PeterDonis's latest activity

I think you mean damping here, and yes, that is important, for the reason you give (and it's the reason why real accelerometers have...

You are right, I should have been more precise about that. In a direct sense it determines ##\ddot{q}_2##. But indirectly it determines...

That’s not starting from the singularity though 😉

But it's not what your description said. You said: That says that the accelerometer is measuring the acceleration of particle 2. But...

OK, now I understand where the controversy comes from. @PeterDonis has already explained it in one of the posts, so I will just rephrase...

And it looks like the TLI burn was successfully completed, so the astronauts are on their way to the Moon.

Moderator's note: Several off topic posts have been deleted. Please keep discussion on topic. Thanks.

Okay, then we're back to my original criticism: the first particle, not the second, is the one that's affected by the electric field. So...

Hm. I see what you mean, but now I question the physical relevance of this toy model, because now you're saying particle 2 isn't...

I think you have it backwards. In your example, particle 2 is the one "moving only under the influence of gravity", so its proper...

I think there's a subtlety here. ##U## is the 4-velocity of an observer at rest in the chosen frame. A charge at rest in the same frame...

Metric theories of gravity all obey all but the strongest form of equivalence principle. So, no Newton-Cartan theory could not...

You can't, because a black hole is not made of anything you can build something from. A black hole is just spacetime geometry. It's not...

Classically, a black hole can have any size. There's a minimum mass for one to form by stellar collapse, because smaller stars don't...

On a re-read, are you using "singularity" and "black hole" as synonyms? They're not the same thing. The singularity is inside the black...