Comments on: Pack your bags, kids
http://www.metafilter.com/96180/Pack-your-bags-kids/
Comments on MetaFilter post Pack your bags, kidsWed, 29 Sep 2010 14:52:38 -0800Wed, 29 Sep 2010 14:52:38 -0800en-ushttp://blogs.law.harvard.edu/tech/rss60Pack your bags, kids
http://www.metafilter.com/96180/Pack-your-bags-kids
Astronomers have found <a href="http://www.wired.com/wiredscience/2010/09/real-habitable-exoplanet/">the first exoplanet within the "habitable" band around a star</a>, or within the distance band around a start that would allow for liquid water. The planet is roughly 3 times the size of the Earth and orbits red dwarf <a href="http://en.wikipedia.org/wiki/Gliese_581">Gliese 581</a> every 36.6 days at a distance of about 13 million miles.post:www.metafilter.com,2010:site.96180Wed, 29 Sep 2010 14:46:54 -0800PunkeyexoplanethabitablediscoverystargatespaceplanetGliese581By: Punkey
http://www.metafilter.com/96180/Pack-your-bags-kids#3304536
Grr, three times the <strong>mass</strong>. It bugs the crap out of me when people mix up size and mass, and there I go. Oh well.comment:www.metafilter.com,2010:site.96180-3304536Wed, 29 Sep 2010 14:52:38 -0800PunkeyBy: Ironmouth
http://www.metafilter.com/96180/Pack-your-bags-kids#3304538
*tentacle covers telescope camera* *static*comment:www.metafilter.com,2010:site.96180-3304538Wed, 29 Sep 2010 14:52:47 -0800IronmouthBy: Cool Papa Bell
http://www.metafilter.com/96180/Pack-your-bags-kids#3304539
DIBS! I call dibs.comment:www.metafilter.com,2010:site.96180-3304539Wed, 29 Sep 2010 14:53:11 -0800Cool Papa BellBy: Artw
http://www.metafilter.com/96180/Pack-your-bags-kids#3304544
Tidally locked as well, which would be a bummer for people expecting such petty conveniences as "night" and "day".comment:www.metafilter.com,2010:site.96180-3304544Wed, 29 Sep 2010 14:54:02 -0800ArtwBy: penduluum
http://www.metafilter.com/96180/Pack-your-bags-kids#3304545
Ah well, we were born too soon. Have fun, future babies. Sorry about ... everything.comment:www.metafilter.com,2010:site.96180-3304545Wed, 29 Sep 2010 14:54:50 -0800penduluumBy: Blazecock Pileon
http://www.metafilter.com/96180/Pack-your-bags-kids#3304549
If we ever move there, we might have the technology to build rotating cities, moving castles, etc.comment:www.metafilter.com,2010:site.96180-3304549Wed, 29 Sep 2010 14:56:16 -0800Blazecock PileonBy: Joe Beese
http://www.metafilter.com/96180/Pack-your-bags-kids#3304552
<em>Tidally locked as well, which would be a bummer for people expecting such petty conveniences as "night" and "day".</em>
Yeah, but 3 times the size of Earth! Think of all the landfill space!comment:www.metafilter.com,2010:site.96180-3304552Wed, 29 Sep 2010 14:57:56 -0800Joe BeeseBy: Artw
http://www.metafilter.com/96180/Pack-your-bags-kids#3304553
Another interesting aspect:
<i>Another advantage for potential life on Gliese 581g is that its star is "effectively immortal," Butler said. "Our sun will go 10 billion years before it goes nova, and life here ceases to exist. But M dwarfs live for tens, hundreds of billions of years, many times the current age of the universe. So life has a long time to get a toehold."</i>comment:www.metafilter.com,2010:site.96180-3304553Wed, 29 Sep 2010 14:57:59 -0800ArtwBy: localroger
http://www.metafilter.com/96180/Pack-your-bags-kids#3304566
So this means <i>The Chronicles of Riddick</i> was a documentary?comment:www.metafilter.com,2010:site.96180-3304566Wed, 29 Sep 2010 15:05:18 -0800localrogerBy: adipocere
http://www.metafilter.com/96180/Pack-your-bags-kids#3304572
Yeah, the tidal lock is an issue. No, we probably won't be able to see if the planet is currently tidal locked (it took until 1965 to show that Mercury wasn't tidally locked to the Sun and instead had an orbital resonance, a fact that did not make it into the textbooks for a while), but that close, it might well be. The sun is smaller and the planet is larger, so that gives it a better chance of not being tidally locked, but it's also much closer, and the distance from planet to star has a hefty exponent that dominates the equation determining time to tidal lock.
The good news is that, if 581g has a moon, that might not tidally locked, and so it would not necessarily suffer the "equatorial band of habitability" issue. If it were massive enough, it could retain an atmosphere and, attached to 581g, it would be in the Goldilocks Zone, too.comment:www.metafilter.com,2010:site.96180-3304572Wed, 29 Sep 2010 15:07:02 -0800adipocereBy: Errant
http://www.metafilter.com/96180/Pack-your-bags-kids#3304582
<em>DIBS! I call dibs.</em>
Do you have a flag?comment:www.metafilter.com,2010:site.96180-3304582Wed, 29 Sep 2010 15:11:35 -0800ErrantBy: These Premises Are Alarmed
http://www.metafilter.com/96180/Pack-your-bags-kids#3304583
<em>Tidally locked as well, which would be a bummer for people expecting such petty conveniences as "night" and "day".</em>
Yeah but any 'people' moving there would've spent how many generations in space prior? I think they could handle it.comment:www.metafilter.com,2010:site.96180-3304583Wed, 29 Sep 2010 15:12:09 -0800These Premises Are AlarmedBy: Artw
http://www.metafilter.com/96180/Pack-your-bags-kids#3304586
Pff. Those guys would probably just want to hang out witha bunch of Transhumanist weirdos in the Oort cloud anyway.comment:www.metafilter.com,2010:site.96180-3304586Wed, 29 Sep 2010 15:14:29 -0800ArtwBy: five fresh fish
http://www.metafilter.com/96180/Pack-your-bags-kids#3304588
The big question is whether we send the hairdressers and telephone sanitizers there, or leave them here.comment:www.metafilter.com,2010:site.96180-3304588Wed, 29 Sep 2010 15:16:00 -0800five fresh fishBy: dances_with_sneetches
http://www.metafilter.com/96180/Pack-your-bags-kids#3304590
So I would be three times the weight and ten times as many years old. Include me out.comment:www.metafilter.com,2010:site.96180-3304590Wed, 29 Sep 2010 15:17:06 -0800dances_with_sneetchesBy: Artw
http://www.metafilter.com/96180/Pack-your-bags-kids#3304591
I hear they need a lot of social media marketing expertise out there...comment:www.metafilter.com,2010:site.96180-3304591Wed, 29 Sep 2010 15:17:32 -0800ArtwBy: goodnewsfortheinsane
http://www.metafilter.com/96180/Pack-your-bags-kids#3304597
Well that's good because Bebo sent a <a href="http://en.wikipedia.org/wiki/A_Message_From_Earth">message</a> there!comment:www.metafilter.com,2010:site.96180-3304597Wed, 29 Sep 2010 15:22:09 -0800goodnewsfortheinsaneBy: brina
http://www.metafilter.com/96180/Pack-your-bags-kids#3304609
The message was sent to 581c, alas, not 581g.comment:www.metafilter.com,2010:site.96180-3304609Wed, 29 Sep 2010 15:29:57 -0800brinaBy: srboisvert
http://www.metafilter.com/96180/Pack-your-bags-kids#3304610
Just what I need. A planet where I can be 10 times older and 3 times as heavy.comment:www.metafilter.com,2010:site.96180-3304610Wed, 29 Sep 2010 15:30:14 -0800srboisvertBy: goodnewsfortheinsane
http://www.metafilter.com/96180/Pack-your-bags-kids#3304619
They will still receive it at 581g, though, right?
<small>Or do they have incompatible broadcast systems there? </small>comment:www.metafilter.com,2010:site.96180-3304619Wed, 29 Sep 2010 15:36:04 -0800goodnewsfortheinsaneBy: brenton
http://www.metafilter.com/96180/Pack-your-bags-kids#3304626
This is one of the most exciting astronomical discoveries this decade for me. I know that more will probably be discovered soon, but there's a part of me that wants to launch a spaceship out there now, accelerating it as fast as we can, so that we can get a closer look before I die. It's 20 lightyears away. If we spent 5 years building it, how fast could we get a space probe there? I think I can hang on another 50 years.
It's been decades since Voyager, it's high time we sent another ship out of our system.comment:www.metafilter.com,2010:site.96180-3304626Wed, 29 Sep 2010 15:41:50 -0800brentonBy: Zephyrial
http://www.metafilter.com/96180/Pack-your-bags-kids#3304636
"Gravity dictates that such a close-in planet would keep the same side facing the star at all times, the same way the moon always shows the same face to Earth. That means the planet has a blazing hot daytime side, a frigid nighttime side, and <i>a band of eternal sunrise or sunset where water — and perhaps life — could subsist comfortably. Any life on this exotic world would be confined to this <b>perpetual twilight zone.</b></i>" <small>(emphasis added)</small>
There's something awfully romantic about this idea - it's practically begging to be fictionalized (if it hasn't already - I'm no sci fi buff). Also, cool discovery, thanks for sharing.comment:www.metafilter.com,2010:site.96180-3304636Wed, 29 Sep 2010 15:49:45 -0800ZephyrialBy: Joe Beese
http://www.metafilter.com/96180/Pack-your-bags-kids#3304640
<em>If we spent 5 years building it, how fast could we get a space probe there?</em>
It's not just the problem of accelerating a probe to relativistic velocities. You've also got to slow the thing down once it gets there.
This will be... challenging.comment:www.metafilter.com,2010:site.96180-3304640Wed, 29 Sep 2010 15:52:21 -0800Joe BeeseBy: zoogleplex
http://www.metafilter.com/96180/Pack-your-bags-kids#3304645
You have to admit that accelerating anything larger than a proton to relativistic velocities is a little beyond us right now.
Unless you want to build Orion, and break the Space Treaty.comment:www.metafilter.com,2010:site.96180-3304645Wed, 29 Sep 2010 15:55:46 -0800zoogleplexBy: delmoi
http://www.metafilter.com/96180/Pack-your-bags-kids#3304651
Actually the equatorial band thing might make it easier for life to evolve. You've got massive heat on one side, and ice on the other. That's going to create a lot of interesting energy gradients, I would imagine. There must be <i>some</i> part of the planet at the right spot.comment:www.metafilter.com,2010:site.96180-3304651Wed, 29 Sep 2010 16:01:04 -0800delmoiBy: Dumsnill
http://www.metafilter.com/96180/Pack-your-bags-kids#3304653
So I guess the <a href="http://www.guardian.co.uk/news/blog/2010/sep/27/un-alien-ambassador-mazlan-othman">UN's "Alien Ambassador" idea</a> wasn't all that stupid.comment:www.metafilter.com,2010:site.96180-3304653Wed, 29 Sep 2010 16:03:41 -0800DumsnillBy: localroger
http://www.metafilter.com/96180/Pack-your-bags-kids#3304656
The problem with the equatorial band is that the whole atmosphere freezes out on the night side, so the balmy equatorial band is in vacuum. If the planet is in resonance instead of locked (which is really, really unlikely for a world at this distance) then you get freezing and searing winds that make hurricanes look like a gentle summer breeze by comparison.comment:www.metafilter.com,2010:site.96180-3304656Wed, 29 Sep 2010 16:06:41 -0800localrogerBy: benzenedream
http://www.metafilter.com/96180/Pack-your-bags-kids#3304659
Heavier than earth with a red sun? I eagerly await the discovery of thought-beasts.comment:www.metafilter.com,2010:site.96180-3304659Wed, 29 Sep 2010 16:08:22 -0800benzenedreamBy: ricochet biscuit
http://www.metafilter.com/96180/Pack-your-bags-kids#3304678
<em>If we spent 5 years building it, how fast could we get a space probe there? I think I can hang on another 50 years.</em>
Assuming you are serious, we would have to build something that travels faster than Voyager 1, which currently is the fastest travelling man-made object outside the solar system. And when I say "faster", I mean many, many thousand times as fast. And then, as Joe points out, you have to find a way to slow it down again. And then wait twenty years for the first signals to come back.
