Recent content by PeroK

When do I start relearning all the physics I know? It's true I took some physics as part of my mathematics degree back in the early 1980's, but I remembered very little of that when I started studying physics when I retired ten years ago. Also, when I was a mathematics student, I generally...

The field lines may be curved when two or more bodies are involved. See here, for example: https://en.wikipedia.org/wiki/Gravitational_field

It's not enough to think something, you have to show that what you think matches the data. When Einstein developed the General Theory of Relativity (GR), he found that a static spacetime was not a possible solution for the entire universe. Space must either be expanding or contracting, but...

When I say all the crackpots are working on unification theories, that's not the same as saying all people working on unification theories are crackpots. It's a common logical fallacy to confuse a statement and its converse. That said, the conditional probability that someone is a crackpot...

Let's suppose I became an editor and to begin with I took every submission seriously. I would read them fully and give the author a reasonable response. What would happen? I'd get an email back from most, if not all, of the authors explaining why I was wrong and why I was being unreasonable...

I'm not convinced you've understood superposition and the linear algebra that describes them. ##L_z = 0## is a complete description of a state. In this state, there are definite no values for ##L_x## and ##L_y##. In this sense, your "configurations" are not quantum mechanical descriptions...

:welcome:

The all-seeing, all-knowing Web suggested this video to me today!

You could always figure it out for yourself. The Wigner rotation is essentially caused by a convention that underlies the Lorentz Transformation: https://www.physicsforums.com/threads/time-dilation-along-multiple-axes.1012568/#post-6602418

Aka "a reality check".

Generally annhiliation is between a particle and its antiparticle. The interaction between an antiproton and a positron would be equivalent to the interaction between a proton and an electron.

In general an expected value does not itself need to be one of the possible values. For example, the expected value of a roll of a standard 6-sided die is 3.5. This comes from a uniform distribution of the numbers 1-6. In this case, you could achieve the expected value of ##\langle L^2_x...

Is this useful? https://arxiv.org/abs/hep-ph/0510213

I'm not convinced by this. Introductory books on Abstract Algebra, Number Theory and Real Analysis etc. would cover a lot of general and specific ground. If you study them thoroughly, this will take significant time. Probably a year or two of serious part-time study. Also, such textbooks are...

Coulomb's law breaks down for high-energy scattering. QED predicts this and presents Coulomb's law as a low-energy approximation. Moreover, representing elementary charged particles as point particles with well-defined position and momentum (as per Coulomb's law) cannot be compatible with...