Okay everyone, there is a fascinating article by S. F. Chronicle science writer Charles Petit that was in yesterday's newspaper. I'm going to quote parts of it:
"Eerie wails of confused atoms caught in a deep identity crisis have been heard for the first time by the human ear, Berkeley physicists say . . . University of California experimenters report having achieved one of the holy grails of physics--proof that atoms under special conditions can be made to vibrate at audible frequencies as they try to be two places at once . . . it could lead to a new generation of spersensitive devices for measuring pressure . . . the noise, which lasted no more than two seconds sounded something like this: EEEEEeeeoooouuwwwplp . . . scientists used the world's most sensitive microphone, capable of amplifying a sound 10,000 trillion times, to get it on tape.
The trills emanaged from a silver-dollar-size container of superfluid helium, buried deep in a powerful refrigerator at nearly 460 degress below zero Fahrenheit.
It fulfills a prediction about the laws of quantum mechanics made independently during the early 1970's by three Nobel laureates: Philip Anderson of Princeton, Brian Josephson of Cambridge University in England and the late Richard Feynman of Caltech.
In the experiment, two adjacent volumes of extraordinarily cold, superfluid helium are snuggled against each other. A thin membrane, with tiny holes only 100 atoms wide, connects them.
Ordinarily atoms would flow through the holes in accord with the mundane laws of hydraulics. But in the superfluid, when slight pressure is applied to one side or the other, atoms vibrate furiously in confusion over which pond of helium to join.
The oscillations are in the frequency range of audible sounds. The higher the pressure, the higher the pitch. In the experiment, pressure dropped with time--hence the soprano-to-bass shift of the sound . . .
The odd sound emanated from inside an eight-foot-high cylinder two feet across, a complex refrigerator that had taken two months to chill two small pools of liquid helium to within a few millionths of a degree of absolute zero, minus 459.67 degrees Fahrenheit.
Absolute zero is where all heat motion stops. Near it, matter behaves in ways that to the layman seem purely weird. It's a realm where quantum mechanics, which describes matter and energy in terms of vibrations and waves, reigns.
Only helium stays fluid, under normal pressure conditions, at temperatures cold enough to form superfluid. In such a superfluid, the quantum mechanical wave equations that normally dominate just the insides of atoms, expand outward to embrace millions, billions, even trillions of atoms. The atoms lose individual identity. They form coherent masses that operate in perfect coordination, flowing without friction.
The tiny holes in the thin membrane separating the superfludis allow the two neighboring wave functions to overlap slightly, but remain distinct.
"Imagine you are a helium atom right at the hole . . . you have to be in one quantum state or another. But at the border, there are two states. You are confused and jump back and forth" said UC assistant physics professor Seamus Davis.
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Over at the "Ask John Galt" thread last year, there was a rousing debate about how molecules move and the implications on the free will versus determinism argument, as I recall. I am not a physics-oriented person, and probably missed the significance of quite a bit over there. But this study does seem to have some relation to the whole thing.
I wondered if people who are more knowledgeable about physics and philosophy could enlighten me here, as to the significance of these findings.
Thanks!!! |
