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Flying Inside A Rotating Torus Space Station (Artificial Gravity)?

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11 comments, last by RivieraKid 7 years, 11 months ago

So..I understand that centrifugal force would push everyone towards the floor, but what if youre not in the floor? Theres any constant force pulling you? I see articles saying its theoretically feasible, just not practical (even nasa proposed stuff like that).

I can see (more or less) inertia allowing you to jump inside it as normally(I guess it throws you in a tangent, and since its spinning, youd end up being still pushed on a realitve downwards direction right? As the floor "follows" you while youre in the air) (Im imagining a city sized station, bare with me)

...But could you fly an helicopter inside it? If you keep too much time in the air theres no centrifugal force anymore right? The helicopter would take flight at the same speed due inertia, but it would start to unsync with the rotation of the torus? No wait..the air inside the torus is also rotating, otherwise it would be really windy..Hmmmmm..But..that means the helicopter would keep a stable position relative to the floor if it keeps in the air? solely due air push?

@.@

What if you throw a baseball..it behaves the same(relative to the floor) regardless if you throw against or in favor of the rotation?

I feel stupid.

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Its real early in the morning here, but the answer is probably no. Centrifugal force only works when you're attached to the thing rotating so you coudn't fly a helicopter in the air inside a rotating spacestation because there is no pull on the hellicopter. Well, you could fly it but not in the traditional sense. there would be nothing to counteract the thrust provided by the blades.

Without gravity you don't really have the requirement for traditional flight.

Someone in the middle of the space station will have no artificial gravity, as the wheel isn't pushing them around. Actually, anyone not moving with the wheel with have no artificial gravity.

If you were on the wheel and were to face away from the direction of motion and fire a cannon, which has the exact same muzzle velocity as the speed that you're moving at, then the cannon ball will come out with zero velocity as seen by someone at the center of the space station... which means it won't be getting flung about by the wheel, which means it would just float there in mid-air!

(however... the next person to come around on the wheel behind you would think that they were standing still and this cannon ball was moving in a straight line towards them, never dropping lower towards the floor! If not cleared away, it would be a permanent hazard to wheel-surface-dwellers!)

So actually, assuming the place is packed full of air with enough density for a wing to gain lift... a helicopter would be possible but with a very different design than an earth-style helicopter! If you launched from and landed at a dock in the center of the wheel (zero artificial gravity), then your whole flight would be in a zero-g environment, so you wouldn't need very much power at all to get around.

maybe they could use this

http://www.bbc.com/news/science-environment-36855705

Someone in the middle of the space station will have no artificial gravity, as the wheel isn't pushing them around. Actually, anyone not moving with the wheel with have no artificial gravity.

This.

Though it's only 99.975% correct. There will be airflow caused by the rotating torus. Laminar flow, oh the joy. That means fastest flow near the floor with quadratic or something (cubic??? I actually forgot how this worked...) falloff, and practically standing still in the middle (at reasonable rotational speeds anyway, it is possible to have the air in the middle flowing noticeably, too... I wouldn't want to be in there, however).

That flow will drag you, or any inanimate objects, around. While it will almost certainly be too weak to drag you onto a circular path and generate artificial gravity, it will however drag you somewhere. The fun part is that since we're talking of a torus, it is not immediately obvious where. Chances are, however, that with some luck you hit the floor eventually. At least as long as you are very slightly over the middle, it will only ever drag you into faster flowing regions. But I guess even on the "inside", your inertia should be able to bring you there, eventually (within some days).

so what really would have happened to John Sheridan?

So the transit thing was running down the axis the wheel was turning on? Well first off he wouldn't notice any real gravity effects there. Forces of artificial gravity would probably be less than the force of random gusts of air from the life support systems. (I would need to sit down and do some reading and math to sort out whether or not you could keep breathable air at the centre of the structure without a forced air system. Or go google for answers from another geek who has already worked that out. I forget if that station's dimensions put it over the limit or not.)

Jumping out of the tram car like that would mean that most of your momentum is still in the direction you were traveling, just angled out a bit.

The fun part of figuring out what happens relies on the distances and air density. Terminal velocity in a station like that is 'technically' zero. You're not under an external force accelerating you in any given direction other than the motion of the air. Your big worry is really whether or not air resistance will slow you down enough before you hit a wall. And then there is the question of which wall: Will you hit the end plate, and how fast are you going by then, or will you hit the cylinder side wall?

Rather complex problem to sort out, with a ton of factors, but the key ones would be over all size and the dynamics of the air flow. You might end up buffeting around near the centre, you might be pushed toward the rotating surface and accelerated along with the air there.

But to be honest the odds are that dude was probably killed by fragmentation from the bomb blast.

Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.
Jumping out of the tram car like that would mean that most of your momentum is still in the direction you were traveling, just angled out a bit.

...and if you look closely, that is exactly what is depicted. He jumps out, but continue to travel with the tram, but away from it.

Then there is a bit of time passing not shown, until the bomb explodes, because he has time to get a bit of distance. (so he is less likely to get shrapneled)

The momentum from jumping out will eventually get him to hit the ground, but as noted by Delenn, he will not be accelerated enough by the wind/air-resistance and the relative speed between him and the rotating ground will kill him.

But Kosh intervenes, sends his angel avatar to accelerate him to match the speed of the ground before hitting it, and thus saving him.

I'd say, for a sci-fi tv-series, they get it pretty accurate :)

Eh, there are a number of problems with how they showed things. One being just how vague Babylon 5 was with specs. That 'sixty miles an hour' puts the diameter fairly large given anything near 1g simulated gravity. And since there is no acceleration due to gravity you only have the air pushing on you as the only active force that is going to matter.

Given the speed that tram appeared to be going compared to how fast a human can push off in a jump... Well hitting the end wall is not an unreasonable expectation, and the critical point becomes the air dynamics on the inner 3/4th of the diameter of the structure.

Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.
And since there is no acceleration due to gravity you only have the air pushing on you as the only active force that is going to matter.

There is no acceleration due to gravity shown or mentioned. All his speed towards the ground is from jumping out of the tram. (pretty slow as shown when they land)

But it is not that speed which will kill him, but the perpendicular (to his movement towards the ground) speed of the ground when he reaches it that will kill him.

I'm too lazy to double check the actual numbers they mention though, I don't doubt there might be some weirdness there.

Also, they might skimp a bit on the air-resistance actually being able to accelerate him more...

But still a lot more accurate then what most sci-fi even tries for :)

Given the speed that tram appeared to be going compared to how fast a human can push off in a jump... Well hitting the end wall is not an unreasonable expectation, and the critical point becomes the air dynamics on the inner 3/4th of the diameter of the structure.

True.

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