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?

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

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

I have been MileHigh, for about 70 odd posts!

I am going to go back to one of them, the Long Solenoid Experiment carried out by Science every day disposes your drawing! I am sorry but it is true!

I am really sorry that you and MarkE are having to debate what you believe to be true!

Like I have always said, Experiment is proof and nothing else can refute Experiment. Physics has real MEASURED DATA to ensure there is no Piffle in these Experiments! Long Solenoid Experiment Wins.

Regards

  Chris

Chris, so why is being in a car like being in a coil?

It's a dead serious question.

It's a dead serious question.

Milehigh - How else would you "Travel through the middle of the Magnet"? Personally I have a Quantum Auto, some might call it a Car?

It's hilarious that you say that, because each experiment you have offered, including three of them in Professor Lewin's excellent lecture all refute your loopy claims.

Oh MarkE - Here we go again! I think you may still have had your Eyes, Ears, and a few other things Closed during the Time of this Lecture!

Really, I have provided how many Links, all showing the same thing!

Others have done the same thing!

You refute these facts simply because you have nothing to backup your Compass experiment or your Iron Filing Experiment!

MarkE - Anyone here can go and do the research, see that your FOOLING them! Its not hard to see this fact already!