Saturday, April 19, 2008

All That Lies Between

Once upon a time there was a man named Schrodinger and he had a cat. In his own words:

One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following device (which must be secured against direct interference by the cat): in a Geiger counter there is a tiny bit of radioactive substance, so small, that perhaps in the course of the hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts.

It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a "blurred model" for representing reality. In itself it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.

Meant to be a thought experiment about quantum physics: When does a quantum system stop existing as a mixture of states and become one or the other? (More technically, when does the actual quantum state stop being a linear combination of states, each of which resemble different classical states, and instead begin to have a unique classical description?)

A question that can be derived from this and/or the Heisenberg Uncertainty Principle is one of observation: What happens to a situation once it is observed. The short answer is that the mere act of observing something changes everything.

When I first started using computers in a serious sense, my school’s library had a 2400 baud modem which could connect to various bulletin board services, BBSs, which one could use for pen pal-style rudimentary communication. In the early 90s this is one of the things which I found myself doing. Though I did not know it, I was networking in my early teen years. I began a lengthy correspondence with a Lutheran pastor from somewhere in Michigan or Wisconsin, I believe (the actual location escapes me), through which we began discussing quantum physics. He posed the ageless rhetorical question to me: If a tree falls in a forest, does it make a sound? I always like bringing this question up as an introduction to the general strangeness of quantum physics. The answer is that if there is no one to perceive—observe—the tree, then it is not there: It does not exist. If no one is there to observe the forest, it does not exist. Therefore, if there is no one able to perceive the action of the tree falling, it does not fall because it does not exist.

It took me some time to reconcile this notion, but eventually came to terms with it. Over time I came to find the universal truth in this notion that anything and everything changes with observation. In our classical world which we can see, feel, taste, touch, and hear on a daily basis we can express the question of “have we observed that?” as a binary function—yes or no, or “1” or “0,” the fundamental essence of a “bit,” or binary digit. Does my cat exist? Yes! (“1”). Is the moon out tonight? No! (“0”). What about if you can’t answer these questions? Herein lies what makes quantum physics so creepy to many. The notion of Schrodinger’s Cat dictates that while something hasn’t been observed it can exist in a state of “superposition,” that is a position that is not necessarily natural and exists outside of a “0” or a “1,” or yes or no.

If you don’t know about something then it exists in an odd place…one that is not easily definable; as a side-note, however, this is how the concept of quantum supercomputing works, in a sense: This sort of theoretical, almost-real device stores bits of ones and zeros in superpositions instead of in absolute states. Because of this it can calculate much faster because it is not constrained by the classic laws posed by Newton in the mechanical world, and computes things much faster than Intel or AMD could muster with their fastest processors.

How can we make this apply to our everyday lives? Have you ever feared something that was “just around the corner,” or otherwise out there in a place in your world that might be slightly unknown enough to you as to cause you to feel things that might be irrational? Fear of something, someone, or some other type of emotion of an event happening which has a low probability or likelihood of actually happening once it is observed? The superposition concept that I discussed earlier wherein any number of all possible states exist, but it isn’t necessarily true or false, is where irrational thought and feeling resides—in a place that even likes to confuse the brightest minds of the 20TH Century deriving the basis for modern science.

Don’t let your fear, depression, anxiety, or other unproductive thoughts or feelings get the best of you. In the end you will find that your emotions or irrational thoughts are skewing the actual values of the situation which you are otherwise making more out of than you should: There is no need to kill the cat unnecessarily!

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