The reason these stars didn't supernova is because they were too small. There is a very definite upper limit to how massive a white dwarf can be before it collapses in on itself and explodes. That limit is 1.4 solar masses (but remember, most of the original star's mass is lost when it's doing the expanding thing, which is why the original star can be up to 8 solar masses). If the companion star accretes too much matter onto the white dwarf, the white dwarf will go over the 1.4 solar mass limit and explode. This is a Type Ia supernova. For the record, the alternative explanation for Type Ia supernovae, which is presently gaining more traction, is two white dwarfs colliding.<br />
<br />
Since white dwarfs are small (1.4 solar masses in a volume roughly the size of Earth), they're not very visible, especially once they start to cool down. See how we might not see that kind of supernova coming? It could potentially not be that difficult to artificially orchestrate, either, if you have enough spare matter to throw at a conveniently placed white dwarf. Well, y'know, sort of easier than some large-scale astro-engineering projects could be.<br />
<br />
<b>Back to the point</b><br />
<br />
If you recall the original question, Katrina asked:<br />
<blockquote class="tr_bq">
<i>My question is, don't
stars that get massive enough to go nova have brief lives and thus not
live long enough for a habitable planet to develop? Can the habitable
zones of massive stars ever actually be inhabited (and then later die in
a supernova)?</i></blockquote>
In general, the bigger the star, the shorter its life. Our sun's total lifespan is something like 10 billion years, a blue giant could live only 10 million years, and a red dwarf's lifespan is in the trillions of years. The current theory is that it took a couple of billion years for (very basic) life to arise on Earth. It then took a long time to progress to where we are now (Earth's age is 4.6 billion years, from memory). If we see this as typical, it seems like there isn't enough time for life to arise around a much larger star. On the other hand, if there was a planet at a suitable distance from the star, it could be inhabited by sufficiently motivated humans with spaceships. They wouldn't be able to stay there indefinitely, but even a few million years is more than ages on human scales, so that's OK.<br />
<br />
The other issue is metallicity. Planets like Earth have rocky cores, which means they have high metallicity. Remember, metallicity in an astronomical sense refers to the abundance of elements heavier than helium, not necessarily just the things chemists/sane people identify as metals. Very massive stars generally form in metal-poor environments and are metal-poor themselves. This makes the presence of heavier elements as requires for rocky planet building less likely. Not necessarily impossible, but much less likely.<br />
<br />
So yes, you can potentially have planets around the sort of stars that go supernova and, while native life probably won't get very complex if it arises at all, said planets could be inhabited by plucky humans.<br />
<br />
<br /></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-12271390654517653442012-03-15T22:53:00.000+01:002012-03-15T22:53:29.495+01:00Review: The Rhesus Factor by Sonny Whitelaw<div dir="ltr" style="text-align: left;" trbidi="on">
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<i>The Rhesus Factor</i> by Sonny Whitelaw has been sitting on my harddrive for a few years, waiting for me to finally get around to reading it. The Australian Women Writers Challenge gave me the push I needed to pick it up. <i>The Rhesus Factor</i> can be downloaded as a free pdf from <a href="http://www.sonnywhitelaw.com/rhesus.html">Whitelaw's website</a> (you have to click on the link in the left menu).<br />
<br />
In essence, <i>The Rhesus Factor</i> is an eco-thriller. Set in the near future when the Gulf Stream has stopped, climate change is decidedly noticeable and drug-resistant epidemics are sweeping the Earth. Since it was written about ten years ago, some of the technology of our very near future isn't quite here (no space planes to hop across the pacific in a matter of hours, not even for the US Airforce) but some of her predictions are eerily true. There was a throwaway paragraph that included severe bushfires in southern Australia and Brisbane flooding, for example. Granted, those aren't exactly outlandish predictions, and the Gulf Stream is still with us, but still, some of the crazy weather Whitelaw describes doesn't feel like it's as outlandish as it would have been ten years ago.<br />
<br />
There was also this great line about the US congress which predicts a situation that has become slightly old news now:<br />
<blockquote class="tr_bq">
<br />
<i><span style="font-family: 'BakerSignet'; font-size: 12.000000pt;">"So you
voted in a Democratic President—but hedged your bets with a Republican Congress that will not entertain any
motion to install a fair and equitable health care system."</span></i></blockquote>
Sound familiar?<br />
<br />
Anyway, back to the story. <i>The Rhesus Factor</i> follows a handful of characters through dramatic* climate change, the discovery of a virus which is on track to sterilising 99% of humanity, terrorist attacks, and assorted other emergencies. Some of the characters are clearly there to demonstrate consequences to ordinary folk, but most of them play some sort of governmental role (including scientific research) in mitigating the damage. A nice touch, I thought, was that almost all of the characters were quite competent and none of the disasters were because of any one person stuffing up. They were all just sort of inevitable.<br />
<br />
My favourite character, and the one I felt was the most developed, was Kristin: an Australian marine engineer, initially based in Vanuatu, who has the unfortunate luck to be present for almost all the on-page explosions. (There are a lot of explosions.) Her back story, complete with an ex-boyfriend who has the emotional intelligence of a wet rag, is well drawn and she's not one of the people who knows everything up front, so it was nice to discover some of what was going on as she did. She also had a strong "Australian, no-nonsense" pragmatism which helped keep up the pace of the book (not that it was ever in any danger of dragging).<br />
<br />
Another enjoyable character to read was the Australian Prime Minister. I suspect half the reason I liked him is because the world would be a better place if we had more political leaders that cut through bullshit and did what needed to be done. The other half is that his scenes — particularly some of the comments he makes when not in front of the press — were some of the most amusing and did a good job of diffusing some of the inherent doom of the novel. The most unbelievable aspect of both his character and the US President is that, before becoming politicians, both were scientists with ecology-related (I forget the specifics) PhDs. I just don't really buy that they got elected, <strike>especially the President,</strike> but it's a good thing for their world that they did.<br />
<br />
I also enjoyed Australia being so central to many of the events taking place. Other prominent settings were Vanuatu and the US, but while the US was obligatory (greatest impact of Gulf Stream failure, powerful government), the Australian scenes were more lovingly carved. From the outback, down to Kristin complaining about Canberran weather.<br />
<br />
<i>The Rhesus Factor</i> is a fast-paced, thriller crammed with one disaster after another. Set in the near future in a world a little bit more disease-ridden, with a slightly more altered climate than ours, it will keep you flipping/tapping the pages to find out what happens next. I should warn you though, Whitelaw set out to present a realistic picture of the near future. The only fabricated factor is, as the title will tell you, the Rhesus factor which acts as a catalyst for some disasters and an also-ran for others. There is no quick-fix offered in the novel and the ending isn't exactly a happy one — though it is somewhat hopeful. Nevertheless, it's an entertaining and, if you're into getting science out of your fiction, an educational<sup>#</sup> one.<br />
<br />
4.5 / 5 stars<br />
<span style="font-size: x-small;"><br /></span><br />
<span style="font-size: x-small;">* I say dramatic because the Gulf Stream failed. It's not quite Hollywood dramatic, if you're wondering.</span><br />
<span style="font-size: x-small;"><sup>#</sup> Actually, <i>The Rhesus Factor</i> is available as a free pdf because at one point it was cited by an Australian MP in Queensland parliament for its realistic and alarming predictions.</span><br />