Voyager 1 has been travelling for just over 33 years now, and is about seventeen million km from earth. A light year is just under ten trillion km. Put another way, if the distance from here to Gliese 581 were the distance from New York to Los Angeles, Voyager 1 has travelled about one foot so far.
In short, don't hold your breath.comment:www.metafilter.com,2010:site.96180-3304678Wed, 29 Sep 2010 16:17:00 -0800ricochet biscuitBy: GuyZero
http://www.metafilter.com/96180/Pack-your-bags-kids#3304686
<i>then you get freezing and searing winds that make hurricanes look like a gentle summer breeze by comparison.</i>
Doesn't seem to have stopped Vin Diesel from kicking ass.comment:www.metafilter.com,2010:site.96180-3304686Wed, 29 Sep 2010 16:21:56 -0800GuyZeroBy: angrycat
http://www.metafilter.com/96180/Pack-your-bags-kids#3304699
So, for those who know stuff, do we know that there's not civilizations there already with radio capabilities? They think of pointing the SETI in its direction?comment:www.metafilter.com,2010:site.96180-3304699Wed, 29 Sep 2010 16:26:34 -0800angrycatBy: keratacon
http://www.metafilter.com/96180/Pack-your-bags-kids#3304704
<em>If we spent 5 years building it, how fast could we get a space probe there?</em>
Well the fastest object yet made by man was the Helios probe in the 70s which went about 150,000 mph, and that was using the gravity of the sun to slingshot it around.
Let's very (very very) optimistically assume we can make something that escapes the gravity of the Solar System at 10x that speed. Gliese 581 is 20.3 light years away. At 1,500,000 miles per hour that would take...
...calculates...
9311 Years. To put that in perspective, if the first Pharaoh of ancient Egypt had had access to technology far in advance of what we now have, his astronauts would still only be a little over half way there.
Interstellar travel is difficult in ways that strain the imagination. If we achieve it in the next 1000 years, I'd be impressed with our species.comment:www.metafilter.com,2010:site.96180-3304704Wed, 29 Sep 2010 16:29:06 -0800kerataconBy: philipy
http://www.metafilter.com/96180/Pack-your-bags-kids#3304706
It's only 20 light years away from what I read.
If we found one this close, such planets could be very common.comment:www.metafilter.com,2010:site.96180-3304706Wed, 29 Sep 2010 16:29:49 -0800philipyBy: justkevin
http://www.metafilter.com/96180/Pack-your-bags-kids#3304707
<em>It's 20 lightyears away. If we spent 5 years building it, how fast could we get a space probe there? I think I can hang on another 50 years. </em>
We are definitely at the point where we could get a probe there faster by waiting.
Our best technology today would probably take tens of thousands of years to get a probe there (Voyager I would take almost half a million years if we'd aimed it at Gliese). If we can get a 1% speed increase in the next a century, a probe launched in 100 years would pass a probe launched now en route.comment:www.metafilter.com,2010:site.96180-3304707Wed, 29 Sep 2010 16:30:10 -0800justkevinBy: brundlefly
http://www.metafilter.com/96180/Pack-your-bags-kids#3304719
I think it's a neat idea that if we send probes into deep space, they might be passed by subsequent, more advanced/faster probes. The first things we send will be the last to arrive.comment:www.metafilter.com,2010:site.96180-3304719Wed, 29 Sep 2010 16:35:03 -0800brundleflyBy: brundlefly
http://www.metafilter.com/96180/Pack-your-bags-kids#3304720
"Out of the way, old man!"comment:www.metafilter.com,2010:site.96180-3304720Wed, 29 Sep 2010 16:35:16 -0800brundleflyBy: vidur
http://www.metafilter.com/96180/Pack-your-bags-kids#3304724
<em><a href="http://www.metafilter.com/96180/Pack-your-bags-kids#3304626">></a> I think I can hang on another 50 years.
