PeterDonis's latest activity

The light path from an arrow tip to an observer right on the photon sphere will be moving radially outward if the arrow is near enough...

What the "altimeter" is actually measuring is the deviation of radial paths from being parallel. That's really a measure of radial tidal...

You do now, at least one part of it. Yes, because it's a Coulomb potential, which is purely scalar. But there's another part as well...

You have a calculated a quantity that has the dimensions of distance over time, and you can interpret it as a speed (it's an...

All that shows is that the Hamiltonian has the form you wrote down. But my issue has nothing to do with that Hamiltonian not being...

That's the only case for which you can take that as a unique result, yes.

Yes, but in that model, at least according to Hawking, there is an event horizon because of the recollapse of the universe. (I'm not...

For a free particle, yes. But you can't just assume that for a particle in an external potential. See, for example, the discussion in...

Where did the ##v_n## in this formula come from? There was no ##v_n## in the previous formula for ##T_n##.

Since the twin paradox has come up, I think the OP would be well advised to look at this sticky thread at the top of this subforum...

When they appear in a series of lectures that aren't peer reviewed, and by his own admission, as I've already shown with a direct quote...

I believe the factor of ##1/4## is what appears in the formula Bekenstein derived for the entropy of a black hole in terms of the area...

And to bring this subthread back to the OP's question, since the paper you reference gives no references to actual scientific papers, it...

If you want to call it "lectures giving the speakers' opinions" instead of "pop science", go ahead. That's a matter of choice of words...

Please note that in my previous post, I was not giving my personal opinion. I was telling you (and the OP of this thread) the PF rules...