04-11-2026, 08:55 AM (This post was last modified: 04-11-2026, 09:12 AM by Verpies.)
(04-11-2026, 08:04 AM)#Que Wrote: Don't try to muddy the waters any more with false assertions that you can't back up.
I am confused. Are you implying my malice or my stupidity ?
In your Reply #12 you have posted the following screenshot:
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Then you wrote:
(04-10-2026, 04:53 PM)#Que Wrote: ...you'll see the difference between the field surrounding a coil of wire and the field surrounding a permanent magnet using both the iron filings and the ferrocell. Interestingly, the inductor does not behave the same way that a magnet behaves which becomes very clear when you see BOTH the iron filings AND the ferro-cell images in the same context.
But you are violating what you preach, because the coil is rotated 90° compared to the permanent magnet so the field of these two object is not compared in the same graphical context.
The same graphical context would look like this:
I have annotated the dimensions of these two objects above with blue color.
Anyone can see that aspect ratio of the permanent magnet (DIAMETER1 ÷ LENGTH1) is very different than the aspect ratio of the coil (DIAMETER2 ÷ LENGTH2) and I have pointed this out in my Reply #13.
...but you have changed the subject and gone off on a tangent about frogs and viewing screen aspect ratios !
If the aspect ratios of the PM and coil were equal, then their magnetic fields would look like this and be almost identical:
Who is muddying the waters and confusing people with false assertions now, huh ?
04-11-2026, 10:05 AM (This post was last modified: 04-11-2026, 10:13 AM by #Que.)
(04-11-2026, 08:55 AM)Verpies Wrote:
(04-11-2026, 08:04 AM)#Que Wrote: Don't try to muddy the waters any more with false assertions that you can't back up.
I am confused. Are you implying my malice or my stupidity ?
In your Reply #12 you have posted the following screenshot:
Guests cannot see images in the messages. Please register at the forum by clicking here to see images.
Then you wrote:
(04-10-2026, 04:53 PM)#Que Wrote: ...you'll see the difference between the field surrounding a coil of wire and the field surrounding a permanent magnet using both the iron filings and the ferrocell. Interestingly, the inductor does not behave the same way that a magnet behaves which becomes very clear when you see BOTH the iron filings AND the ferro-cell images in the same context.
But you are violating what you preach, because the coil is rotated 90° compared to the permanent magnet so the field of these two object is not compared in the same graphical context.
The same graphical context would look like this:
I have annotated the dimensions of these two objects above with blue color.
Anyone can see that aspect ratio of the permanent magnet (DIAMETER1 ÷ LENGTH1) is very different than the aspect ratio of the coil (DIAMETER2 ÷ LENGTH2) and I have pointed this out in my Reply #13.
...but you have changed the subject and gone off on a tangent about frogs and viewing screen aspect ratios !
If the aspect ratios of the PM and coil were equal, then their magnetic fields would look like this and be almost identical:
Who is muddying the waters and confusing people with false assertions now, huh ?
Ok. The inventor of the ferrocell, Tim Vanderelli, did an experiment showing the field surrounding an electromagnet is not orthogonal to the permanent magnet. By comparing apples to apples, it is clear that they are the same (see attached image). On the left is an electromagnet and on the right is a cylinder magnet. clearly these are showing exactly the same field geometry under the ferrocell.
I missed how the iron filling of the copper coil is a cross section of a doughnut, therefore they cannot be compared, for they are not the same shape. its only giving the illusion of a bar magnet because of the angle of the photo. I stand corrected! However, according to experiments, there appears to be differences between electromagnets and permanent magnets. Do you agree with this or not?
04-11-2026, 10:14 AM (This post was last modified: 04-11-2026, 10:17 AM by Verpies.)
(04-10-2026, 04:53 PM)#Que Wrote: However, according to experiments, there appears to be differences between electromagnets and permanent magnets. Do you agree with this or not?
There are minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers. I wrote about this in detail here.
Smudge also recently wrote a paper that addresses the space between atoms of a permanent magnet here.
04-11-2026, 11:02 AM (This post was last modified: 04-11-2026, 11:18 AM by #Que.)
(04-11-2026, 10:14 AM)Verpies Wrote:
(04-10-2026, 04:53 PM)#Que Wrote: However, according to experiments, there appears to be differences between electromagnets and permanent magnets. Do you agree with this or not?
There are minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers. I wrote about this in detail here.
Smudge also recently wrote a paper that addresses the space between atoms of a permanent magnet here.
I don't have access to that forum. I personally talked to Chet on the phone and the admin (Peter) approved my registration. However, I'm unable to gain access to it due to my password and login id not matching. I sent Peter an email, and I never heard anything back. I was a long time member of overunity.com before Stephan archived it. I have had many discussions with you on that forum.
An ac electromagnet has a significant oscillating electric field around the windings that radiates outwards. A permanent magnet has no measurable external electric field. I don't see how an electromagnet and permanent magnet will always show the same behavior when an external object may interact with the electric field of an electromagnet, which would give a different result when interacting with a permanent magnet with no external electric field. Please feel free to correct me if I am wrong.
I find it interesting you mentioned minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers. In one of the videos or papers on this special electromagnet, they mentioned something about using either an odd number or even number of washers with a small gap (the space between atoms of a permanent magnet?) between each washer (if my memory serves me correctly). I'll see if I can't find this reference. The copper metal ring embedded in an electromagnet is like a single turn coil. This special electromagnet is similar to the primary and secondary coils of a transformer.
(04-11-2026, 11:02 AM)#Que Wrote: A permanent magnet has no measurable external electric field.
Neither does a DC electromagnet
While it is often assumed that a conductor carrying current has no external electric field due to electrical neutrality, in practice, a small external static electric field can exist, particularly in high-voltage or specific, non-ideal conditions. While typically the net charge in a wire is zero, a small static electric field can be present around the conductor due to potential differences between turns of the coil or external charge accumulation (see attached image. Ai isn't always right). I'll take your word over Ai if it's not correct. Is a small static electric field the reason for the minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers? The odd number of helical winding layers would create potential differences between the turns of the coil or cause an external charge accumulation, which would cause minor differences in the field shape due to a small static electric field. Anyways, I'm going to read and study the two links you provided so I can get a better idea of what is happening.
04-11-2026, 12:56 PM (This post was last modified: 04-11-2026, 01:15 PM by Verpies.)
(04-11-2026, 12:15 PM)#Que Wrote: Is a small static electric field the reason for the minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers?
No. Since it is the current that generates the magnetic field of an electromagnet (not the voltage) it is the uncancelled pitch-component of that current which is responsible for skewing the magnetic field. This is well illustrated graphically, in that link I've provided, with a series of toroidal windings that in each case make one full trip around the circumference of the core while making various number of trips around the toroidal body of the core.
All toroidal conclusions are also applicable to helical windings on solenoids, since a solenoid is just a fragment of a very large toroid.
Strong electric fields can be and are present between the turns and layers of windings driven with high frequency current. Not at DC though.
With a HF PDC or AC drive, the displacement currents "jump" between the winding turns and layers. As the frequency is increased this effect eventually transforms the winding from an inductor to a capacitor. This severely distorts the magnetic field generated by the winding. I hope Unimmortal reads this.
04-11-2026, 02:40 PM (This post was last modified: 04-11-2026, 02:41 PM by #Que.)
(04-11-2026, 12:56 PM)Verpies Wrote:
(04-11-2026, 12:15 PM)#Que Wrote: Is a small static electric field the reason for the minor differences in the field shape when a solenoidal electromagnet is wound with an odd number of helical winding layers?
No. Since it is the current that generates the magnetic field of an electromagnet (not the voltage) it is the uncancelled pitch-component of that current which is responsible for skewing the magnetic field. This is well illustrated graphically,
I have always used same-pitch layers. I wonder how common this mistake is. We should always use an even number of opposite-pitch layers that cover the entire core equally and uniformly, as you have said. It is definitely well illustrated graphically! I'll be rewinding my electromagnet, lol.
