Quantum Gravity

All of the ideas about the formation of the universe and its demise are wrong!

Well, that statement is not precisely correct, but it means that cosmologists are confused by some current observations, namely, the absence of the discovery of supersymmetry particles, gravity wave discoveries, and confusion about the real expansion of the universe.

The reason why the formation of the universe is in question is because of the Planck Length, which works out to be 1.616229 X 10 to -35 meters. This is incredibly small, but it's the limit to how small anything can be.

It's possible to theorize smaller dimensions, but the reality is that there is a finite limit to how small things could be. In other words an infinitely tiny thing is not possible, at least not according to current physics.

Now, the next part of this idea requires a stretch. If we assume that infinity doesn't exist then it means that a singularity, which is an infinitely tiny point, could not exist. Therefore, the Big Bang was not a tiny point of infinite energy appearing from nothing but rather a Big Bounce, which means that our universe came into existence from the collapse of a universe that existed before it.

It also means that a black hole does not have a singularity at its center but is the result of the collapse of a large star's core that will end up in a bounce that will make it explode. We could call this a Small Bounce; although, I wouldn't want to be near it when it did explode.

Why, you ask, don't we observe these Black Hole explosions? The answer is; we may have but don't realize that's what we're observing. Think of it this way. If one could travel to a Black Hole and approach the Event Horizon, our time relative to most of the rest of the universe would slow down and actually stop. One would not notice this, but if one moved away from the Black Hole one would be in the future. What this means is that a Black Hole would not explode until way into the future.

It turns out that a Black Hole is hot, according to Stephen Hawking, and actually evaporates with time. This is the result of the vibration of atoms in its Event Horizon. Vibrations never slow down unless you could cool something to absolute zero. Atomic vibrations are evidence of heat.

These radical ideas are the result of Loop Quantum Gravity, the theory that unites Einstein's General theory of Relativity with quantum physics. This theory suggests that everything is quanta. This includes space, time, matter and energy. Space, time, and everything is made up of fields, which are how quantum things interact. This is why space is never a true vacuum but is rather alive with energy and particles coming in and out of existence. Quantum physics thinks of space as an energy field. Loop quantum physics extends this into quanta linked together as if a network of finite loops, which are limited by the Planck length.

Think of it this way. Photons are quanta of light in the theory of electromagnetism. Space and time are also considered quanta with finite size by using the same concepts as to how energy and momentum are quantized in quantum mechanics. The relationship between the spacetime continuum and quanta of space is like the relationship of electromagnetic waves and photons. Photons are the way that waves interact. The quanta of gravity are the way that space and time interact. What quantum gravity theory does is to get rid of space and time as being the framework of the world. Space and time are macro concepts of the quantum world. They're what we deal with for being creatures of the macro world. By getting rid of them, quantum gravity is able to reconcile General Relativity with quantum physics.
The problem with all of this is that we can't see the very tiny quantum aspect of reality. We can only see the macro aspects, and they don't look like anything that quantum physics is telling us. Combine this with very difficult math and you could easily see why it's hard to understand.

Loop Quantum Gravity theory is not a proof of everything because it doesn't deal with trying to understand all of particle physics. In other words, it's not a fixed framework system. String theory is based on a fixed framework that everything can be boiled down to very tiny strings. However, it doesn't explain how quantum gravity works and doesn't unify Einstein's General Relativity with quantum physics.

The other main difference between string theory and quantum loop gravity theory is that loop-gravity does away with the extra dimensions that string theory proposes. It sticks with three dimensions and makes time into a quantum. Basically, quantum gravity theory does away with the idea that space and time are continuous, and the idea that something can be infinite.

This is not a new idea. The ancient Greek Democritus postulated around 440-450 BC that everything in nature is granulated and indivisible. His idea led to the concept of the atom before anyone understood what an atom was comprised of.

Keep in mind that Einstein said that gravity is not a force. His General Relativity theory explained gravity as a bending of space-time by anything that has mass. Loop quantum gravity theory gets around this by quantizing space-time and making it similar to how photons are handled in the theory of electromagnetism. Space-time is granulated and connected together in spin-networks by means of loops.

Basically, Loop Quantum Gravity theory tries to explain how things occur and how they interact, not how they are. In other words, it is only concerned about processes. Spacetime becomes a covariant quantum field, which is the primal substance from which everything is formed, and quantum gravity functions in this primal substance.

The math that explains all of this would fill several books. It's way beyond the average person's ability to understand it. This is one of the reasons that most people could care less about these theories. Despite that, many people try to postulate concepts about the beginning of the universe without understanding how difficult it is to explain it. Most true scientists, including those that have developed Loop Quantum Gravity theory, admit that it's nowhere complete and there are many aspects of it that need more work. In other words, no one really understands how the universe began or where it came from.

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