UC Colony gravity

[X10A-Freedom]

Is there gravity in the center of a colony? I think I get the basic theory about how there is gravity in a colony it spins at a controlled rate and causes centrifical force(artificial gravity)to act so people can walk on the inside walls of the colony if thats true or I sould say if I have that right then in the center of the cylinder would there be any gravity or would it be reduced depending on how big the cylinders diameter is?

any help making this make sense would be appreciated sorry if i've been using the wrong terms and if this has been done before.

[Wingnut]

I would say no. And if by some chance there is, very little. We see MS flying around inside a colony many times (especially in F91) as if they were in space with nothing to slow them down.

[CYNICISM AT IT'S BEST]

Yeah the law's of gravity limit the gravity zone's to the wall's of the Colony?

[Black Knight]

Yeah the law's of gravity limit the gravity zone's to the wall's of the Colony?

No, it's more that the centripetal force which is mimicking gravity in a rotating colony is strongest on the walls, and gets proportionally weaker the closer an object gets to the axis of rotation. Consider, most of the scenes taking place in the dock area (MSG's opening episodes, parts of 0080, etc) show some gravity, but not much; the dock areas on Island III colonies are very close to the centerline of the colony, where the false "gravity" is weakest.

Unless someone was at the line going through the exact center of the colony cylinder, they're going to feel some of the centripetal force from the colony's rotation, as well as some of the pressure from the air, which is also rotating. Often, the acceleration felt by MS flying at near the centerline of the colony is so weak that it doesn't impact operations very much, certainly not enough for the animators to depict it.

[Koshernova]

The best example, in fact, is presented in the opening scenes of Zeta Gundam. Char enters the colony from its port, and proceeds to scout out Titans facilities by floating through the axis of rotation. He has a small jetpack with him, which he uses to make small corrections, presumably for whenever he deviates from the zero-G axis.

[DAG101]

The best example, in fact, is presented in the opening scenes of Zeta Gundam. Char enters the colony from its port, and proceeds to scout out Titans facilities by floating through the axis of rotation. He has a small jetpack with him, which he uses to make small corrections, presumably for whenever he deviates from the zero-G axis.

Which makes sense: there would be 0-G at the center of the colony, and if one were to be flying through the middle, and drifted off of this path, one would begin to fall

[Koshernova]

The thing is, with the old UC colonies, it'd be relatively easy to veer off-path. After all, theoretically, only the very central axis of the colony is zero-G, and any deviations from that, no matter how minimal, would start to orient the floating object/human in a certain direction. This is especially relevant with the old UC colonies, which have no central physical axis of rotations (like the ones in G-Saviour or Heliopolis in SEED). So, one would have little point of reference to realise one is starting to drift downwards. Char, knowing this, brings along a jetpack to make sure he doesn't end up a red stain in the colonial landscape of Gryps

[ZeonfromHell]

The best example, in fact, is presented in the opening scenes of Zeta Gundam. Char enters the colony from its port, and proceeds to scout out Titans facilities by floating through the axis of rotation. He has a small jetpack with him, which he uses to make small corrections, presumably for whenever he deviates from the zero-G axis.

Which makes sense: there would be 0-G at the center of the colony, and if one were to be flying through the middle, and drifted off of this path, one would begin to fall

That would also support the question of why the Gundam Mark II was apparently flying more easily in Gryps. It was very well off the ground and up in the air, where the suit could use less thrust and still travel quickly.

[turkishproverb]

Wow. You guys are solving a problem without Mark.

Cool, but kind've weird.

[ironscythe]

Actually, if you were to apply the right amount of thrust in the opposite direction of the colony's rotation, you could cancel-out the centrifugal effect and float freely. There might be some turbulence from the atmosphere near the ground, but that way you wouldn't need to be on the axis of rotation. Of course, you would be drifting quite a bit in relation to the inner wall of the colony...

Also, in an early episode of ZZ, it's noted that the "gravity" is weaker on the rocky hills that descend from the dock area at either end of the colony. It seems to me that, if a hiker were able to climb all the way up one of those hills they could reach the rotational axis (or come very close). Who knows--it could be a common recreational activity.

[supperrfreek]

I was originally thinking centrifugal force, but that would only work in certain types of colonies.

[Dynames]

From what i have seen, from watching the first couple episodes of Zeta gundam when quattro is flying his Dias in the colony, he doesen't seem to have his boosters on when hes hovering in the middle of the colony. So i would say that there is not gravity or very little gravity in the middle of the colonys. Though i could be wrong

[ironscythe]

I was originally thinking centrifugal force, but that would only work in certain types of colonies.

That's the only kind of colony in the Universal Century. They're called O'Neill Cylinders.

From what i have seen, from watching the first couple episodes of Zeta gundam when quattro is flying his Dias in the colony, he doesen't seem to have his boosters on when hes hovering in the middle of the colony. So i would say that there is not gravity or very little gravity in the middle of the colonys. Though i could be wrong

You should read the previous posts and maybe look stuff up on wikipedia before you talk about it. The "gravity" is simply the result of centrifugal acceleration against the inner walls of the colony. In the exact center of the colony (its axis of rotation) there is no acceleration. Simple physics.

[Koshernova]

He didn't use them much, but he had them with him for a reason. One little accidental deviation and splat! Char pudding in the colonial landscape. He had the backpack with him for corrections.

[Wingnut]

I was originally thinking centrifugal force, but that would only work in certain types of colonies.

That's the only kind of colony in the Universal Century. They're called O'Neill Cylinders.

Wrong. There are also what are called Island 1 Bernal spheres in the UC as well. Mainly used as construction hubs for the larger Island 3 units. Moon Moon is one example of an Island one type colony.

[Seraphic]

Does anyone know how to calculate the simulated gravity due to rotation? I'm trying to figure how big of a radius or how quick a rotation is needed to produce a certain simulated acceleration.

[Apache]

High Frontier has a pretty big article on the whole colony and how it works. It goes into detail in the sixth paragraph about gravity.
http://www.dyarstraights.com/msgundam/opentype.html

[Prana]

To help digest the formulas (since such a "simple" physics question was asked! ) you have that to get 1g (the gravity on Earth):

S = .946 / sqrt(R)

With the rotation speed S measured in rpm (rounds per minute) and the radius R in kilometers, while sqrt() is the square root.

The inverse is:

R = .895 / S^2

Consider that rotation speed has to be maintained low to reduce/avoid Coriolis effect. Half a round per minute (or lower) is an acceptable value.

[Ryujin]

It should also be noted that the CGI colonies, as depicted in CCA, were rotating faster than they should have. This was done not out of ignorance, but as a cinematographer's decision.