Black holes are formed by immense gravity, so I guess the question is if energy in the form of photons can produce a gravitational pull (instead of just being affected by it).

My understanding of quantum physics is limited but I thought the answer was no, photons don't create gravity.

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Bleh, should have read wikipedia first I guess.

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"On March 10, 2009, NIF became the first laser to break the megajoule barrier, firing all 192 beams and delivering 1.1 MJ of ultraviolet light, known as 3ω, to the target chamber center in a shaped ignition pulse."

This is the most powerful laser I am aware of. National Ignition Facility

I was an astronomy dweeb as a kid, and IIRC they'd solved the spherical aberration problem long ago. Chromatic aberration was much harder (and still isn't solved perfectly) but since a laser is one wavelength, that wouldn't matter.

yes and if you use einsteins e = mc^2 formula you could roughly estimate the amount of energy required that would be equivalent to a solar mass.

Also a decreased volume to photon count would create an increased amount of gravity.

So a trillion bazillion photons in a centimeter cube would create more gravity than the same amount of photons in a volume of the earth.

I tried finding some easy equation relating gravitational force to mass density but I'm not sure how it would work for bose einstein statistics (or photons). You can theoretically pack as many photons as imaginable into a volume of space because photons (bosons) dont behave like fermions, although if the volume of space "condenses" into a black hole then obviously theres an upper limit to bose einstein statistics and adding more photons into a black hole would increase the mass of the black hole.

And the difference is...?

Uh... right.

I keep saying it: the source of gravity is energy, not mass, which is just a form of energy.
Anyway, I forgot the details but apparently you can't build a self-gravitating object out of photons. Having a high photon density means photon-photon (weak) interactions become important and that means you'll probably have large energy losses (from neutrinos) that the effect goes against you.

Huh?
What do you mean?

The force of attraction between two bodies is defined by mass of each & the distance between them, and has nothing to do with energy.

Ah. No, that's just Newtonian gravity, which is the low-energy weak-field limit for general relativity. In general relativity, energy (density) is the source-term for the gravitational field.
In the classical limit the energy density is dominated by what we call the mass density.

EDIT: Wikipedia link.
Also, for you information and in case you don't think I know what I'm talking about (your last message sortof suggests that), I actually have a university degree in physics. Doesn't make me an expert on everything, obviously, but this is fairly basic.

Which is actually just a big ball of rest energy.

<= First time it actually represents my face.

Append:

"The reason why it just doesn't suit in to my head":
Let's say I encapsulate some gas with a timed ignition in to a ball of steel, take it to space, blah blah- so that I can really measure how it is attracting other objects. The ignition goes, the gas burns(the system remains closed, and accordingly to the "energy saving"(or how is it in English), although the mass decreases, the energy remains same(how can it get away through the steel? Or can it? If so, some other material to encapsulate it, please. Or some other energy matter even, or anti energy or whatever). So.. It's mass reduced, it'll attract stuff weaker. Although energy is the same.

Assuming the rest energy is the thing attracting stuff around, how is it possible gravitation force changed with energy staying the same?

Chemical reactions (I guess that's what you're talking about when you're talking about "ignition") conserve mass (well, except the binding energy of the molecules may change, which you'd in principle be able to measure as a change in mass, but it's absolutely tiny).

No.
The total energy content is the same, therefore the curvature of space-time ("gravity") remains the same.

It's not just rest energy, it's total energy.

I remember the actual flash of insight in science class way back around '71 when a most excellent teacher named Harris Nelson was explaining that since E=MC^2 and the burning of combustibles releases energy, the molecules produced by combustion weigh less than the molecules which went into the reaction. It made perfect sense given that everybody accepted that helium isn't quite twice as heavy as two deuterium (hydrogen isotope) atoms, but the weight reduction was much smaller given the minuscule release of energy released by chemical reactions.

Here's a URL that says the same thing.
http://www.newton.dep.anl.gov/askasci/chem03/chem03534.htm