Recent content by PAllen

Wow, I love that!!!

There can be two topologically different manifolds with the same metric everywhere, neither of which is incomplete in any way. A pure Riemannian example is the flat Torus vs the flat plane. This is where analytic extension comes in, to provide uniqueness. In GR, Birkhoffs theorem is quasi local...

Ok, so if I stretch a rubber band over 2 pegs, so it is stretched, you would claim you must consider that there is no force anywhere, as opposed to balanced forces which sum to 0 at each point. In the case of my simple tidal detector, there a force exerted by the spring on the ball. There must...

Definitely. If you define a force as that which is mediated by particle exchange, and treat gravity as a theory of gravitons, then all aspects would be defined as true force, even when not measurable. The spring device I described, I think, counts as an accelerometer. It just has to be big...

You may adopt that definition. But the definition accepted by most in this thread is whether it can be measured. Tidal effects and energy transferred by GW can be measured directly. Another example of direct measurement of tidal gravity as a force: 2 balls connected by a spring. Move it from...

You can’t transform away tidal gravity. In every frame there some non EM force that the EM force resists until it can’t. Even more simply, just consider two bodies at mutual rest in free fall. With tidal gravity, they will either get closer together or move apart, depending on orientation. This...

I think earlier it is mentioned that tidal gravity, the actual manifestation of curvature, is not fictitious. GW would similarly not be fictitious.

By removing the singularity, quantum gravity would have only geodesically complete slices and there would also be an apparent horizon else the theory wouldn't match observations.

This whole section responds to a (to me) surprising interpretation of what I wrote. If someone says "quantum theory converts the expected radiative collapse of atoms into orbitals characterized by quantum numbers" is it normal to assume a dynamic conversion is proposed or a comparison of...

In the case of a black hole from collapse, I think it is legitimate to talk about mass (or stress energy, more broadly) matter being the source of the vacuum geometry around the BH. I would hope this is admitted for a normal body. In the case of a BH from collapse, all spatial slices that are...

It does for me.

For a true point particle, there would be no limit, of this kind at least. Note the post begins: as soon as you give a particle finite size.

Yes.

No, it implies that there is an upper limit to energy in circular accelerator that is way beyond what has ever been achieved on practice. The implied limit on energy in mass terms would be sqrt of the ratio of ring radius over proton radius times proton mass. This is so far beyond any other...

@pervect , I have come to agree with you. My prior post was looking at something like some generalization of spring behavior, where work would necessarily have to be done during spin up. But then I was playing with the SET for just the idealized disc of post #1, and playing with just adding...