Some people suggest the idea of a multiverse with each universe having a unique set of laws of physics governing it, but not many delve deeper into this. I was wondering if it was even possible to imagine a universe that is different to ours in this regard.
The universe could share some of the laws from our universe yet still be different enough that it is not a matter of just tweaking a few digits of the gravitational constant or the speed of light. Also the universe with those set of laws should be able to sustain itself through the same period as our universe has been so far, meaning it shouldn’t implode or instantaneously cease to exist the moment it is born.
Is it even possible to imagine this? If not, is this due to us having become so accustomed to the logic of our universe that we cannot come up with any such idea that does not exist here, or is it just that our universe happens to be the only possible one to exist, at least while maintaining the harmony between each law of physics and avoiding any paradoxes to occur?
My partner is pursuing their PhD in Philosophy and studies history and phil of science and has dealt with this question a bit, so I’ll take a stab from that perspective.
My answer will rely on the possible worlds framework (a la Lewis) along with a tiny bit of knowledge about Newtonian mechanics.
Is it possible to imagine our world with different physics? Yes. Prior to discovering special relativity and quantum effects, we had newton’s Classical Mechanics, which was able to precisely and accurately describe and predict the movement of bodies in Euclidean space. So, if we can imagine our physics without the complications of curved space and quantum effects, we can imagine our world with an alternate physics that has been somewhat rigorously tested.
Additionally, we can easily imagine the world without the curvature of space and quantum effects (which should be clear by the fact that it’s not too long ago that we thought that was the best picture).
Classical Mechanics offers a working physics that just didn’t turn out to be correct in our (curvy) world. However, relying on the possible world’s framework, it would be easy to stipulate a possible world where Newtonian mechanics was true, or even a possible world where physics shifted from one set of laws to the other.
If we believe the evidence that physics could be otherwise, we might conclude that the laws of physics are relative to a world and a time (and, importantly to metaphysicians, not more fundamental than those two things).
I think a working physics lacking space-time or motion might be impossible to imagine.