Two days ago, I told you about my fascination with quantum computing. Today, let's talk about another scientific subject: nanotechnology. But I warn you: it's going to be technical.
We'll start with the abstract of a paper published by the Physical Review Letters in its July 29, 2002 issue.
Ready for the abstract? Here we go.
The title is "Experimental Demonstration of Violations of the Second Law of Thermodynamics for Small Systems and Short Time Scales."
We experimentally demonstrate the fluctuation theorem, which predicts appreciable and measurable violations of the second law of thermodynamics for small systems over short time scales, by following the trajectory of a colloidal particle captured in an optical trap that is translated relative to surrounding water molecules. From each particle trajectory, we calculate the entropy production/consumption over the duration of the trajectory and determine the fraction of second law-defying trajectories. Our results show entropy consumption can occur over colloidal length and time scales.
Of course, this abstract is not written in "English for Dummies." So let's turn to the Science section of the Wall Street Journal (WSJ) for explanations in -- almost -- plain english.
Sharon Begley wrote a story for the Journal on August 2, 2002. Unfortunately, you have to be a paid subscriber of the WSJ to read the full contents of the article. Here are some quotes.
There are several ways to express the Second Law, but the basic idea is twofold. First, in a closed system, entropy (disorder) increases. Or as that great thermodynamicist William Butler Yeats said, things fall apart.
In addition, you can't harvest heat energy from cooler surroundings and turn it into work. If such a trick were possible, then machines could create electrical power rather than gobble it up, perpetual-motion machines could hum merrily forever.
Chemist Denis Evans of Australian National University in Canberra theorized in 1993 that "for brief periods, tiny particles can suck up entropy, converting heat from their surroundings into useful work."
With the help of his colleagues, he did some experiments which -- apparently -- prove this is possible to break the Second Law of Thermodynamics for as long as two seconds.
If the microworld can violate the Second Law, "biological machinery might take advantage of this," says Dr. Evans. Molecules could briefly extract energy from their surroundings, combining in ways that would otherwise be impossible in practice. The loophole in the Second Law -- for tiny objects for short periods of time -- might be big enough to let miracles through.
Nanoproducts will be real one day -- but when?
Source: Sharon Begley, The Wall Street Journal, August 2, 2002; Physical Review Letters, July 29, 2002
6:33:15 PM
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