Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Obscure Magnetic effects on copper wire

  1. May 5, 2010 #1
    Hello All,

    I am trying to do some research to see how many known magnetic effects (related specifically to conductors) have been discovered. So far, I know of the most common one, The Lorentz Force, which is due to the effect of an electromagnetic wave moving across a wire. I am specifically interested in knowing if there are any other similar effects that are less well known but hidden in the literature somewhere?

    The reason I am asking this is because I am wondering under what conditions a current can be caused to flow down a piece of copper wire (other than the obvious choices, voltage potential mechanically applied, or magnet swiped perpendicular to the wire). I am also ruling out any chemical effects, as I am specifically wondering if anyone here is aware of any other known magnetic or electromagnetic effects out there.

    Thank you,
    Jason O
     
  2. jcsd
  3. May 5, 2010 #2
    I guess you could put the copper in a centrifuge, and use inertia (i.e. gravity) to shift a slight charge to one end of the lattice.

    Maybe you're looking for something more like the magnetic Hall effect?

    ..or with high frequency EM fields, you could use the photoelectric effect..
     
    Last edited: May 5, 2010
  4. May 5, 2010 #3
    Hi Cesiumfrog,

    Thanks for the great ideas! Actually, I did consider the Hall Effect as one possible candidate, but I was under the assumption that the Hall effect is really due to the Lorentz force?

    As for the inertial charge idea, this is definitely a novel concept. Is there an 'official' name for something like that?

    To answer your question though, I am really focused on any magnetic or other effects that use external fields to influence the current in a wire. One thing I was looking at a while back was the Rotating magnetic field Current Drive effect, which I posted about in this old thread here:
    https://www.physicsforums.com/showthread.php?t=223019

    I thought this effect was very interesting (though nobody bothered to comment on it). I posted this at the time because I was wondering if the mentioned effect could also apply to free electrons in a copper wire as well as a plasma.

    A second post that I made a long time ago involves another interesting effect known as Magnetic Reconnection. Again, most papers I have found relegate this effect to astronomical scales and involving plasmas. Here's a link to the post about it:
    https://www.physicsforums.com/showthread.php?t=145368

    This thread also has an interesting thought experiment I proposed some time ago that's along the same lines as this thread (only looking at the electrostatic potential side rather than the magnetic):
    https://www.physicsforums.com/showthread.php?t=135812

    There is one other interesting magnetic effect I found that I thought would be a relevant addition to the current discussion. It's called the magnetic bottle effect. Here's a video illustrating it:
    http://www.youtube.com/watch?v=FiwqNDJuGkI&feature=related

    One question I have is if the magnetic field that creates this bottle effect were moved down the length of a copper wire, I wonder if an electric current could be 'dragged' along the wire with the movement of the field. It's an interesting contemplation. Any thoughts?

    - Jason O
     
  5. May 6, 2010 #4
    All of these microscopic processes are related. Thermodynamic properties such as temperature and pressure affect the movement of atoms and the electrons of the copper, so doing work on one end would push the piece out of equilibrium and cause electrons to move, yes? We do use magnets to drive currents....generators.
     
  6. May 6, 2010 #5
    This smells like crackpot free energy... but I'll answer anyhow.

    The laws of concern are all well known. The Maxwell equations are superb in describing pretty much all electromagnetical phenomena. All the effects you mentioned are a consequence of these. So in a way there is only one effect that moves charges. If you understand the Maxwell equations, and see how they describe things like transformers or the Lorenz force you might get new ideas.
    But be assured that you will not find a cheap way to produce electricity. The Maxwell equations do not violate the laws of thermodynamics, and thus you will need a source for your energy. Finding a way to tap an energy source is the hard part, getting the electrons to flow is the easy part.
    For example there is tremendous energy in the earth's magnetic field. You could extract some with a large coil, from the natural fluctuations of the field, but if you went through the calculations you would notice that it will be barely detectable. The main part of the energy you cannot access. There are many more interesting things like thunderstorms, ocean currents, earthquakes, that we cannot tap into so far...

    Sorry if I am way off about your intentions but these questions tend to be asked by similar people...
     
  7. May 6, 2010 #6
    Hi 0xDEADBEEF,

    First of all, No, I am not a crackpot free energy researcher, though I am interested in alternative energy research and the exploration of unconventional sources of energy. That being said, I have no problem with the laws of Conservation of Energy nor thermodynamics. I am simply studying some interesting phenomena that I have been experimenting with and am looking at other known physical effects to aid me in my research.

    Yes I realize that there are some people out there who are making claims of perpetual motion etc, but given that there are already many well documented and undisputed sources of energy to tap into, I see no need to delve into that subject. I am simply developing some practical engineering models based on empirical tests and I am always on the lookout for interesting effects to explore.

    Thank you for your input.

    - Jason O
     
  8. May 6, 2010 #7
  9. May 6, 2010 #8
    Thank you for the interesting link. Yes I have heard of this before as NASA had pursued such a venture some time ago.

    I would like to clarify to all here that I am not asking how to capture free energy from magnetic fields. I am simply looking for various magnetic effects that can cause current flow in a wire other than the conventional induction methods employed by most generators. Obviously there has to be an energy source (weather natural or man-made, I'm not disputing that point here). Anyway, I hope i have made my intentions clear.

    One thing I have been exploring is the use of effects that are generally associated only with plasmas to see if any of them can find application using conductors.

    Thank you,
    Jason O
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook