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Re: The Nature of Charge

Posted: Tue Feb 21, 2006 6:41 am
by Hayabusa
I'm guessing that the self focussing effect (if it in fact exists) is do to the magnetic field.

As the electrons move they produce a magnetic field, and with more then one electron these fields combine, and create a force in the direction of pulling the electrons in closer.

If my guess (above) is correct, then wouldn't this effect become more pronounced with increasing electron velocities (i.e. higher voltages)?


Re: The Nature of Charge

Posted: Tue Feb 21, 2006 6:51 am
by Todd Massure
I see that some other messages have been posted since I started writing, so excuse the partial redundancy.
The self focusing effect would not come from the charge density going away or any of the charge becoming positive, It would come from the magnetic field being produced by the current of the beam which would continually deflect the electrons back in on themselves. The electrons both produce the magnetic field and are affected by it obeying the right hand rule in both cases.
Actually it seems that the only way that the scenario can agree with relativity would be if it were in fact impossible to have a self focusing beam. If the current density required for for a self focusing beam approaches infinity then only a beam traveling at light speed would not spread out (theoretically impossible) and an observer travelling at light speed would not percieve the passing of time. I probably won't attempt to calc it out tonight, but this is one that's puzzled me for a while.

Re: The Nature of Charge

Posted: Tue Feb 21, 2006 7:16 am
by Hayabusa
Another property, which has puzzled me, is the idea of an electron perfectly (very near to) orbiting a proton (nucleus).

The analogies of comparing the orbit of a satellite around the earth, I find to be in adequate, as much effort is put into placing it there. Where as an electron seems to find this stable orbit all by itself. Why doesn't it just spiral into the proton? What forces guide these electrons in to these orbits?


Re: The Nature of Charge

Posted: Tue Feb 21, 2006 4:13 pm
by Richard Hull
Roger, physics can answer your question with a riddle and the need for faith. (read this as they don't know really). The important thing is that the electron doesn't classically orbit as you might imagine in a simple planetary model fashion. This Bohr-Sommerfield atom sorta' died for the high end physicists in the 1920's.

We are told the electron doesn't radiate yet to orbit in the classical sense, it would have to be in constant acceleration and thus radiate. Instead, it just comes to a dead stop in a kinda' orbit or energy band just shy of killing itself smashing into the proton.

I find solice in that it doesn't obliterate the proton charge due to the ultimate law of physics. Charge can neither be created or destroyed. Nature does what it does by whatever process to prevent this by finding the closest observed approach of a proton and electron in the neutron, (atomically), and in the hydrogen atom, (molecularly).

Many mysteries with no solution in hand that truly satisfies the mind.

Quantum mechanics makes a number of ridiculous suggestions and assumptions to make it go both mathematically and physically. This is all due to experiments that gave whacky results about 100 years ago that they had to 'splain away to their mathematical satisfaction.

It is probably best to just take things on faith for the moment until more understanding is at hand. Follow what the quantumists say, but don, t really believe a word of it.

I know a few annointed physicists who follow the dogma in lock step but chuckle to each other in private. wink, wink, nudge, nudge.

Richard Hull

Re: The Nature of Charge

Posted: Tue Feb 21, 2006 5:50 pm
by 3l
Hi Roger:

Richard and Dave are both correct.
Relativity relates matter in motion and energy at rest E=mc^2
But what they won't tell you spitttz come into the back alley.
Look in my truck.
When you wind a spring the energy you put into deforming that spring using hooks law is actually relativistic. HUH? Just what I said. Any system that uses conservation of energy rules is relativistic. The spring actually gains mass equal to the input tiny that no one can measure it with normal means.
Leave it to Tricky Dick (Richard Feinman) to actually measure it at Cal Tech. He proved it by hanging a dry cell battery on a balance and used an inferometer at the balance pan to measure it. Well the pan balance didn't show anything. Dick almost lost a 1000 dollar bet to NBS but the inferometer showed the weight gain when that dry cell was charged the energy the dry cell used to charge with was plugged into e=mc^2 and blamo the mass checked.

Charge is mass independent no matter how you slice it ...can't change it. Ex. Fission a U235 nucleus the charge balance on the electric side never changes at all all the pieces (fission fragments) and all the original electrons in the unsplit U235 are equal despite the fact 200 mev of mass just vanished. Therefore charge does NOT behave relativistically. The electrons with the destroyed mass fraction still remain the same. unchanged. What is a charge? Tell me where God is and I'll get right back to ya!

Happy Fusoring!
Larry Leins
Fusor Tech

Re: The Nature of Charge

Posted: Fri Feb 24, 2006 2:54 am
by Alex Aitken
Todd is actually much closer to the money. I came up with the same question a few years ago after playing with rareified gas tubes and magnets. A few ma will collapse from a diffuse plasma against the scattering effects of the gas ions due to the magnetic field produced by the beam. A weak magnet would send the thing into loops, so that suggested magnetism was indeed strong enough to be responsible.

At first glance the passage of electrons does apear to be different in different frames of reference, and there is no need to invoke einstein, this is newtonian relativity.

The solution to the basic quandry is actually rather simple, the universe is neutral. So if you have static electrons, with no current in one frame of reference, then you also have counterbalencing positive charges (ions, nuclei, positrons doesnt matter). The electrons do not move relative to the positive charges, and so there is no magnetic field in the stationary frame of reference. Change to a moving frame of reference and the positive charges and negative charges move in the same direction at the same speed. Still no current, and still no magnetic field. Whatever frame of reference you choose the relative speed between the positive charges and electrons remains the same, so the current is the same and the magnetic field does not depend on the frame of reference.

There are relativistic solutions to the problem of a single electron, they are beyond me.

Re: The Nature of Charge

Posted: Fri Feb 24, 2006 5:06 am
by Donald McKinley

Could you amplify on your last post in this thread? There are one or two details I found ambiguous.


Re: The Nature of Charge

Posted: Fri Feb 24, 2006 4:20 pm
by Richard Hull
Marvin's discussion of how easily an electron stream of a few ma is deflected and coiled with a weak magnet. To his view this meant the electron stream had a pretty decent mag field around it.

Quite the contrary is the case. The electron beam coiled and twisted in the "intense field" of the "weak" magnet due to the electron's ultra low mass and thus kinetic energy. A magnetic field strength is related to amp turns a 20 ma beam of electrons would have a tiny magnetic field. Even a klutz kids magnet would have a 500 gauss field! The turning of the beam is a function of the velocity of the charges and the KE of the individual particles in any given field.

So, even a 40kev electron beam of a few ma is easily turned not by the BEAMS magnetic field's reaction to an externally applied field so much as a function of the indivdual micro massed, charged particle's reaction while in motion within the exeternally applied field. One needs to just forget a beam's magnetic field strength unless it is an arc of many amps.

Current makes magnetic fields This is related solely to the number of charged particles moving past a point. The more charges moving past that point, then there more little micro magnetic fields add to the net magnetic field at that point.

Richard Hull

Re: The Nature of Charge

Posted: Sat Feb 25, 2006 3:27 am
by Alex Aitken
Not quite, though I admit standards of proof are somewhat lower for high school than would get into Nature.

Firstly my beam was not a pure electron beam, it was an arc in a low pressure gas. They do collapse into a single stream fairly easily, but at very low currents fill the whole tube.

This is distinct from an electron beam in a TV in that is it microscopically as well as macroscopically neutral. So for a TV the counterbalencing positive charges are a long way from the beam, and thus the magnetic field is spread over a wide area and not concentrated. For an arc, being neutral, the magnetic field is most concentrated around a very thin filiment of conductive gas/electrons. The actual field strength at surface could easily be in the gauss range for a 20ma discharge and it only has to be enough to counteract diffusion in the tube, this does not require very strong forces.

From my limited experience it takes a significant field to deflect an electron beam even slightly, the neutral plasma current was much more dramatic, the fairly weak magnet made it do some spectacular cork screws, but it shows from the magnetude of the response that a gauss range magnetic field could be responsable for the collapse.

In a TV tube the magnetic field is spread out and weak but also the high energy of the electrons makes them much harder to steer. This fits what we know, TV beams do not self focus, to any extent we can see.

For a discharge in a gas there is a magnetic field concentrated around the filiment that forms, and this is in a direction that causes the filiment to self confine. Two wires with current flowing in the same direction attract eachother. The electron energy is also many orders of magnetude smaller than in the TV tube. This also fits what we know, diffuse discharges in a gas above a certain current collapse into an arc.

Its also worth remebering just as a sense of perspective, that in a wire with flowing current the energy is contained mainly, not in the kinetics of the electrons, but in the magnetic field surrounding it.

The specific question I asked is why the beam confinement does not lead to a paradox, as the magnetic field produced by individual electrons would seem to seem to overlap in our frame of reference to produce a force that keeps them together, but in their frame of reference nothing is moving, so the like charges should force them to seperate. Its quite plausable in post einstein relativity you could argue that a magnetic field strength may or may not change in certain frames of reference and noone would know any different, its rather harder to accept that in one frame the physics dictates things collapse and in another expand.

The answer that from the electrons perspective its the field created by the moving positive charges that keeps them in line is good for this observation in a gas tube, and the apparent paradox of 'just electrons' in TV tubes. The paradox itself arises from nothing more than the assumption that you can have a closed system that is not neutral.

Re: The Nature of Charge

Posted: Wed Mar 22, 2006 1:09 pm
by EGPreston
For this topic you may enjoy seeing this paper:
However, this model is inconsistent with experimental data showing the electron to be a purely point particle. Neither do any models include the role neutrinos play. All the electron models I have seen are inconsistent with observations. The correct electron model has yet to be formulated.