Skip to main content
Physics

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Required fields*

11
  • 1
    $\begingroup$ bechira: I find it very difficult to reconcile your answer with W. Rindler's dictum: "We should, strictly speaking, differentiate between an inertial frame and an inertial coordinate system {...} An inertial frame is simply an infinite set of point particles sitting still in space relative to each other.". Does "point $p$" in your answer mean "point particle $p$" (as for Rindler), or does it instead mean "element $p$ of the manifold" ?? $\endgroup$ Commented Apr 2, 2015 at 16:56
  • $\begingroup$ $p$ is a point in spacetime (or slightly more confusingly, some people call it an event). $\endgroup$ Commented Apr 2, 2015 at 17:13
  • $\begingroup$ bechira: "$p$ is a point in spacetime [...]" -- Well, then your answer is all the harder to relate to W. Rindler's notion; because, surely, any one of Rindler's "point particles" would be characterized by a (suitable) set of several "points in spacetime". Also: Shouldn't your answer therefore have referred to "Poincaré transformations", or some suitable generalization(s) of those, instead of "Lorentz transformations, as expected." ?? $\endgroup$ Commented Apr 2, 2015 at 17:26
  • $\begingroup$ Not sure what you're getting at, why would local frames at the same point on a general spacetime be related by a translation? Also didn't read that article by Rindler yet, so really not sure what notion of a point particle you're using, I can post a reply later. $\endgroup$ Commented Apr 2, 2015 at 18:19
  • $\begingroup$ But looking at the diagrams it looks like the usual introduction to special relativity - I would take a point particle to be a timelike curve $\mathbb{R} \rightarrow M$ (assuming Lorentzian metric). The point $p$ I'm referring to above is a single point in $M$. $\endgroup$ Commented Apr 2, 2015 at 18:23