Relativity Basics

 

References

Basic Relativity

Introduction to Relativity

An Introduction to Relativity

Video on Faster Than Light Neutrinos



There’s a common mistake that this is a problem for relativity but it is not. Relativity forbids is accelerating up to and past the speed of light but does not for bid particles that naturally travel faster than the speed of light. Such particles have been speculated about for decades under name tachyons.

The only real difficulty is that neutrinos have a small but real rest mass and so should not be traveling faster than the speed of light. In that case the issue is most likely with our understanding of neutrinos and relativity

Quantum Mechanics allows particles to skip part of space instantly and so could be clocked at faster than the speed of light while going sub-light through the space it actually goes through. This is the most likely explanation of this observation given calculations from India.  See in Faster Than Light Neutrinos Fl aw Found.

Why Faster than Light Neutrinos are not a Problem for Relativity.

When CERN reported measuring neutrinos going faster than the speed of light it created speculation that it showed a problem withSpecial Relativity. The measurement was about 20 parts per million faster than light so since the speed of light is 299,792,458 m/s the neutrinos were going 6 km/s faster than light which could easily be an experimental error.

If it is confirmed it would still not be a problem for Special Relativity since not traveling at or faster than the speed of light only applies to particles with a real non zero rest mass. A particle like a photon that has a zero rest mass travels at the speed of light. Particles that travel faster than light have been speculated for years under the name tachyons. Tachyons would have a negative imaginary rest mass giving it a real non zero mass at speeds above the speed of light. It would however be incapable of being decelerated to the speed of light below it.

Furthermore quantum effects such as quantum tunneling provided another way around the light barrier by allowing particles to instantly skip over an area of space without actually going through it while traveling sub light through the space it does go through thus not violating Special Relativity.