Dipole magnet as a cathode

Jun 2019
6
1
Hey physics professionals.
This is a somewhat odd request for info but I thought I'd run it up the flagpole here, see who salutes; I'm aware a dipole magnet can't be a cathode, what I can't find is any specific information as to why. The kicker is I'm going to attempt to explain this to an audience that likley wont understand physics so I'll need as close to a layman term as I can get.
Thanks in advance to anyone willing to help. Mike
 
Jun 2019
6
1
Suppose I should explain further for clarity.
Just for entertainment purposes I'm going to be debating an 'electric universe' or 'plasma universe's proponent in a live stream. In preparation I've read into their, ahem, 'theorys' and found it to have so many glaring obvious problems even find it a ridiculous concept.
The guy I'm debating is pretty fluid with the linguistics and concepts and somewhat with conventional physics also, physics I likely never learned or have been radically developed since. Thus ideally I need to stick to what I do know and how that alone counters his claim.. the issue I have here is while I may know it, I would be required to prove it in some way, or at least convey the concept coherently. It's been a long time since I put pen to paper for any physics problem and many laws are but a distant memory.
Again, thanks in advance.
 
Mar 2019
758
40
cosmos
@Gentley:
This semi - tramp is not a physics professional but only a physics curious, so he salute to any physics flagpole.
I think that you know the physical principle clearly: the magnetic field of the magnet will deviate the electron from the normal moving route in eletric field.
But what you want is a vivid and philosophical analogy, isn't it?
 

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topsquark

Forum Staff
Apr 2008
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On the dance floor, baby!
Hey physics professionals.
This is a somewhat odd request for info but I thought I'd run it up the flagpole here, see who salutes; I'm aware a dipole magnet can't be a cathode, what I can't find is any specific information as to why. The kicker is I'm going to attempt to explain this to an audience that likley wont understand physics so I'll need as close to a layman term as I can get.
Thanks in advance to anyone willing to help. Mike
Yes and no. A cathode is a device that attracts electrons. Since a dipole magnet has no electric charge on it to attract electrons it can't be a cathode.

On the other hand, if the dipole is located in a stream of plasma then the magnetic field will indeed move the charges in the plasma so we see a migration of electrons to one pole of the magnet. Technically not a dipole but on a small scale (compared to the physical size of the magnet) one end of the magnet can look like a cathode.

-Dan
 
Mar 2019
758
40
cosmos
@Dan:
What's the term "dipole magnet" mean exactly in English? I feel it means "a magnet with two poles"?
 

topsquark

Forum Staff
Apr 2008
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627
On the dance floor, baby!
@Dan:
What's the term "dipole magnet" mean exactly in English? I feel it means "a magnet with two poles"?
Yes, magnets have dipole moments. North and South, like a compass. (There have been no deteced monopoles.) But you can have higher polar moments as well by placing a system of magnets in the right positions.

-Dan
 
Mar 2019
758
40
cosmos
@Dan:
What's the difference between "dipole magnet" and "magnetic dipole" in English?
 
Apr 2017
523
126
I don't see why a dipole magnet cant become a cathode ....

Just wrap the negative wire around a magnet , put it in the solution and it becomes a cathode ...

 
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Jun 2019
6
1
Thanks for the replies.
I did try to post a follow up with more detail but due to my first post being held for moderation the second never appeared.

So to clarify; Just for entertainment purposes I will be debating an 'electric universe' proponent in a live stream. I've already had one very brief exchange with him, I was totally unprepared and hadn't fully understood what the 'EU' theory even was. He went on to discard E=mc2 and suggest redshift wasn't due to the dopler effect on a stars em wave.. he did so quite elequently using current physics models, yeah, it threw me to say the least.
I want our second discussion to go very much in my favour, so I've read all I can stand of the pseudoscience behind their 'theorie' and have prepared rebuttals to some of the more glaringly obvious flaws.
One such flaw is the reason for the topic title question: if electricity is flowing from star to star in the form of some kind of dark mode plasma stream (you read that right!) that the dipolar magnetism of the sun would break down due to the current. I was pretty sure EM follows the electron flow along the conductor, thus couldn't center a magnetic field on the star (which in effect would be a cathode and in the middle of the conductor)

It's been a very long time, 2 decades or more, since I put pen to paper to for any physics problem or electronics theory, and to be honest I wasn't that great even then. The guy I'm debating on the other hand is very fluent in the linguistic, his EU ideas and somewhat with current physics also, so the liklihood of me getting totally snowballed is pretty high at this point.

Am I wrong in asserting that in the given example a cathode can't also be a dipole magnet? And please, if anyone has any other really great 'audience friendly' arguments against 'EU theory' that I haven't though of I'd be grateful to hear it.

Thanks again for the replies. Mike
 
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Jun 2016
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I think Topsquarks original interpretation of the cathode as in an old cathode ray screen is what the OP was thinking of.

The problem then would be that you want the electrons to travel in as straight a line as possible away from the cathode,
so that you can subsequently bend it in a very precise controlled manner to create the picture on the screen.

However if the cathode were magnetic, the electrons it emitted would follow a curved path through the magnetic field it generates.
 
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