Sorry, I guess I don't see why a comment about force in GR is "off topic" for a question about whether gravity is a force. It sure isn't worth splitting hairs over, though.
Although I have not read every posting on this thread, I find it surprising that so many state that gravity IS curvature of spacetime. What I have learned is that general relativity is a field theory and therefore may be thought of as a force. Curvature is just one possible way to describe the...
So, is this an official naming, like a Newton is the unit of force in the SI system, or is it what you like to call it? I can understand it if you want to call it everything which, in any way, involves the quantum ideas, but I would still contend that the naming is semantic, not really right or...
I have a question: when a distant black hole eats a nearby star it has to gain mass. But if, from our perspective, we see the captured star stop at the event horizon, how do we see the mass increase? And clearly from gravity waves we see a merger of two black holes but we shouldn't see a merger...
My take is that what "quantum physics (QP)" is is mainly a semantics issue. The way I have sorted out this particular label for myself is that it is all the semi-classical stuff that came before the notion of a wave function arose; like black-body radiation, Bohr atom, Bohr-Sommerfeld atomic...
For some time I found myself puzzled by why quantum gravity was being pursued since I subscribed to something like "general relativity is just geometry". What satisfied me in the end was that it has been noted that warped space-time is just one possible interpretation of Einstein's equations. It...
I guess I don't really understand why you need that. Would you keep Chrome around even if it were not your default browser? I guess when I think of syncing I think of a given app on different computers always has the same stuff in it on all machines. It is a shame when google/chrome has you by...
I had an unrelated problem with chrome a few months ago which I could find no solution to. I installed firefox and found it to take less space and to be quicker in general. Syncing all settings, bookmarks, etc from chrome to firefox was trivial and quick.
My goodness, this is a long chain of discussion! I haven't read it all but what I did read did not mention something which I always taught my intro students in the first class. Newtonian physics requires that we somehow understand intuitively without derivation four concepts: length, time...
I just put a "stick" in there to make it more "laymanish". I could have said that there is a length L in the Earth frame which contracts in the moving frame.
There is a simple way to understand the twin paradox which does not have to get into the complications which are rife throughout this thread. It requires the acceptance of length contraction and time dilation is unnecessary to explicitly include. Think of the distance between the Earth and the...
First I must agree that experimental verification is imperative; physics is, after all, supposed to describe the universe as it is, not as we would like it to be. Also, unambiguous is too strong. But I think you missed my point, that the constancy of the speed of light is a result of the...
The principle of relativity is that the laws of physics are the same in all inertial frames of reference. Maxwell's equations comprise a law of physics. Maxwell's equations unambiguously predict a wave which travels with speed c in vacuum and which depends only on two properties of empty space...