Ok, apologies if my understanding is limited or even wrong but I know I'll learn something from your replies even if my question turns out to be idiotic! Relativity gives us length contraction as we approach the speed of light but quantum mechanics gives us uncertainty as to a particles velocity vs. it's position. So on the one hand you have an accelerated particle contracting under increased velocity in relativity and on the other, you have the same particle's position taking the form of an ever lengthening probability wave in quantum mechanics with increased velocity. Which is the more relevant theory with regard to the LHO? More importantly, does it even matter? Am I wrong or is this another one of those cases where the 2 theories fail spectacularly to agree?