Tuesday, July 20, 2010

Superposition and Eternity

The world of the quantum is a very weird place. In that world it's possible for particles to move in opposite directions at the same time, it's possible for them to exist in more than one place, and more than one state, at the same time. In fact, in some interpretations, particles don't even exist at all until they've been somehow observed. It's all very bizarre.

This article in New Scientist gives us a hint of the weirdness:

Take the simple process of measuring the spin of a photon [a particle of light energy]. Thanks to the strange nature of the quantum world, it can actually be spinning in two directions at once, a phenomenon known as superposition. When we use a detector to measure the spin, however, the superposition disappears and we register a spin occurring in one direction or the other.

Quantum theory does not explain why this happens. "We don't really understand the measurement process," admits Stephen Adler at the Institute for Advanced Study in Princeton, New Jersey.

If you want to know how little we know, ask a roomful of physicists what goes on when we measure a particle's properties. All will be able to calculate the result of the measurement, but the explanation they give will differ wildly. Some will tell you that new parallel universes necessarily sprang into being. Others will say that, before a measurement is performed, talk of particles having real properties is meaningless. Still others will say that hidden properties come into play.

Researchers fire a single quantum particle, such as a photon, towards two apertures in a screen. Common sense says the photon has to go through one aperture or the other. However, as long as you don't measure which aperture it went through, something remarkable happens.

At a screen on the far side of the twin slits, an interference pattern [an interference pattern is a series of light and dark bands that are formed by the interaction of two waves] forms. This can only occur if the photon goes through both slits at the same time and interferes with itself. In other words, as long as nobody is watching, the photon exists in two different places at once.

A measurement changes everything, however. If you set up the experiment so you can see which slit the photon goes through, the interference pattern disappears; the photon will have gone through one slit or the other, but not both.

This all has, I think, interesting metaphysical implications. Suppose it is true that we have immortal souls. Suppose further that our existence beyond our physical death occurs outside the temporal world, i.e. we exist in a timeless realm in which the past, present and future of this world are all in our present.

If that's a possible state of affairs then it follows that our deaths, which are for us still future events, have already happened for those, like our ancestors, who have already died. Indeed, for them all events which are still in our future are in their eternal present. This means that for them we have already died and could be experiencing union with them now even as we are living out our temporal existence on this earth.

In other words, like quantum particles in a state of superposition, we could exist in two different states (or "places") at once.

Not only does this suggest that we could already be experiencing eternity with those who went before us - as well as those who will die after us - it also gives us an answer to the question that has perplexed theists throughout history: If there's going to be an "end of the world" (in Christianity, a second coming of Christ) when will it happen? If what we have been suggesting here is correct then the answer is, it will happen at the moment that we die. At that moment, for us, the entire future collapses into the present and all of history lies before us like a page in a book.

Sound too bizarre to be true? Perhaps, but it's really no more bizarre than the reality that physicists are discovering at the sub-atomic level of scale.

RLC