please answer question no 2 only. provide reasonable explanation

1* Are photons SD? 2" Some scientists treat the universe cold spots as a potential collision with a different universe (following the theory that the big bang was a part of many big bangs). Building on top of that hypothesis, what would happen if a universe with 00 gravity collides with ours, and we inherit some of its physics (lets say, iannite gravity). Can you describe the chain of events? Will all plants and stars (assuming existing mass + infinite gravity) become black holes? Will all become a single black hole? if our entire universe becomes one black hole - does the big bang gets recreated? 3. Assuming cold spots are indeed collision points of universes, does that mean the space where the multiverse exists has gravity? a