Magnet Myths and Misconceptions

[EMJunkie]

LOL, you've just posted yet another reference that is at complete odds with your claims.  Note that the compass' that lay along the equatorial projections point:  wait for it ... essentially parallel to the earth's magnetic dipole.  Note that the magnetic lines connect uninterrupted between the to magnetic poles.  Note that there is no curl from each pole to the magnetic equator.

When are you going to give up this put on act of yours?

To All following!

I propose something crazy!

All Magnetic Fields are drawn throughout history to represent the Iron Filing Experiment. The Iron Filing Experiment is the Basis for Closed Line Magnetic Fields.

Does everyone agree with this Crazy fact?

Regards

  Chris

[EMJunkie]

Chris:

For the solenoid, if I can ask you to just look at just one clip, it's this one.  You will note adding and canceling magnetic field effects and how the field outside the coil loops from the north end back to the south end.  Of course it's much less dense outside the coil because it has to fill all of 3D space.

Then he uses Ampere's Law to calculate the field at the center of the solenoid. He does this by drawing an Amperian Loop to take a 'bite' out of the coil.  You then take a "walk around the loop" and do a summation to calculate the field - a closed-loop line integral.   It's a simple and elegant solution that is very easy on the difficulty scale for understanding and following integrals.

There is a part 2 but you can find it if you want to go the whole way.

https://www.youtube.com/watch?v=4c6fRmyh4q8

Honesty, it's giving you the actual architecture of a coil.  Please look at it and see if it fits into your "world view."

Just for fun I have a 'litmus test' question for you, and the nature of this question would apply to your first pdf and other pdfs that you linked to.

These two equations describe how a coil works in an electronic circuit:

v = L di/dt

i = 1/L integral v dt

Are you familiar with them and do you understand them and ever use them?  If you understand them they give you more insight into how coils work.

I know that there is no point repeating this, but there is a wide gulf between what you "see" and what there really is.  I would hope that one day you bridge that gap.  Especially if you are interested in this stuff and have fun with it.  Like you could... Measure the value of an inductor with your scope.  Or you could measure how much energy you can store in a transformer core.  Doing things like that bring coils "down to earth" also.

I will leave you with this final thought:  When you get into your car, and put on the gas, it's like you are a coil.  lol  1/2 L i^2 = 1/2 M v^2!

MileHigh

MileHigh - Brilliant Work! Its your best yet! What are the Red Bits?

[MarkE]

Mark
Here is the problems I have with the compass test-1i have mentioned before with the two magnets with a spacer between them will show the same result, even though we know fore sure there is both poles present. The second is this-my compass needle will swing toward a magnets pole over 3 feet away insted of showing earths north/south fields.

Tinman, let's see if we can get to a test that we agree upon.

Do you agree that if we take two dipole magnets and separate them by a large distance that a compass will show the curl at the near poles of each?
Do you agree that if we bring them together such that they look like just one magnet that effect disappears?
Do you then agree that if we make a very long magnet and that it shows only flattenening, IE becoming more parallel as we approach the center that will mean that there is no curling towards the center?

[MileHigh]

Mark
Here is the problems I have with the compass test-1i have mentioned before with the two magnets with a spacer between them will show the same result, even though we know fore sure there is both poles present. The second is this-my compass needle will swing toward a magnets pole over 3 feet away insted of showing earths north/south fields.

For the two magnets with the spacer in between them, here is where the "poles" analogy breaks down.  The applies when the gap between the magnets is relatively small.  The best way to look at this is the north pole is at the end of one magnet and the south pole is at the end of the other magnet:

[N>>>>>>>]==[>>>>>>>S]

Or perhaps even better this:

[N>>>>>>>]>>[>>>>>>>S]

The majority of the magnetic flux in the gap goes from one magnet to the other.  In that sense the two magnets look much more like a single magnet than they look like two magnets.

So when you look at what is taking place in the gap, is it north and south?  Or north-south?  You have kind of lost your frame of reference for describing something as a "pole."   A "pole" is always at the "free end" of a magnet.   The bulk of the magnetic field between the magnets is "trapped."  So in that sense there is not a north pole and a south pole facing each other in the gap in the way one would normally associate that concept.

Then what happens in the limit as the gap gets smaller and smaller?

MileHigh

[MileHigh]

MileHigh - Brilliant Work! Its your best yet! What are the Red Bits?

If you don't want to be serious, that's up to you.