I read a lot of sci-fi, and simulated gravity is a frequent feature of space sci-fi. I am interested in real physics, not hand-wavy magic artificial gravity. In the Expanse, highly efficient nuclear rockets create the experience of gravity by way of constant acceleration. This is easy for me to understand – on the vessel, the deck you are standing on is accelerating and pushing against your feet.
What I do not under is how centrifugal force acts in a way similar to gravity. I have a scenario in my imagination that illustrates my confusion. I imagine that a torus-shaped station in space has stopped rotating and everyone evacuated. A repair person in a space suit has floated into the station to repair it. He or she travels in microgravity in a space between the inner walls and outer walls of the station, almost like someone floating inside of a holo donut. While inside the immobile torus, and suspended between the walls in such a way that he or she isn’t touching either the innermost or outermost walls of the donut, s/he completes the repair needed to spin up the station again.
What happens next? The sci-fi I have read would lead me to believe that as the torus begins to spin up, the repair person will experience an effect similar to gravity and will coast toward the outermost wall until the inside of that wall becomes like a floor to them. If that is true, why? I would think that a person suspended within the boundaries of a torus would continue to float while the innermost and outermost walls in front of and behind them spun in their cycle. I don’t get why this spinning will make the repair person drift to one side and create a “down” to their perspective. Can anyone enlighten me?
Tl;dr: centrifugal force confuses me, and I don’t know why it works in microgravity(or just fundamentally misunderstand it)
In: Physics
Imagine you’re riding the teapot rides in Disney world, and you’re spinning really fast. Essentially, your body will want to be flung off the teacup but it can’t, because the seat is applying a force keeping you in the teacup.
Now imagine instead of being seated against the chair of the tea cup, you were standing up (your feet are where your back would be). The teacup is now simulating a force holding you in the teacup; the same way we feel the earth pushing against us to avoid gravity.
There also are the amusement park rides where they spin really fast and then drop the ground – same basic principle. If you stood up perpendicular to the wall, it would be the exact same thing as spinning in space (except spinning in space attempts to simulate gravity, whereas those rides overcome the force applied by gravity, so centripetal force in space does not require as much effort)
Worth adding: all of this requires you to be touching the walls. Once you’re touching the walls, you’d feel a sudden force to get you up to speed with the centripetal force (imagine jumping onto a moving train), but once you’re up to speed you’d only feel the force pushing you away from the center of the circle. If you jumped into the air, you’d be floating, because you’re no longer feeling that force pushing you towards the center of the circle.
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