Saturday, August 2, 2014

Metaphysics Is Physics--Just Think About It.

We tend to think of thoughts as nonphysical, nothing but the results of electrical activity in our brains. But are they all nonphysical? What about atemporal existence?  As I explained in this post, it’s a thought that exists in itself because it’s conscious—it thinks itself. I say that makes it physical. as solidly real as any other thing you can think of, and certainly more so than you or me, since it’s immortal and we’re not. By “physical,” I mean exactly what you’d think—stuff you can touch and feel.

Am I saying that all thoughts are physical, then? Not at all. Thoughts that are generated in our brains certainly aren’t. But atemporal existence, as well as all of the thoughts that exist within it—or all of the thoughts directly implied by it (thoughts are logical entities)—can be thought of as physical things. In that same previous post, I showed how the thoughts directly implied by existence come in a logical progression that proceeds in steps, with the number of thoughts expanding at each step. I pointed out that the steps look like time and the ensemble of thoughts looks like an expanding space.

Now comes the magic. All we have to do to get the physical universe is to say that the steps are time and the thoughts are space. This is another duality covered by the principle of complementarity. These primordial thoughts have two aspects, one logical and one physical. You can think of them either way, and physically, they are the stuff the universe is made of. The temporal universe is emergent from the collective physical behavior of these primordial thoughts. Suddenly we’re not talking metaphysics any more. Now we’re doing physics. This is what I meant when I said that physics makes progress when it pushes back the boundaries of religion and philosophy, when we realize that what we thought was metaphysics is physics after all. My physics model shows exactly how this temporal universe arises from atemporal existence. I’ll begin to explain it here.

If we’re going to do physics we have to use physical terminology. The thoughts the universe is made of I call spacetime points. Physically, we don’t know anything about them, but we can assume that as physical entities, they are identical. They all look the same. However, they’re not all the same entity, so there must be some way to distinguish one from another. Obviously, we can label each one with the time step at which it is generated. Then, within the group of points generated at that time step, we can assign each one a different relative position. Finally, each one could be oriented in a different direction relative to its neighbors.

Nothing tells us what numbers to assign to these properties of points. They could be anything that’s possible. Now, we know that in this kind of situation in this universe, quantum mechanics takes over and assigns some probability measure to each possible value. That’s called the wave function. When one of these properties is measured, one value is observed. The wave function is said to collapse.

In other words, spacetime as we know it is a quantum field. The quanta of the field are the spacetime points, which are quantum entities or quantum states. The properties that distinguish one point from another are quantum numbers. We know from long experience that position is a set of three real numbers, time is a real number, and orientation manifests itself as an angular momentum, which is called spin. Spin is quantized in multiples of h = h/2π, where h is Planck’s constant.

Notice that this picture of spacetime is very different from the current paradigm. There are only discrete points, nothing else. Time is discrete, not continuous. There is no continuous three-dimensional space in which points exist, and there is no requirement that between any two points with different positions there must be a point with an intermediate position. The quantum numbers of points are intrinsic. They are labels. It’s always been accepted that spin is an intrinsic quantum number of particles. Now we see that all three quantum numbers are intrinsic to points, which are like protoparticles. So now we have a quantum field we call spacetime, which consists of discrete quanta called points. The points look identical but represent different quantum states by virtue of having different quantum numbers—position, time of creation, and spin.

As I explained here, existence is really three thoughts in one—observing existence, observed existence, and the relation between them. So, physically we start out with a single point that implies three points. Any combination of thoughts results in a new thought, so any combination of points creates a new point. From three points we get at least seven, and in general, from N points we get at least 2N – 1. At each step, N of the new points are copies of the previous step’s N points, and the rest are entirely new. All of the 2N – 1 points, even the points that are copies, have random quantum numbers. In particular, the position of any copy is different from its predecessor’s. These are quantum fluctuations, and they make all of the points seem to be vibrating madly.

Points would keep multiplying and vibrating and never do anything interesting were it not for the law of spin and statistics, a quantum mechanical principle that I would nominate as one of two fundamental forces in nature, the other being symmetry in its various manifestations. If you have a system consisting of two identical points and nothing happens to the system wave function when you switch the points, the points are bosons. If you put them in two boxes, there is a higher probability that they will end up in the same box than in separate boxes. In other words, identical bosons tend towards the same quantum state (the same quantum numbers). On the other hand, if you switch the two points and the wave function changes sign, the points are fermions. There is zero probability that identical fermions will end up in the same state.  Bosons are said to obey Bose-Einstein statistics and fermions are said to obey Fermi-Dirac statistics. Experimentally, bosons are found to have integer spin (h, 2h, …) while fermions are found to have half-integer spin (h/2, 3h/2, ...). This is called the law of spin and statistics.

Are spacetime points fermions or bosons? That is undetermined, so quantum mechanics tells us to expect that on any observation, any given point has some probability of being a fermion and a probability of one minus the fermion probability of being a boson. There aren’t any other possibilities. Thus points are mixed states, quantum superpositions of a fermion state and a boson state. On any observation (or equivalently, any step, or any time tick), spacetime is a quantum field consisting of fermionic points and bosonic points.  It also looks exactly like two quantum fields, one consisting of only fermionic points and one consisting of only bosonic points, except that these fields are coupled because every point is a mixed state and therefore sometimes in one field and sometimes in the other. One field or two? You can’t tell the difference, so from now on I’m going to treat spacetime as two coupled fields. Coupled means they interact; they influence each other.

Now we’re ready to do some real physics, but I think I’ve given you enough to think about for now. To be continued.