PERPETUAL MOTION
by Milton Rothman - posted by Eric Krieg at http://www.phact.org/e/z/miltperp.htm
Discussions of perpetual motion (PM) often fall into confusion because the
words
used to describe the devices in question are not applied properly. This
semantic
confusion can be avoided by paying close attention to the various meanings of
the
term "perpetual motion" and by recognizing that there actually are at
least three
distinct categories of perpetual motion devices.
I have always known two kinds of perpetual motion. However, a look at
the
McGraw-Hill Dictionary of Scientific and Technical Terms (5th Edition, 1994), a
very thick, weighty, and useful tome, informs us
that there are three officially recognized kinds of PM. These are:
1. A Perpetual Motion Machine of the First Kind is a mechanism which,
once set
in motion, continues to do useful work without an input of energy, or which
produces more energy than is absorbed in its operation. This kind of PM
is
impossible because it violates the principle of conservation of energy.
(Further
discussion below.)
2. A Perpetual Motion Machine of the Second Kind is a device that
extracts heat
from a source and then converts this heat completely into other forms of
energy.
This kind of PM is impossible because it violates the second law of
thermodynamics.
3. A Perpetual Motion Machine of the Third Kind is a device which has
a
component that can keep moving forever. An example is a superconducting
ring in
which an electric current can flow flow indefinitely once started. Other
examples are the planets and stars that move throughout the universe and will
continue to move until they are stopped by some natural cause. This kind
of
device is clearly not impossible.
Some people like to say that "nothing is impossible." But
this statement is a
modern myth. One of the major functions of physics is to separate the
possible
from the impossible. The law of conservation of energy is our prime tool
in this
task. This law states that: In a closed system the total amount of
energy
cannot change. Another way of saying it is that energy cannot be created
or
destroyed, even though it may be changed from one form to another. For
this
reason, any device that claims to create energy, or to export more energy than
it
imports, is impossible.
It is not necessary to test every proposed PM machine to prove that it will
not
work. This is because everything is made of atoms, and if conservation of
energy
is true on an atomic scale, then it must be true for everything made of atoms.
The most fundamental verifications of conservation of energy are done with
nuclear reactions, and certain observations made with a reaction called The
Mossbauer Effect can be accurate to better than one part out of ten to the
fifteenth power. These observations are so precise that they are limited
only by
the Heisenberg uncertainty principle. You can't make them any more
precise than
that. Details of how these experiments are done can be found in a book:
DISCOVERING THE NATURAL LAWS: The Experimental Basis of Physics, by Milton A.
Rothman (Doubleday, 1972, Dover Publications, 1989).
The reason experiments such as these can verify conservation of energy is
that
there are only four kinds of energy in existence, in addition to kinetic
energy.
These are: electromagnetic energy, weak nuclear energy, strong nuclear energy,
and gravitational energy. (Actually, the first two are now known to be
just one
form of energy, called electroweak. It is hoped that a unified theory
will
combine all four to make a single form of energy. But we don't have to be
concerned with such details.) All human-sized devices are governed
by
electromagnetic and nuclear forces. Mossbauer effect experiments
demonstrate
that no reaction governed by these forces can create or destroy energy.
From
this it follows that no machine made by human hands can generate energy without
converting some kind of stored internal energy into into mechanical energy,
electromagnetic energy, or heat.
The second law of thermodynamics is another kind of law. It deals with
heat as a
form of energy. However, heat is not really a separate and distinct form
of
energy -- it is nothing more than the average kinetic energy of all the
molecules
in a substance. In its most general form, the second law states that
there is a
preferred direction for any sort of process. This seems to contradict the
fundamental laws of interactions between elementary particles, which tell us
that
you can't tell the difference between a reaction going forward in time and the
same reaction going backwards in time. However, in dealing with huge
numbers of
molecules, a statistical analysis of the molecular motion tells us that certain
arrangements of the system are much more probable than other arrangements, and
that any reaction will go in the direction of greatest probability. For
example,
in a container of a gas there is very little chance of finding the gas
spontaneously moving to one end of the container. The chance of finding
the gas
evenly spread throughout the container is much greater than that of any other
arrangement. Any discussion of methods for getting energy out of a volume
of
heated gas must answer the question: How do you convert the random motion
of the
molecules in the gas to the directed motion of a machine? And: what is
the most
efficient way of doing this?
