How do magnets work? Seriously.

[mistermack]

The photon is the interactive particle of electro-magnetism. A magnetic-field is an area in which photons are being exchanged between one object and the next. When two object carrying the same charge repel it is said to be like two ice-skaters throwing a bowling ball back and forth to each other as they skate. They will be pushed further and further apart with each throw. When objects of opposite charges come together it's like two ice-skaters tugging on a rope.

Or something. It's a long time since I've read a physics books, I tend more toward biology/geology.

Yeh, that's something like what I read, except that they said ''virtual'' photons, which were ''ripples'' in the quantum field.

[Blind groper]

A moving electron has a magnetic field. This field attracts or repels other fields depending on alignment. A single electron has the property called spin. This spin gives it a magnetic field, albeit one that is very weak.

Now imagine hephalumptillions of electrons, all lined up so they spin the same direction. All those magnetic fields point in the same direction, and reinforce each other. That is what happens in a fixed magnet.

[pErvinalia]

So magnets work because of magnetic fields? Who would have thunk it, eh?

[Pappa]

The thing that really bothers me is the "free" energy magnets seem to have. They can induce movement in other objects without seemingly expending any energy.

[pErvinalia]

FREE ENERGY!!

No, i don't think that is right. For a magnet to induce movement in another object, it has to be moved into a relevant position with that object. Moving a magnet through other magnetic fields requires work. No free energy, I'm afraid..

[pErvinalia]

Think of it this way: It's like saying that a tennis ball held at head height has free energy, as when you let go of it, it moves. But it had to get that gravitational potential first before it could utilise it.

[pErvinalia]

Actually, expanding a bit... A magnet has magnetic potential probably due to some past imparting of magnetism via a field. How it keeps that magnetism, I don't really know (and that's basically what you are asking in your OP). But work was done to impart that potential in the past.

[FBM]

The thing that really bothers me is the "free" energy magnets seem to have. They can induce movement in other objects without seemingly expending any energy.

It's only apparently free. At the end of the month, they still have to mail in a payment depending on the size and number of things they've moved.

[JimC]

The thing that really bothers me is the "free" energy magnets seem to have. They can induce movement in other objects without seemingly expending any energy.

Not really. If I bring 2 bar magnets together, north pole to north pole, I have to exert a force over a distance - I have done work, and from my expenditure of energy, the system of 2 magnets has gained potential energy. Once I release them, they can do work on something else, releasing the energy I originally granted them.

Electromagnets can do do work that is proportional to the electrical energy they consume (minus some lost as heat, normally)

[JimC]

So magnets work because of magnetic fields? Who would have thunk it, eh?

BG's post contained more information than that. Even if still somewhat mysterious, the fact that a magnetic field is a property of a moving or spinning electrical charge is a fairly vital piece of the puzzle...

[pErvinalia]

Yeah, but I explained potential energy before you did, so nya nya nya nya nya.

[Xamonas Chegwé]

The thing that really bothers me is the "free" energy magnets seem to have. They can induce movement in other objects without seemingly expending any energy.

The energy has already been expended in aligning the innards of the magnet so that all of its whatsits are pointing in the same direction.

There is a total CHUNK of energy in an aligned whatsit - like fucking SHITLOADS! But pulling and pushing stuff around with the power of your innards causes them to slowly unalign - it might seem like a magnet just stays sticky FOREVAH - but it doesn't - it's just that the electromagnetic force is pretty damn HUGE compared to gravity (1036 times as MASSIVE!) and a little goes a long way. Stick an anvil to a magnet and dangle it - sooner or later the magneticisticism will run out and the anvil will fall directly onto the head of any passing coyote - but it will take a while - go have a cup of coffee and come back later... Magnetism can be preserved by inducing it with electrickery, or some shit, in which case, as long as you keep jamming volts into it, your anvil will hang there until the universe heat-death catches up with it - but energy free lunches only exist in fairy tales.

[laklak]

It's TANSTAAFL all the way down.

[Xamonas Chegwé]

It's TANSTAAFL all the way down.

Only if you've already paid to get up in the first place.

[mistermack]

The thing that really bothers me is the "free" energy magnets seem to have. They can induce movement in other objects without seemingly expending any energy.

Yeh, what others have said.

When something drops under gravity, it originally had POTENTIAL energy and that converts to the kinetic energy of the moving object.

The magnet and the piece of iron possess potential energy in the same way, and that converts to kinetic when they move. To put them back where they were, you need to expend similar energy as work to separate them, and that is then stored, as potential energy again.

There is never free energy. It either gets converted from one energy form to another, or comes from the conversion of mass to energy, as in e=mc2.