Thursday, May 8, 2008

a philosophical take on quantum realism

I got the latest issue of SEED (#16) and was instantly captivated by the article on p.50 "The Reality Tests". The article goes into one of the more controversial questions of quantum mechanics, the idea that particles might not really exist until they are observed. Many physicists (including Einstein) have disagreed with this idea because it is so alien when compared with our everyday experience (i.e. the moon doesn't cease to exist because we stop looking at it, right?).

But the article explains that new experiments disagree with the idea of "realism", (i.e. that particles have an independent existence before measurement) by more than 80 orders of magnitude. So are we left with the unavoidable conclusion that we can create reality simply by observing it?

I'm not a physicist, but even without physics there are some philosophical problems with such a question.

First, in its most basic form, the explanation that reality is created by observation isn't an explanation. It simply pushes the problem into a different space: "observation" and what it means to be "observed".

I'm not aware of any accepted rigorous definitions of those terms, however the ideas of an observer "creating" reality seem to unavoidably involve free will. After all, it's commonly implied that the observer gets to choose what to observe, right? Except we don't really seem to have conscious control over what gets created "in the large". (For example, I would like to observe a million dollars in my living room right now... nope. didn't work.)

Maybe we don't have conscious control over our observations... but then we have to explain why observers create the same (or even a similar) classical reality that we perceive as coherent when theory says there could be an infinite number of alternate classical realities that are equally possible. Why this particular one? Collective unconscious?

If we disregard a "collective unconscious" of some sort, we are left with something even more dramatic: for some reason, the science of observations collapse on the same reality regardless of all the possibilities -- i.e. you are drawn back to a system of fate without any free will.

But a deterministic system by any other name is still a deterministic system. We started out wanting to say that the particle had no particular existence before observation and instead ended up with a system where observations are as deterministic as the previous definitions of the particles they tried to explain.

So, really, when we're talking about "observer" and "create", we are talking about something very special that doesn't match our everyday meanings. We should figure out what those terms mean before using them in quantum theory.

p.s. there is another wrinkle with "observer" -- quantum physics says you can't observe things without affecting them, so at the simplest level it sounds like observers are just participants in interactions. But interactions affect all matter and energy, so does this mean that everything is an "observer"? If not, what is special about "observers" then?

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