Does Light have a Mass? How This Can Be Concluded?

Question

Refrences!

Answer 1

I doudt light has a mass a correct term for mass would be anything that occupies space or has a weight(ratio) then light certainly does not have a mass

Answer 2

Lights kind of an odd duck because it acts both as a wave of energy (which of course would have no mass) and a particle (which would have mass).  However light particles (photons) are electromagnetic "packets" of waves.  So no light has no mass and that's why.

Answer 3

common misconception, light has mass. for some reason people completely forget the word "rest" in front of the word "mass". light has 0 rest mass. light has energy, everyone knows that. energy is mass. so light has mass.

physicists rearrange E=mc^2 to find mass. the mass of a single particle is usually represented by the equation m=E/c^2. the electron for example, has a mass of .511 MeV/c^2.

photons do have a mass, its just not realistic to say that they do. photons have relativistic mass, not rest mass. relativistic mass is mass that is gained as an object accelerates due to the energy it gains in the process. since a photon would have no energy if it were motionless, it has no rest mass. but since it is always in motion because it always has energy, it has relativistic mass

relativistic mass isnt used really at all. most equations your going to use require rest mass, not relativistic mass. so for all mathematical intents and purposes, the photon is massless.

Answer 4

one may also argue that since planks constant (h) is equal to lambda*m*v, (wavelength * mass * velocity), then any source of light (or radiation for that matter), traveling at 3*10^8m/s ought to have a (even if, very small) amount of mass

Answer 5

By E=m*c^2:

Given:  the speed of light = 299 792 458 m/s

and a  photon with E=0.511 Mev of energy

This photon has a mass equivalent of:

mass equivalent = 0.511 Mev / (299792458^2) = 9.10940144*10^-31 kg

Given the fact that light can be forced to bend by gravity,

it is probable that light has mass. Imagine "tons" of light

trapped in a perfectly reflecting bottle. Now weigh the bottle

with and without the light.

Edit:

In this thought experiment, as you keep adding light to

the bottle, the total "localized" mass must increase. I

believe the law of gravity would give us the answer at

some point.

Answer 6

It is scientifically accepted that anything with mass can't reach the speed of light.