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Old September 2nd 05 posted to sci.physics
Sam Wormley
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Posts: 16,743
Default Does any of this make sense ???

Yrael wrote:
"De-Mystifying" Theoretical Physics

I am not a professional physicist. I am nothing but an enthusiastic
amateur. Neither am I a professional mathematician. I would rate my level
of mathematical knowledge as probably just above A-Level standard. So I am
unable to manipulate the tensors of String Theory, and I am also unable to
completely understand the technical details behind most Quantum Physics
experiments. But I believe that my lack of formal knowledge may have
actually helped me to uncover certain valid identifications of semantic and
philosophical errors in Theoretical Physics which many esteemed
professionals either seem to deliberately ignore or not consider as
important.


Uh Oh.... not a good sign!




Reality Check: Has the Second Law Been Falsified
http://www.csicop.org/sb/2002-09/reality-check.html

Pushing the Second Law to the Limit
http://www.aip.org/enews/physnews/2002/split/598-1.html

Critical Thinking
http://www.csicop.org/si/9012/critical-thinking.html

Tuning Up Your Crank Filters
http://www.colorado.edu/philosophy/v...fs/Cranks.html

Reality Check
Has the Second Law Been Falsified?

Victor J. Stenger

On Thursday, July 18, 2002, 11:09 GMT the BBC Online News reported
breathlessly: "One of the most important principles of physics, that
disorder, or entropy, always increases, has been shown to be untrue."
The article, written by Online News Science editor David Whitehouse,
described new observations by scientists at the Australian National
University in which the entropy of a system of microscopic beads in a
water filled container was found to decrease for periods up to a two
seconds. (G.M. Wang et al. Physical Review Letters 89 050601 [2002]).
Here's how the BBC explained the significance of this result:

The law of entropy, or the Second Law of Thermodynamics, is one of
the bedrocks on which modern theoretical physics is based. It is one
of a handful of laws about which physicists feel most certain. So
much so that there is a common adage that if anyone has a theory
that violates the Second Law then, without any discussion, that
theory must certainly be wrong. The Second Law states that the
entropy-or disorder-of a closed system always increases. Put simply,
it says that things fall apart, disorder overcomes everything
-eventually. But when this principle is applied to small systems
such as collections of molecules there is a paradox.

Contrast this report with one provided the previous day by the American
Institute of Physics in its online Physics News Update. The article by
Phil Schewe, James Riordon, and Ben Stein stated that Australian
researchers have experimentally shown that microscopic systems (a nano-
machine) may spontaneously become more orderly for short periods of
time-a development that would be tantamount to violating the second law
of thermodynamics, if it happened in a larger system. Don't worry,
nature still rigorously enforces the venerable second law in
macroscopic systems, but engineers will want to keep limits to the
second law in mind when designing nanoscale machines.

This is a far more accurate statement than the one provided by the BBC.
In the nineteenth century, Lord Kelvin introduced the second law to
describe the observation that heat always flows from hot to cold. The
first law of thermodynamics, conservation of energy, allows for energy
to be exchanged in any direction. Students and patent officers are
taught that the second law forbids a perpetual motion machine-an engine
that can do work by taking energy from its environment. Rudolph
Claussius framed the second law in terms of a quantity called entropy
which is required to remain constant or increase for any isolated
system. This implied that certain thermodynamic processes such as heat
flow are irreversible.

Toward the end of the nineteenth century, Ludwig Boltzmann showed that
that second law of thermodynamics is a statistical statement about the
behavior of particles. He proved that the molecules of a system tend to
approach their equilibrium distribution when started off away from
equilibrium. That equilibrium is characterized by a certain quantity H,
which is essentially negative entropy, approaching a minimum. In short,
Boltzmann basically derived the second law by assuming that matter was
composed of particulate bodies-atoms and molecules-and applying
Newtonian particle mechanics along with principles of statistics.

So, has a violation of the second law of thermodynamics been
demonstrated in an Australian laboratory? Hardly. This minimum in H, or
maximum in entropy, is just a statistical average and real systems will
fluctuate about this average. These fluctuations are very small for the
large number of molecules in common objects, but the fact remains that
entropy will fluctuate up and down. About the only surprise in these
new results is that violations can be found in a system as large as
micron-sized beads in water. The authors claim they are consistent with
their previously published fluctational theorem, derived from
established physics.

If the experiment is correct, the beads momentarily gained energy from
their environment. However, this perpetual motion machine only worked
for about two seconds and is not a likely practical device. Over longer
time periods, the average behavior will be governed by the statistics
of the second law. The main implication is that engineers building
nanoscale machines need to be prepared for them to behave strangely,
occasionally running backwards. Such effects may also be seen in
microbiology where cells and microbes are of comparable dimensions.

An interesting philosophical issue is raised by these results. It has
long been known that a direction of time cannot be found in the
equations of classical physics. In modern physics, a small time
asymmetry is seen in very rare processes, but no known mechanism
provides for the stark time irreversibility of common experience.
Although the issue is still hotly debated, some quantum processes may
even provide evidence for "backward causality," as I discussed in my
book Timeless Reality (Prometheus, 2000).

Sir Arthur Eddington coined the term "Arrow of Time" to describe the
direction of time provided by the second law. In that case, the second
law is really not a "law" at all but a definition of the Arrow of Time.
The direction of time is simply the direction in which the total
entropy of an isolated system increase. As such, it is useful only for
systems of large numbers of particles, such as those of common
experience. While no physicist will be astonished by the Australian
result, philosophers should regard it as an empirical confirmation of
the fact that the direction of time is arbitrary. All that prevents
sequences of events from happening in the time direction opposite to
that of common experience are the laws of chance.

About the Author

Victor J. Stenger is professor emeritus of physics and astronomy at the
University of Hawaii and now lives in the state of Colorado. His Web
site is still located at spot.colorado.edu/~vstenger
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