Re: "Can the Second Law of Thermodynamics Be Circumvented?"
- From: Obama Insane <obamas_insane@xxxxxxxxx>
- Date: Sat, 30 Aug 2008 18:17:20 -0700 (PDT)
On Aug 30, 8:21 am, Y <yanar...@xxxxxxxxxxx> wrote:
Anig wrote:
"Can the Second Law of Thermodynamics Be Circumvented?"
The validity of the First and Second Laws of Thermodynamics seems to be
beyond question. Under the first law, the total energy content of a closed
system must remain constant. Under the second law, the availability of that
energy for useful purposes must always decrease or remain constant. In
effect, the First Law of Thermodynamics states that you can't win and the
Second Law states that, furthermore, you can't break even. The First Law of
Thermodynamics is unquestionably true, energy can neither be created nor
destroyed, General Relativity not withstanding. The Second Law of
Thermodynamics stands on less firm ground because it is a law based upon
statistics. As such, it is in the same category as an actuarial table. An
insurance company can predict quite accurately how many people will die in a
given year. They cannot
predict who those people will be. Statistical laws are valid for large
numbers of events; they become less significant as the number of events is
reduced. As an example, if one patronizes a casino, he might initially win a
large sum of money playing a slot machine, but if he continues to play he
not only will give all his winnings back to the casino, he will sustain a
significant loss. The question then arises as to whether it is possible to
by-pass the Second Law of
Thermodynamics though the use of nanomachines. (A nanomachine is a mechanism
whose significant dimensions are measured in nanometers, the size scale of
atoms.)
One who observes Brownian motion in a microscope might reasonably
conclude that,in principle at least, a nanomachine could be built which
would bypass the Second Law of Thermodynamics. When a liquid containing
microscopic particles is observed, the particles are seen to be in
continuous (Brownian) motion. That motion is caused by random thermal
impacts between the molecules of the liquid and the particles. If the
thermal motion of water molecules can produce a visibly observable motion in
particles which are at least 10^15 times as massive, it certainly not
unreasonable to believe that suitable nanomachines could organize the effect
to produce a useful mechanical output. The postulated nanomachines would
then be able to export energy to the outside environment that it obtained by
reducing the temperature of the liquid. The exported energy would be
converted to heat and raise the temperature of the external environment as
the output performed useful work. The resultant temperature difference
between the environment and the liquid will then cause the energy which had
done useful work to flow back into the liquid to return it to its original
temperature and allows the process to continue indefinitely.
James Clark Maxwell proposed a hypothetical perpetual motion machine,
known as Maxwell's Demon, which was not proven to be THEORETICALLY
unworkable for 75 years. In that machine, Maxwell imagined that a demon
controlled a microscopic gate between two gas filled chambers. Making use of
the fact that, in a gas, the velocity of the molecules is random and that
the temperature of the gas is determined by the mean velocity of those
molecules, Maxwell proposed the concept that, if an appropriate demon
existed, he could sense the speed of molecules approaching the gate and open
the gate only when a fast molecule approached it from one side or when a
slow molecule approached it from the other side. By operating the gate in
this manner, the demon would sort the molecules so that one chamber
contained fast molecules and the other chamber contained slow molecules..
Since the temperature of a gas is determined by the mean velocity of its
molecules, such a process will maintain a temperature difference between the
chambers that can be exploited to produce useful work in a direct violation
of the Second Law of Thermodynamics. It took 75 years before a rigorous
proof was found which was able to show that the energy required for
Maxwell's Demon to identify the fast and slow molecules and allow the gate
to operate was at least as great as the energy that could be released and
Maxwell's Demon was shown to be an unworkable concept.
There is a modification to the concept of Maxwell's Demon for which
there is, at least as yet, no valid theoretical objection. Suppose that the
two chambers of the Maxwell's Demon example no longer rely on a demon but
are separated by a diffusion membrane having a permeability from side A to
side B which is higher than the permeability from side B to side A. The
energy required to allow the membrane to make the decisions it needs to make
in order for it to function in this manner is available in the kinetic
energy of the gas molecules passing through it. In diffusing through the
membrane, molecules can provide the energy needed by being slowed from their
average room temperature velocity of about 1300 feet per second to a much
lower exit velocity. The lower velocity of the gas leaving the membrane
means that side B is colder than the ambient temperature. The loss of
kinetic energy by the molecules as they pass though membrane provides the
energy required to operate the differential diffusion mechanism in the
membrane pores, and the membrane becomes warmer than the ambient
temperature. If the surface areas are sufficiently large, the temperature of
the gas on both sides of the membrane and of the membrane itself must remain
close to the temperature of the environment. As a result, the pressure in
chamber B will be higher than the pressure in chamber A. That difference in
pressure can be used to operate a turbine and provide useful output power.
As the gas flowing through the turbine produces output power, the chambers
are cooled below the ambient temperature and energy flows from the
environment to the chambers to replace the energy delivered by the turbine.
The arrangement would extract useful energy from its environment in direct
contradiction to the Second Law of Thermodynamics. See
http://einsteinhoax.com/cf153.gif.
Conceptually, the membrane might be constructed with pores that were
covered by pring-loaded trapdoors, as shown in
http://einsteinhoax.com/cf154.gif. In this illustration, a molecule
represented by a ball approaches the right side of the membrane at a
velocity, which was appropriate to its temperature, knock the trapdoor open,
and pass through it. A similar molecule approaching the trapdoor from the
left side would bounce back and not pass through to the right side. When the
molecule on the right passed through the trapdoor, it would lose most of its
kinetic energy to the trapdoor and exit at a low velocity. As a result, the
trapdoor and the membrane would be heated and the molecule which passed
though it would be cooled. The process
would generate a local temperature difference that would quickly be
equalized by any reasonable level of heat transfer.
The first theoretical objection to this type of perpetual motion
machine that the author has found in literature is that it cannot work
because it violates the Second Law of Thermodynamics. This is hardly a valid
objection since the arrangement is specifically designed to bypass the
limitations of that law. The Second Law of Thermodynamics is a statistical
law and it is not binding on nanomachinery since such mechanisms deal with
molecules on an individual basis and the pores of the assumed diffusion
membranes certainly qualify as nanomechanisms. (The Second Law of
Thermodynamics, or the Law of Entropy increase if you prefer, does apply to
the membrane itself and to the gas in the chambers since they involve large
numbers of randomly interacting
particles. It does not apply to the pores of the diffusion mechanism. Each
pore is an independently acting nanomechanism and, as such, is not bound by
the Second Law of Thermodynamics (Entropy). The only other theoretical
objection that the author has found was provided in another book by Dr.
Feynmann in which he described a nanomechanism consisting of a riverboat
type of paddle wheel mounted on a shaft inside a cylinder containing a
fluid. The paddle wheel was bombarded by the random motion of the molecules
of the fluid and caused the shaft undergo a random rotary oscillation. To
convert this motion to a useful output, an EXTERNAL one-way ratchet was
attached to the shaft. Dr. Feynmann then demonstrated that the device would
not work because the motion of the ratchet pawl would generate enough heat
so that the resultant thermal molecular motion of the ratchet and pawl would
make the pawl bounce sufficiently to render the one way mechanism
inoperative.
From the description provided, it is obvious that, while Dr. Feynmann
is undoubtedly an excellent theoretical physicist, he is not as effective as
a design engineer. Relocating the ratchet mechanism to the interior of the
fluid chamber must cool it close to the temperature of the fluid and dampen
its bounce. As a result, Dr. Feynmann's objections would vanish. When the
model is modified, Dr. Feynmann probably would be forced to agree, that
unless another objection could devised, the concept should represent a
physically realizable device that would by-pass the Second Law of
Thermodynamics. A theoretical demonstration that the mechanism suggested by
the author cannot work requires a proof that the permeability of all
possible diffusion membranes must be the same in both directions. Deriving
such a proof may be particularly difficult because the pores of the required
membrane are allowed to extract energy from the molecules that pass though
them. CONSIDERABLE EFFORT IS JUSTIFIED IN DEVELOPING SUCH A PROOF. IF THAT
PROOF CANNOT FOUND,- Hide quoted text -
- Show quoted text -...
read more »
***************
.
- Prev by Date: Re: Ajay Sharma kicked around
- Next by Date: Re: IaSNe observations
- Previous by thread: Re: Ajay Sharma kicked around
- Next by thread: Faster than c
- Index(es):
Relevant Pages
|
