I've been keeping my brain occupied on long drives by trying to come up with a theory of everything, because... why not?

My current pet hypothesis is that all fundamental particles are sort-of like tiny black holes, and that the space-time distortion caused by black holes is precisely the same thing that ordinary matter causes. All matter and energy are space-time distortions, which is why mass-energy bends space time. It's not a secondary effect, the bending is what everything is, not a property that things have. (This is essentially just a variant of Kaluza Klein theory, or others like it.)

Particles are kept apart by their spin, same as in well-established physics. Matter is still mostly empty space, same as normal.

In this toy model, neutron stars are like a boba tea, with the black holes of particles close-packed but still not touching.

When forced into forming a black hole, the event horizons of individual particles begins to merge, forming a "super-particle" that expands out. When fully-formed, the black hole is hairy, with a very dense packed crust of still-separate particles layered over a very lumpy surface, inside which there is... nothing. Not even space-time. The surface is where space-time ends.

It's like... imagine if we lived on a knitted jumper or a space-time like woven cloth and could only follow threads. If someone were to poke a hole in the weave with a finger, pushing aside the threads, then it would be meaningless to ask what threads are inside that hole. There aren't any. The "weave space" doesn't extend into the hole.

This simultaneously satisfies a long list of requirements gathered from modern physics:

1. Black hole formation is a gradual, continuous process at both microscopic and macroscopic scales. This model can start all the way down with the first pair of particles that got squished together and then can be extended all the way up to something the size of a star.

2. Black holes are hairy instead of smooth, satisfying thermodynamics and quantum information theory.

3. There's no paradox of what happens when you go past the event horizon. There's no singularity. The event horizon is a surface, essentially just a highly red-shifted neutron star. Hitting it is the same as hitting a neutron star. You do not go through. You get squished.

4. There's no need for complex maths to explain black hole evaporation. In a sense, black holes don't exist, they're just a very time-dilated neutron star, and their evaporation is just an ultra-slow-motion explosion of a neutron star.

5. A well-established theorem is that many properties of a black hole grow in proportion to their surface area (2D), not their volume (3D). This theory matches that. There is no volume, there's only the surface. The inside doesn't exist. When approaching from normal flat 3D space, space gradually becomes fractal (2.x dimensional), smoothly transitioning to a 2D space, which is the event horizon.

6. It is time-reversible. Seen backwards in time, "fingers" of 3D space invade into the event horizon, splitting it up into smaller and smaller chunks that bud off to form small, stable spheres that evaporate away. These are the particles that made up the black hole.