There is positive energy of the matter/energy and there is the negative energy of the gravity which is a consequence that space and time are warped and they perfectly balance such that they sum to zero. And since they sum to zero, the creation of space and time from nothing does not violate the law of conservation.
How do you know that spacetime is warped? It's a good model to explan gravity, but it could be an attractive force between two masses. I've read of experiments to show gravity could be different due to the surface at various points on Earth.
I'd suggest we look in the bible for a comprehensive description of gravity. Who needs experiments when ''the gods did it'' answers all questions.
There are no thought experiments to show the creation of spacetime (along which our three dimensions would come with). We can't have quantum mechanics without spacetime. Once that is created, then we have the three dimensions and a beginning. What people are arguing about is what came about after this singularity. There was nothing and then something or beginning. That's the true singulairty. We call this x, y, and z axis of space our universe and it had nothing so it was dark. The atheists have to have this nothing as the beginning for their singularity. Thus, some assume that time and space were always there. Otherwise, it's difficult to explain the beginning of spacetime just happened in my opinion.
So the singularity of infinite temperature and infinite density couldn't possibly exist without spacetime. That nothing state of no spacetime is difficult if not impossible to overcome.
The other thing
ding wants is GR and the warping of space. I agree that that's what large masses do, but is that the only explanation? I think both smaller and larger masses still attract each other as our bodies feel that with the Earth. We see that with the apple falling from the tree to the ground. Is
ding going to tell me that with GR if I throw the apple that it will curve around the tree that it fell from before falling to the ground?
So with quantum mechanics, that brings up the quantum entanglement or action at a distance topic. We still don't have good explanation for it, but maybe the best one lies with Bell's Theorem. His theorem basically states that it is just a matter of probability that the spin of one photon determines the spin of its entangled pair. He states the times when they aren't the same or not equal will show itself. When we do the experiments to show this, we find that his inequalities do not hold. Einstein thought this was the spooky action at a distance and thought there was some kind of faster than light communications. Instead, Bell thought one of his assumptions were failing in that of locality or physical reality was failing. With QE, it was locality.
Bell's Theorem helped solidify the idea that the interactions in quantum physics between entangled particles are instantaneous and non-local in nature.
www.thoughtco.com
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It's a simple theorem, but not easy to explain in action with quantum entanglement. It lead to Einstein and his people thinking of faster than light communications. One can see it in action without the entanglement or measuring being done in the following youtube. Sorry, it's kinda long. Basically it shows the failure of Bell's locality without the QE experiments: