# Is it posible to reverse permntly polarity of a permanentmagnet?

## Main Question or Discussion Point

Im working at this at the moment on this and i was wondering if is posible to reverse polarity of a permanent magnet without expending huge ammounts of energy and keep that polarity

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berkeman
Mentor
Yes. Magnets are made out of "hard" magnetic materials that retain their magnetic polarization. Google B-H curves and hard magnetic material to learn more.

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Hurkyl
Staff Emeritus
Gold Member
The easiest way would be to simply turn it around.

Newton's law applies here. You would have to have a force equal or greater than the magnetic field of the magnet to which it is applied.

Curious3141
Homework Helper
usp8riot said:
Newton's law applies here. You would have to have a force equal or greater than the magnetic field of the magnet to which it is applied.

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Yes, it maybe seems vague if you don't know the concept. All energy can be negated with energy of equal or greater value. It is a scientific fact. What is wrong with my statement? Did that not answer his question. Short answer, no. Not without equal or greater work. And I take it as 'huge' amounts of energy mean more than the original energy the magnet is exerting. Is that still too vague?

Curious3141
Homework Helper
usp8riot said:
Yes, it maybe seems vague if you don't know the concept. All energy can be negated with energy of equal or greater value. It is a scientific fact. What is wrong with my statement? Did that not answer his question. Short answer, no. Not without equal or greater work. And I take it as 'huge' amounts of energy mean more than the original energy the magnet is exerting. Is that still too vague?
I would strongly suggest that you sit down and devote some time to reading basic high school and then college level Physics texts (not pop science books) cover to cover. You really need to acquire a proper foundation in Physics if you want to talk about it. At the moment you are uninfomed or (worse) misinformed about a lot of basic Physics. Nothing wrong in being uninformed, anyway, we've all been there. The important thing is to work toward acquiring correct knowledge.

Am I uninformed of the law of conservation of energy? That is what applies here. I can see how you would see I'm uninformed since I don't argue semantics. But I do have an understanding of physics. I am knowledgeable from the ground up, to the ground down. You are thinking I'm looking too far ahead probably, as into sub-particle physics, the basic algorithms in which mass/energy work. I don't study what is, so much as what is that makes what is. Maybe that's where my outlook seems miscontrived to you. But I assure you as there is light in the day, I've studied physics, and moreso, observed it, more than your average guy. But I will leave the forum if that's what you wish since you don't think I am up to the level to reply.

Doc Al
Mentor
usp8riot: I urge you to take Curious3141's suggestion seriously. Pick up a physics book and start reading.

Frankly, your posts are chock full of vague nonsense:
usp8riot said:
Newton's law applies here. You would have to have a force equal or greater than the magnetic field of the magnet to which it is applied.
Say what? You give the impression that you don't know what Newton's laws are.
All energy can be negated with energy of equal or greater value.
Say what?

Not knowing is not a crime, but posting vaguely worded nonsense will not be tolerated here. So stop it.

Regarding the original question, can you reverse the polarity of a permanent magnet? Yes, as berkeman stated. It requires a very strong magnetizing field. It generally takes more energy to reverse the polarity of a magnet than it did to originally magnetize it, which should make sense since you have to reverse the domains.

It generally takes more energy to reverse the polarity of a magnet than it did to originally magnetize it, which should make sense since you have to reverse the domains.
Is that not what I just said?

It requires a very strong magnetizing field.
Of course it takes a magnifying field to reverse a magnifying field. Is this not vague? I posted pretty much the same thing and you're down my back except I didn't say it takes a magnifying field. I assumed he already knew it would take another magnetic field. Did you not understand when I said all energy can be negated by energy greater than or equal to it? Why did that get a 'say what', you do know physics, right? And of course Newton's first law would seem vague to you at the level we're talking. But down past the molecular or atomic level, magnetism is forces which are allied with each other and require forces to act upon those with equal or greater force to change the polarity. Geez, is this some sort of newb annitiation ritual?

arildno
Homework Helper
Gold Member
Dearly Missed
Are you able to STATE Newton's first law at all, usp8riot?
Do you know what it is about?

It sure doesn't seem so.

berkeman
Mentor
usp8riot said:
Geez, is this some sort of newb annitiation ritual?
Yes it is, welcome to PF. Consider yourself initiated. I kind of understood what you were saying, but when helping others here, it's a good idea to try to make the statement so it will be fairly clear to the OP (original poster). I understood your metaphor of Newton's Laws, but that might have been a pretty big leap for the OP to understand.

Let's all just leave this thread lie, and see how the next few threads go, okay?