The most celebrated scientists, quantum mechanics experts, astro physicist are asked this question. What happened before the Big Bang, was there a Big Bang? Can the universe spawn itself through some time warping? Are we in one of multiple universes? These questions can really fascinate, and drive people to spend decades to find an answer. I have thought about this and other aspects of physics, quantum mechanics for decades now, so maybe my answer is interesting..
At one time I believed the vacuum was empty. But then I read about quantum fluctuations in the vacuum, so it was not empty, but rather a seething medium from which particles could pop out, to quickly disappear. The Cazimir effect proved this was true. Puzzling reality.
I skip the part where I become aware of the gluon storm in every neutron and proton, although it made me think about mass, and how it may stem from redirecting many particles that travel at light speed (which gluons do afaik). That takes time.
Then the gravitational wave detector (LIGO) showed space was like a chrystal, or a piece of steel with regular structure, because you could send a vibration through it over vast distances. This send me on a search for scientists that looked at it that way. Many asked is space-time a lattice. If spacetime is some kind of lattice then everything is a perturbation of that lattice, so particles are waves propagating in it, photons are a special case of propagation of deformations.
The problem with the lattice view is that you can’t assume some rigid structure, even though it is obviously there to transmit gravitationaly waves. Quantum dynamics exists, its very effective in prediction outcomes. So where to go from there? Thad Roberts who I learned about in my lattice phase does no longer seem interested in the underlying structure or nature of what he calles a quantum liquid, but his quantum liquid does help him explain all of the constants of nature. All of them. This is quite a thing. He can’t at this point explain how his findings help do stuff, he just found a way to link all the constants of nature and one of his assumptions to do it is that reality is in its fundament a ‘quantum liquid’.
The idea that particles are whirls in some quantum liquid explains the wide range of them, and how it is possible so many new types of whirls show up when you smash two known whirls together at tremendous speed
I think Thad found indeed a minimal shape (hyperbolic figure eight knot) that shows how this quantum liquid can bring about all the constants of nature, but that this shape, like a torus is never seen in its pure form, but is part of flow patterns of the quantum liquid. For his purposes you can assume the liquid consists of balls with the diameter of 1 Planck length that flow along each other without any friction. Flow of the liquid can thus separate space, because in order to flow without fiction they have to repulse each other quite strongly. This repulsion is one of the basic theories I have about the fundamental makeup of the universe. I proposed to him to make a universe computer, by building a box with styrofoam balls that have been charged statically to see if his flow patterns emerge. I may do it on my own just to intrigue myself.
The problem with balls with a Planck length diameter is that they will have a surface and inside, and have to repluse somehow in what way etc. etc. Its just another Matryoshka doll layer and it solves nothing, while it does seem we landed on a level that should pretty much explain everything. Its also clearly 3 dimensional, which is unlikely to be true. So how to solve this?
One thing to consider is : We don’t know about continuity on this level, which is quite a way lower than the world of quantum mechanics, in which continuity is also impossible to prove (its all statistics). We would not know if time stopped and restarted, we don’t know if parts of space away from us are moving slower or faster (as the light passes true it always at the same speed). There’s many things we can measure because the measurement is itself a quantum phenomenon. So we do not need to envision pure Planck spheres at the basis of our reality even if they seem to exist.
So the behaviour of stacked spheres or spheres occupying a space can be achieved in other ways than using spheres. It can be a result of vertexes and edges self organizing (a vertex can be where two edges meet, so technically you only need edges). Say you have a point (vertex) with one edge, and the edges repulse each other, or try to occupy as much space as they can, then one edge will move around the vertex and the other end of it, will cover a surface of a sphere. If it where two it would be easier, and both can cover the same sphere, but always opposite so with half the period (although the sphere surface is technically infinite). This introduces the Vertex and Edge view of the quantum liquid Planck Sphere.
Now if you say that edges repulse each other, that they can stack if forced to, that they are always trying to unstack and take the maximum amount of ‘space’ by twisting and turning around the vertexes, you can imagine some interesting things. First stacked spheres are a graph of vertexes and edges where the edges maximally repulse each other under the existing ‘pressure’.
Beware we are not in a space of any dimensions. This is because there is never any reliable extention of anything as all there can be is a series of edges (all of 1/2 Planck Length) which can bypass vertexes that are occupied and extend quite a distance. The graph that forms is like a huge mess of tense wires, but most of them are very short. There is enormous ‘energy’ in this non-dimensional static cobweb because the edges are constantly moving to places where they can be unstacked and farthest away from other edges. The way these edges move when linked must be interesting too. You migth as well assume that the end points repulse less so they end up connecting.
Now Thad Roberts believes that the quantum balls move along each other in such a way that they create a barrier, a boundary, but there is no explanation why that would be. But if the balls are vertexes and edges, then the connectivity between vertexes and edges determines whether it can be a ‘ball’ or its just a surface connection. And if the edges are oriented in the same direction in parallel, they will repulse each other and not seek to connect to each others vertexes. Thus the graph can develop boundaries and the graph dynamics on either side of those boundaries may never connect with an edge.
You may think “When is he going to answer the why is there something instead of nothing” question, but I already did. The volume of a vertex is zero, the volume of an edge is zero. If reality is made up out of vertexes and edges then if you stack up all the edges the volume would technically (and really) still be zero. So a stack of infinite nr. of half Planck length edges occupies -no- space. So even on the most fundamental level, without the behavior of these edges, their repulsion, there would be nothing.
As soon as you say “any edge wants to ‘unfold’ around or ‘slide out over’ its end point to occupy more space” and “any edge will repulse any other edge” the game begins. That moment is the Big Bang. Within picoseconds a graph develops that looks like an ocean of Planck Spheres, but as their makeup is one level down and the degress of freedom are infinite the dynamics of the spheres or the graph will never rest. On top of that it must be that edges are tremendously stacked to begin with. There is enormous ‘pressure’ for new Planck Spheres to form, new space from nothing. This never stop, it has not stopped.
At a certain point boundaries show up, become possible, this is when particles and the laws of nature start to assert themselves within the quantum liquid. But this is only the beginning. There should be a relationship between the un stacking or stacking of edges and time and space, I don’t have my thoughts on that ready atm. But the above may have been entertaining enough for now 😉