did you know, that a, "Photon", (a particle representing a quantum of light or other electromagnetic radiation. A photon carries energy proportional to the radiation frequency but has zero rest mass, light has energy and momentum which couples to gravity. ... A mass-less particle can have energy E and momentum p, because mass is related to these by the equation m2 = E2/c4 - p2/c2, which is zero for a photon because E = pc for mass-less radiation, M =mass), but if a photon has zero mass, why then does gravity have an effect on it, after all the theory states, that its a intangible particle, IE nothing can touch it or act upon it, which is compleatly wrong, all you have to do to know its wrong, is look at the effect of gravitational lensing, Energy and mass are the same thing, as you wrote. If gravity affects mass, you may as well say it affects energy. 2) Light is moving, therefore it has kinetic energy, therefore it is affected by gravity. 3) Kinetic energy of an object is merely a side effect of changing the inertial frame. Any object standing still on Earth at any given moment, is actually drifting away from some distant star at speed c, and taking in to consideration also the fact that energy bends space-time and thus changes the direction of the light wave, There are two important concepts here, that explain the influence of gravity on light, (photons). The theory of Special Relativity, partially proved in 1905 (or rather the 2nd paper of that year on the subject), gives an equation for the relativistic energy of a particle;
where m0m0 is the rest mass of the particle (0 in the case of a photon). Hence this reduces to E=pcE=pc. Einstein also introduced the concept of relativistic mass (and the related mass-energy equivalence) in the same paper; we can then write
where mm is the relativistic mass here, hence
In other words, a photon does have relativistic mass proportional to its momentum.
an early result of quantum theory (specifically wave-particle duality), states that
where hh is simply Planck's constant. This gives
Hence combining the two results, we get
again, paying attention to the fact that mm is relativistic mass.
And here we have it: photons have 'mass' inversely proportional to their wavelength! Then simply by Newton's theory of gravity, they have gravitational influence. (To dispel a potential source of confusion, Einstein specifically proved that relativistic mass is an extension/generalisation of Newtonian mass, so we should conceptually be able to treat the two the same as, standardz, hahahahahahaha, :) #edio