Woo-Woo Why are there countless attempts to make magnets power generators..

[Moha99]

This thread reminded me of a meme:

people attribute supernatural properties to that which they do not understand.

Um.
Magnets at first seem magical, but when studied briefly turn to be shocking and when studied complexly turns out to be an astonishing phenomena.

 

[Moha99]

So far no one has a problem with the idea that magnets can do work right?

 

[TbirdMan]

Moha, a good explanation from someone smarter then me: http://van.physics.illinois.edu/qa/listing.php?id=17176

 

[(*steve*)]

So far no one has a problem with the idea that magnets can do work right?

I do.

The magnet never does work.

The field *may*, but only be removing energy from it. To re-establish the field, the exact same energy must be put back into it.

 

[Moha99]

I do.

The magnet never does work.

The field *may*, but only be removing energy from it. To re-establish the field, the exact same energy must be put back into it.

Ow dear.
I'll have to prepare a rational explanation with evidence I'll get back to you soon.

 

[Moha99]

Moha, a good explanation from someone smarter then me: http://van.physics.illinois.edu/qa/listing.php?id=17176

Thanks,
But I've been through that already.

 

[Moha99]

I do.

The magnet never does work.

The field *may*, but only be removing energy from it. To re-establish the field, the exact same energy must be put back into it.

Well, that depends on the type of magnet your working with.
This can happen with ceramic magnets where the field weakens as two magnets attract/repel.
But what abou Neodymium or new idea of stronger magnets?

Speaking about Neodymium specifically their magnetic field can last for a long timer and every longer at absolute zero... During the time when two Neodymium magnets attract/repel isn't that work being done? When you put a magnet on a table and move it closer to another magnet things can really go intense!

Aside from that, many articles and physics books exclude the reason of magnets doing work in case of a dipole/dipole interaction I guess that supports my point?

The only case where I agree is when a magnetic field not able to do work on a point charge.

 

[Moha99]

When I studied electromagnetism I discovered the more complex explanation, that an electric field can be the cause of work? But what is the cause of that electric field? The magnet.
So regardless of what you agree, at the end magnets are a cause of work or the electric field that work.

 

[Moha99]

Aside from that. I have no reason to think why? Magnet/Magnet interaction can not do work...

I tend to find an object able to lift/push/pull/flip another magnet able to do work.

 

[Moha99]

If needed I'll use Formulas.

 

[Moha99]

This can be useful.
If you think about it, even if the magnetic field would induce an electric field(Based on Faraday's Law) the electric field is proportional to the rate of te magnetic field. And possibly other factors.

But its really interesting what goes on when two magnets attract/repel.

 

[Moha99]

I'll keep this for reference to support my argument.

Finally, I wanted to say that the "permanent" magnetic field would create an electric field that cause the work. But whatever value that magnetic field it is converted equally to the electric field.

Mf = Ef
If one is 100N the other is equally the same at 100N.
They work equally.

 

[davenn]

the electric field is proportional to the rate of the magnetic field.

... the rate of change of the magnetic field

if the magnetic field is stationary and the wire within the field is stationary, there will be no induced current

Dave

 

[Moha99]

... the rate of change of the magnetic field

if the magnetic field is stationary and the wire within the field is stationary, there will be no induced current

Dave

Yes of course!
I keep forgetting to right down the details! I assume you all knew that! Darn it!

If the B field is static there is no induced current or "change" in energy I would say since that motion in converted.

 

[Moha99]

I do.

The magnet never does work.

The field *may*, but only be removing energy from it. To re-establish the field, the exact same energy must be put back into it.

The field is the property of the magnet. Since the field is surrounding the interior of the magnet and its exterior you can say the magnet = a magnetic field.

Bring a magnet on a table.
bring a piece of steal of another magnet.
Notice, the amount of force applied over a distance. Ow wait a minute! That sound familiar!

W = Fd

 

[davenn]

Yes of course!
I keep forgetting to right down the details! I assume you all knew that! Darn it!

I might, but other reading may not

if you are going to do and discuss physics properly, you need to be precise in your writings so that what is being said is clear and accurate. Else you can lead those with less knowledge on the subject well astray.

I have a problem with another comment you made on the previous page in response to steve's reply. you said ...

Well, that depends on the type of magnet your working with.
This can happen with ceramic magnets where the field weakens as two magnets attract/repel.
But what abou Neodymium or new idea of stronger magnets?

No it doesnt
A magnet is a magnet ... period! doesnt matter how the field is created, electromagnet or permanent magnet, the resulting magnetic field will still follow the same laws

Dave

 

[(*steve*)]

Notice, the amount of force applied over a distance. Ow wait a minute! That sound familiar!

W = Fd

The magnet did no work.

The field is there (in a permanent magnet) because of the spin states of the electrons in the magnet.

As the metal approaches the magnet the magnetic field changes.

It changes to a lower energy state.

Energy has been removed from the field.

The field has done work.

The magnet just sat there.

If the magnet was not fixed and it moved to the piece of metal, would you say the metal did work? No. And neither did the magnet. The field did it.

The same is true of gravity. (And I went through this with you a long time ago)

What is potential energy? IS it energy in something? No, it is the energy that would be released by the gravitational field working to bring 2 masses together.

If you fall off a cliff have you done work? No. Has the earth? No. But work has been done. By what? The gravitational field of you and the earth moving to a lower energy state.

In either case work must be done to set things how they were. That work placed the fields in a higher energy state, i.e. it puts energy back into the fields.

 

[Moha99]

I do.

The magnet never does work.

The field *may*, but only be removing energy from it. To re-establish the field, the exact same energy must be put back into it.

What?!
So if the field does work it weakens?!
While studying the subject I never seen this idea.
What reference can I resort to?! To review this.

 

[Moha99]

The magnet did no work.

The field is there (in a permanent magnet) because of the spin states of the electrons in the magnet.

As the metal approaches the magnet the magnetic field changes.

It changes to a lower energy state.

Energy has been removed from the field.

The field has done work.

The magnet just sat there.

If the magnet was not fixed and it moved to the piece of metal, would you say the metal did work? No. And neither did the magnet. The field did it.

The same is true of gravity. (And I went through this with you a long time ago)

What is potential energy? IS it energy in something? No, it is the energy that would be released by the gravitational field working to bring 2 masses together.

If you fall off a cliff have you done work? No. Has the earth? No. But work has been done. By what? The gravitational field of you and the earth moving to a lower energy state.

In either case work must be done to set things how they were. That work placed the fields in a higher energy state, i.e. it puts energy back into the fields.

Why are you addressing the field to be separate from the magnet?

Well said explanation about the cause of the field.
So the metal piece is being attracted by the field and that would change the potential energy from high to low. I agree
The field of course is truly the reason for work being done. And in all cases the field is the cause of work.
However, the magnet can be a "carrier" for that field. After all the field only existed because of the magnets atomic structure after magnetization.
If I fall off a cliff that's work being done on me, and there was a state of high potential energy when I was on the cliff till I dropped ( ow and landed safely like superman, felt bad for the ground though...).


Steve I did get the last part could you explain more in detail of what you meant?
Because I clearly misunderstood it before based on Dave's reply.

 

[Moha99]

No it doesnt
A magnet is a magnet ... period! doesnt matter how the field is created, electromagnet or permanent magnet, the resulting magnetic field will still follow the same laws

Dave

What laws?
Again I said something wrongly...
What I meant with that post is the field's different attributes in each type of magnet...
And how the field under cool temperatures can last for a very long time.
I seem to think from Steve's post that the field weakens after every interaction...