ELI5: all about magnets. What’s actually happening when you “magnetize” an object? Do magnets consume energy to do “work,” like moving another object? If you fix 2 magnets in place close enough to apply force to one another, will they eventually “run out” and stop pulling/pushing the other?
No, conceptually this is a lot closer to Gravity. Massive objects don’t use themselves up when they pull on each other; gravity doesn’t cost energy. In fact, two magnets getting closer together actually releases (provides) energy, just like two gravitational objects getting closer together. But that just means that the system is in a lower potential energy state — some of the potential energy in the universe has been released. If you want to pull the objects back apart to their previous positioning, you’ll have to pay the energy price (do work). It is that work, in turn, that is later consumed if they come together again, so you can’t extract more energy from the system than you put into it.
So two magnets far apart function sort of like a Battery: they have stored potential energy. This stored potential energy is released by permitting the magnets to stick together. Once they’re stuck together, their battery is exhausted, but it can be recharged by pulling them apart.
for all of your intuitions just think “magnet is spring that goes through thing and only pulls iron”
If you tape 2 springs together do they run out? obviously not.
Do springs consume energy to do work? Obviously not.
As for how they work, atoms have electrons. electrons have spin, and spinning electrons make magnetic fields. (and changing magnetic fields make electrons move) this is how both generators and motors work.
In most elements this spin direction cancels out within an atom, but in some there is a slight bias to which way the spin goes.
So if you align all the atoms in the same direction, that bias stacks with near by magnetic fields and makes a larger magnetic field.
This is how permanent magnets work.
Electromagnets are the same thing, but we use moving electrons in electricity going through coiled wires to make them curve.
Magnets typically retain their magnetism for a century or more as long as the magnet is properly cared for and isn’t damaged. They do gradually lose their strength over time, but it’s such a small amount that you or I would likely never notice the degradation during our lifetimes.
This is different than, say one of those rubber-like fridge magnets or magnetic tape. Those will only last maybe 20 or 30 years at most.
I can help with the first bit. Everything is made up of chunks of smaller stuff. Normally the chunks are randomly arranged. But, in certain material, those bits can be made to line up with all the north and south (I’m assuming it’s polarity but not sure) ends pointing the same way when they get near a magnet. When you pull them away, the chunks fall back to a random state. However, if you get close to a material that attracts to a magnet, sometimes the pieces don’t all fall back to random and you made a magnet. Interestingly, you can take a piece of iron, like a screwdriver, and whack it with a hammer. Sometimes this will cause the chunks to line up and become a magnet for a while.
When you have a bunch of charged particles moving in the same direction, a field of influence is created called a magnetic field which can interact with other charged particles.
Electrons are negatively charged particles, and these particles can spin upwards or downwards. When you magnetize an object, you align these electrons such that all (or at least more than not) are spinning in the same direction which strengthens the magnetic field of the object.
As far as if they apply work, I’ll defer to the physicists and to answer if putting them close to one another is a form of potential energy.
For what you usually think of as a magnet that isn’t anything complicated like an electromagnet the atoms in your magnet get lined up and the magnetic field that they make actually gets synced up enough to be noticeable. Magnets have two poles and if all of your iron (an example) atoms are fighting over where they are they can’t get anything done. The better they’re lined up the stronger it is.
Not really! Electromagnetism is one of the four fundamental forces and the other one you’ve heard of is gravity. So it’s kind of like asking if energy is consumed when you drop something.
It makes a force with its magnetic field but it doesn’t really have any energy in it because force and energy are actually different things. It just converts energy and moves it around based on the field.
Instead of gravity making things become attracted towards each other based on mass magnets have a field around a “north” and “south” pole. The opposite poles stick together, the same poles push apart, and if you out down a magnet and some iron shavings you can actually see the shape of the field itself.
They can’t run out of energy because they dont actually have any. However you can make a magnet weaken or lose the field by heating it up, smacking it really hard, or anything else that knocks the atoms back out of order. You can fix it again with another magnet or running an electric current through it.
The potential energy between two magnets exists in the magnetic field wiki.
This energy does not “run out” unless it gets converted into another form (conservation of energy) such as kinetic energy, gravitational energy, heat, sound, etc. So if you fix two magnets in place they will never stop pulling on each other assuming nothing chemically changes within them (which would likely release heat energy instead).
As an analogy, if you fix an object a certain distance above the Earth, will gravity “run out” of energy to make it fall? No, the energy is stored as gravitational potential energy until it can be converted into another form of energy.
Alright so others have explained the physics of magnetic fields pretty well – but I’ll do my best to explain “what magnetism is” in ELI5 terms.
Go to ptable.com to follow along. Stay with me through the intro because it all does come back to magnets I swear.
First: atoms are made of three (simplified) things – protons (positively charged), neutrons (no charge), and electrons (negative charge). Protons and neutrons occupy the center [nucleus] – the number of protons in the nucleus determine which element the atom is (Hydrogen has one proton, helium has two protons, lithium has three protons, and there it goes down the line). Electrons occupy different distinct “clouds”/”shells” that surround and orbit the nucleus. Every atom in its native state has an equal number of protons and electrons to balance the total charge of the atom.
