Re:Speculoos-2c: A new potentially habitable earth
by layer8 on Wednesday September 07, 2022 @10:01AM
(#32750772)
> The equator of the Earth is spinning much faster, on a much tighter radius.
Centrifugal force is proportional to the radius, so a smaller radius actually decreases it, for the same angular velocity. The reason we associate smaller radiuses with increased force is actually because if the energy stays the same, reducing the radius increases the angular velocity (like in a pirouette), which then “feels” like a stronger force.
Re:Speculoos-2c: A new potentially habitable earth
by ncmncm on Wednesday September 07, 2022 @10:28AM
(#32751081)
Centrifugal force is v^2/r, so smaller r increases it. And we have higher v, besides.
Re:Speculoos-2c: A new potentially habitable earth
by layer8 on Wednesday September 07, 2022 @10:49AM
(#32751377)
Centrifugal force is mω²r. Of course, v = ω2πr, which is why you have to divide v² by r. But if you compare based on the rotation period, increasing r increases the force, for the same rotation period.
It does actually affect your weight a bit, but if you mean what I think you mean that it would be something you perceptibly feel, it is not.
Moreover, this merely shows that the idea that the magnitude is significant isn't a good one. Even more importantly, you don't "feel" anything in an orbit ever, because when you're on a geodesic, you're in "zero g". You never "feel" anything in an orbit, no matter how fast it is. People on the ISS don't "feel centrifugal force", because they're in zero G.
(Except tides, if you're large enough, but a single person in this orbit is nowhere near large enough or sensitive enough to feel any tides.)