"The counterfactuals that matter to science and physics, and that have so far been neglected, are facts about what could or could not be made to happen to physi

"The counterfactuals that matter to science and physics, and that have so far been neglected, are facts about what could or could not be made to happen to physical systems; about what is possible or impossible." On the contrary, if I had to describe theoretical physics in a nutshell, I would say it is entirely about what is impossible. Pick any physical law or theorem. I cannot exceed the speed of light. I cannot globally decrease entropy. I cannot measure a force between two static electric charges in vacuum that deviates from the Coulomb force law.