Magnetic fields within a toroid inductor.

[Dave45]

Lets say we have 2 toroid cores and wind them the same. Then use a ferrite rod through the toroids centers like an axle with wheels. I wonder if input to one would induce the other? Just thinking. If we can run 1 wire through the toroid, equal to 1/4 turn, really, and get output from that wire, then why not see if we can draw out any flexing fields from one core to another via an axle core.  Also, how would a core in the hole of a toroid affect the toroid coil function, or value. All things to try.

Mags

[MileHigh]

Xee2:

If you have a space filled with multiple magnetic field generators, as you move about the space there may be places where the magnetic field strength goes to zero. If the magnetic fields actually disappeared, then where did the energy in the magnetic field go? The only reasonable answer, is that the fields and their energy are always there. It is only measured strength that goes to zero. Back when I started in electronic engineering (a long time ago) we used slot lines (which are slots cut in wave guide) with a probe to measure the e-field strength inside the wave guide as a way of determining microwave frequency. If the signal really disappeared when the e-field went to zero there would be no wave coming out the end of the wave guide (but there was). I feel that teaching that the field disappears creates a lot of confusion about what is really happening.

You are missing an important distinction.  We were talking about an example were there were interacting fields from two wires with DC current going through them.  In that case there will be places in the 3D field where there is no magnetic field and by definition there is no electric field.

Here is a thought experiment:  You have a 10-meter length of straight wire.  So that's an inductor.  You put 10 volts across the ends of the wire and let's say 10 amps of current flow.  It takes a short while to overcome the inductance and build up the magnetic field that surrounds the wire.  So we know that there is a certain amount of energy stored in the magnetic field around the wire.

Now, lets take the same same wire and make a 180-degree bend at the 5-meter point so that the wire is folded over and the two ends of the wire are right next to each other.  You put 10 volts across the terminals and 10 amps of current flow.  However, there is a huge difference here.  The parallel halves of the wire create magnetic fields that mostly cancel each other out.  Therefore the inductance for this wire configuration is much much smaller than for the straight wire.  Therefore the current rises to 10 amps much much faster, and there is much much less energy stored in the magnetic field around the wire.  So there is no "energy that was always there" in this configuration.  There is simply less energy from the get-go.  Everything balances out like it is supposed to.

In your case, you are making reference to standing waves in a microwave waveguide cavity.  I vaguely remember doing the experiment where you stick a sensor needle into the slit in the waveguide to sense for the intensity of the electric field.  I am not qualified to state exactly what is going on there but I can say that this is an AC resonator-type configuration and not a DC configuration.  So it's a whole different ball of wax and when you aren't sensing the electric field there may be a complimentary magnetic field at play.  I get a headache just thinking about it.

Let's look at a more manageable AC standing wave setup.  You set up standing waves with a skipping rope.  So is there no energy at the nodes where rope is not moving?  The answer is no, when the skipping rope standing wave reaches the peak of the oscillation and stops for a brief second, all of the energy is stored in the stretched rope.  So the non-moving node is actually the center of a stretched linear spring in this example.  You have a rough analogy were the AC rope velocity and the AC rope stretched spring tension are equivalent to the AC electric field and the AC magnetic field.

It's a good segway into thinking about an analogy for an energized inductor.  I think many people on the forums might just think that "it happens."  Think of holding a big beryllium copper torsion bar in between your two hands.  You twist it and takes a lot of work to bend it.  You can only hold it in the bent position for 10 seconds max.  So you release the pressure and it kicks back.  There is your "collapsing magnetic field."  If you are straining to hold it in the twisted position, it may feel like your body is doing work on the bar, but of course that's not the case.  You hold it for as long as you can and then the work you put in will be kicked back at you.  People on the forums often fail to visualize the work aspect to energize a coil and the fact that the magnetic field is kind of "stressing" the space in the immediate area and the space wants to stress right back and get back to normal.  You are "bending the space" and it doesn't like it and wants to get back to the unbent position.  Instead, they daydream about the clockwork of the Universe, or they search for "magical" coil configurations, bla bla bla.  It's much more basic than that.

MileHigh

[Dave45]

You are missing an important distinction.  We were talking about an example were there were interacting fields from two wires with DC current going through them.  In that case there will be places in the 3D field where there is no magnetic field and by definition there is no electric field.

Not true, you dont know what you are talking about, period.
I could prove you wrong but will not waste my time.

[MileHigh]

Dave45:

Not true, you dont know what you are talking about, period.
I could prove you wrong but will not waste my time.

I do know what I am talking about.  There is an electric field but in the context of this example there is no electric field that merits being part of the discussion.  Also, the dismissive "waste my time" shtick is getting tiring and it's rude.  Likewise, saying "you don't know what you are talking about" is just a cop out on your part.  I have been around this forum long enough so that many people will state that I do know what I am talking about and I try to make a point of only discussing what I know about.  By the same token I am human and not perfect.

So, like I said before, make your case and be straight with no hints, no teases, no smoke and mirrors.  Please stop making these "spooky" postings.  Just be real.  Can you do that?

For reference, here is the example from the earlier posting:  We were talking about an example were there were interacting fields from two wires with DC current going through them.  In that case there will be places in the 3D field where there is no magnetic field and by definition there is no electric field.

Where is the electric field in this example Dave?  Please state your proof that I am wrong.

[Dave45]

Your right it was rude and I apologize
Here's some more pseudoscience for ya

this is a coil powered with 12v dc