Humans (and Astrophysicists) Are Special After All
Nov 25th, 2007 by Micah Tillman | 5 Comments |
Here’s my hypothesis:
The astrophysicists who claim that global warming is caused by solar activity (e.g., this team) were getting all the press, so the other ones had to come up with a way to cash in on the crisis.
Hence this:
Mankind ’shortening the universe’s life’
(Actually, a few scientists did it, and they just made it less probable that the universe will last as long as it was probably going to.)
Mr. Stevens will clearly know more about this than I do, but it has to do with the fact that observing subatomic phenomena (supposedly?) changes what is going on. According to quantum mechanics (which I find really fascinating). Heisenberg’s uncertainty principle, and all that.
Evidently, some physicists take quantum mechanics to mean that everything would happen normally if there weren’t any humans around to register what was happening. (The article implies that there are others who disagree).
Which means that they can’t think humans are like everything else. There has to be something special about humans if they’re the ones messing things up.
As someone once said, “What humans do cannot be unnatural unless humans are supernatural.”
So there you have it. Quantum mechanics is proof of the human soul.
Well, I believe this interpretation is pure nonsense, of course. Humans are doing nothing “special” at all. The article says, “Not all agree, since his interpretation hinges on one of the issues at the heart of quantum theory - do you need people to do the observing?”
The answer is “of course not.” (And, I may add, there is not even the tiniest bit of evidence to support such a view.) Sadly, there are lunatics and mystics in science as well as in other fields.
My favorite quote was: “Incredible as it seems, our detection of the dark energy may have reduced the life-expectancy of the universe,” Prof Krauss tells New Scientist.
But, of course, it may not. And this seems much more credible.
The “observer effect” is really quite simple and obvious and not nearly as profound as people think. Let us imagine that I am clocking a foot race. In order to clock the competitors, I need to bounce photons off of them so I can see them and record their times. On a macro-level experiment like this, my bouncing photons will have such a negligible effect on the race that we can safely ignore it. However, if I’m clocking a race between electrons, how I bounce the photons off of them will have an enormous effect. Electrons are so small that even a single photon will disturb it and change the outcome of the race. This effect then merely says that in order to measure something, I must physically interfere with it. This is always true. We don’t think of it much because the interference is so negligible in most experiments. However, it stops being negligible on a sufficiently small scale.
The Heisenberg Uncertainty Principle doesn’t have anything to do with observation and is more profound. As a direct consequence of the mathematics, it is not possible for a particle to simultaneously have an arbitrarily accurate position and to have an arbitrarily accurate momentum. The reason this is profound is because the mathematics implies that it is true prior to measurement (although Heisenberg himself was confused about this point, and explained it in terms of the “observer effect,” which gave rise to the sort of nonsense expressed in this article). This odd “wave-particle duality” has many possible interpretations.
My own personal favorite theory is given here. If you’re up to it, it’s well worth reading in its entirety. My favorite quote from the article, since I have found it to be almost universally true is: “Many physicists pay lip service to the Copenhagen interpretation — that quantum mechanics is fundamentally about observation or results of measurement. But it is becoming increasingly difficult to find any who, when pressed, will defend this interpretation.” No less a physicist than Einstein (as well as Schrodinger himself) refused to take Copenhagen seriously. Einstein probably would not be happy with Bohmian mechanics either. It is explicitly non-local, thereby pointing out that general relativity is not a complete theory, but this is absolutely necessary due to Bell’s Inequality and quantum entanglement. (Sorry, non-local means that there is what Einstein called “spooky action at a distance.” I.e. that there can be a cause with an instantaneous effect. Thus, information is being exchanged faster than the speed of light.) Einstein was holding out for a deterministic local “hidden variables” theory. Bohm’s is a deterministic non-local “hidden variables” theory. However, Bell proved that any interpretation of quantum mechanics must be non-local, including Copenhagen. (Actually, I’m not clear whether this is true in the Many Worlds Hypothesis. Bell’s proof probably assumed a single world.)
