Space swimming pool?

DannMcGrew

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I'm reading Pohl Anderson's Tau Zero and there is a swimming pool on the space craft. How would you do that? Yeah when underway they've established 1G, but still?
 

Elckerlyc

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You don't need water to 'swim' in space when in free-fall. But it could be an intriguing experience. Just make sure that the water can't slosh.:D

In Neal Stephenson's Anathem the visiting spaceship consist of huge spheres that are half filled with water on which houseboats float. The spheres are spinning to create 1G gravity.
 

Ursa major

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Speaking as someone who gave up watching the film as it became creepy (and not in a "good" way), perhaps I'm misremembering (and not paying proper attention to the clip), but based on this ignorance, I have the following questions:
  1. If the gravity is caused by the ship spinning, why did the ship suddenly stop spinning? It isn't as if there's much friction in the (almost completely empty) space outside to slow it down. To stop, the ship would have to actively stop itself spinning, wouldn't it? Why would it do that? It isn't as if it's designed to land at its destination. (Or is it...?) And even if it was designed to do that, why would it be so sudden?
  2. If it's not sudden (and I can't see any good reason for it being so), why does the water suddenly react to the loss of gravity? If the ships rotation slows down (for whatever illogical reason), the artifical gravity would gradually lessen in line with the spin slowing down, wouldn't it?
  3. If the gravity is caused by the ship spinning and the water ends up in a big ball floating in the air, how does the ship starting to spin again cause that water to drop down into the pool (or anywhere, for that matter: it would come into contact with the nearest approach bulkhead)? The water isn't being moved by the ship: it's floating independently inside the ship.
  4. And in any case, why does the water suddenly drop? Surely it takes time for the spinning to get up to full speed.

It seems to me that I caught a break by being creeped out by the behaviour of the main male character.
 

-K2-

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Speaking as someone who gave up watching the film as it became creepy (and not in a "good" way), perhaps I'm misremembering (and not paying proper attantion to the clip), but based on this ignorance, I have the following questions:
  1. If the gravity is caused by the ship spinning, why did the ship suddenly stop spinning? It isn't as if there's much friction in the (almost completely empty) space outside to slow it down. To stop, the ship would have to actively stop itself spinning, wouldn't it? Why would it do that? It isn't as if it's designed to land at its destination. (Or is it...?) And even if it was designed to do that, why would it be so sudden?
  2. If it's not sudden (and I can't see any good reason for it being so), why does the water suddenly react to the loss of gravity? If the ships rotation slows down (for whatever illogical reason), the artifical gravity would gradually lessen in line with the spin slowing down, wouldn't it?
  3. If the gravity is caused by the ship spinning and the water ends up in a big ball floating in the air, how does the ship starting to spin again cause that water to drop down into the pool (or anywhere, for that matter: it would come into contact with the nearest approach bulkhead)? The water isn't being moved by the ship: it's floating independently inside the ship.
  4. And in any case, why does the water suddenly drop? Surely it takes time for the spinning to get up to full speed.

It seems to me that I caught a break by being creeped out by the behaviour of the main male character.
I never watched the whole thing either (for much the same reason), Anywho: 1. Because it wouldn't make for a dramatic scene, otherwise. 2. It did to some degree--why Pine started floating away, the waves and so on--momentum carrying them slightly before full stop. 3 & 4. See @DannMcGrew 's post. That said, now I'm curious how the thing ends. I remember what they predicted (something like 90+ years to their destination), yet i quit watching when she discovered what he had done...WHICH how was nonsense. Who would ever program a robotic bartender to be a blabbermouth? There is a bartender code after all.

K2
 

Major Eazy

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I'm reading Pohl Anderson's Tau Zero and there is a swimming pool on the space craft. How would you do that? Yeah when underway they've established 1G, but still?
Well, as the genre is "science fiction" so you could just make up a fictional reasons for why it would work. Examples being, artificial gravity, etc.,
 

Astro Pen

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Speaking as someone who gave up watching the film as it became creepy (and not in a "good" way), ...

It seems to me that I caught a break by being creeped out by the behaviour of the main male character.
I watched it all a couple of weeks back and agree completely, a creep. His saccharine 'redemption' would have probably annoyed you had you persevered.
 

Ursa major

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The closer water gets to the poles...










...the more likely it is to freeze (although the likelihood does vary depending on the season)....
 

Venusian Broon

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I'm reading Pohl Anderson's Tau Zero and there is a swimming pool on the space craft. How would you do that? Yeah when underway they've established 1G, but still?
I haven't read Tau Zero - what's the problem with the swimming pool?

Actually water on an interstellar space craft is a jolly good idea - not just for the fact that us humans require it, but also it acts as a very effective shield against cosmic rays, of which there will be higher quantities of when you leave the protection of the sun's heliosphere. So I'd like my hull to have a layer of water somewhere. Or on the outside in the form of ice* to act as an ablative shield to take the hits of cosmic debris and atoms that the ship will go through as it travels.

Add to that the fact you can split it into hydrogen and oxygen, which you could recombine if you require rockets, or just breath the oxygen. Oh and its dirt cheap, light and should be abundant everywhere in the universe, so should be easy to restock when you arrive at your destination.

---------------------------------------------

* Ice would be good for cocktails too.
 

DannMcGrew

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I haven't read Tau Zero - what's the problem with the swimming pool?
Not a problem, per se, I'm just curious what the mechanics of such a thing might be -- just create a pool and pour in water? Does the ship movement never cause it to slosh out? As in the movie clip above, what happens if gravity is lost/diminishes. Etc., etc., and so forth.
 

Venusian Broon

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Not a problem, per se, I'm just curious what the mechanics of such a thing might be -- just create a pool and pour in water? Does the ship movement never cause it to slosh out? As in the movie clip above, what happens if gravity is lost/diminishes. Etc., etc., and so forth.
So how does the ship work?

If it, say, always produces 1G of thrust constantly, then you could just fill up a swimming pool normally like you would on Earth, as the thrust would be constantly applied to the whole ship and everything in it, then Newtons 3rd law gives you your 'gravity'. Just that this gravity would be parallel to the direction of travel. So it would be like you are in a flying skyscraper I suppose.

There would be a problem when you switch off the engine, turn the ship around and fire the engines at 1G again to decelerate at the half-way point....but I assume that it would be sensible to drain the pool and store the water till you've done the manoeuver.

That's how Alastair Reynold's Lighthuggers basically travel.

I have no idea how really feasible it would be to have an engine constantly produce 1G of thrust.
 

tegeus-Cromis

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But how would one come up for air...?
I was figuring a ball of water in the center of, but smaller than the room. So there are at least, say, eight feet of air between the walls and the surface of the water. You "dive" by propelling yourself off the wall. And you can swim in any direction, since you're in zero G, after all.

(Note: naturally, this would require some kind of forcefield keeping the water in the center of the sphere. But since it's science fiction we're talking about -- there, done.)
 

StilLearning

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Water clings like a bugger in microgravity, you almost have to scrape it off,. Then it goes everywhere as droplets that don't stop until they hit something solid. How about a lunar gravity pool? With some snowshoes or flippers you could stand on it IIRC.
 
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