nice calculator to help design rotating habitats

[F33D]

http://www.artificial-gravity.com/sw/SpinCalc/SpinCalc.htm

 

[Captain Jonah]

Yep, very usefull site.

Great for Cthonian stars, 2300 and other non gravity space games.

 

[Ash247]

I was asked a question by one of my players that got me thinking and i didn't really know the answers.

In a spun habitat with say a "gravity" of 1 at the surface, if you were at the centre or spindle the gravity would be 0, as you move away from the centre to the surface the perceived gravity will increase, but only if you are holding onto something correct? say for example you float away from the centre slowly towards the surface you would still be in zero gravity correct?

This then brought up other questions like jumping off of the surface or throwing an object up, and flying vehicles in the large spun habitats that you see in the artwork all the time. As once you leave the ground there is no gravity to slow you back down again right, i know you would have momentum in the spin direction, but if you could throw something in the right direction with the right force then it should carry on correct?

The atmosphere might have an affect as the "air" would be moving somewhat but the discussion went with what would happen in a habitat with no atmosphere.

I might be way off here but that's why I'm asking here.

 

[Dave Chase]

I was asked a question by one of my players that got me thinking and i didn't really know the answers.

In a spun habitat with say a "gravity" of 1 at the surface, if you were at the centre or spindle the gravity would be 0, as you move away from the centre to the surface the perceived gravity will increase, but only if you are holding onto something correct? say for example you float away from the centre slowly towards the surface you would still be in zero gravity correct?

More like freefall. See, the body is still moving the direction of the spin otherwise as soon as you let go of some support, you would slam into the back side of a wall.

This then brought up other questions like jumping off of the surface or throwing an object up, and flying vehicles in the large spun habitats that you see in the artwork all the time. As once you leave the ground there is no gravity to slow you back down again right, i know you would have momentum in the spin direction, but if you could throw something in the right direction with the right force then it should carry on correct?

Not 100% correct but, someone else who is more of an expert in this should try and explain this. It's physics.

The atmosphere might have an affect as the "air" would be moving somewhat but the discussion went with what would happen in a habitat with no atmosphere.

I might be way off here but that's why I'm asking here.

See the above answer about it being physics. An object in motion tends to stay in motion until act upon by other forces.

Even with out air, once you are in motion (ie you stand on a rotating platform in one spot) you keep that motion (you maintain some of the enegry of the spin direction).

If you were standing on the inside outer ring of spinning habit and you tossed dropped a ball forward spin (the direction the habit is spinning) the ball will land slightly behind you. Why? Because it has some of the energy of the spin which keeps it from landing why behind you and the energy of the spin also gives it some of its drop (the feeling of gravity).

Not the best explaination but the simpliest one.

Dave Chase

 

[lastbesthope]

Try googling baseball + coriolis

LBH

 

[Ash247]

I get that. So here is a better example for the question i have.

Assume the spun habitat is open ended and has no atmosphere, an object floats in one end travelling along the axis from one end to the other, and it enters floating 1 foot above the surface. There are no forces acting on the object correct and it would float along happily and exit the other end correct?

 

[F33D]

I get that. So here is a better example for the question i have.

Assume the spun habitat is open ended and has no atmosphere, an object floats in one end travelling along the axis from one end to the other, and it enters floating 1 foot above the surface. There are no forces acting on the object correct and it would float along happily and exit the other end correct?

A spinning tube? Yes, that would be correct.

 

[Captain Jonah]

Re the first question.

Coriolis only has an effect if you are in contact with the rotational element. As long as you are not in contact then the rotational force does not affect you so you float.

Say you were in a 1 RPM spin habitat 900m in radius to simulate 1G.

In a cylinder spinning on its long axis you would only be under the affect of that 1G is you were in physical contact with the cylinder floor. So long as you start in the micro G at the spine and do not contact the cylinder at all you will remain in microG. If however you come into contact with that floor or get hit by a structure on the floor you find two things. Firstly you are now subject to the rotational 1G and secondly you just got hit by a building moving at 94m/sec.

If, on the other hand you were in a wheel habitat and were climbing down a ladder in one of the legs you are in contact with and therefore rotating with the wheel. As you climb down you become subject to great levels of simulated gravity. 10m down the ladder the gravity seems to be 0.01G. 100m down it would seem to be 0.11G. At 500m you would be in 0.55G.

If you remember the B5 episode where the Centari terrorists set a bomb in the spine train which was at zeroG. The commander jumped out of the train before it exploded. He was in zero G but because he jumped he had momentum which carried him towards the cylinders wall which was the floor due to the rotation. Had he not been rescued by Kosh he would have hit the floor with a few metres a second of velocity from his jump but the surface and buildings on that floor were in effect moving sideways at 360Kph, he would have been splattered all over the floor.

With regard to the baseball. If you have ranks in ZeroG then yes it would end up where you wanted it to go. For those without such skill you have to factor in that the person throwing the baseball is moving in a circle, the place you are aiming at is moving round in a circle, the ball was moving in a circle prior to being thrown. There were some good diagrams of this online and I did see a youtube animation a while ago.

Basically an infantry type without ZeroG skill throwing grenades in a spin habitat is going to be very dangerous to everyone around him. :shock: :lol: