Thursday, July 2, 2009

Weekend At Bernies 2: Electron Boogaloo (3 of 5)

In my last installment, I described what I, for this series of posts, am calling the Electron Boogaloo - a dance where a tiny particle is not just Here or There, but in weird dance of Kind of Here and Kind of There, and Kind of Nowhere, and Kind of Everywhere At Once. I described the dance hall of that dance using a scenario known to science as the Double Slit Experiment. I also included a youtube video that explained the experiment and its bizarre implications about reality at the quantum level.

Quantum particles, when not being observed or measured, do not like particles; they do not act like tiny billiard balls that simply are, and are fully, actually, definitely present, in one place, doing one thing. When they are not being observed, quantum particles are not particles in the original sense of the word. They are whirling waves of probability, in which all the possible locations and states of a particle interact with one another the way crests and troughs of waves interfere with each other. They are mysterious clouds of all the things they Could Be. Instead of just actually being one thing and not another, in one place and not another, doing one thing and not another, moving in one direction and not another, quantum phenomena are, when unobserved, in all their possible places and states at once, moving, not This Way or That, but rather This Way and That, at the same time! They are not just Here or There before we look to find out where they are. They are both Here And There until we look - until we, by observing the phenomena, by taking a measurement - collapse the wave.

This is a very counterintuitive view of the ultimate reality of things, and thus most people recoil from it intellectually. This is a problem, because quantum mechanics is irrefutable and indispensable. Everything electronic uses the quantum effects with the Alice-In-Wonderland weirdness that goes with them. Anyone who doubts this can take up this challenge - tell me how a tunnel diode works without invoking an explanation that defies common sense.

I have another way out. Quantum theory is true, but it is not the ultimate reality of things. Atoms are not more real than the objects of our sense experience, but less. It is not the case that rocks, trees, pigeons and people are simply piles or collections that come about through the collision and fusion of the tiny particles that are the ultimately real things. On the contrary, the rocks, the trees, the birds, the fish, the dolphins, the dogs, the people, the planets and stars, are what are truly real. They are not composed of particles in the sense of being aggregates put together mechanically out of their smallest component pieces. They are composed of particles in the sense of being divisible into them. There is a difference. The particles derive their reality from the real things of our everyday lives, not the other way around. They exist, to be sure, but their actuality is compromised. They are not fully real. They are quasi-real. Their existence is foggy, nebulous, Not All There. They do not enjoy the same degree of objective, observer-independent reality that are enjoyed by us, or by the objects of our everyday experiences. We are more real than our protons, neutrons, and electrons. It is not the case that we do what we do because our smallest bits are doing their thing, in obedience to the laws of physics. It is the other way around - we make our choices, we decide what to do, and move ourselves into action. As a consequence, our bodies, which are divisible into particles, move those particles in motions which, due to the uncertainty of quantum mechanics, are not in violation of the any deterministic laws of physics, because on the level of the micro-particles, there are no deterministic laws! Causality, when applied to human action, is not from the bottom-up, but from the top-down. We are wholes, not mere collections of parts, and our actions are holistic. We move our parts, rather than being moved by them. Epicurus was right that our freedom is related to atomic swerve. But he was wrong about the motive direction of causal power. Our free actions cause the particles in our bodies to have their particular Epicurean swerve. Rather than being grounded in and caused by that swerve from the bottom-up, they are the source of our atoms' particular "random" swerves from the top-down.

I’ll never forget when I was in class attending my graduate seminar on the Philosophy of the Human Person, and one of the people there opined that, if there is such a thing as a soul, we should expect to see some of the physically determined motions of some particles in our body (in our brain, presumably) veer off their otherwise pre-determined paths, and sort of Do Their Own Thing. I do not recall anyone labeling that intuition as such at the time, but I do not hesitate to do so now - that is the classic Epicurean Swerve intuition, the clinamen.

John Searle said something similar in his 1984 Reith lecture:

In order for us to have radical freedom, it looks as if we would have to postulate that inside each of us was a self that was capable of interfering with the causal order of nature. That is, it looks as if we would have to contain some entity that was capable of making molecules swerve from their paths. (Minds, Brains, and Science; Cambridge: Harvard University Press, 1984, p. 98 - Well, not necessarily molecules, and Searle knew that. Earlier in the same lecture, he tries to flippantly dismiss such a swerve on the quantum level - unsuccessfully in my view)

I held my tongue in class that day. I didn’t want to be the only person in that class to bring up quantum physics. I knew that it would make no impact - it would only peg me as an insufferable know-it-all. They wouldn’t get. I don’t even get it. Who does? It’s too crazy! But I knew he was wrong. We should never expect to see anything of the sort, because nature does not allow us to see anything on the quantum level with that kind of precision. The Uncertainty Principle forbids it. Mother Nature has a kind of basic, primordial modesty about Her. No matter how badly scientists want to look up Her skirt and see Her Goodies, they will not succeed. She’s keeping her Secrets. Laplace’s Ideal Observer will never exist, at least not in this physical world. Maybe God could theoretically know all the positions and momentums of every particle in the universe, but I am inclined to doubt even that - until the waves of the various particles collapse, there is no one totally real thing on that level for even God to know.