</em>
<em><a href="http://www.metafilter.com/96180/Pack-your-bags-kids#3304678">>></a> In short, don't hold your breath.</em>
Heh.comment:www.metafilter.com,2010:site.96180-3304724Wed, 29 Sep 2010 16:36:35 -0800vidurBy: The Whelk
http://www.metafilter.com/96180/Pack-your-bags-kids#3304804
I've got a Bumblebee class ship, an empty cargo hold and 40 pounds of Centuari Glue-Hash. Who's in?comment:www.metafilter.com,2010:site.96180-3304804Wed, 29 Sep 2010 17:03:55 -0800The WhelkBy: AkzidenzGrotesk
http://www.metafilter.com/96180/Pack-your-bags-kids#3304866
Okay I have the whole tidal lock/circadian thing figured out. I am going to get in on the land rush early (obviously this will require massive bribes paid to William Swearengen-Blagojevich XVII or whoever ends up being appointed planetary governor, but that's cool because I will put $0.01 in a savings account just before I place myself into suspended animation) and buy a huge rectangular strip of land whose long axis is perpendicular to the terminator. I will then install a giant oval railroad on this strip with lots of exciting scenery all around. People will be able to lease (on terms extremely favorable to me and probably also to Gov. WSB) permanent dwellings aboard this train, which will allow them to experience "day" and "night" and thereby differentiate themselves from the dirty peons toiling in the beryllium mines! Oh and the train will be powered by the temperature differential between the light and dark sides or something.comment:www.metafilter.com,2010:site.96180-3304866Wed, 29 Sep 2010 17:44:42 -0800AkzidenzGroteskBy: zota
http://www.metafilter.com/96180/Pack-your-bags-kids#3304887
I'm afraid my associate, George Hearst Beeblebrox, has already laid claim to the pocket of spacetime encompassing your interesting little railroad.comment:www.metafilter.com,2010:site.96180-3304887Wed, 29 Sep 2010 17:55:21 -0800zotaBy: -harlequin-
http://www.metafilter.com/96180/Pack-your-bags-kids#3304898
<i>"I think it's a neat idea that if we send probes into deep space, they might be passed by subsequent, more advanced/faster probes. The first things we send will be the last to arrive."</i>
There is a neat sci-fi short story about interstellar safari hunting, and how it got banned. About fifty years later, humanity decides to learn more about some of the prize beasts and scientific missions started reopening the old hunting routes.
Scientists arrive, study the beasts, learn a lot about them, man and beast become quite friendly with each other. Anyway, gotta head back to earth.
The next week, some more earthlings arrive. The beasts amble up to the ship to greet the scientists, and trophy-seeking hunters hop out and kill them. Lambs to the slaughter.
(A hunting ship from 50 years ago got passed en route by the more advanced science ship)comment:www.metafilter.com,2010:site.96180-3304898Wed, 29 Sep 2010 18:06:23 -0800-harlequin-By: bwg
http://www.metafilter.com/96180/Pack-your-bags-kids#3304899
You can be Madison Avenue is already scrambling to exploit this.comment:www.metafilter.com,2010:site.96180-3304899Wed, 29 Sep 2010 18:06:24 -0800bwgBy: Nyrath
http://www.metafilter.com/96180/Pack-your-bags-kids#3304918
It is possible that the atmosphere will NOT all freeze on the dark side.
<a href="http://www.treitel.org/Richard/rass/tidelock01.txt">"Simulations of the Atmospheres of Synchronously Rotating Terrestrial Planets Orbiting M Dwarfs: Conditions for Atmospheric Collapse and the Implications for Habitability", Icarus V129, pp450-465, 1997
</a>
Such "twilight" worlds have appeared in science fiction, and yes, they are romantic. I recall one in George R. R. Martin's <strong>Dying of the Light</strong>, and in Isaac Asimov's <strong>Foundation And Empire.</strong>
I calculate that if the average separation between habitable planets is 20 light years, then a sphere 100 light years in diameter would contain about 125 such planets.comment:www.metafilter.com,2010:site.96180-3304918Wed, 29 Sep 2010 18:23:22 -0800NyrathBy: eritain
http://www.metafilter.com/96180/Pack-your-bags-kids#3304941
Well, so it's not gonna be Gaia II. But if it's got an orbital resonance it might at least be Trenco.comment:www.metafilter.com,2010:site.96180-3304941Wed, 29 Sep 2010 18:50:59 -0800eritainBy: indubitable
http://www.metafilter.com/96180/Pack-your-bags-kids#3304956
FUCK THE OUTER SPACE TREATY LET'S BUILD NUCLEAR ROCKET SHIPS AND DO THIS THINGcomment:www.metafilter.com,2010:site.96180-3304956Wed, 29 Sep 2010 19:03:49 -0800indubitableBy: heathkit
http://www.metafilter.com/96180/Pack-your-bags-kids#3304967
<i>I calculate that if the average separation between habitable planets is 20 light years, then a sphere 100 light years in diameter would contain about 125 such planets.</i>
And just because that made me look it up, the galaxy can be approximated as a cylinder 100k light years in diameter and 100 light years tall. Of course, stars aren't distributed uniformly and I bet there's an "uninhabitable" zone towards the center of the galaxy, but still.comment:www.metafilter.com,2010:site.96180-3304967Wed, 29 Sep 2010 19:13:21 -0800heathkitBy: blue_beetle
http://www.metafilter.com/96180/Pack-your-bags-kids#3304974
Ants huh?comment:www.metafilter.com,2010:site.96180-3304974Wed, 29 Sep 2010 19:15:22 -0800blue_beetleBy: AElfwine Evenstar
http://www.metafilter.com/96180/Pack-your-bags-kids#3304984
<em>I think I can hang on another 50 years.</em>
If we used 1950's thermonuclear pulse drive technology you could theoretically get there in around 200 years. Maybe even sooner if we updated designs.
<a href="http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)">Later studies indicate that the top cruise velocity that can theoretically be achieved by a thermonuclear Orion starship is about 8% to 10% of the speed of light (0.08-0.1c).[1] An atomic (fission) Orion can achieve perhaps 3%-5% of the speed of light. A nuclear pulse drive starship powered by matter-antimatter pulse units would be theoretically capable of obtaining a velocity between 50% to 80% of the speed of light.
