Earth's Ergosphere?

Question

Do we not notice an ergosphere of Earth because it isn't massive enough, or does one not exist around Earth? I'm assuming that because Earth is rotating, it has to have an ergosphere, though due to its extremely small mass comapred to other celestial object, the Ergosphere is not noticeable, though can its affects be measured?

Answer 1

An ergosphere is defined as a region in which remaining stationary (as determined by a distant observer) is not possible. There is no such thing around the Earth. Only black holes and bizarre theoretical monstrosities have them.

Yes, the GPS constellation must correct for a very small amount of frame-dragging.

Answer 2

You are correct.  We don't notice it because the earth isn't massive enough / doesn't have enough angular momentum.  If anything could notice it, it would be the GPS satellites, but I think the regular old Shwarzchild time dilation fixes them to as good as their accuracy.

--Actually I take that back--I think the strict definition requires there to actually be an event horizon.  But the earth would cause a teeny tiny amount of frame dragging.

--Jose, I don't think GPS can measure frame dragging.  But there are experiments such as gravity probe B that are supposed to find it.  They may have done so already.