The fact that, at the level of quantum phenomena, there is an ineliminable statistical indeterminacy, means that there is a lot of room leftover from the gaps in physics for possibility of active influences from invisible, non-physical agents, i.e. souls or spirits. The soul fits perfectly in the quantum causal gap. The indeterminism at the level of the quantum does not prove that there are such things, but that is unnecessary. The point is, we already know that we are free agents capable of introducing new, spontaneous, unprecedented causal chains into the physical world every time we make a new decision. The only thing that ever made anyone doubt that was a commitment to Materialism and the Laplacian Determinism that it entailed. Quantum physics has killed that Determinism. It is no longer a viable natural philosophy. Since deterministic Materialism is dead, there is no more barrier to accepting the prima facie evidence of our own obvious and self-evident liberty of action (which we cannot, in practice, consistently deny). So with no more reason to doubt that which we cannot help but believe anyway, we can accept it as true, along with what it entails - that there is more to us than our physical bodies. We are souls, too.

Here is the link to installment 4 of this series:

Weekend At Bernie's 2: Electron Boogaloo (2 of 5)

To see electrons do their boogoaloo, you need a special apparatus for them to use as their dance hall. You need a device that can fire electrons in streams, or in tiny bursts of single, isolated particles one at a time. You need a box with a hole on one side for the electrons to shoot through into the box and a pair of slits on the other side through which to leave the box. You need a wall on the other side of the box (the one with the slits). You need the wall to have a special material fastened to it that will react to the presence of electrons and make the impacts of electrons on it visible.

The dance takes place in steps. The last step is the really dramatic one. First you cover one slit - either slit will do, and fire up the electron gun. It doesn’t matter whether you have the gun set to fire a steady ray of electrons in a constant stream of bombardment, or to only release one electron intermittently at intervals - it will show the same thing - in the latter case it would just take longer for the individual electron impacts to form the pattern. The pattern when one slit is covered is a single band (the shape of the one uncovered slit) on the wall beyond the box. The electrons, whether in a stream or all alone, act like individual particles, or at least the wave characteristics are not detectable during this first step of the dance.

For the next step you uncover the slit that you had covered and fire the electron gun to send out a stream of electrons through both uncovered slits. If electrons were merely particles, you would see the two-slit pattern form behind the wall, but that’s not what you see here. You see several bands, the ligher, weaker ones closer to the outer edges, the strongest ones toward the center. That is an interference pattern. It shows that the stream of electrons is propagating like a wave of electrical energy. When waves are broken up into sets of waves as they bisect to pass through the slits, the sets of waves interfere with each other - their crests and troughs cancel each other out. In between those cancellations there is a richer degree of interaction. The net result is an interference pattern more complicated than the behavior of single discrete particles confined to a definite location or moving in a definite trajectory.

Ok, you might argue, that may be interesting, but that doesn’t mean individual particles do that. We fired a stream of many such particles, so perhaps it is no surprise that they would interfere with each other and move in a wave. What would happen if we fired single electrons intermittently one at a time through whichever of the two slits each would happen to go through? (Note for later that there is no causal explanation, no physical fact, known or unknown, that determines which slit an electron will exit the box through). If electrons were merely particles then surely now all we’ll see is two bands slowly form from the accumulation of marks from individual electron impacts.

Third and final step - intermittently fire individual electrons through the two open slits and see what happens. So what happens? Does a two slit pattern form?

No! An interference pattern emerges again! How can that be? It is only one individual electron (presumably) going through only one of the slits at any given time! What could be interfering with the electron if not other electrons in a stream? What could be causing the wavy behavior of an individual electron?

The electron is, in that instance, a wave interfering with itself. And what is interfering with what? The answer is that different possible states of the electron are all co-existing in a strange, foggy quasi-reality of less than full actual potentials. The possibility that the electron goes through the left slit is interacting with the possibility that it goes through the right slit. In a very real and valid sense, the electron, even as a single particle, goes through both slits at the same time! In another sense, it does not actually go through either one. In fact, in a very real sense, according to the equation governing subatomic wave collapse, the electron does not have any definite position or single trajectory until after it impacts on the wall and is thus observed and measured.

That is the Electron Boogaloo - a dance where a tiny particle is not just Here or There, but Kind of Here and Kind of There, and Kind of Nowhere, and Kind of Everywhere At Once. The dance hall scenario is known to science as the Double Slit Experiment.

Check out this video on youtube. (url link here: ) It illustrates what I have said, and also adds an important point I have left unsaid, simply because it is unbelievable. It is true, but you won't believe it. You can also click the image below:

Below is the link to installment 3 of this series: