On 28/7/2007 3:53 AM, Michel Jullian wrote: > ----- Original Message ----- > From: "Harry Veeder" <[EMAIL PROTECTED]> > Sent: Saturday, July 28, 2007 6:43 AM > ... >> Here is another way looking at it. For the sake of balance, imagine a wheel >> is setup on opposite sides of the equator. One wheel has the brake on and >> the other has the brake off. >> >> If you could stop the Earth rotating, the wheel that has the brake on will >> continue to remain at rest wrt to the ground but the other wheel will >> continue to turn once per day wrt to the ground. >> >> The two motions differ, but the difference is masked by the rotation of the >> Earth. >> >> Do you agree? > > I would say on the contrary that they do not differ, unless the Earth stops > rotating. Releasing a brake between parts which have no tendency to move wrt > each other will make no difference whatsoever, agreed? > > Michel >
No, and here is an argument without stopping the Earth's rotation. Mount each supporting frame on its own turntable. A slight turn of each turntable will show that only the wheel with the braked released is rotating about its own centre. Harry
