# Zet

Senior Members

57

-2 Poor

• Rank
Meson

## Profile Information

• Favorite Area of Science
physics
1. ## what happens at a distance when an electromagnet is turned off?

I get it. I was wrong. (Well, I don't totally get it. I need to spend some time studying this area of physics. But I get, I think, the basic overall logic of it.) So, when we have two electromagnets attracted to one another (and they have been for some time) the "center of energy density" is halfway between them (assuming the two electromagnets are the same). They are accelerating towards one another. One is then turned off. It stops accelerating. But the other one (the still turned on one) continues to accelerate for a while. This increased amount of momentum of th
2. ## what happens at a distance when an electromagnet is turned off?

. Yes, the supplicant has the burden of proof and not the pedagogue, if he is trying to prove something. However, if the supplicant asks a question and the pedagogue does not directly answer the question but rather points to a field of study, then, presumably, the teacher is saying that the answer lays in that area of study, and simply leaves it to the student to put the pieces together. So, in the thought experiment above where there are two electromagnets and they are turned on and off in such a way that the one is set into greater motion towards the other, if the response to
3. ## what happens at a distance when an electromagnet is turned off?

There is nothing in your last post that I disagree with. However, there is nothing in you last post that addresses the issue. No one is asking you to give us a MOOC on electromagnetic theory. The issue raised is whether or not the third law of motion is violated in this case. And no one is even asking you in particular to address this either. However, if you seemly purport to have addressed it and seemly purport to have put the matter to rest, but you actually don't, then you are going to get called out on it. You seem to conclude with the speed of changes in a magnetic field in
4. ## what happens at a distance when an electromagnet is turned off?

"Newton's third law is only seemingly violated in such situations. You need to remember that the electromagnetic field itself carries momentum." - ajb Okay. So make your case. Assertions are like opinions ... everybody's got one.

. Um ... ? .
6. ## a magnet is demagnetized

. hey moth ... I believe I understand your point. In a closed system, the amount of energy in that system, is frame dependent. If you move from one inertial frame of reference to another, say in a system such as the Universe, the total amount of energy within that system will change. And so if you look at things from the faster moving magnet at rest and from the slower moving magnet at rest, you will get two different amounts of total energies between the two systems. Is this what you’re getting at? If so, I tried to address this in endnote #9 (but, again, the
7. ## a magnet is demagnetized

. I don’t. My original post is an easy read but it is very long. And I totally understand the idea that no one wants to waste their time reading that much text “knowing” that there must be some simple flaw (or flaws) buried somewhere in all that text. I get it. That’s why I spent time working with the issue to present it in another way and in a much shorter form (post #21). I don’t see how anyone could read your post #24 as anything other than a complaint about my use of fonts and their formatting. If there is another hidden implication in
8. ## a magnet is demagnetized

. I guess I would characterize your response as “reductio ad absurdum with font formatting.” That’s it? Am I to understand that the problem with my question in post #21 is not logical or factual but rather “an improper use of fonts”? The endnotes in post #21 are superfluous to the question and so are accordingly diminished in size. They are merely there in anticipation of the kinds of tangential issues that may arise when addressing the question. The actual question itself should be easily readable. I realize the original post in this thread is very long and probabl
9. ## a magnet is demagnetized

. Silence, generally, means consent. “Silence implies consent” http://c2.com/cgi/wiki?SilenceImpliesConsent “he who is silent is taken to agree” http://en.wikipedia.org/wiki/Silence_procedure “Silence means consent” https://www.englishclub.com/ref/esl/Sayings/S/Silence_means_consent_925.htm “Silence gives consent” http://idioms.thefreedictionary.com/Silence+gives+consent Can I take the collective silence of the members of Science Forums to mean that I found a violation of the Law of Conservation of Energy in post #21? (I realize
10. ## a magnet is demagnetized

. Hello. If anyone has the time, could you please show me why the question in post #21 does not lead to a violation of the Law of Conservation of Energy? Thank you. - Zet I’m always willing to learn. I worked hard on the question. .
11. ## a magnet is demagnetized

. (Please note: I posted this question as its own new separate thread ... I thought it was distinct enough to warrant a new conversation ... I was wrong ... I misjudged the parameters of the rules of this forum ... I apologize ... I hope that I am now able/allowed to post it here, in this thread, even though I've already posted it in its own separate (and locked) thread ... thank you ... and, again, I apologize for my misjudgment.) There is an even simpler form of this question; with demagnetized and moving magnets. There are two closed system
12. ## an even simpler form of the question, with demagnetized and moving magnets

. A Question about the Logic of the Law of Conservation of Energy with Demagnetized and Moving Magnets. There are two closed systems. In terms of energy each system is identical. In each system, there are two magnetically aligned ferromagnets. One is fixed in place, and the other one is in motion moving towards the fixed one due to their mutual attraction. In each system, there is a chemical heat pack. If the chemicals are exposed to one another thermal energy will be generated. The temperature in the vicinity of the heat pack after the chemical exposure wi
13. ## a magnet is demagnetized

. The demagnetized state is the higher energy state and magnetized state is the lower energy state. “... this torque tends to line up the magnetic moment with the magnetic field B, so this represents its lowest energy configuration” http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magmom.html “... the energy is lowest when the magnetic moment is aligned with the magnetic field.” http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magpot.html “This reduces the electrostatic energy of the electrons when their spins are parallel compared to their energy w
14. ## airfoil rising

Yeah. I tried to set up my thought experiment to avoid issues of “thrust” or “different amounts of initial kinetic energy” and just get to where I’m having a problem (different decreases in pressures on the top and bottom adding to the rise of the airfoils). I tried, ... but I don’t think I succeeded. Airfoils are complicated things, and I probably should stay away from them. I do thank you all for adding to my understanding of the issue. Whether you all believe me or not, I have learned from this discussion. Thank you for all of your time, effort, and ... patience!
15. ## airfoil rising

. So, when the fluid moves over the airfoil there is a certain amount of "dynamic" potential energy. If the airfoil is free to rise, it will. When it rises this potential energy becomes kinetic energy. Okay ... cool. What then happens to this "dynamic" potential energy when the airfoil does not rise ... and after the fluid passes and this potential energy is then gone? The Law of Conservation of Energy states that energy can change forms, but the total amount remains. Are you suggesting that there was an amount of energy in the form of "dynamic" pot
×