<span style="font-size: x-small;"><br /></span><br />
<span style="font-size: x-small;"><br /></span><br />
<span style="font-size: x-small;"><br /></span></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com1tag:blogger.com,1999:blog-119383823552885882.post-64991083121503037482012-03-10T09:42:00.000+01:002012-10-01T20:19:53.925+02:00Sciencefail rant: Across the Universe by Beth Revis<div dir="ltr" style="text-align: left;" trbidi="on">
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First things first: sorry it's been a while between posts. Life has been busier of late and I haven't quite had the brain space to devote to writing a serious sciencey blog post. Until now. I was reading <i>Across the Universe</i> by Beth Revis, a recent YA science fiction book set on a generation ship and just as I got up to the "ooh, things are getting interesting" plot-thickening part, I was smacked in the face by an epic science fail. This is what I am now going to rant about.<br />
<br />
There will be spoilers. Many crucial spoilers. If you'd rather read a spoiler-free review and live in science fail ignorance, then you can read my ordinary review <a href="http://tsanasreads.tumblr.com/post/19049665686/across-the-universe-by-beth-revis">here</a>.<br />
<br />
~<br />
<br />
I mentioned spoiler-warning, right?<br />
<br />
~<br />
<br />
Don't read on if you don't want to be spoiled.<br />
<br />
~ <br />
<br />
<b>The Fail of the Science</b><br />
<br />
<i>Some background</i><br />
<br />
In <i>Across the Universe</i> we have two main characters: an American teenage girl and the future leader of the generation ship. The girl gets frozen and loaded onto the ship as cargo because her parents are part of the colonisation mission on the new planet they're going to. For reasons unimportant to science fail (and which I hence won't spoil), she is accidentally unfrozen early, supposedly 50 years before they're due to land. The entire journey was supposed to take 300 years.<br />
<br />
When she wakes up, she finds herself in a very different world to the Earth she left behind. Blah, blah, dystopia -- if you're interested in that aspect, go read my proper <a href="http://tsanasreads.tumblr.com/post/19049665686/across-the-universe-by-beth-revis">review</a>. In the course of events, the two main characters discover that among all the secrets and lies aboard ship is the secret of what's going on with the ship's engine.<br />
<br />
The parts I don't have a problem with is that the engine nuclear and they have some sort of process which is supposed to recycle the uranium so that it keeps running long enough. I mean, I'm sceptical of the whole re-enriching uranium part -- entropy, conservation of energy, the lack of a particle accelerator on board, etc -- but I'm willing to buy future technology with fancy engines. If we didn't have future tech with better <i>stuff</i> than our present tech, then science fiction would be a little dull.<br />
<br />
Unfortunately for the residents (and cryo-residents, I suppose) of the generation ship, there is something wrong with the engine. It is losing efficiency. Given the magic physics that was making it run in the first place, this isn't surprising either. Do you know what <i>is</i> surprising? The fact that the engine failing is somehow <i>slowing the ship down</i>.<br />
<span style="font-size: x-large;"><br /></span>
<span style="font-size: x-large;"><i>SPACE IS NOT AN OCEAN!</i></span><br />
<br />
I know, I know, I don't usually actually scream when I'm ranting, but this blatant disregard for one of the most basic and fundamental ideas in physics infuriated me. I shouted, in real life, and bashed the book on the couch in my frustration* at this neglect of research. Ask anyone who's taken a first year university physics subject, gosh, even anyone who passed high school physics, and they should be able to tell you what happens on a spaceship when the engines fail.<br />
<br />
<i>It keeps going in a straight line until it hits something.</i><br />
<br />
IT DOES NOT SLOW DOWN.<br />
<br />
Galileo, who lived way back in the 1500s–1600s, worked out that an object will continue to move in a straight line. Newton, in 1687, appropriated this concept and dubbed it his first law of motion:<br />
<blockquote class="tr_bq">
<i>A body in motion will continue moving with a constant velocity unless an external force is applied to it.</i></blockquote>
On Earth, friction is usually that external force. Your car's engine has to keep running while you drive because if it doesn't, you're car will eventually roll to a stop as the friction between the axle holding the wheel in and whatever's on the other end of the axle. A boat slows down because of the drag force of the water around it -- drag force being a type of friction. Your bike might roll down a hill, but if you don't pedal, friction in the axles will eventually bring you to a stop. An aeroplane needs to keep firing its engines because of the drag force of the air slowing it down (they can sometimes coast down to a landing if the engines fail, but they need to over come the drag to maintain a constant speed so that they can stay in the air because of other physics I'm not going to go into right now).<br />
<br />
You get the idea.<br />
<br />
The drag force happens because something -- air particles, water molecules, etc -- collide with the moving object and push it slightly in the opposite direction. If only one particle hit the much larger object, it wouldn't make a difference, but there are very many particles in the air around you right now. There are even more surrounding a boat (or person) in water. That's why it's harder to move underwater than in air. The fewer particles around to collide with an object down, the less it will be slowed down.<br />
<br />
Space, unlike the surface and atmosphere of Earth, is characterised by its vacuum. It's lack of anything substantial. There is no air in space. Sure, there are a few stray molecules and atoms floating around but, except in the densest of nebulae/molecular clouds, they are far sparser than even the best industrial vacuum we can create on Earth.<br />
<br />
In space, there is no drag force. There is nothing to slow you down. If your engine failed, you wouldn't slow down, you would just keep going, indefinitely, until you collided with something, or came close enough to a gravitational field (of a star, for example) to change direction. Then you would keep going in that direction unless you were particularly well aimed to go into orbit around that star.<br />
<br />
So when the engine of the generation ship in <i>Across the Universe</i> starts to fail, their problem isn't that it will take them longer to reach their destination. If it fails completely, they will <i>not</i> be "dead in the water". There is no water. It might be called a space<i>ship</i>, but that doesn't mean it shares the same watery drag force as an ocean liner.<br />
<br />
Their problems are more likely to be related to not being able to land or go into orbit around their destination, or not being able to make course corrections, or not being able to slow down and zooming straight past their destination.<br />
<br />
By a similar token, people or things ejected out of the airlock wouldn't get left behind. Again, space is not an ocean. Once the airlock is opened and the air rushes out (pushing any lose objects out with it, perhaps), the ejected objects would appear to float close to the ship, continuing to move in the same direction along with the ship. If someone was thrown out an airlock, their body would only stop shadowing the ship when the ship did one of: speed up, slow down or change direction.<br />
<br />
I grant that if the ship has magic artificial gravity (which the generation ship in <i>Across the Universe</i> does), some strange things might happen to throw the body further away from the ship, or make it somehow react unusually with the artificial gravitational field, but there was absolutely no indication of that being the case in this book.<br />
<br />
<span style="font-size: x-small;">* Don't worry, the book was unharmed.</span> <br />
<br />
<b>Acceleration?<b></b></b><br />
<b><b><br /></b></b>
My first thought, in my brain's desperate attempt to fix the gaping science fail hole in <i>Across the Universe</i>, was that maybe the ship was accelerating and that's why they needed the engine to maintain efficiency and why things thrown out of the air lock got left behind.<br />
<br />
Unfortunately, it can't have been.<br />
<br />
According to the original mission plan (which the book gives us no reason to believe is a trick), the voyage is supposed to take 300 years. Also, their destination is called Centauri-Earth (and our world is referred to as Sol-Earth). This could refer to Alpha Centauri, the closest star, but given the fact that the planet they're headed for is supposed to be habitable, that doesn't seem likely (Alpha Centauri is a triple star system and the chances of conveniently habitable planet being there are slim). So it must be another star with Centauri in the name. There are lots. <a href="http://en.wikipedia.org/wiki/List_of_stars_in_Centaurus">Here is Wiki's list of stars in the Centaurus constellation</a>. If you sort that list by distance, you see that there aren't <i>that</i> many stars within 300 light years.<br />
<br />
Since no relativistic effects are ever mentioned (see <a href="http://tsanad.blogspot.com/2012/01/rapid-slow-space-travel.html">this blog</a> about travelling close to the speed of light, and <a href="http://tsanad.blogspot.com/2012/02/relatively-faster.html">this one</a> about accelerating up to fractions of the speed of light), it seems fair to assume that they never reach an appreciable fraction of the speed of light. Let's say that means less than around five percent time dilation goes on (see aforementioned links for previous posts if you're lost at this point). Well, travelling at a third of the speed of light gives us six percent time dilation, so close enough. So the maximum speed we're allowing is 0.33c. If we ignore acceleration, that limits us to stars within 100 light years. Habitability is probably limited to F, G, K and maybe M stars. Within 100 light years in the Centaurus constellation, that leaves us with... 14 viable stars (11 of which don't actually have Centauri in their name...). The furthest with Centauri in the name (not an unreasonable requirement, given the context of the book. If they were going to a star with a dull designation, surely they would have given it their own name?) is about 60 light years away.<br />
<br />
If we assume they're accelerating until they get half way, then decelerating the rest of the way (the fastest way of getting there and also the main way to require the engine running the entire time), that requires a very low acceleration of 0.0013g or 1.3 cm/s<sup>2</sup>. Which at least explains why a uranium engine might be the fuel source of choice. (For the record, if their destination <i>was</i> Alpha Centauri, then this value wouldn't change appreciably - it would be about 0.05 cm/s<sup>2</sup> less. Furthermore, for Alpha Centauri it would make much more sense to accelerate a bit and then spend most of the journey coasting until they needed to slow down at the other end.) The maximum velocity the ship would reach would be 0.37c, so that's not too far above my imposed limit of 0.33.<br />
<br />
This low acceleration means that my point about bodies not being left behind when ejected from the airlock still stands. They still wouldn't appear to drift away that quickly.<br />
<br />
The final piece of information we're given in the book is that the engine started failing when they were about halfway through their journey. What does this mean? It means that they wouldn't be able to <i>decelerate</i>, would reach their destination <i>faster</i> not slower and would zoom straight past it too quickly to go into orbit. Pretty much the exact opposite of the problems described in the book.<br />
<b><b><br /></b></b>
<b><b><b>Over-reaction?</b></b></b><br />
<b><b><br /></b></b>
No. For two reasons. The first is just it's bad writing -- the science fail error jolted me completely out of the story and undermined my suspension of disbelief and plausibility of the whole setting. To achieve the same plot-mandated end, the author could have had the engine start to fail while accelerating or, without much consequence to the plot (as far as book 1 in the trilogy goes, at any rate) the ship could be unable to slow down, unable to correct its course or they could have found out that the planet wasn't as viable as they originally thought. Each of these things would have got the job done, but no, the author chose to not check physics.<br />
<br />
The second reason is twofold. From a personal point of view, when learning physics for the first time, in high school or university, it's usual to relate everyday situations to the concepts you learn. In this way, you can intuitively predict basic mechanics based on experience. However, everyday situations tend to take place on the surface of Earth, so when trying to predict the mechanics of what happens in space (which, yes, does come up in physics classes -- take some if you don't believe me) the situations the student has to fall back on are what's portrayed in various media -- books, movies, perhaps computer games. However, thanks to the the generalised scientific illiteracy of most of society, half of these portrayals are plain wrong. They're why I have this blog, in fact. Honestly, having taught physics to new students, I have seen a lot of evidence for this sort of thing contributing to poor understanding and requiring a lot of unlearning.<br />
<br />
Hollywood, poorly researched books, and other media undermine what little science education kids get. At least if the media surrounding us strived for some semblance of accuracy, perhaps people would pick up some science by osmosis. Then the climate debate wouldn't be so controversial, <a href="http://www.theage.com.au/technology/sci-tech/watch-this-space-republican-candidate-promises-moon-colony-20120127-1qke4.html">US presidential candidates wouldn't think a moon colony in 20 years</a> was a viable idea, and we wouldn't have an <a href="http://en.wikipedia.org/wiki/Vaccine_controversies">anti-vaccination movement</a>. Scientific literacy is important and, really, science fiction as a genre is uniquely positioned to encourage an interest in science. Sure, this wasn't a hard SF tech-centric book, but it was a giant spaceship. That's the sort of thing that can capture an imagination and ingraining wrong science while doing so is just irresponsible.<br />
<br />
And it makes me angry.<br />
<br />
(Other than the science fail aspect, this isn't a terrible book. I give it 3.5 / 5 stars -- half a star subtracted for the science fail. For a less science-oriented discussion of the book -- y'know, an actual review -- see <a href="http://tsanasreads.tumblr.com/post/19049665686/across-the-universe-by-beth-revis">my book reviews blog</a>.)<br />
<b><b><br /></b></b>
<b><b><br /></b></b></div>
Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com8tag:blogger.com,1999:blog-119383823552885882.post-52798571238042961142012-02-13T18:16:00.000+01:002012-02-13T18:36:43.026+01:00Review: Wanted: One Scoundrel by Jenny Schwartz<div dir="ltr" style="text-align: left;" trbidi="on">
I stumbled upon this book quite by accident after following a link that took me to the <a href="http://authorjennyschwartz.com/">author's website</a>. When I saw she had written a steampunk novella<i> set in Australia</i>, how could I possibly resist <a href="http://bit.ly/WantedScoundrel">buying it</a>? I didn't really need the added incentive of being able to count it towards the <a href="http://www.australianwomenwriters.com/p/australian-women-writers-book-challenge_25.html">Australian Women Writers Challenge</a>. And before you argue, steampunk counts as science fiction because of the technological and scientific sentiment inherent in (the characters) inventing new old tech.<br />
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<i>Wanted: One Scoundrel</i> by Jenny Schwartz is set in and around the Swan River colony -- mostly in Perth and Fremantle. The protagonist, Esme, is the daughter of a gold prospector and inventor who struck it rich relatively recently. She is also a suffragette spearheading a political party with the goal of giving women and non-Anglos rights and votes.<br />
<br />
The story opens with her realisation that, since her main political opponent has somehow arranged for all political debates to take place at gentlemen's clubs, she needs a male spokesperson to be a figurehead leader. Unfortunately, all her present male supporters are too busy with their own affairs to devote sufficient time to actually leading a political party. So, with the aid of her captain uncle, she set about finding herself a newly arrived scoundrel ("fresh off the boat" -- would that there weren't other connotations to that phrase) whom she intends to pay to be her puppet.<br />
<br />
Enter Jed. A conveniently unknown American recently arrived from England with her uncle's (steam-powered) ship. Jed quickly agrees to be the front-runner for her political party and a friendship/attraction blossoms between them (well, it is also a romance story).<br />
<br />
Esme's main rival is an old-money easterner (insofar as there is any aristocracy in pre-federation Australia, he seems to be a prime example). Unlikeable to the bone, he doesn't seem to realise that Esme finds his desire to prevent anyone that isn't male, white or rich (or, really, anyone that isn't him or his friends) from voting abhorrent. He started off merely an arrogant prat, but this escalated for the climax in an exciting way, I thought. (No spoilers.)<br />
<br />
The steampunk elements are scattered throughout the story. For example there are the steam powered boats that make it to Swan River from England in a matter of weeks, not months, miscellaneous minor steam-powered contraptions and even forays into electricity and magnetism (Tesla gets a very brief mention, too). From a scientific point of view, I found no obvious faults, although I'm a little sceptical of the kangaroo-inspired land vehicle mentioned at one point.<br />
<br />
As I implied at the start, the thought of a steampunk story set in Australia made me very keen to read this and I was not disappointed. I hereby encourage more Australian authors to write Australian steampunk. Steam + gold rush allows for a wealth of material to draw from.<br />
<br />
Speaking of the gold rush, being an easterner myself, I only really know a bit about Victoria's gold rush, and next to nothing about Western Australia's (arguably, I know more about Western Australia's <i>current</i> mining boom than any of the past). It was nice to read about a slightly different gold rush. I even learnt about the significant Indian population of the time (cf Chinese miners in Victoria).<br />
<br />
The writing was ever so slightly clunky in places, mostly when there was an instance of head-hopping (between Esme and Jed) within the same scene. I also found the story got more amusing as it went along -- after a slightly uneventful beginning -- and I really enjoyed the climax and ending. It had my laughing out loud a few times in the second half. I loved Esme, who was strong, progressive (obviously) and kept her head in trying circumstances. Overall, I recommend this to anyone with a passing interest in steampunk or Australian history.<br />
<br />
(Oh and if you're wondering, the Christmas element is extremely minor, limited to a single Christmas in July ball, so yeah, ignore that subtitle. Well, unless you like Christmas, in which case, read the book anyway.) <br />
<br />
4 / 5 stars.</div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com4tag:blogger.com,1999:blog-119383823552885882.post-74850118462577085002012-02-11T23:02:00.000+01:002012-02-12T20:21:39.248+01:00Relatively Faster<div dir="ltr" style="text-align: left;" trbidi="on">
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://apod.nasa.gov/apod/image/1107/atlantisapproach_nasa_900.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="213" src="http://apod.nasa.gov/apod/image/1107/atlantisapproach_nasa_900.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Space shuttle moves pretty slowly and stays close to Earth. <br />
<a href="http://apod.nasa.gov/apod/ap110713.html">Image credit: ISS Expedition 28 Crew, NASA</a></td></tr>
</tbody></table>
Following on from <a href="http://tsanad.blogspot.com/2012/01/rapid-slow-space-travel.html">my last blog</a>,
in which I talked about travelling at an appreciable fraction of the
speed of light, today I'm going to add acceleration into the mix. But
first, a few other funky consequences and transformations that apply
when travelling close to the speed of light.<br />
<br />
To recap
last week's post, when travelling close to the speed of light, time
dilates and length contracts. That means time moves more slowly and
distance shrinks. The factor which dictates how much is called the
Lorentz factor and is denoted by the Greek letter gamma:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpdQ5s1VHHgtBprLoDjUSzoTqGt2Tora9REpkl4ZCIpH1dcBzyjHzUf8R7vBglV7QHudh3z64ue9rFEN6dafEXSY-C_2Rv6RlzS8qtkY8kftpu1VuRSZt9qHx0vu3dl-6g_LgxsZedaGUm/s1600/latex-image-2.png" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpdQ5s1VHHgtBprLoDjUSzoTqGt2Tora9REpkl4ZCIpH1dcBzyjHzUf8R7vBglV7QHudh3z64ue9rFEN6dafEXSY-C_2Rv6RlzS8qtkY8kftpu1VuRSZt9qHx0vu3dl-6g_LgxsZedaGUm/s1600/latex-image-2.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Here <i>v</i> is the speed of your rocket or whatever and <i>c</i> = 3 x 10<sup>8</sup> m/s is the speed of light.</td></tr>
</tbody></table>
The rate at which time appears to pass (to an outside
observer) in a rocket travelling at v is given by the time that passes
for the observer multiplied by gamma (which is always greater than or
equal to 1). This is also called the proper time for the people inside
the rocket. The apparent distance between A and B for a moving observer
is given by the distance between A and B as seen by an observer at rest
with respect to the two points (so that A and B don't seem to be moving)
divided by gamma.<br />
<br />
<b>Moving on</b><br />
<br />
Another
funky thing that changes with speed is mass -- it increases
proportionally with gamma. Well, it's sort of more accurate to say
momentum, and it doesn't mean that you'll feel heavier when you're in a
fast-moving rocket, but that it will take more energy or force to
accelerate you further. Basically, what this boils down to is the faster
you're going, the harder it is to go faster.<br />
<br />
What
about if we have two rockets, travelling in opposite directions at 0.75c
(that is, three quarters of the speed of light)? The apparent speed of
one rocket as seen from the other must be less than the speed of light
(all speeds of massive objects are less than the speed of light in all
inertial reference frames). So we need to use another transformation to
work it out. Without going into too much mathematical detail, the
equation we need is:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEii8AkIJ95SfNTvIv7tFuCsO05Hvym6nFoyNFuVcGuWQQM72Aa70VcMtmkrbYwfZFi7v3X4CRZNRuNDiNmHeO6rWOflyADI9l2jOYae7HXBJi7xEesKuhf2wqFu2CndW8P59b6jFQKsDkWo/s1600/latex-image-1.png" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEii8AkIJ95SfNTvIv7tFuCsO05Hvym6nFoyNFuVcGuWQQM72Aa70VcMtmkrbYwfZFi7v3X4CRZNRuNDiNmHeO6rWOflyADI9l2jOYae7HXBJi7xEesKuhf2wqFu2CndW8P59b6jFQKsDkWo/s1600/latex-image-1.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">See below for slightly complicated explanation of values.</td></tr>
</tbody></table>
The tricky part is that now we're talking
about three frames of reference, not two. There's a frame of reference
for each of our moving spaceships, and the third frame which is
dictating how quickly the two spaceships are travelling (in their own
frame, of course, each spaceship is stationary and we don't have a
problem to work out). This third frame we're going to call the rest frame. We want to work out <i>u</i>, which is how fast spaceship A appears to be travelling from spaceship B's point of view. <i>U</i> is the velocity of spaceship A from the rest frame, <i>v</i> is the velocity of spaceship B from the rest frame. For the equation to make sense, one of <i>U</i> or <i>v</i> has to be negative (to account for the opposite directions part) <i>c</i> remains the speed of light (3x10<sup>8</sup> m/s).<br />
<br />
Whew, OK, bit complicated to keep track of things there.<br />
<br />
<br />
<b>Getting faster</b><br />
<br />
Next up, let's talk about acceleration when travelling at relativistic speeds. So far, we've only considered things moving at a constant speed. Accelerating frames are, by definition, not inertial (since an inertial frame is defined as not accelerating), so we can't quite apply all the same assumptions to them. When you are accelerating, you are moving into a different inertial frame for each instant that your speed is changing. (Of course, when you stop accelerating, you'll stay in your last frame unless you decelerate.)<br />
<br />
If you're in an inertial frame and a relativistic spaceship accelerates past, what acceleration does it appear to have? Well, the following formula will tell us and, it's interesting to note, the apparent acceleration changes with the ship's velocity, even though, from on board the ship, the acceleration feels constant.<br />
<br />
I was going to include the equation, but upon further consideration, it's not terribly useful or relevant. Moving on to more practical relativistic space travel, I'd like to point you in the direction of <a href="http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html" target="_blank">this excellent website</a>. The set of rocket equations as explained on that site are as follows:<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDirMrjZpulXK_NchYHuwN8trS5iHoYJZ1t6lqnkGfs9URuw35mgvxowOgaVy58OyADsEc6kQ_Zkc_zsclCJpcCh9r3iTafPNQAAmpoSmrpofG2nbPdOGiFLDNjN1Ubiez06ORokaRpHbg/s1600/latex-image-3.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDirMrjZpulXK_NchYHuwN8trS5iHoYJZ1t6lqnkGfs9URuw35mgvxowOgaVy58OyADsEc6kQ_Zkc_zsclCJpcCh9r3iTafPNQAAmpoSmrpofG2nbPdOGiFLDNjN1Ubiez06ORokaRpHbg/s320/latex-image-3.png" width="292" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Equations taken (and re-typeset) from <a href="http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html" target="_blank">this excellent website</a>.</td></tr>
