photon mass

A Photon has no mass. It can’t rest.

A) A Photon has no mass. B) A implies “It can’t rest”. C) Therefore it doesn’t have rest mass. D) Photon rest mass is zero.

Assertion and reasoning; A is correct. B is correct and follows from A. C is correct, it does follow from B. But D is incorrect it does not follow from A, B, or C. Its erroneous, a sloppy language that has been thought to be correct for ages now.

The trick is to realize there is no property called mass of photon — at-least in the same sense as it is for other particles with mass, therefore no rest mass. To say rest mass is zero is a special value of mass or rest mass. It just doesn’t have rest mass, as it neither has mass, nor rest, which are equivalent formulations, one leads to other. But A, B or C do not lead to D. They are not equivalent way of saying each other. They invalidate each other actually.

Photo-Electric Effect, Quantum Mechanics, Quantization, Wave Particle Duality !!

The fact that zero mass particles exist simply might be a coincidence of nature, that a very small energy was produced randomly. Again since it transmitted a longer distance or infinite distance might only happen for EM force only because of the nature of phenomena. Probably we need to think more why, what are any fundamental differences between different fundamental forces.

Why scientists think photon is mass-less ?

There are a bunch of values from various experiments that can be said to be a measured value of the mass of the photon ..

A photon mass ranges from 10^{-7} eV – 10^{-27}. With such wide range of a mass we still have a firm founding on why photon can not be taken to be an extremely small mass rather it is taken to be a zero mass.

Even with the highest possible value measured it is by a factor 10^{-12} smaller than the mass of the electron — imagine a photon is associated with a hypothetical charge of the electron, for comparison sake of mass, we can give it the charge for free.

The photon is at-least by a factor 10^{-7} times smaller than the almost mass-less neutrino which is by a factor 10^{-5} smaller than the electron mass even if it were to have a charge of an electron, which it does not.

Why nothing moves faster than light !!

There is an interesting discussion on twitter why “nothing can move faster than light”. I could not resist myself from a simple explanation

I also think a similar one might have been given by Einstein himself, long time ago, so forgotten by most when they try to explain it.

How does something go faster !! by burning mass.

In case of a car to move faster and faster one has to burn the fuel, more mass in less time.