# Artificial gravity ship: Floor?

A.T.
The curve (of the 'other' object) should be a circle, in both frames.
In general, an object moving uniformly in an inertial frame, moves on a spiral in the rotating frame. The circle is a special case.

sophiecentaur
Gold Member
In general, an object moving uniformly in an inertial frame, moves on a spiral in the rotating frame. The circle is a special case.
And this is a 'special' situation? I think.
I think the main point about this thread is that the simulation of g by rotating is much more limited than one might think, at first sight. (But much better than nothing or magnetic boots!)

A.T.
And this is a 'special' situation?
No, the special case where the trajectory in the rotating frame is a circle, is when the object is at rest in the inertial rest frame of the rotation axis. When you jump radially of the wall of a rotating station, you move linearly in the inertial frame, so your path in the rotating frame is not a circle.

sophiecentaur
Gold Member
OH yes, I see now. The apparent circle for the Foucault pendulum (in the movie) must be because the motion is not uniform but sinusoidal.

The harder you jump (your radial velocity) the bigger the difference in your landing position and where you started from.
So if one were to jump "really hard", would that enable one to land on a different spot than the one you jumped off from?

Nugatory
Mentor
So if one were to jump "really hard", would that enable one to land on a different spot than the one you jumped off from?
Yes, because the higher your jump and the longer you spend in the air traveling a straight line while your jumping-off point is following the curved path, the less accurate the small-angle approximation becomes.

Something similar happens when you jump on the curved surface of the earth. You don't notice or worry about the rotation and curvature of the earth when you make a normal human-sized jump. But if you're aiming very long-range artillery (the artillery shell is "jumping" many kilometers and spending an appreciable time in flight) you do.

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sophiecentaur