It’s my understanding that very early in the history of the universe that all 4 forces were united before things cooled down enough for gravity and the other forces to eventually separate.
My question is exactly what exactly does it mean by separate? Would the 4 forces behave exactly the same way as they do now or would they behave entirely differently such as gravity having no effect until diverging? Or is just a mathematical method to describe all the forces as a single equation? Or something else entirely?
How the forces act depends on the energy scale you’re at. At low energies, for instance, the Weak Force is (unsurprisingly) significantly weaker than the Strong Force. But as energies increase, the Weak Force gets stronger, and the Strong Force gets weaker. So eventually, one would expect that you would get to an energy scale where they have the same strength.
So far, this is pretty uncontroversial, among physicists. Nobody’s sure of all of the details, since we’ve never reached that energy scale experimentally, but I think pretty much all particle physicists agree that there’s some energy scale where the Strong and Weak forces unify, as well as more or less agreeing on where that energy scale is, and the qualitative implications of said unification.
What’s more controversial is gravity. Gravity may or may not ever unify with the other forces, and if it does, it may or may not be at the same energy scale. I think that the most popular guess is that it does eventually unify, but not until you get up to somewhere in the vicinity of the Planck energy. But that’s just a guess.
As I understand it, at high enough energy (Planck Energy?) the four forces have the same strength over the same range…the are all essentially the same force.
How could that be? Same strength sure – maybe whatever that means, but does an electron ever interact via the strong nuclear force? And if it doesn’t what does “essentially the same force” mean?
I’ve seen graphs like that, but force depends on some property (mass, charge, something, somethind else), and distance plus maybe other things. When they say the forces have the same strength what does that mean. The same electrostatic force between two electrons and two protons the same distance apart is about the same. The gravitational force would be .0005^2 times smaller between two electrons than it is between two protons.
And I don’t believe electrons feel the strong force at all so at least for electrons the strong force is the weakest.
I may be mistaken, but I think that the cloud of virtual particles around the electron includes particles that feel the strong force, and the cloud of virtual particles around the gluons include charged particles, so there could be an interaction between an electron and an gluon, even though a “bare” electron wouldn’t feel the strong force.
Is part of the problem in visualizing the unification of forces due to the fact that we speak of various particles even though their fields are more fundamental?
I think you’re right but I don’t think we can speak accurately about this level of physics without using equations - any description in everyday English is going to be incomplete/misleading. Unfortunately (as the fact that I used everyday English above suggests) I’m not up enough in the field to do anything but talking about it that way, so all I can do is hope that my suggested description is helpful and not too misleading.