Quantum Theory

The only 'quantum' thing I know about is when I did chemistry. In relation to electron orbitals, and I understood it as the likelihood of a particular electron being found in a particular orbital.

very good now keep going!

One day, there were some funny little atoms. They decided that a great prank to play on the students of tomorrow would be to invent a form of chemistry so difficult to understand, that many would go crazy from the attempt. Unfortunately, they failed because they were too small to make any sort of difference yet because they were so small they unintentionally created quantum physics. That's one of the great paradoxes of our time: did they succeed or fail?

No Clue

It has been rightly said that anyone who claims to understand Quantum Physics and Theory is a fool. Part of the problem is that it is counter-intuitive. You can't see or directly experience whatever it is that makes up quanta. Everything that we think we know about the universe by observing it and living in a four dimensional world turns out to be false, and it's awfully hard to get around that. Virtually the only way to deal with this subject, even on a minimal basis, requires far more mathematical sophistication than almost anyone actually has. That certainly includes me.

The starting point for understanding is almost certainly the work of Heisenburg whose Uncertainty Principle lies at the heart of quantum thinking. Greatly simplified, you may know the position of a subatomic, or you may know its velocity, but you can't know both. In the subatomic world things don't obey the same rules of existence that we expect of the larger world. In that world, an electron might co-exist in two places at once, or travel a relatively great distance with no time spent in transit. There are forces In the sub-atomic world that are totally foreign to our scale of things.

Back in your undergraduate days, you probably learned that electrons are negative, protons are positive, and neutrons are neutral in charge. None of these "things" has real substance being instead a "bundle" of something that we call energy. The nucleus of the atom we now know is made up of many other particles, all of which have strange properties. The means of discovering sub-atomic particles is to cause high-energy collisions between atoms. As the 20th century drew to a close physicists had a pretty good grasp of the insubstantial constituents of the sub-atomic world, and mathematics had progressed to the point where the forces that operate in the sub-atomic world were reasonably well understood. Events where Quanta behavior are observed, and there are some, render results that are baffling.

I'll give here only one example, and leave it to you the reader to find others. You have a box divided into two sections with a small hole in it. When you introduce one photon into the box it will go through the hole in a straight line casting a single spot on the opposite wall. That's reasonable, right? Now we put a second hole in the dividing wall and release two photons. What do we get? Two light spots on the opposite wall? Wrong. What you get is an interference pattern. What if you only introduce one indivisible photon? One spot, or two? Both are wrong, you still get an interference pattern. Its as if the photon behaves in accordance with all the probabilities available. Now I know that doesn't make a whole lot of sense to those who live in a world where only one probability path at a time is possible. Welcome to the Quantum World.

Einstein's physics have provided a wonderful and accurate description of how the macroscopic universe operates. Using Einstein's equations, plus the work done by his able successors, we can predict pretty well what effects to expect given a cause. Unfortunately, the laws that govern the macroscopic universe do not appear to apply to the extreme microscopic universe. At very small scales, Quantum Physics/Theory has proven to be just as accurate in describing what happens and giving us tentative reasons why things happen as conventional physics are when applied to the macroscopic universe. The Holy Grail of modern mathematics and physics is to find the Unified Field Theory, or the Theory that Explains Everything. We expect elegance, we expect that ultimately a single set of equations will reconcile the physics of the very large with the physics of the very small. That is the task of current work in Quantum Theory.

Currently folks are working at levels that are almost unbelievably small and insubstantial. This is the Plank Scale. To help you visualize how small this is, imagine that one Plank Unit is about the size of a full grown oak tree. Relative to our scale of things, that oak tree would be much, much smaller than the distance from Albuquerque to the most distant "edge" of the universe. What exists at this miniscule scale, and why should we care? Well, theorist hope to find in that of the almost infinitely small the fundamental laws that govern everything. At this very small scale, we believe that "things" are made up of multidimensional figures, that interact in strange ways. It is impossible to imagine how multidimensional "things" interact because all we know are four dimensions, but mathematics can and does work. It's just that no one has been able to figure out how to test the mathematics and their predictions about what happens in such a foreign "place/time/direction".

O.K., that should get you started. However, if you aren't a teenage math prodigy, its probably too late and too difficult to really understand. Oh, how I wish that I could follow the equations that are being worked on today. One of my dear friends, and Grad School companions, is one of those guys who are thinking this stuff through. Bob was one of the bright boys at JPL, but now he's waiting around to die of a bad heart. "Don't write anymore", he's said, "I want to use what time I have left to work on some mathematical problems".