</tbody></table>
<br />
So these equations assume that the ship is travelling at a constant acceleration, <i>a</i>. The velocity, <i>v</i>, is the speed it reaches, as measured from a "stationary" reference frame -- which for the sake of brevity I'll call Earth* -- after a <i>t</i>-long period of acceleration. The distance over which the acceleration takes place is <i>d</i> and τ (pronounced tau) is the time that passes for the rocket and the people inside it (generally speaking, less time will pass inside the rocket than for people on Earth).<br />
<br />
That inverse cosh function (also called arccosh) in the last equation is a bit of an odd one. It's short for inverse hyperbolic cosine. A good scientific calculator should have the appropriate function (you'd probably have to use the shift key to get to it) and failing that, there's always <a href="http://wolframalpha.com/">WolframAlpha.com</a>. <br />
<br />
There are a few ways to use these equations, depending on the circumstances of your spaceship.<br />
<br />
<i>Accelerate constantly until the half way mark, then decelerate until destination</i><br />
<br />
<ul style="text-align: left;">
<li>So, acceleration is good for us. It maintains things like muscle mass and bone density. It's broadly a good idea to maintain Earth acceleration (9.8 m/s<sup>2</sup> is the acceleration due to gravity).</li>
<li>If we accelerate the whole way, we'll go splat at our destination. The sensible thing, if we want to accelerate the whole time, is to accelerate constantly to the half way mark, flip the ship and then decelerate the rest of the way. (Flipping the ship is so that the floor doesn't turn into the ceiling. Obviously you'd have to stop the accelerating to do the flipping.)</li>
<li>So we use the time taken equation (the first one) but put in half the distance (because we're only accelerating 'til the halfway mark), then double the resultant time to include the time taken to decelerate (conveniently, these things are symmetric).</li>
</ul>
In general, it's easier to deal with light years (rather than meters) and years (rather than seconds) when we're talking about interstellar distances. However, to get a sensible answer out, we need to put acceleration into years and light years as well. Skipping the maths, 1g = 9.8 m/s<sup>2</sup> = 1.03 ly/yr<sup>2</sup> so you can use that value for <i>a</i>. You can also just multiply by a factor if you decide you'd like to save fuel by accelerating at only 0.5g or 0.75g. Or save time by going at 1.5g (which humans might be able to adapt to). Also, remember that the speed of light in these units is 1 ly/yr.<br />
<br />
To work out the time taken, follow the same procedure as above, but using the time equation (whichever one you're interested in). Again, put in half the distance then double the result.<br />
<br />
<i>Accelerate up to a set velocity</i><br />
<br />
Because accelerating for an indefinite period of time might get a bit silly and use up an unrealistic amount of fuel. Also, you'd be smashing into atoms pretty hard and starlight (and the cosmic background radiation if you end up going fast enough) would get blueshifted to higher frequencies. Both of these phenomena would require extra radiation shielding, which adds extra mass and requires extra fuel. So, let's accelerate just up to a set velocity, travel at that velocity for the bulk of the journey and then decelerate again.<br />
<ul style="text-align: left;">
<li>First we need to know the distance required to reach our desired velocity (and potentially also the time). The procedure isn't too different to the first case. We do need to rearrange the velocity equation a little first. Using <i>c</i> = 1 ly/yr we get: </li>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimzr4Moiw_HiqfHV7XN0Z6LxoT8zm5kqy-jQ7ho7HOQM_oSvd2Kxl1sdmLY39a8cLwaqolOSaQIGHwFGSyf0LCY-ThrxsUzFylH4P2t2LnkrccjH07RZjoejR81dfbWwdWikKaM15espdy/s1600/latex-image-4.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimzr4Moiw_HiqfHV7XN0Z6LxoT8zm5kqy-jQ7ho7HOQM_oSvd2Kxl1sdmLY39a8cLwaqolOSaQIGHwFGSyf0LCY-ThrxsUzFylH4P2t2LnkrccjH07RZjoejR81dfbWwdWikKaM15espdy/s1600/latex-image-4.png" /></a></div>
<li>Throw in our final velocity and the desired acceleration and we get the time taken (from an Earthly reference frame). Throw the time into the distance equation and we get out how far we've come when we stop accelerating. Double this to account for the distance and/or time taken decelerating again, subtract that from the total distance and we're left with the distance spent travelling at a constant velocity.</li>
<li>You can work out the time that section of travel takes from last time's blog (<a href="http://tsanad.blogspot.com/2012/01/rapid-slow-space-travel.html">here</a>).</li>
</ul>
<br />
And there you have it, journey times at relativistic speeds with accelerations. Huzzah!<br />
<br />
<br />
<br />
<span style="font-size: x-small;">* Technically not inertial, but it'll do if you ignore the gravity and the motion around the sun. Theoretically we should take the sun as our standard rest frame, so you can pretend I really mean the sun when I say Earth if that makes you feel better. </span><br />
<br />
<br /></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-79661519498671491292012-01-23T11:06:00.002+01:002012-12-15T17:35:39.844+01:00Review: Nightsiders by Sue Isle<div dir="ltr" style="text-align: left;" trbidi="on">
<div class="separator" style="clear: both; text-align: center;">
<a href="http://www.twelfthplanetpress.com/store-items/nightsiders" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://pics.librarything.com/picsizes/8c/3e/8c3e368ca3d709d59785a525a41434d414f4541.jpg" /></a></div>
<i>Nightsiders</i> by Sue Isle is a collection of four short stories set in the same world. It is part of <a href="http://www.twelfthplanetpress.com/">Twelfth Planet Press</a>'s <a href="http://www.twelfthplanetpress.com/category/store-items/twelve-planets-store-items">Twelve Planets series</a>, twelve collections which are showcasing the work of twelve Australian female authors. I believe it's the only one so far to be entirely science fictional (that said, the only other I've read is <i>Love and Romanpunk</i> by Tansy Rayner Roberts -- an excellent blend of Roman mythology, the past and the future -- and I'm not sure what's planned for the rest of the series).<br />
<br />
<i>Nightsiders</i> is set in Western Australia, in and around Perth. I want to say it's post-apocalyptic, but that's not quite true. It seems part local apocalypse, part generalised catastrophic climate change. The Australian climate has changed so that the west coast is no longer particularly habitable, with hints at the start that things are better in the east. The former city of Perth is now generally referred to as Nightside, because the people living there have turned nocturnal, seeking shelter during the heat of the day and going about their business in the marginally cooler nights.<br />
<br />
A few words on each of the stories: <br />
<br />
<br />
<b>The Painted Girl</b><br />
<br />
13 year old girl has been with walking with an older woman (who isn't her mother) as long as she remembers. One day, her life abruptly changes and she learns there's more to it than she'd realised.<br />
<br />
<b>The Nation of the Night</b><br />
<br />
Ash, 17 year old a trans boy, goes east for an operation. The story is mostly about the stark differences between the parched west and the drowning east. He quickly learns that life is far from perfect in Melbourne, even if they still have hospitals and infrastructure. In Nightside (aka Perth), everyone helps their neighbours, in Melbourne, the infrastructure is overcrowded and they're trying to keep out as many surplus people as they can manage.<br />
<br />
<b>Paper Dragons</b><br />
<br />
Some of the kids in Nightside put on a play based on some old TV scripts they found in an abandoned home. Turns out it's a soap about the trivialities of teenage life as in our time. Nightside's entire population of old folk (who remember life before the bombings and the evacuation) turn out to watch. <br />
<br />
<b>The Schoolteacher's Tale</b><br />
<br />
