Recent content by OJ Bernander

PAllen, no, there is no peer review yet. I didn't mean to hide that fact. So the paper offers one actual solution, for classical collapse. It's the Oppenheimer-Snyder dustball collapse transformed from comoving coordinates to standard coordinates. This solution should be correct Then the paper...

Thanks for your reply. You may not have gotten to read the Discussion section yet, which acknowledges that there will be a modification to the exterior Schwarzschild metric, for example something like Vaidya's. The point of the paper is to put constraints on what the modification to classical...

This old nut is often dismissed as flawed thinking by a naive student. It’s been discussed here too, I know. However, when you do the math in standard (Schwarzschild-like) coordinates: Dustball collapse and evaporation in standard coordinates (Arxiv) A. the (coordinate) speed of light...

The OP comes across as setting up BU as an alternative to LET. I always thought of BU as an alternative to Presentism (a sliding "now"). LET, meanwhile posits the existence of a medium, a different issue altogether, as it can exist (or not) in but BU and Presentism.

Carter's Visual Group Theory. If you are just reviewing Group Theory, it may be a bit slow, but it gave me several new visuals, so worth the time, in my case. The focus are almost all on small, finite groups, but you get to know those groups inside and out.

Brilliant (dot org) has online self-study courses at several levels. Their format is to have a paragraph of explanation, immediately followed by a question (and answer) so you don't read too far without checking your understanding. They are under $100 for a one-year subscription, and with some...

For a GR intro, I really liked Foster and Nightingale's "A Short Course in General Relativity" because it progresses very naturally like this: 1. Curvilinear coordinate systems in flat space (e.g. polar or spherical) 2. Curvilinear coordinate systems for a curved surface in flat space (e.g. a...

Thanks Berkeman and Wrichik! I'll try out submitting one. I've got a positive response from some physicist-friends, but it I'd like to see how non-friends react.

Well, sort of. I leaned 3d animation in order to help explain difficult, fundamental concepts. Here's my website, so far offering "Visual General Relativity": << Mentor Note: Link deleted after a Mentor discussion >> I promise not spam with links. I'll only link to my videos if they truly...