Originally Posted By: kallog
Originally Posted By: Bill S.

Could it not be argued that on the roundabout we know we are moving because we have experienced acceleration, whereas the world around us has not.


Sorry but it's exactly how I thought things worked too. Tho there is that possibility the roundabout might be enclosed in a massive spinning sphere, so we'd feel acceleration even tho we're not rotating relative to the distant stars. But it seems like more of a special theoretical case rather than what actually happens.

Seems to me that either one accepts or does not accept that there is no single reference point from which all motion is measured - i.e., that all motion is relative. If one takes rotational velocity to be an exception, then one has the task of explaining why. But hey, I reserve the right to be wrong twice before breakfast smile

"Time is what prevents everything from happening at once" - John Wheeler