RE: Speed-of-light experiments give baffling result at Cern
September 23, 2011 at 9:05 am
(This post was last modified: September 23, 2011 at 9:10 am by little_monkey.)
(September 23, 2011 at 7:00 am)Napoleon Wrote: Why is it so confusing that something can exceed the speed of light, especially if it's sub-atomic? Can someone explain that to a guy who doesn't know much about physics? I've always thought that there was no reason to think that some kind of matter could not possibly exceed the speed of light. Is this not evidence that something can?
One of the fundamental concept in physics is Lorentz invariance. What this means is that if I apply the Lorentz transformations to an equation that I think is valid in one frame of reference, the equation would not changed under this transformation in another frame of reference.
Now, in the Lorentz transformation, we get this factor ( 1 - (v/c)2)½. Should the speed of a particle be greater than the speed of light ( v > c), then that factor becomes an imaginary number! This brings humongus headache to the theory. One way out is to postulate that the particle has an imaginary mass (tachyons) since this factor often multiplies the mass of the particle, and the product of two imaginary number is a real number. In the real world, masses are real quantity, not imaginary, so particles with a mass must travel at a speed less than the speed of light, and only massless particles can travel at the speed c.
In this case, that doesn't work, as neutrinos have a real mass and shouldn't be traveling at a speed greater than c. That's why the findings, if confirmed, would be disturbing, to say the least.
