Light has energy and therefore has gravity from general relativity. But it still puzzles me.
Perhaps you can help me out.
Consider the early universe when matter and anti-matter still existed. Supposedly the Higgs symmetry was still the rule, so there was no mass. But there certainly was gravity. Otherwise the universe would have blown itself aparet from the first. OK so far.
But the anti-matter combined with almost all the matter, something like 0.99999999 of it (I never have been able to pin down that number exactly).
Still OK. Energy did not change and mass not yet invented, so to speak, by Higgs.
But now the paradox. The 0.00000001 uncombined matter, the very small amount that did not become light, today has an Omega of 1/3 (mostly dark matter) and dark enegy has an omega of 2/3.
What happened to the gravity of the energy that went into all that light. When first formed it must have had an omega of 0.9999999- right? And the universe had to be flat, or close to flat to keep expanding. The light is massless but not gravityless. It's still energy. There is still 9999999 times more photons than matter particles in the universe. That is the paradox.
Furthermore, scientists ignore the omega of the energy that is in the total number of photons in the universe.
So either GR is again wrong (first wrong concerning EPR paradox) and photons have no gravity, and our universe exists (has not immediately recollapsed) or
OR, no alternative.
But then how did the universe expand it the first place with all that extra matter and anti-matter around. Maybe because it had no mass yet. Maybe Higgs is the god particle that kept the universe from being blown apart by creating mass. GR again wrong.
I'll have to look up how much the universe had to expand in order for the Higgs symmetry to break. Any ideas?