Why is the speed of light different from all other speeds?

[Pasta]

@Chronos

Do you just mean massless spin 1 particles, there? Because the W would be a counterexample otherwise.

Yes, there is an implicit “massless” throughout that paragraph.

[Find_Friends]

@Pasta

After looking through more than a dozen journal articles, I conclude that this is a complicated question.

The short answer seems to be: yes, you can have massless charged particles. There are a couple of papers demonstrating that you can get self-consistent classical behavior. There are some showing that the “usual” electromagnetic charge is incompatible with spin 1 or higher particles, lest angular momentum conservation be damaged. (I have not reconciled this with the fact than a version of the standard model in which SU(2) remains unbroken leads to massless charged vector bosons, but this may have to do with the next sentence.) Some argue that you can solve some of the Lorentz invariance issues for the high-spin cases by giving the particle other couplings, and then there are some that show these solutions typically (in turn) introduce mass terms indirectly anyway. I should note that the original paper demonstrating that charge is incompatible with spin-1+ particles does not itself prove that it is compatible with spin-0 or spin-1/2 particles.

However, I’m sticking with a summary answer of: yes, because the standard model with unbroken gauge symmetries (or, alternatively, a Higgs field vacuum expectation value taken to zero) would lead to massless charged particles, and I know of no reason why you can’t do either of these things.

Wow. There seems to be a never-ending depth to just understanding the material to date. As I indicated above, it never becomes boring. In conjunction with that, it gets awfully frustrating.

Another “wow” is that I asked a question that inspired a search through no less than six journal articles. By coincidence, just yesterday I received a huge compliment about one of my ideas for an interview question during a brainstorming session with one other fellow from our staff selection committee. The compliment came from the president of our sponsoring agency. (And she was just getting over the shock of noticing that I am able to tell the day of the week from any year, month and date, taking anywhere from a few seconds down to apparently instantly. She then wanted to take me everywhere. Don’t get the wrong idea. ;))

Original questions r "us" –

I may have rocks in my head but I still rock.

[ZomZom]

@Chronos

Well, for instance, a photon that goes from the fluorescent light bulb above me to my desk won’t ever be in Des Moines, Iowa.

But that photon didn’t begin at the light bulb and didn’t end at the desk.

[Chronos]

But that photon didn’t begin at the light bulb and didn’t end at the desk.

Most of them did. A few came from somewhere else and bounced off the bulb, and a few bounced off the desk and went someplace else, but none of them went very far.