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Comments
thisisjustascreename t1_j0aeanx wrote
This answers "the question" but it fails to answer the actual point of the question.
What if I get in a car and drive 75 mph against the rotation?
ok46reddit t1_j0afkf7 wrote
The car would loose control as it nears 70 mph and crash into something.
thisisjustascreename t1_j0ag33o wrote
What if it’s a flat cylinder with infinite coefficient of friction and nothing to crash into
ok46reddit t1_j0ahc45 wrote
To be fair, it depends on the aerodynamics of the car. But let's say that somehow the aerodynamics are neutral, it just experiences drag, but the airflow does not result in a net uplift or push down the car. At a certain point approaching 70 mph the tires would start to lose traction and would not be able to provide enough friction to overcome air resistance. It might even happen well before that speed depending on the actual air drag. But it would never be able to achieve 75 mph.
But let's say that there is aerodynamics that push the car down as its relative speed increased. As it approaches the speed of the ring, about 70 mph, the driver would feel weightless, but because the car is aerodynamically coupled to the surface it could still go faster, and as it does the driver would start to feel the sensation of weight returning.
Alvsvar t1_j0a5zwp wrote
Its not really gravity its Centripetal acceleration right?
Excellent-Practice t1_j0a7wrq wrote
Yeah, it's a pseudo force. The space station would act like a centrifuge or a merry-go-round and produce an effect that, under the right conditions, would feel very much like gravity
Alvsvar t1_j0jdozl wrote
Yea Iv seen the countless plans for them, it seems it would drive you crazy.
But the human body cant last that long in space with out gravity. Space sucks like that.
Excellent-Practice t1_j0a7ise wrote
One way to think about this is to put it in familiar terms. Instead of a spinning centrifuge, think of it as a steep hill. If you run fast enough down a steep enough hill, you can get some hang time. If you run up that hill, you're not going to run very fast. In a centrifugal space station, going downhill is moving opposite the direction of rotation, and going uphill is moving in the same direction as rotation. "Down", the direction that objects fall toward, won't follow a radius from the center but instead will be angled back against the direction of rotation and will vary with distance from the axis of rotation as a result of the coriolis effect
zoinkability t1_j09gme3 wrote
According to this calculator a roughly 100m ring going 3 rpm would have a tangential velocity of about 30 m/s. Which is about 70 miles per hour. So while it is an interesting theoretical question, practically you’re not running nearly that fast unless you’re a cheetah.
Equivalent_Ad_8413 t1_j09jt7i wrote
How about a gocart?
decomposition_ t1_j0a7baq wrote
A car driving 70mph?
zoinkability t1_j0a8b8u wrote
With the rotation = 2g
Against = 0g
Probably the practical limitation there would be that the car’s grip would reduce as it sped up running against the rotation, so it might be hard to actually get going that fast.
Assuming there was some kind of track or other setup that allowed the vehicle to get to 70 safely, yes, the person would experience weightlessness and basically fly.
scottimusprimus t1_j0br2py wrote
Out of curiosity, I just used that calculator to find that a windmill with a 209 foot radius running at 10 rpm (which is at the low end) will pull 7 Gs at the tip of the blades. 28.5 Gs at the high end (20 rpm). I got these lengths and speeds while searching for averages from google, so they could be off.
Bipogram t1_j0alyzv wrote
Yes.
This is a common problem with ring roads on O'Neill colony habitats.
Drive along the Equatorial Route #1 prograde, and your suspension creaks.
Drive along it retrograde and you might lose traction.
Banks deals with this in Consider Phlebas.
cain071546 t1_j0av1wd wrote
Excession is my favorite.
All his books are great really,
WictImov t1_j09dady wrote
You wouldn't float, you would fly. You would lose traction so could not run anymore. As soon as a wall came up it would smack you down.
Running in the same direction is something I am still thinking about.
Conedddd OP t1_j09gha3 wrote
Yeah that makes sense. I assumed you wouldn't just float, because you'll just immediately be thrown back into the floor. But yeah its an interesting thought and I wonder how anything affected by this would be dealt with when we construct a gravity ring for real.
MountainBrains t1_j0a9rrt wrote
Viewing the ring as a cross section you would be stationary, but your own experience would be like flying along the corridor. The closer you get to counteracting the rotational velocity the farther you would “fly” until you basically you are “orbiting” inside the ring. The air inside would push you though so as soon as you left the ground the air would start accelerating you back into the ring rotation.
CremePuffBandit t1_j09sq00 wrote
The easiest way to mitigate the problem it is to make the ring bigger, so it has a larger tangential velocity for the same artificial gravity. It would be pretty hard to do for our first stations, but for future giant space habitats, it becomes less of an issue.
Cradosskk t1_j0a3d4j wrote
Iirc, one of the biggest issues is the difference in gravity you experience across your body. If the difference is too great, people get nauseous. That puts as lower limit on how small the ring can be. When the ring gets big enough, it’s moving too quickly for walking the opposite way to be an issue. Assuming you’re planning everything around 1g.
scottimusprimus t1_j0bs5vh wrote
Looks like a radius of 10 feet at 17 rpm would give you a 1 G setup that you could outrun (12.2 mph), but you'd probably lose traction before getting up to speed. If you jumped as high as you could at as fast as you could run, you might be able to escape the floor, at least for a little while. A 7 foot ladder might be a better option. That would be such a strange environment!
RoyalWaldo t1_j0aqpaf wrote
It's possible that running in the opposite direction of the rotation of an artificial gravity ring could cause you to feel weightless, but it's also possible that it wouldn't have any effect at all.
The key factor in determining whether or not you would float is the magnitude of the rotational velocity of the ring and how closely it approximates the force of gravity at the surface of the ring.
In order for an artificial gravity ring to create a sensation of weight, it would need to rotate at a high enough speed to produce a centrifugal force that is similar in magnitude to the force of gravity at the surface of the ring. If the rotational velocity of the ring is too low, then you would not feel any sensation of weight, even if you were running around the ring in the opposite direction of its rotation.
If you were running in the same direction as the rotation of the ring, it's possible that the sensation of gravity could increase, but this would depend on the specific design of the gravity ring and the rotational velocity at which it is operating. It's also worth noting that running in either direction around the ring could potentially be dangerous, as the high rotational speeds of the ring could cause you to lose your footing and potentially fall off the ring.
Reddit-runner t1_j0awwap wrote
>would you start to float? Since you're cancelling out the rotational velocity?
That's 100% what would happen.
>Same thing but vice-versa, if you were to run clockwise around the ring would the "gravity" increase?
Also absolutely correct.
Selfless- t1_j0azfdm wrote
If you are floating inside the ring you are floating; no force as it spins beneath you. There is no gravity being generated here.
SatansLeftZelenskyy t1_j0av1ms wrote
FUUUK!!
why is reddit full of fucking dumb hunams.
ok46reddit t1_j09g0uo wrote
https://www.artificial-gravity.com/sw/SpinCalc/
At 1g:
Ring radius= 99.36 m
Tangential Velocity= 31.22 m/s
An average male runs at about 3.58 m/s so if they ran with the ring the 'downward' accelleration they would experience would be about 1.11 g. And if they ran in the opposite direction the acceleration would be .89 g.