I'm aware that a half life is not movement speed. It just seemed that something like an electron's lifespan was more set in stone so to speak than the speed of light (Weird to say that, but whatever).
I also thought that after a certain point of travel a photon would accumulate the energy of an...
I'm not a physics person (did not take it in high school), but I was wondering why the speed of light is the constant (in relativity) and not the half life of an electron or positron.
The name of a good introductory book to physics would be good too.
Thanks in advance.