Another great quote from the article is also from John Bell (1987):
“A final moral concerns terminology. Why did such serious people take so seriously axioms which now seem so arbitrary? I suspect that they were misled by the pernicious misuse of the word ‘measurement’ in contemporary theory. This word very strongly suggests the ascertaining of some preexisting property of some thing, any instrument involved playing a purely passive role. Quantum experiments are just not like that, as we learned especially from Bohr. The results have to be regarded as the joint product of ‘system’ and ‘apparatus,’ the complete experimental set-up. But the misuse of the word ‘measurement’ makes it easy to forget this and then to expect that the ‘results of measurements’ should obey some simple logic in which the apparatus is not mentioned. The resulting difficulties soon show that any such logic is not ordinary logic. It is my impression that the whole vast subject of ‘Quantum Logic’ has arisen in this way from the misuse of a word. I am convinced that the word ‘measurement’ has now been so abused that the field would be significantly advanced by banning its use altogether, in favour for example of the word ‘experiment.’”
I’m not as smart as Andrew on this topic.
Isn’t it interesting that it’s “the scientists” who brought about this change in the Universe, when it’s also “the scientists” who are trying to save us from the effects of Global Warming. If the Universe runs down, I don’t think Global Warming will be all that important. And if human beings are the “problem,” then our extinction obviously will be a good thing for the rest of the Universe.
Andrew–
Thanks for the clarifications, especially regarding my equation of the observer effect and the uncertainty principle. Bringing “strategic distinctions” (as my dissertation director would say) into confused situations is one of the greatest contributions a thinker can make to an area of study. :-)
I fully intend to read that article. I love this stuff, and know I know so little.
RG–
*grin* That’s what I was thinking. It’s just too much fun. This is one of those posts where all the value really comes from the comment-section, but I couldn’t help pretending the post itself was worth writing.
Rush Limbaugh frequently talks about the profound arrogance of thinking you can destroy or save the world just by going about your daily life. Then seeing that kind of arrogance applied to the universe as a whole! *laugh*
You have to think the two scientists quoted in the article were not taking themselves too seriously.
Believe me, you’re not remotely the only one to mix up the “observer effect” and the Uncertainty Principle. It was only very recently that I learned that a sharp distinction can (and should) be made between them. Even Heisenberg himself often used the “observer effect” to explain the Uncertainty Principle (bouncing photons, in fact, which is where I got my own example for the “observer effect”). But the Uncertainty Principle is much more profound than that and is the actual root of all quantum “weirdness.” The photon analogy confuses people, though, because they think it can be overcome if we can just do the measurements without using light. However, I can think of no way in which a measurement can be carried out without in some way touching what we’re measuring, not even in principle, so we’re almost certainly always going to be stuck with the “observer effect.”
As for Dr. Krauss, he has apparently backed off any claim of causality. He posted on this thread the following quote: “I have decided that indeed the final two sentences of the paper left the incorrect impression that causality was somehow involved. The purpose of these comments was to refer to work I have been discussing with Alan Guth related to this paper.. namely to what extent cosmological observations made today constrain the nature of the wavefunction and our quantum state in a way that may imply we are not in the late-decaying phase.. This is what I should have said, rather than leaving the incorrect impression that somehow actually making the measurement has a causal effect.. it does not.. it merely constrains our quantum state.. The new version of the paper with the last two sentences changed removes this ambiguity I hope, for all future journalists who look at it.” It wasn’t really the main thrust of the paper and I suspect it was always meant somewhat tongue-in-cheek anyway.
However, there are people who believe consciousness causes collapse. This is a very popular theory with the sorts of people who write books like The Tao of Physics or The Dancing Wu Li Masters, mysticism dressed up with a bit of pseudo-science. Please don’t ever read either of these books.
My favorite geeky quantum physics joke:
Hiesenberg was pulled over by a police officer. The officer came to the window and said “Excuse me, sir. Do you have any idea how fast you were going?”
Heisenberg shakes his head sadly. “No, but I do know exactly where I’m going!”