From: kbk@netcom.com (Ken Krovchuck)
Subject: Thermodynamics
Keywords: second law, experiment
Organization: Netcom - Online Communication Services 
Distribution: usa
Date: Mon, 5 Oct 1992 05:05:09 GMT

    Consider a charged particle moving in a magnetic field from point A to 
point B. The path it takes will be curved because of the magnetic field.
If the particle were to then travel from B back to A, it will follow a curve
opposite to the first, it cannot follow the same path.

    Since the path taken from A to B is different than from B to A, it would
be simple to physically block one of the paths, favoring motion in one
direction or the other. For example, path AB could be unobstructed, and path
BA blocked with some sort of barrier. In order to get past the barrier the
particle would have to go through a long series of collisions, each collision
sending the particle in a new direction, until it finally reaches point A.

    With an appropriately shaped vessel and magnetic field, and where the
particles derive their energy from the heat of the vessel, it seems possible
to have a system where there would be an electrical current between the two
points. I have simulated several different designs, all of which do just that.
A charge will build between the two points, which will eventually overcome
the current, balancing the system. The work done to create this charge will
be provided by the heat of the vessel itself, by contributing thermal energy
to the particles when they are slowed by traveling 'up' the electrical field
between the two points. All of this is very dependent on the free path, or
average distance between collisions, of the particles. In order to have any
noticeable effect, the distance between A and B must be smaller than the free
path of the particles. In most cases the free path of a particle is very
short, forcing any device of this kind to be very small.

    Here is a more specific example. Two flat thin metal plates, with a
gap of only about 0.01 mm between them, are mounted onto a piece of insulating
material. The insulator also fills the gap between the plates, so that the
surface remains smooth. A strong magnetic field is aligned such that the
'lines of force' travel edge on to the metal, parallel to the gap. Some sort
of device exists to measure the charge of the two plates. The apparatus is
placed in a vacuum, and heated to a high temperature such that the metal
will eject free electrons into the vacuum. It is important that the temperature
be completely uniform, otherwise currents may be produced by thermoelectric
effects: 

 = -->conductor.           ******==========*============******* 
 * -->insulator.           ************************************
 (magnetic field points
 toward you)

    In this example, assume the magnetic field is such that the electrons
circle in a clockwise direction with an average radius (which depends on
temperature) about twice the size of the gap. The conducting plate on the
left is A, the other is B. The high temperature of the metal ejects electrons
into the vacuum (like a vacuum tube does). Electrons from A easily hop
over towards the right, and some hop over the gap onto plate B. Electrons
on B, however, can't get to A, since they follow clockwise circles which will
turn them back around onto B again. They can only get to A if they collide
with a particle above the plate, (hence the need for a strong vacuum),
or walk all the way around the insulator, (this is the before mentioned
barrier - which can be made arbitrarily large), or by an electric force
modifying it's trajectory (which only comes into effect after a noticeable
current has flowed to plate B).

    This example does have some flaws. One of which is the need for a high
temperature, which always allows the possibility of accidentally making
some sort of thermoelectric generator. This can be avoided by heating the entire
apparatus and it's surroundings to the required temperature and checking
to see if the device can cool itself without outside influence. The other
problem is the magnetic field. Most magnets (that I'm aware of) don't fare
well at the 1000+ C temperatures needed here, which is especially important in 
light of the previous statement. These problems have to do with the example,
however, and not with the basic idea of the thing. I have not built any such
device, since I do not yet have the proper equipment to do so. 

    All of this goes directly against the second law of thermodynamics, which
states that such a system is impossible. The physics involved, however, seem
to be so simple that either I am missing something embarrassingly simple or
something quite subtle.


                                                        -- Ken Krovchuck
                                                        -- kbk@netcom.com