Is it right that the first part of 2 paralell rays of light will not join despite their gravit. attraction?

Question

As we already know, will 2 light rays attract each other by their gravity (E=M*C^2), though its extremly little. But I have read that Einsteins prediction that gravity is not faster than light has now been proven. That would mean that dependend on the distance between the 2 rays the gravitational attraction of the first phtons of the ray can never reach the first photons of the other ray, but all later coming photons ! So the the first photons will not attract each other, while the others do and will join somewhere in the universe. What do you think ? Right or wrong ?

Quotation:
Light, or photons, have zero **rest mass**, and this enables them to travel at the speed of light.

However, photons do have energy, and as such have an equivalent mass according to Einstein's famous equation,

E = m c^2
or
m = E / c^2

This is different than the "rest mass" (which is zero). And while it is not zero, it is a very small mass for most photons. As an example, for visible green light photons it is 4 x 10^-36 kilograms. That's a decimal point, followed by thirty-five zeroes, then the number four. Incredibly tiny.

So photons do have a gravitational attraction to each other, but because the masses involved are so small we could not detect the attraction with our current technology.

Answer 1

Your premise is wrong. Light beams DO NOT exercise gravitational attraction each other.
Probably what you have in mind is the fact that light can be deviated by masses, as in the famous Eddington experiment, or more evidently, as in black holes. But according to general relativity, that is not due to a pulling force but to the spacetime curvature caused by the mass.
Light beams (or photons, if you prefer quantum mechanics wording: in this case it's the same) propagate on geodetic lines, without being pulled by any force: it's just that the presence of mass distorts the geodetic lines themselves.
So, in your hypothetical experiment, assuming there aren't masses around, the two beams are just parallel.

Answer 2

no longer something with mass can commute on the linked fee of sunshine. this could be a consequence of Einsteins' concept of Relativity. Photons commute on the linked fee of sunshine. for this reason, they won't be able to have mass. Gravity is a stress that operates on mass. as a results of fact that photons are massless, there isn't any gravitational charm between gentle rays. areas of severe gravitational field will reason gentle rays to deviate, as in gravitational lensing which has been stated astronomically. besides the undeniable fact that, that is not gravity attracting gentle if so, yet gravity distorting area itself, the medium during which the gentle travels. From the attitude of an observer using the gentle beam in this curved area environment, he could see the gentle vacationing in a on the instant course.

Answer 3

Wrong. Light is carried as a massless particle known as a photon. Because it has no mass, not only can it travel at the speed of light, but it has nothing to create a graviational field. Ergo, the photons will continue to infinity without ever attracting each other, unless they fall sway to an outside graviational source.

Answer 4

strange enough, photon will not able to interact with another photon. Interactions are possible if there is an electron available and act as the mediator between the two photons. This is the basic rules of QED.
Of course, they will not interact through gravitational forces since they are massless.

For more information, please read: Feynman's "Strange Stories of QED"
http://www.pupress.princeton.edu/chapters/i8169.html

Answer 5

E=M*C^2 doesn't tell you how much mass a photon with that much energy HAS. It tells you the equivalent amount of mass that would be needed, to be converted into a photon with that much energy or if you were converting the energy into mass, how much mass you could change that much energy into.