Following my physics network theory. A change of matter configuration. Would be similar to convergence in machine learning. My speculation is that the atom network updates depends on light as the parameter, w(i) values in the layers. So because you have something like entanglement. I speculate that entangled light are involved in update changes that lead to fusion. Since it would make the update ?algorithm possible.
So I guess that fusion in the sun is aware of the cold space around it. Since some light leaves the big network and you have spooky action at a distance revealing instances of ?surrounding potential differences.
So its the light that adapts the atom network for fusion.
This would mean that the fusion reactor needs a transparent window to a colder outer surroundings.