At 0.1c, Orion thermonuclear starships would require a flight time of at least 44 years to reach Alpha Centauri, not counting time needed to reach that speed (about 36 days at constant acceleration of 1g or 9.8 m/s2). <strong>At 0.1c, an Orion starship would require 100 years to travel 10 light years.</strong> The late astronomer Carl Sagan suggested that this would be an excellent use for current stockpiles of nuclear weapons.</a>comment:www.metafilter.com,2010:site.96180-3304984Wed, 29 Sep 2010 19:20:47 -0800AElfwine EvenstarBy: lupus_yonderboy
http://www.metafilter.com/96180/Pack-your-bags-kids#3305008
It could be quite habitable, actually.
For one thing, the gravitational acceleration at the equator is only going to be about 45% more than the Earth's - because the mass is three times as big, but the radius is (the cube root of 3) times as big.
For another, just because it's tidally locked, doesn't mean that it doesn't <a href="http://en.wikipedia.org/wiki/Libration">librate</a>... so that perhaps a pretty large portion of the surface gets to see the sun at some point.comment:www.metafilter.com,2010:site.96180-3305008Wed, 29 Sep 2010 19:33:10 -0800lupus_yonderboyBy: Danf
http://www.metafilter.com/96180/Pack-your-bags-kids#3305032
The crucial question that I am surprised no one has asked: How long would it take to get there at Warp 9?comment:www.metafilter.com,2010:site.96180-3305032Wed, 29 Sep 2010 19:44:15 -0800DanfBy: The Whelk
http://www.metafilter.com/96180/Pack-your-bags-kids#3305035
basically I am so into this it hurts like passing a stone.comment:www.metafilter.com,2010:site.96180-3305035Wed, 29 Sep 2010 19:47:14 -0800The WhelkBy: five fresh fish
http://www.metafilter.com/96180/Pack-your-bags-kids#3305042
The problem isn't so much in going fast, as it is in not colliding with stuff. You've seen what small gravel does to your windshield. At relativistic speeds it will do real damage.comment:www.metafilter.com,2010:site.96180-3305042Wed, 29 Sep 2010 19:50:32 -0800five fresh fishBy: AElfwine Evenstar
http://www.metafilter.com/96180/Pack-your-bags-kids#3305100
<em>The problem isn't so much in going fast, as it is in not colliding with stuff. You've seen what small gravel does to your windshield. At relativistic speeds it will do real damage.</em>
Don't worry James Cameron has it all figured out.
<a href="http://www.pandorapedia.com/human_operations/vehicles/isv_venture_star"><em>When acceleration is completed, the ship is rotated 180 degrees so that the mirror shield faces forward. Now the shield performs another role, acting as a multi-layer interstellar debris shield. Although intense magnetic fields are used to deflect stray gas molecules, the occasional dust grain requires a physical barrier. The shield is in multiple layers, spaced one hundred meters apart. Impact of a debris grain (traveling at a relative speed of 0.7C) with the first layer of the shield causes vaporization into a plasma. The spray of plasma particles strikes the second layer, and the impacts cause spalling from the back of the second layer. These particles are stopped by the third layer. A fourth layer acts as a backup in the unlikely event that something gets past the third layer. Once cruise speed is reached, this shield is detached and moved by small thrusters thousands of miles in front of the ship, to improve survivability if a larger particle of debris is encountered.</em></a>comment:www.metafilter.com,2010:site.96180-3305100Wed, 29 Sep 2010 20:40:53 -0800AElfwine EvenstarBy: zoogleplex
http://www.metafilter.com/96180/Pack-your-bags-kids#3305101
"Shields! SHIELDS!"comment:www.metafilter.com,2010:site.96180-3305101Wed, 29 Sep 2010 20:40:55 -0800zoogleplexBy: otherthings_
http://www.metafilter.com/96180/Pack-your-bags-kids#3305158
So, with a nice temperature gradient it could sustain life at some particular latitude... But could it sustain the conditions needed for technologically advanced, intelligent life? I'm thinking "Guns, Germs, and Steel" stuff here. Would a circular strip topology be worse, or better, in those terms?comment:www.metafilter.com,2010:site.96180-3305158Wed, 29 Sep 2010 21:32:51 -0800otherthings_By: Grimgrin
http://www.metafilter.com/96180/Pack-your-bags-kids#3305171
If we have the energy to move a ship at relativistic velocity to spare, will we have the energy to just spin the planet back up again? Wikipedia says the Earth has a rotational kinetic energy of 2.14×10^29 J Which is staggering, but only about a hundred million times more than the amount of energy needed to accelerate a thousand ton ship to .2 c and back down again, so not completely impossible.
It'd be an engineering challenge sure, and a long term project, but if you've got the ship in orbit, why not give it a go?comment:www.metafilter.com,2010:site.96180-3305171Wed, 29 Sep 2010 21:44:18 -0800GrimgrinBy: IvoShandor
http://www.metafilter.com/96180/Pack-your-bags-kids#3305178
<a href="http://blogs.discovermagazine.com/badastronomy/2010/09/29/possible-earthlike-planet-found-in-the-goldilocks-zone-of-a-nearby-star/#more-21644">Bad Astronomer Phil Plait has a pretty good write up</a>.comment:www.metafilter.com,2010:site.96180-3305178Wed, 29 Sep 2010 21:53:20 -0800IvoShandorBy: twirlip
http://www.metafilter.com/96180/Pack-your-bags-kids#3305179
I imagine it would be catastrophic for the existing biosphere, if there is one.comment:www.metafilter.com,2010:site.96180-3305179Wed, 29 Sep 2010 21:53:21 -0800twirlipBy: DigDugDag
http://www.metafilter.com/96180/Pack-your-bags-kids#3305187
I call top bunk!comment:www.metafilter.com,2010:site.96180-3305187Wed, 29 Sep 2010 22:02:24 -0800DigDugDagBy: AElfwine Evenstar
http://www.metafilter.com/96180/Pack-your-bags-kids#3305202
<em>I imagine it would be catastrophic for the existing biosphere, if there is one.</em>
Who went and put that existing biosphere on our planet???comment:www.metafilter.com,2010:site.96180-3305202Wed, 29 Sep 2010 22:16:04 -0800AElfwine EvenstarBy: twirlip
http://www.metafilter.com/96180/Pack-your-bags-kids#3305204
If there's no biosphere, I'm staying home.comment:www.metafilter.com,2010:site.96180-3305204Wed, 29 Sep 2010 22:17:42 -0800twirlipBy: cftarnas
http://www.metafilter.com/96180/Pack-your-bags-kids#3305242
The happened a bit <a href="http://arbesman.net/blog/2010/09/13/when-will-the-first-earth-like-planet-be-discovered/">early</a>. This was not supposed to happen until next year. Someone has been mucking with flux capacitors again.comment:www.metafilter.com,2010:site.96180-3305242Wed, 29 Sep 2010 23:11:43 -0800cftarnasBy: From Bklyn
http://www.metafilter.com/96180/Pack-your-bags-kids#3305284
(I've been reading Tintin lately and when he goes to the moon they do it in a nuclear powered rocket. Just sayin'.)comment:www.metafilter.com,2010:site.96180-3305284Thu, 30 Sep 2010 00:09:51 -0800From BklynBy: hattifattener
http://www.metafilter.com/96180/Pack-your-bags-kids#3305303
<i>Oh and the train will be powered by the temperature differential between the light and dark sides or something.</i>
I've read that story! The city-on-rails was motivated/powered by the thermal expansion and contraction of the rails it rode around the planet. Was that a John Varley short set on Mercury?
<a href="#3305158">otherthings_</a>: <i>I'm thinking "Guns, Germs, and Steel" stuff here. Would a circular strip topology be worse, or better, in those terms?</i>
Seems like it would be the same, since we basically have a circular-strip topology here on Earth. The poles are uninhabitable, and civilization developed in the equatorial and temperate regions. On a tide-locked planet, you'd have basically the same geometry, with the subsolar and darkside areas as "poles". Of course the actual geometry would be different (how wide is the strip? we don't know), and lots of Diamond's reasoning is about the sizes and shapes of particular climate regions within the earthly habitable zone.
Hmm, if libration is significant, as <a href="#3305008">l_y suggests</a> then there would also be a pretty fundamental variation in climate depending on whether you're near the equator (where the terminator moves the most) or the pole (where it moves the least). If life on the planet favors a sweet spot (a balance between spatial and temporal uniformity, maybe?) then there could potentially be four <em>disconnected</em> habitable regions on the planet, separated by a mindboggling variety of different kinds of impassable wastes. This totally cries out for some sort of Hal Clement / Fritz Leiber / Rosemary Kirstein threeway mashup. <small>I'll be in my bunk.</small>comment:www.metafilter.com,2010:site.96180-3305303Thu, 30 Sep 2010 00:38:45 -0800hattifattenerBy: heathkit
http://www.metafilter.com/96180/Pack-your-bags-kids#3305353
<i>The crucial question that I am surprised no one has asked: How long would it take to get there at Warp 9?</i>
<a href="http://en.wikipedia.org/wiki/Warp_drive_(Star_Trek)#Warp_velocities">Warp 9 is 1000x the speed of light on the TNG scale, so about a week. </a>comment:www.metafilter.com,2010:site.96180-3305353Thu, 30 Sep 2010 02:57:09 -0800heathkitBy: brenton
http://www.metafilter.com/96180/Pack-your-bags-kids#3305367
> <i> Put another way, if the distance from here to Gliese 581 were the distance from New York to Los Angeles, Voyager 1 has travelled about one foot so far.</i>
Very interesting replies to my initial question! Though of course there's no need to slow down when it's going to be closer than a light year for several years. At this point it seems the biggest challenge is the cost of lifting things into space. If each Voyager amount of fuel gets you one foot closer to New York, that's a fairly attainable number of Voyager-equivalent-fuel's to get us to New York. And by attainable, I mean, if we dedicated all of the planets resources to lifting fuel for the next decade. Which we obviously should do!comment:www.metafilter.com,2010:site.96180-3305367Thu, 30 Sep 2010 03:26:26 -0800brentonBy: AugieAugustus
http://www.metafilter.com/96180/Pack-your-bags-kids#3305415
<i>Men, women, and children wanted for hazardous journey. No wages, bitter cold, long years of complete darkness. Safe return doubtful. Honour and recognition in event of success.</i>comment:www.metafilter.com,2010:site.96180-3305415Thu, 30 Sep 2010 04:37:16 -0800AugieAugustusBy: papercrane
http://www.metafilter.com/96180/Pack-your-bags-kids#3305439
<i>I've read that story! The city-on-rails was motivated/powered by the thermal expansion and contraction of the rails it rode around the planet. Was that a John Varley short set on Mercury?</i>
Kim Stanley Robinson's "Blue Mars" novel had this. I don't know if it was an original idea or not.comment:www.metafilter.com,2010:site.96180-3305439Thu, 30 Sep 2010 05:07:31 -0800papercraneBy: Debaser626
http://www.metafilter.com/96180/Pack-your-bags-kids#3305457
A thin band of habitable land in a hostile environment, eh? So it's like a ring... or maybe a Halo?