This was my favourite story. Mostly, I think, because it filled in some of the gaps left by the other stories with teenage protagonists who didn't know life before Nightside. The titular schoolteacher is a 70 year old woman who had been mentioned as a key figure in the lives of the characters in the previous two stories. We are exposed to some of her reminiscences of how much the world has changed and, through the story, we learn a bit of where Nightside is headed in the future.<br />
<br />
<div style="text-align: center;">
~</div>
<br />
It sort of feels strange that I can summarise each of the stories in a few sentences but barely even touch on what the stories are really about. Partly this is avoiding spoilers, and partly because there are some themes and ideas that run through all four stories which are hard to pin down to just one of them. <br />
<br />
An idea that runs through all the stories (though features the most in the first one) is that of the Drainers. They are a group of people with a genetic mutation that gives them a tolerance for the harsh sun and helps them go a bit longer between sips of water. They come out during the day when everyone else is sleeping, and hide in caves and drains (hence the name, I suppose) at night. There are stories of them eating people or draining their blood and, because they move about when everyone else is sleeping, they're regarded almost as reverse vampires, a notion which appealed to me.<br />
<br />
All the children protagonists have adapted better to life in Nightside than the adults. They have good night vision (and poor day vision) and, of course, they are used to the only life they have ever known. One theme that ran heavily through the first three stories is that of abandonment. In the two middle stories, the children were abandoned by parents who went east during the evacuation. There's a heavy implication that this happened to almost all of the children of Nightside, with some of the remaining adults acting as foster parents to many of them. It sort of felt a bit much. Of course, the children that weren't abandoned when their parents went east wouldn't have still been around. But really, children are pretty much top of the list of things parents take with them when leaving a war zone. Where are the parents that stayed behind with children? Where are the children whose parents were killed rather than left? I appreciate that the theme of abandonment fits in with the greater theme of Nightside being abandoned by its former inhabitants and the rest of the country, but it felt a little bit lopsided by the time I got to the end.<br />
<br />
On a happier note, this was a collection full of strong and well drawn female characters. With the exception of Ash (trans) in the second story, all the protagonists were female. There was also a good balance of male and female secondary/background characters, which is always nice to see.<br />
<br />
To a small degree, the setting put me in mind of <i>Daughters of Moab</i> by Kim Westwood, but the writing style was very different and thematically the setting and the idea of adaptation to a hostile environment were the only things the two have in common.<br />
<br />
Overall, I found <i>Nightsiders</i> an interesting read.<br />
<br />
Rating 4 / 5 stars </div>
Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com4tag:blogger.com,1999:blog-119383823552885882.post-66725688289920120792012-01-22T22:42:00.000+01:002012-02-11T23:03:21.720+01:00Rapid slow space travel<div dir="ltr" style="text-align: left;" trbidi="on">
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://www.blogger.com/goog_455022780" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="213" src="http://apod.nasa.gov/apod/image/1004/DRocketGard_craigcrawford.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><a href="http://apod.nasa.gov/apod/ap100409.html">Credit: Craig Crawford on APoD</a></td></tr>
</tbody></table>
I have <a href="http://tsanad.blogspot.com/2011/10/propulsion-not-just-rocket-science.html">posted in the past about mundane space travel</a> such as might be used with the solar system (or another star system if we're talking aliens or whatnot). However, with speeds that slow, it would take an extremely long time to reach another star, even the closest. To have any hope of reaching another star, we need to be able to travel much faster.<br />
<br />
Right now, we aren't technologically equipped to do so and that's not what this post is about. What I'm going to talk about is what happens when we (or rabbits or clocks or whatever) travel at high speeds. Because strange and interesting things do happen. Welcome to the weird and wonderful world of Einstein's special relativity.<br />
<br />
<b>Immutable</b><br />
<br />
We live in a world with three spatial dimensions and one time dimension. All this really means is that we can define a co-ordinate system (for example x-, y- and z-axes) which can define any point in space by listing three numbers (the x, y, z co-ordinates) and which can define any point in time with a single number (although it doesn't look like a single number, that's how we can think of "11:00 am on 21 January 2012"). Any point in spacetime (that is to say, our universe, past and present) can be defined by combining those two co-ordinate systems to give four numbers, unique to each point.<br />
<br />
Now, say you're in a long corridor. There are several ways you might try to measure how long it is. You might walk along it and count steps or use a measuring tape. You might jog or walk at a know speed and time how long it takes to get to the other end. If you were particularly eager and the corridor sufficiently long, you could bounce light (or radio waves) off the far end and time how long it takes to complete a round trip.<br />
<br />
Of these three options, I'd hazard that most people would use a length-based measurement as per the first option.<br />
<br />
Now suppose your room is actually a space ship traveling close to the speed of light with you inside it. (For now we're ignoring how it got up to that speed.) You can still use the same three methods to measure it. Remember, when you're moving at a constant speed, you don't feel the movement. Aside from bumpiness due to uneven roads/train tracks/turbulence, the only sort of movement you can detect without looking out a window are the periods of acceleration and deceleration. So, if you're traveling at a constant velocity in a spaceship with no windows, you would have no way of checking how fast you're going, but other than that, nothing weird would seem to be happening.<br />
<br />
On the other hand, if you were outside the spaceship watching it go past, how could you measure how long it was? Being on the outside rules out walking along it with a tape measure (unless it's stationary, but then it's not going past, is it?), but the other two methods more or less work. If you know how fast it's going, you can time how long it takes to go past. If you know how long it is, you can time how long it takes to go past and work out how fast it's going.<br />
<br />
Intuitively, we might expect that spaceship length doesn't change and that the speed of the spaceship is the only thing that determines the time taken for it to go past. This isn't strictly true.<br />
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The one immutable quantity when we're talking about moving objects in a vacuum (that is, spaceships in space) is not how long they are or, strictly speaking, how fast they're going. It is, in fact, the speed of light. The old mantra of special relativity is:<br />
<br />
<div style="text-align: center;">
<i>The speed of light is constant in all inertial reference frames.</i></div>
<br />
A definition before I go on: <i>inertial reference frame</i> is a set of
co-ordinates which isn't accelerating. If you are in an inertial
reference frame, you can define your spacetime position with respect to
those co-ordinates.<br />
<br />
Also, an important point is that it's not possible for any object with mass to move at the speed of light (or faster). The only reason light gets away with it is because photons, particles of light, are massless. <br />
<br />
<b> </b><br />
<b>Goin' fast</b><br />
<br />
Say your fancy long spaceship is constantly going at half the speed of light. Because the speed of light is constant in all inertial reference frames, light from a torch you shine inside the spaceship will still travel at the same speed of light as it would anywhere else. Furthermore, just because you're traveling at half the speed of light doesn't mean the light from your torch will appear to travel at one and a half times the speed of light to someone outside your spaceship who can look inside.<br />
<br />
Sounds paradoxical, doesn't it?<br />
<br />
