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
gravity is an acceleration
an acceleration is a change of velocity
velocity is a speed in a direction
so acceleration can be a change in direction you are moving, not just a change in speed.
in a spinning ring, if you are in contact with the ring, your direction of motion is constantly changing, so you are experiencing an acceleration, just like gravity
If your not in contact with the ring (the repair person), this has no effect on you.
If you were in contact with the ring and jumped, you would move in a straight line through space, but since you are inside a ring, you will eventually hit the side of the ring again, so it will “feel” kinda like you fell.
Its not a perfect gravitational stand-in, and some of the physics gets super weird (like how bullets would do different things depending on the direction they were shot), but it should work well enough for people sitting on the object
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