<small> I GOT F-ING DIBS ON THE BANSHEE, SWORD, AND THE BR RIFLE... NOOBS.</small>comment:www.metafilter.com,2010:site.96180-3305457Thu, 30 Sep 2010 05:28:05 -0800Debaser626By: miyabo
http://www.metafilter.com/96180/Pack-your-bags-kids#3305468
<i>If each Voyager amount of fuel gets you one foot closer to New York, that's a fairly attainable number of Voyager-equivalent-fuel's to get us to New York. </i>
Voyager <i>will</i> go past 20 light years, and even past hundreds of thousands of light years to the edge of the galaxy. The only problem is we'll all be dead. We need to increase speed, not distance, which is annoying because of the whole 1/2mv^2 thing and because you have to carry all the fuel that you need for both acceleration and deceleration.comment:www.metafilter.com,2010:site.96180-3305468Thu, 30 Sep 2010 05:38:34 -0800miyaboBy: localroger
http://www.metafilter.com/96180/Pack-your-bags-kids#3305470
Interesting link, Nyrath, thanks for the pointer.comment:www.metafilter.com,2010:site.96180-3305470Thu, 30 Sep 2010 05:39:31 -0800localrogerBy: angrycat
http://www.metafilter.com/96180/Pack-your-bags-kids#3305478
What I'm confused about is now scientists are saying, this is just the tip of the iceberg, we might find planets in the Alpha Centauri system.
Why didn't they look there first? Bit closer and all.comment:www.metafilter.com,2010:site.96180-3305478Thu, 30 Sep 2010 05:49:35 -0800angrycatBy: papercrane
http://www.metafilter.com/96180/Pack-your-bags-kids#3305492
<i>Why didn't they look there first? Bit closer and all.</i>
As I understand it, our current technology requires us to be observing the target system 'edge on.' Alpha Centauri isn't oriented in such a way, making it very difficult for us to observe planets passing in front of the host star.comment:www.metafilter.com,2010:site.96180-3305492Thu, 30 Sep 2010 06:05:35 -0800papercraneBy: sonika
http://www.metafilter.com/96180/Pack-your-bags-kids#3305610
Via a scientist friend: <a href="http://newearthcommunity.wordpress.com/2010/09/30/gliese-581g-another-earth-laser-pulse-from-gliese-581e/">Laser like pulses detected on Gliese 581g</a>.
Dibs may have already been had.comment:www.metafilter.com,2010:site.96180-3305610Thu, 30 Sep 2010 07:41:08 -0800sonikaBy: lukemeister
http://www.metafilter.com/96180/Pack-your-bags-kids#3305623
papercrane,
One of the planet detection techniques, transits, does require that the target system be edge-on. The Kepler spacecraft uses that technique. The discovery of Gliese 581's planets was done by measuring radial velocities, which doesn't require any special orientation.
The Alpha Centauri system has been searched for planets, but none have been found yet. Speaking of which, this <a href="http://www.centauri-dreams.org/">blog</a> has more on the Gliese 581 system.comment:www.metafilter.com,2010:site.96180-3305623Thu, 30 Sep 2010 07:49:18 -0800lukemeisterBy: Xezlec
http://www.metafilter.com/96180/Pack-your-bags-kids#3305741
The Yahoo News comments on this news item are just amazing. No wonder NASA keeps losing funding. There wasn't even one single comment to the effect of "this is neat." This one reminds me of several arguments I've had here on MeFi:
<i>could be...might be....if this, if that. plus we will NEVER be able to travel there. "several generations" to get there. that means peeps would have to live and die for a couple hundreds years on a craft traveling there....all for what? you get there and find it is a giant rock!?! go back and watch more stargate peeps. no wonder there are still starving peeps all over the world. look at all the energy that man wastes daydreaming, staring at the stars and wondering...."what if"....instead of doing something useful.</i>
OK, so maybe normal human society has forever passed the brief point at which it was interested in space. Fine. I will build and fly the damn ship all by my lonesome, if I have to. One less mouth to feed on Earth. That should help with the starving peeps.
I'll send you all a postcard.comment:www.metafilter.com,2010:site.96180-3305741Thu, 30 Sep 2010 08:31:34 -0800XezlecBy: Cool Papa Bell
http://www.metafilter.com/96180/Pack-your-bags-kids#3305859
<em>Dibs may have already been had.</em>
/me reaches for stash of smallpox-infected blanketscomment:www.metafilter.com,2010:site.96180-3305859Thu, 30 Sep 2010 09:10:35 -0800Cool Papa BellBy: lukemeister
http://www.metafilter.com/96180/Pack-your-bags-kids#3305997
Xezlec,
You certainly have the name for interstellar exploration!comment:www.metafilter.com,2010:site.96180-3305997Thu, 30 Sep 2010 10:11:11 -0800lukemeisterBy: AkzidenzGrotesk
http://www.metafilter.com/96180/Pack-your-bags-kids#3306364
Thanks, everyone, for all the pointers (here and <a href="http://ask.metafilter.com/166550/Tidally-locked-planets-in-science-fiction">here</a>) to sf stories about tidally locked planets! I should have known that there is no new thing under any sun.comment:www.metafilter.com,2010:site.96180-3306364Thu, 30 Sep 2010 12:52:04 -0800AkzidenzGroteskBy: thsmchnekllsfascists
http://www.metafilter.com/96180/Pack-your-bags-kids#3306403
<em>FUCK THE OUTER SPACE TREATY LET'S BUILD NUCLEAR ROCKET SHIPS AND DO THIS THING</em>
IM IN.comment:www.metafilter.com,2010:site.96180-3306403Thu, 30 Sep 2010 13:06:26 -0800thsmchnekllsfascistsBy: The Lady is a designer
http://www.metafilter.com/96180/Pack-your-bags-kids#3307384
Has this already been posted or discussed or is it even real? (been searching the blue but could be overlooking the thread)
<a href="http://www.telegraph.co.uk/news/newstopics/howaboutthat/ufo/8026971/Aliens-have-deactivated-British-and-US-nuclear-missiles-say-US-military-pilots.html">
Aliens have deactivated British and US nuclear missiles, say US military pilots
Aliens have landed, infiltrated British nuclear missile sites and deactivated the weapons, according to US military pilots.</a>comment:www.metafilter.com,2010:site.96180-3307384Fri, 01 Oct 2010 09:09:25 -0800The Lady is a designerBy: hattifattener
http://www.metafilter.com/96180/Pack-your-bags-kids#3307822
TLiaD: <a href="http://www.metafilter.com/96100/Interstellar-Atomic-Energy-Agency">Already posted</a> (but a different link).comment:www.metafilter.com,2010:site.96180-3307822Fri, 01 Oct 2010 12:34:08 -0800hattifattenerBy: IvoShandor
http://www.metafilter.com/96180/Pack-your-bags-kids#3324485
Seems that <a href="http://www.msnbc.msn.com/id/39640401/ns/technology_and_science-space/">Gliese 581 g may not exist afterall</a>.comment:www.metafilter.com,2010:site.96180-3324485Wed, 13 Oct 2010 00:08:26 -0800IvoShandorBy: The Whelk
http://www.metafilter.com/96180/Pack-your-bags-kids#3324494
Stop pooping on my dreams.comment:www.metafilter.com,2010:site.96180-3324494Wed, 13 Oct 2010 00:53:36 -0800The WhelkBy: IvoShandor
http://www.metafilter.com/96180/Pack-your-bags-kids#3324497
And: <i><a href="http://www.universetoday.com/75581/buzz-about-gliese-581g-doubts-of-its-existence-aliens-signals-detected/">an astrophysicist from Australia claims that while doing a SETI search two years ago, he picked up a "suspicious signal" from the vicinity of the Gliese 581 system, and a couple of websites have connected some dots between that signal and a potentially habitable Gliese 581g</a>.</i>
A link from the above link: <a href="http://planetary.org/news/2010/1006_Billions_and_Billions_Discovery_of.html">a 2009 article about the mysterious signal</a>. Frank Drake: <i>"<a href="http://www.space.com/scienceastronomy/gliese581g-mysterious-light-pulse-101008.html">I know the scientist, and when he first announced it, I asked him for the details, and he wouldn't send them to me," astronomer and SETI pioneer Frank Drake told SPACE.com. "I'm very suspicious.</a>"
Even so, I've no doubt that this civilization is on the verge of discoveries that will make even Gliese 581 g forgettable in the long run.</i>comment:www.metafilter.com,2010:site.96180-3324497Wed, 13 Oct 2010 01:08:59 -0800IvoShandor
"Yes. Something that interested us yesterday when we saw it." "Where is she?" His lodgings were situated at the lower end of the town. The accommodation consisted[Pg 64] of a small bedroom, which he shared with a fellow clerk, and a place at table with the other inmates of the house. The street was very dirty, and Mrs. Flack's house alone presented some sign of decency and respectability. It was a two-storied red brick cottage. There was no front garden, and you entered directly into a living room through a door, upon which a brass plate was fixed that bore the following announcement:¡ª The woman by her side was slowly recovering herself. A minute later and she was her cold calm self again. As a rule, ornament should never be carried further than graceful proportions; the arrangement of framing should follow as nearly as possible the lines of strain. Extraneous decoration, such as detached filagree work of iron, or painting in colours, is [159] so repulsive to the taste of the true engineer and mechanic that it is unnecessary to speak against it. Dear Daddy, Schopenhauer for tomorrow. The professor doesn't seem to realize Down the middle of the Ganges a white bundle is being borne, and on it a crow pecking the body of a child wrapped in its winding-sheet. 53 The attention of the public was now again drawn to those unnatural feuds which disturbed the Royal Family. The exhibition of domestic discord and hatred in the House of Hanover had, from its first ascension of the throne, been most odious and revolting. The quarrels of the king and his son, like those of the first two Georges, had begun in Hanover, and had been imported along with them only to assume greater malignancy in foreign and richer soil. The Prince of Wales, whilst still in Germany, had formed a strong attachment to the Princess Royal of Prussia. George forbade the connection. The prince was instantly summoned to England, where he duly arrived in 1728. "But they've been arrested without due process of law. They've been arrested in violation of the Constitution and laws of the State of Indiana, which provide¡ª" "I know of Marvor and will take you to him. It is not far to where he stays." Reuben did not go to the Fair that autumn¡ªthere being no reason why he should and several why he shouldn't. He went instead to see Richard, who was down for a week's rest after a tiring case. Reuben thought a dignified aloofness the best attitude to maintain towards his son¡ªthere was no need for them to be on bad terms, but he did not want anyone to imagine that he approved of Richard or thought his success worth while. Richard, for his part, felt kindly disposed towards his father, and a little sorry for him in his isolation. He invited him to dinner once or twice, and, realising his picturesqueness, was not ashamed to show him to his friends. Stephen Holgrave ascended the marble steps, and proceeded on till he stood at the baron's feet. He then unclasped the belt of his waist, and having his head uncovered, knelt down, and holding up both his hands. De Boteler took them within his own, and the yeoman said in a loud, distinct voice¡ª HoME²¨¶àÒ°´²Ï·ÊÓÆµ ѸÀ×ÏÂÔØ ѸÀ×ÏÂÔØ
ENTER NUMBET 0016www.ko7.com.cn www.jfljb.net.cn www.lhghhk.net.cn excled.com.cn www.jawcdn.com.cn www.langnest.com.cn qbchain.com.cn www.mmcpew.com.cn rlywxu.com.cn www.nvjiao.com.cn