Do photons obey the 1/r^2 gravity law?

This is obviously easier said than done to be shown in full in a thread. Why don't you try it yourself?

[itex]L_{EM} = -\sqrt{-g}g^{ac}g^{bd}\triangledown_{[a}A_{b]}\triangledown_{[c}A_{d]}[/itex] so take the total lagrangian density that includes this matter field lagrangian density and the einstein lagrangian density, vary the respective action to obtain the field equations and solve it if you want (=D). I don't see why you have a problem with the idea that the maxwell field can contribute to curvature. It isn't just mass density that contributes to the curvature. Look up the lens thirring effect as a correction to newtonian mechanics where the OTHER parts of the energy momentum tensor contribute to the non vanishing of the gravito - magnetic field.

Field? I'd say eight fields, two electric and six of them magnetic, but no, that's not what mainstream theory would tell you.

A photon is quanta of electromagnetic radiation, and despite the name, despite there are, I mean could very well be, magnetic and electric fields constituting a photon, it is still electrically and magnetically neutral, which means its electric and magnetic field is measured to be zero. Ok?

Yes, this is an important part of GR. The two types of solutions you will want to look at are null dust solutions and pp-wave spacetimes:
http://en.wikipedia.org/wiki/Null_dust_solution
http://en.wikipedia.org/wiki/Pp-wave_spacetime

If you know someone has calculated or measured this photon gravity filed, then please just tell me the number.

No, mainstream theory would tell you that a general electromagnetic field has six independent components, three electric and three magnetic.

A "photon", at least in the classical approximation that's appropriate here, is a special case of an EM field where there are only two independent components.

EM radiation has zero charge, but nonzero electric and magnetic fields.

Barry_G I have no idea what you are saying, in relativity we only talk bout the electromagnetic four tensor, not the electric field and magnetic field since it is not a frame independent idea.
it seems to me that you might need to go learn physics first before discussing it qualitatively.

Barry_G please stop before you say something even more humiliating, you don't sound like you have any idea how GR and EM work.

Really? But you somehow understand everyone else? Pay closer attention and realize it is K^2 who said: "You do realize that a photon IS electromagnetic field, right?". Now tell him to go and learn physics, will ya? Then go learn some physics yourself and realize electric charge of a photon is zero. After that you may try to bend a beam of light with magnetic fields and you will realize photons magnetic charge is zero as well.

What is the point of being condescending? I could be very well be older and more educated than you, so that's not only inappropriate but also very unnecessary. Just keep your personal comments to yourself and talk about the topic at hand, if you have anything to say about it.

As has been pointed out numerous times, there can't be a clear answer to 'gavity of one photon'.

In classical GR, there is no such thing as photons at all.

No, that has not been pointed out, and if you are going to, then point it to K^2, who said in post #12: "Photons do generate gravity in GR".




Post #12, K^2 said: "Photons do generate gravity in GR". Take it with him or someone else who made claims about it in this thread, I'm mostly just asking questions in relation to those statements.

As others have said, 1/r^2 law applies to classical electrostatics, magnetostatics and gravitostatics. Photons are not part of classical theories whatsoever.