Wednesday, September 21, 2005


By now, everyone knows that the contracts for recovery in New Orleans are being offered up without bidding to the same kind of Republican-loving corporations who got all the contracts "without bidding" in Iraq. This administration is the most corrupt and unscrupulous I've ever experienced, maybe the worst in history, and Bush and company still remain popular with 40 percent of the American people. This is about the same percentage of Americans who, with the magical thinking of children, still accept Genesis as absolutely true. Our poor educational systems are finally bearing fruit for the Republican Party faithful.


The following three segments about quantum mechanics are by David Freedman in his essay "Quantum Liaisons" in MYSTERIES OF LIFE AND THE UNIVERSE, edited by William Shore. I don't know nothing about the subject. I read and I read and I still struggle with it, but this makes a little of the fog clear out of my brain.

[Open quote] Ever since it burst onto the scene in the 1920s, quantum mechanics has been stupefyingly efficient at predicting the inner workings of everything from stars to digital watches. The theory is also a mortal enemy of common sense. At its heart is the pronouncement that the result of any observation or measurement is influenced by chance; even worse, it insists that when an object is not being observed it is at once everywhere and nowhere. Physicists are quick to claim that quantum mechanical weirdness applies only to submicroscopic specks of matter like atoms and quarks, and not to everyday, full-sized objects like socks, which apparently disappear for other reasons. But physicists, who are normally regarded as a tell-it-like-it-is kind of people, are not being entirely ingenuous in this matter. A glance out the window does indeed provide evidence that the world at large is protected from quantum-mechanical bizarreness, but the truth is that no one has ever been able to offer a convincing explanation as to why this might be so.

Einstein fumed at this indefinite, chancy view of nature and charged that quantum mechanics was at best an incomplete theory. But Niels Bohr, Einstein's nemesis in this regard, responded with the physics version of Don't Worry, Be Happy: if quantum mechanics doesn't jibe with our view of reality, he said, then our view of reality is wrong. Generations of physicists have been only too happy to treat Bohr's intellectual shrug as the last word on the question, conveniently allowing them to employ quantum mechanics every day in their laboratories without ever having to fret over the fact that the lab and everything in it supposedly melt into a Twilight Zone of indeterminate possibilities as soon as they turn out the lights and leave. [Close quote]


[Open quote] Then, in 1984, in mulling over Einstein's thought experiment in which a measurement of one particle instantly affects a second particle some vast distance away, Aharonov [a physicist] was drawn back to his old future-past idea. It had suddenly occurred to him that according to the special theory of relativity—which states that observers moving at different speeds won't agree on the simultaneity of two events at different locations—an observer whizzing by at high speed could find that the second particle registers an effect just before the measurement is made to the first particle. "To that observer," he says, "it would seem that the results of the measurement to the first particle have come from the future to influence the second particle." Could such a bizarre effect be demonstrated?

A certain catch-22 built into quantum mechanics appeared to eliminate that intriguing possibility. Common sense declares that performing an experiment on a particle in the present has an effect on experiments performed in the future (you can confirm this in your backyard with croquet balls), and for once, quantum mechanics concurs with common sense. Thus if you want to test the effect of the future on the present, you'd better not make any measurements now, lest you disturb the future before the future has a chance to disturb what you're doing now. According to the time-honored interpretation of quantum mechanics, if there is no measurement, then there is no reality. In other words, the future may have an effect on the past—but only if you don't try to find out what that effect is. [Close quote]

All I got to say is, "Hunh?"


"In other words, because quantum mechanics dictates that any experiment will always be subject to an element of randomness, the experimenter simply doesn't have the freedom to determine an experiment's outcome completely. That means you can't reliably rig an experiment to produce a result that will influence the past in such a way as to violate causality. And therein, from his point of view, lies Aharonov's real triumph: in showing how quantum-mechanical uncertainty acts as a sort of anti-causality-violation Scotchgard for the fabric of reality, he has given nature an excuse for intimately incorporating randomness in its structure."

All I gotta add is you should try to get hold of this book and read the essay yourself if your as dense in this field as I am. It's fascinating reading and trying to rap your noggin around it.


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