To make up for the apparent paradox, two things happen. Remember that speed or velocity is basically the amount of distance covered in a stretch of time. To keep the speed of light constant, both distance and time change, depending on how fast you're observing from.<br />
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A fast moving object appears to be shorter than it would were both object and observer in the same reference frame (that is, traveling at the same speed in the same direction). This applies to the outside distance for a fast-moving spaceship -- the distance traveled/left to go appears shorter than if the spaceship was stationary with respect to it. This is called length contraction.<br />
<br />
<span style="font-size: x-small;">Quick side note: this means that all distance is relative and there is no such thing as being truly stationary, just stationary with respect to some other reference frame.</span><br />
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The faster your spaceship goes, the more slowly time passes for you. Well, actually, to you it would seem that between starting your journey and ending it, time passed more quickly planetside than it did for you. (It's all relative, see?) This is called time dilation.<br />
<br />
The amount by which time slows down or distance shrinks is dictated by the relative speed of your spaceship. There's a mathematical quantity called the Lorentz factor, represented by the Greek letter gamma, which tells us how much.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpdQ5s1VHHgtBprLoDjUSzoTqGt2Tora9REpkl4ZCIpH1dcBzyjHzUf8R7vBglV7QHudh3z64ue9rFEN6dafEXSY-C_2Rv6RlzS8qtkY8kftpu1VuRSZt9qHx0vu3dl-6g_LgxsZedaGUm/s1600/latex-image-2.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpdQ5s1VHHgtBprLoDjUSzoTqGt2Tora9REpkl4ZCIpH1dcBzyjHzUf8R7vBglV7QHudh3z64ue9rFEN6dafEXSY-C_2Rv6RlzS8qtkY8kftpu1VuRSZt9qHx0vu3dl-6g_LgxsZedaGUm/s1600/latex-image-2.png" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Gamma, the squiggle on the left, is the Lorentz factor, <i>v</i> is the speed the spaceship or whatever is traveling, and <i>c</i> is the speed of light, equal to 3 x 10<sup>8</sup> metres per second.</td></tr>
</tbody></table>
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<span id="goog_2107751223"></span><span id="goog_2107751224"></span><br />
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<div class="separator" style="clear: both; text-align: center;">
</div>
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<br />
So if you're traveling at half the speed of light, gamma would be equal to about 1.15, so time would pass 1.15 times more slowly. An hour on the spaceship would take about 69 minutes to pass on Earth. The length of the spaceship, to someone on Earth, would be 1.15 times shorter. One metre would appear to be about 87 cm long.<br />
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Some other values of gamma for speeds which are significant fractions of the speed of light are:<br />
<ul style="text-align: left;">
<li>Speed: 0.75<i>c, </i>gamma =1.51</li>
<li>Speed: 0.867<i>c</i>, gamma = 2</li>
<li>Speed: 0.9<i>c</i>, gamma = 2.3</li>
<li>Speed: 0.95<i>c</i>, gamma = 3.2 </li>
<li>Speed: 0.99<i>c</i>, gamma =7.1</li>
<li>Speed: 0.9999<i>c</i>, gamma =70.7</li>
</ul>
To work out the time dilation, multiply by gamma, to work out the length contraction, divide by gamma.<br />
<br />
This isn't quite all there is to know. For example, objects traveling at relativistic velocities (at an appreciable fraction of the speed of light) also increase in mass by the same factor of gamma and accelerating up to high speeds is also a bit strange. More on that next week.<br />
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And in case you're wondering how fast you have to go for these relativistic effects to kick in, or even how we know they're real... well, they exist no matter how fast you're going, it's just that at the sort of speeds we experience on a day to day basis, the time differences are entirely negligible. We have been able to test relativity, however, in a couple of ways. Flying super-precise atomic clocks around on aeroplanes has shown that time passes more slowly for them relative to us. The same has been shown for GPS and possibly other satellites. On a much larger scale, measurements of binary <a href="http://en.wikipedia.org/wiki/Pulsar">pulsars</a> have also confirmed Einstein's theory of special relativity.<br />
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Stay tuned for more next week.<br />
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<br />
<br /></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0tag:blogger.com,1999:blog-119383823552885882.post-48776670954633941332012-01-15T19:22:00.000+01:002012-01-15T19:22:08.371+01:00Review: Spare Parts by Sally Rogers-Davidson<div dir="ltr" style="text-align: left;" trbidi="on">
You may recall me <a href="http://tsanad.blogspot.com/2011/12/australian-women-writers-challenge.html">posting</a>
about the Australian Women Writers Challenge at the end of last year. Well I just finished reading my first science fiction book for the
challenge, which I will review in this post. Actually, I'm undertaking two challenges, the other not being restricted to only science fiction books (although it is mostly fantasy). One of the books I've read that I've decided to count as not science fiction was a bit borderline. That's <i>Hoodwink</i> by Rhonda Roberts, which is about a time-travelling PI. The time-travelling part is obviously the science fiction element, but since the book doesn't spend much time talking about the mechanics or physics of time travel (it's mentioned briefly and I suspect may become more important in other books), I've counted it towards the other challenge. If you're interested, you can read my 4.5 / 5 star review <a href="http://dukenarrativium.tumblr.com/post/15822745521/review-hoodwink-by-rhonda-roberts">here</a>.<br />
<br />
<b><i>Spare Parts<i> </i></i>by Sally Rogers-Davidson</b><i><i><br /></i></i><br />
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<a href="http://pics.librarything.com/picsizes/65/1d/651d181c32c28845979784a6151434d414f4541.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" src="http://pics.librarything.com/picsizes/65/1d/651d181c32c28845979784a6151434d414f4541.jpg" /></a>
This was actually a fairly difficult book to track down. When I first made my list of possible science fiction books by Australian women, many were out of print. This was one of them. Or so I thought at first, since it was published in 1999 and not readily available in the usual places. I actually found it on <a href="http://www.audible.com/pd/ref=sr_1_1?asin=B004C45KPA&qid=1326648080&sr=1-1">Audible</a> in audiobook form (if you become a member, even briefly, it's much cheaper to buy audiobooks from them, FYI). It was read by Suzi Dougherty, who has apparently also read many/most of John Marsden's audiobooks. The Australian accent was appreciated since most audiofiction I come across, with a few British exceptions, is American.<br />
<br />But enough about the format.<br />
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<i>Spare Parts</i> is about Kelty, a 19 year old "C-grader" (in a caste system which goes down to D), whose prospects were reduced when she narrowly missed out on a place at university (because C-graders can only get in with scholarships). The book is set about a hundred years in the future in the sprawling suburbia of Melbourne, albeit a Melbourne more filled with high-rises and with even dodgier trains than at present.<br />
<br />
When Kelty's best friend is grievously injured in an industrial accident, Kelty decides to sell her body and join the space corps to save her friend. This is a world where the rich discard their old, decrepit (or sometimes merely slightly wrinkled) bodies and have their brains transplanted into the young bodies of people of the lower classes, for a nice fee. The people who've sold their bodies then get to have their brains transplanted into cyborg bodies. The catch? Cyborgs (or cybermorphs as is the politically correct term) aren't allowed to live permanently on Earth.<br />
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When I first started reading, I thought this was a dystopian novel and was convinced that Kelty was going to discover that the evil A and B graders were killing the poor for their bodies and organs. It's possible that I've read too many YA dystopias of late. To alleviate any confusion such as what I suffered, I want to make it clear that this is not really a dystopian novel. Sure, it's not all rainbows and sunshine for the poor, criminals wear tracker bracelets which electrocute them if they feel angry (so they don't attack bystanders) but it's not terribly different to our world. The class boundaries are just a little more emphasised so that the rich live in high-rises and ride cable cars around the city and the poor live in dodgy areas and ride the subway. The main thing which distinguishes <i>Spare Parts</i> from books like <i>The Hunger Games</i> and <i>Divergent</i> or even <i>1984</i> is that there is no government conspiracy keeping everyone oppressed. The poor are just poor and have to either sell their bodies and join the space corps or be smart enough for a scholarship to university to improve their situation.<br />
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Of course, I'm not saying that the characters, rich or otherwise, are necessarily all on the up and up, but if I hadn't automatically assumed dystopia, I think I would have enjoyed the start more, instead of spending it being deeply suspicious of the society. That's more an issue with my expectations than with the book itself, however.<br />
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I thought the way the cyborg bodies were explained and treated was well done. The space corps is composed entirely of cyborgs because ordinary human bodies aren't resilient enough to withstand the accelerations and radiation and other dangers of space. Human brains can't just be plonked in a cyborg body and be expected to know how to manipulate it (especially given the extra senses they have, like infrared and UV vision, for example). Rogers-Davidson deals with this by giving each cyborg an AI assistant which interfaces with their systems and helps them acclimate to the world. They can even mitigate or postpone the effects of alcohol. Kelty's snarky AI was one of the really fun parts of the novel. (She's so "state-of-the-art" she can even be sarcastic.)<br />
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I also enjoyed the human aspect of the novel. It was nice to see a wide range of female characters and their relationships were equally varied and well drawn particularly between the main character and others (since this was written in first person, that's to be expected). In fact, I think there was only one prominent male character, and he was only really around in the first half of the book, which is rare to see. Another key difference between <i>Spare Parts</i> and many more recent YA books is the lack of a romantic plot line. Which I found endearing. Given all the changes she's going through -- changing bodies, changing socioeconomic circumstances -- Kelty really has much more important things to worry about than boys. It really is nice to read about a teenager who doesn't think important life choices have to include boys. <br />
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Rating: 5 / 5 stars<br />
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<br /></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com3tag:blogger.com,1999:blog-119383823552885882.post-14374749693208896242012-01-08T23:15:00.000+01:002012-01-08T23:15:35.416+01:00Living in the Future<div dir="ltr" style="text-align: left;" trbidi="on">
It being the new year and all, I thought it might be nice to reflect upon what we, as a whole, have achieved that was once science fiction but is now commonplace. Or at least existent. And I'm not going to focus on the big obvious things, because those are boring and, well, we <i>know</i> smartphones and iPads and modern medicine are crazy futuristic devices/advances. That's obvious. But what about the little things? Specifically, what about food?<br />
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<b>Foodtastic</b><br />
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I was inspired to write this post when I was eating a fried egg and cheese toasted sandwich that was both gluten and dairy-free. The cheese was made of soy and the bread was specially processed to get rid of the gluten, as well as being made with alternate flours (that is to say, it has gluten-free wheat starch as a key ingredient as well as non-wheat flours).<b> </b> If you're wondering, the cheese stuff does sort of taste of cheese (without the evil taste of doom that I associate with dairy products), particularly if it's mixed with something else, like egg and bread. Other magic pseudo-dairy products I have in my fridge include rice milk, oat milk, soyghurt, oat milk-based ice cream, oat milk fauxghurt, rice milk-based cream, soy-based sour cream, two types of pretend cheese (another flavour of the slices and a solid type one I haven't actually tried yet) and dairy-free margarine.<br />
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The more exotic of these are relatively recent inventions. In terms of food (intentionally) not containing gluten*, coeliac disease (and hence the negative impact of gluten on sufferers) was discovered circa World War II (thanks to bread shortages, I believe), margarine has been around <a href="http://en.wikipedia.org/wiki/Margarine">for a while</a>, <a href="http://en.wikipedia.org/wiki/Soy_milk">soy</a> and <a href="http://en.wikipedia.org/wiki/Grain_milk">grain milk</a>s even longer, although less so in the western world. Another relatively recent development is vegetarian products which resemble miscellaneous meat products. There's not-bacon (it even comes with not-fat bits), slices pretending to be ham, a variety of sausages -- from pseudo hot dog to chorizo to pseudo chicken and gourmet -- faux chicken nuggets, kebablike things and probably something else that's slipped my mind.<br />
<br />
All these things already exist.<br />
<br />
Science fiction often has us eating vat-grown protein (Bujold's Vorkosigan books), hydroponic vegetables (lots of things) soy moulded into all sorts of unusual and interesting-tasting things (Asimov and others). We already have hydroponic vegetables -- I'm pretty sure that's where my tomatoes come from these days -- and soy disguised as all sorts of things. The main difference is that we're growing these things on Earth, not in space. But we're getting there.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/4/41/Quinoa.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="239" src="http://upload.wikimedia.org/wikipedia/commons/4/41/Quinoa.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Uncooked quinoa. Nabbed from wiki <a href="http://en.wikipedia.org/wiki/File:Quinoa.jpg">here</a>.</td></tr>
</tbody></table>
NASA <a href="http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB0QFjAA&url=http%3A%2F%2Fntrs.nasa.gov%2Farchive%2Fnasa%2Fcasi.ntrs.nasa.gov%2F19940015664_1994015664.pdf&ei=-wsKT6D2MMeQ4gTfuLyNCA&usg=AFQjCNErDmxcpFGih9oorXWDZXz9l-5z4g&sig2=Ze8tOXat4Snf7pYWhOV9Dw">has looked into</a> (pdf) using <a href="http://en.wikipedia.org/wiki/Quinoa">quinoa</a> as a space crop because, unlike soy, quinoa is a complete protein. This means that it contains all the essential amino acids we need (just like meat does). As well as being high in protein, it's high in fibre, iron and other useful things. And in terms of off-world farming, crops are much easier to deal with than animals. That pdf I linked at the start of this paragraph is pretty old, and I suspect NASA's research is directed elsewhere for the moment, but there's no reason for this not to be taken further in the future.<br />
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Another aspect I want to touch on is additives. There is a certain magic to making something taste like a thing that hasn't even been within a metre of the production line. More importantly, and more relevantly, are preservatives, both the chemical and the food-storage kind. The fact that we <i>can</i> ship things all around the globe without them going off before they reach their destination is also a little bit magic, when you think about what our pre-refrigeration ancestors had to contend with. To say nothing of freeze-drying or long-life (dairy) milk.<br />
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And I haven't even begun to talk about mass production farming and all that jazz. Although, despite continuing research/advances in those areas, aspects of that are a little less futuristic-<i>feeling</i> than pretend sausages. Unless we're talking about genetic modification, but that's a whole other can of worms.<br />
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So. We might not quite be up to growing crops in space yet, but in terms of what we can do with food, I think we're already living a little bit in the future.<br />
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<span style="font-size: x-small;">*which isn't actually the substance I have issues with, but that's beside the point.</span></div>Tsana Dolichvahttp://www.blogger.com/profile/16213478548320312760noreply@blogger.com0