There are many ways of stating the second law of thermodynamics. One
is: "No
process is possible whose sole result is the transfer of heat from a cooler to
a
hotter body." Another is: "No process is possible whose
sole result is the
absorption of heat from a reservoir at a single temperature and the conversion
of
this heat completely into mechanical work." Every process must take
heat from a
reservoir at a high temperature, convert some of it into mechanical energy, and
release the rest of the heat to a reservoir at a low temperature.
It is impossible in this space to go into a detailed discussion of how
scientists
have arrived at these conclusions. Any good physics textbook should
supply those
details. (e.g., that good old standby "College Physics," by
Sears, Zemansky, and
Young, Addison-Wesley, 1974.) The most sophisticated methods use a
statistical
analysis of molecular motion to determine the changes in gases resulting from
changes in temperature and pressure.
As for the third kind of PM, this simply represents a logical consequence of
energy conservation. If a device has a part that is able to move without
losing
any of its kinetic energy, then there is nothing to slow it down or stop
it. The
only thing it can do is to keep on going. The trick is to find a way to
eliminate friction. Nothing else will do. The superconductor does
this because
the current running through it is carried by electron pairs that do not
interact
with their surroundings. Therefore there is no electrical
resistance. . When I
worked at the Princeton Plasma Physics Laboratory, there was a group that
experimentally investigated how long an electric current would flow around a
superconducting ring. They found that within the limits of their
measurements
the time was greater than five thousand years. Theoretically, the time
should be
infinity.
Occasionally someone comes along claiming that he can make a machine that
runs
forever, and therefore he has built a perpetual motion machine. Assuming
that he
has learned to do away with friction, there is no law forbidding this machine.
However, we see that it is a PM of the third kind, which is a perfectly useless
device from an energy-producing point of view. Because as soon as you try
to
take energy out of this machine it is going to slow down and stop.
We see how keeping the three kinds of perpetual motion clearly in mind
allows us
to untangle the various claims that ambitious inventors make. PM of the
first
kind is the classical machine which creates energy by the motion of wheels and
gears. These machines were invented hundreds of years before anybody knew
what
energy was, so that the inventors knew no reason why they should not
work. The
perpetual failure of these devices led to the idea of energy conservation.
PM of the second kind has become popular in recent years, especially
among those
espousing "free energy" devices. After all, with all the energy
abounding in the
atmosphere and oceans, one should be able to put it to some sort of use.
Well,
you can make use of it, but not as efficiently as you hope.
First and
Second Law - put to music
More from Milt on free
energy
go back to more rants hosted by Eric Krieg
LINKS
Tom Bearden's MEG device A rational review of meg
claims and Randi's info
and very
good skeptical information on Bearden
back to Eric's main Dennis Lee page what about Joe Newman? Also, Amin, Mills (who may be legit?) Tilley, Perendev, and Bedini's Motor , Bearden Lutec, Tewari Greer's offer VMSK Moray, Bedini, betavolt, Adams, Mallove, Jack Carey , GWE, Searl
Discussion of Bearden's 20 year old theory promising free energy
A closer look at some of Bearden's theory http://www.tinaja.com/pseudo01.html - a look at psuedoscience on the web
my $10000 prize for proof of free energy of Carl Tilley's free energy scam EXPOSED
· The Museum of Unworkable Devices a great overview of them
· INE Free Energy Devices Database - - another great
list of FE claims
his skeptic
pages and crack pot pages
Milt's discussion of Free
Energy and Ceti