babbler wrote:If I'm standing bang one of the earth's poles (the axis one/true north) and I look straight up, shouldn't the stars directly above me (those closest to the pole stars I'd imagine) be visibly moving in a circle?
Yes. Polaris (assuming you are at the North Pole) will be directly overhead and will be moving imperceptibly (to the eye). The other stars will be rotating around Polaris, at about one rotation per day (exactly one rotation per
sidereal day). So a star near the horizon will appear to follow the horizon, all the way around, over a day.
This assumes the earth is very much like a spinning top and those at the very 'top' spin around faster than those at the mid-range equator...no?
Well... you may be confusing angular velocity with the velocity of a point on the surface. It doesn't matter where you are on the Earth, the angular velocity is the same- one revolution per [sidereal] day. It's that at the poles, at mid-latitudes, at the equator. Certainly, if you are at a pole, your surface velocity is zero, and if you're at the equator it is around 1700 km/h. But that surface velocity doesn't affect the appearance of star trails.
Star trails look the same from everywhere, except that the half of the sky that is visible above the horizons changes with location.
