| From: Chris (Avatar) | 21/12/2000
13:19:52 |
| Subject: re: Mach's Principle | post id:
191256 |
Sure. Mach's principle is about inertia. He theorised that it didn't make sense to talk about acceleration relative to absolute space, it made more sense to talk about acceleration relative to "the distant stars". If you think about this it implies that the inertial mass of an object here is somehow affected (caused?) by the mass of the rest of the visible universe. We still don't have a very good explanation for inertia today. We have a great description - it's a measure of resistance to acceleration - but not a good explanation. Mach's ideas are still useful, and Einstein was influenced by them in his formulation of GR. You can learn a lot about inertia and understand Mach's principle better by considering the behaviour of a single massive object in its own universe (ie nothing else in the universe). Can you determine whether or not the object is rotating or more generally accelerating? Mach's principle would argue "no", and it is interesting to think about how this might be so. Hope this helps! Chris | |