Does the photon have mass? After all, it has energy and energy is equivalent to mass.
DOES PHOTON HAVE MASS
Nine answers:
Boris
2008-01-17 04:42:50 UTC
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/960731.html Read it same question better replies than any you will get here :)
anonymous
2008-01-17 04:43:17 UTC
A new limit on photon mass, less than 10-51 grams or 7 x 10-19 electron volts, has been established by an experiment in which light is aimed at a sensitive torsion balance; if light had mass, the rotating balance would suffer an additional tiny torque. This represents a 20-fold improvement over previous limits on photon mass.
Photon mass is expected to be zero by most physicists, but this is an assumption which must be checked experimentally. A nonzero mass would make trouble for special relativity, Maxwell's equations, and for Coulomb's inverse-square law for electrical attraction.
Stray Dog
2008-01-17 07:06:02 UTC
This topic has been a cause of rift between quantum mechanics and traditional theorists. Energy Mass equivalence is not that simple. Very Very brief answer is that 'mass' in equivalence equation is 'relative mass'. Photon has 0 rest mass...which means it does not exist at rest.
If you consider 'quantum electrodynamics' (way way advance maths), Heisenberg's uncertainty - photon is a matrix of numbers!
It will sound weird but - behavior changes on observation! Heard of Schrödinger's cat experiment and Copenhagen interpretation? This a DSc / DEng type research topic and you may get a Nobel to answer it with logic and experiment!
READ: Atom
Piers Bizony
Jim Al-Khalili
ICON books
dansinger61
2008-01-17 06:59:22 UTC
A photon has zero rest mass (mass at zero velocity). It is a requirement of the laws of relativity that any particle that can travel at the speed of light MUST have zero rest mass. However, since mass changes as a function of relativistic speed, the mass of a photon at speed (c) is expressed as its momentum.
anonymous
2008-01-17 05:22:53 UTC
Photon does not have mass, but it has momentum.
For eg, Light is made up of photons and it does not have any mass.
Energy only has mass when it is compressed. I remember reading that Matter is, in fact, compresed energy.
?
2016-12-02 10:14:05 UTC
I dont be responsive to with reference to the masses yet a photon is very a 'packet' of sunshine. whilst an electron is worked up from its floor state, it quickly drops circulate into opposite to the floor state dropping the surplus potential interior the approach. the surplus potential is given off as a photon.
ZikZak
2008-01-17 05:29:33 UTC
The expectation that the photon has zero mass is NOT an "assumption." It is a prediction of the standard model of quantum field theory.
anonymous
2008-01-18 07:22:02 UTC
according to einstein
light is made up uf small massless particles called photons