Every electron has its own orientation (“spin”) that either points up or down – and the quantum mechanics of it works out that two electrons “want” to pair with each other in a one-up-one-down orientation more than either want to be off on their own. This electron pairing is literally what all chemical covalent bonds are and is like THE fundamental concept of chemistry.
So as we go down the periodic table – you’ll see all the really important biological elements towards the top right. After the first two rows (periods) you’ll see a big gap populated that wasn’t there in the previous two rows. These are the “transition metals” – and now the quantum mechanics of it work out so that electrons don’t get paired off but start to go off on their own all with their own spin (all aligned in the same direction). That maximizes at iron (Fe, #26) with 5 total unpaired electrons in its outermost shell. All of those electrons are all aligned in the same direction.
Unpaired electrons in any atom dictate the strength of that atom’s magnetic (and electric) field. When you apply an external magnetic field to those unpaired electrons – they will all align in the same direction. If a US Nickel was made from pure iron it would have about 60,000,000,000,000,000,000,000 iron atoms in it. All those unpaired electrons in the nickel (while incredibly weak on their own) once aligned they’ll stay locked in that orientation and will then try to bring other external electrons in the same direction as the nickel’s. That’s what the average layman would describe as magnetism.
Congratulations if you’ve made it this far and kind of get – you have a very basic introduction to quantum mechanics! Pretty sweet right!?
This is also a series of gross oversimplifications – but I think I got the core ideas across.
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No, conceptually this is a lot closer to Gravity. Massive objects don’t use themselves up when they pull on each other; gravity doesn’t cost energy. In fact, two magnets getting closer together actually releases (provides) energy, just like two gravitational objects getting closer together. But that just means that the system is in a lower potential energy state — some of the potential energy in the universe has been released. If you want to pull the objects back apart to their previous positioning, you’ll have to pay the energy price (do work). It is that work, in turn, that is later consumed if they come together again, so you can’t extract more energy from the system than you put into it.
So two magnets far apart function sort of like a Battery: they have stored potential energy. This stored potential energy is released by permitting the magnets to stick together. Once they’re stuck together, their battery is exhausted, but it can be recharged by pulling them apart.
for all of your intuitions just think “magnet is spring that goes through thing and only pulls iron”
If you tape 2 springs together do they run out? obviously not.
Do springs consume energy to do work? Obviously not.
As for how they work, atoms have electrons. electrons have spin, and spinning electrons make magnetic fields. (and changing magnetic fields make electrons move) this is how both generators and motors work.
In most elements this spin direction cancels out within an atom, but in some there is a slight bias to which way the spin goes.
So if you align all the atoms in the same direction, that bias stacks with near by magnetic fields and makes a larger magnetic field.
This is how permanent magnets work.
Electromagnets are the same thing, but we use moving electrons in electricity going through coiled wires to make them curve.
Magnets typically retain their magnetism for a century or more as long as the magnet is properly cared for and isn’t damaged. They do gradually lose their strength over time, but it’s such a small amount that you or I would likely never notice the degradation during our lifetimes.
This is different than, say one of those rubber-like fridge magnets or magnetic tape. Those will only last maybe 20 or 30 years at most.
I can help with the first bit. Everything is made up of chunks of smaller stuff. Normally the chunks are randomly arranged. But, in certain material, those bits can be made to line up with all the north and south (I’m assuming it’s polarity but not sure) ends pointing the same way when they get near a magnet. When you pull them away, the chunks fall back to a random state. However, if you get close to a material that attracts to a magnet, sometimes the pieces don’t all fall back to random and you made a magnet. Interestingly, you can take a piece of iron, like a screwdriver, and whack it with a hammer. Sometimes this will cause the chunks to line up and become a magnet for a while.
Richard Feynman was known for his ability to simplify things and explain it so that almost anyone can understand it.
Here he is spending about 7 minutes to explain why he cannot explain magnets to someone like you or me.
https://youtu.be/MO0r930Sn_8?si=eJypXDAPCvmNT10W
When you have a bunch of charged particles moving in the same direction, a field of influence is created called a magnetic field which can interact with other charged particles.
Electrons are negatively charged particles, and these particles can spin upwards or downwards. When you magnetize an object, you align these electrons such that all (or at least more than not) are spinning in the same direction which strengthens the magnetic field of the object.
As far as if they apply work, I’ll defer to the physicists and to answer if putting them close to one another is a form of potential energy.
For what you usually think of as a magnet that isn’t anything complicated like an electromagnet the atoms in your magnet get lined up and the magnetic field that they make actually gets synced up enough to be noticeable. Magnets have two poles and if all of your iron (an example) atoms are fighting over where they are they can’t get anything done. The better they’re lined up the stronger it is.
Not really! Electromagnetism is one of the four fundamental forces and the other one you’ve heard of is gravity. So it’s kind of like asking if energy is consumed when you drop something.
It makes a force with its magnetic field but it doesn’t really have any energy in it because force and energy are actually different things. It just converts energy and moves it around based on the field.
Instead of gravity making things become attracted towards each other based on mass magnets have a field around a “north” and “south” pole. The opposite poles stick together, the same poles push apart, and if you out down a magnet and some iron shavings you can actually see the shape of the field itself.
James Clerk Maxwell got all the myriad equations together into a set that explains all of that https://simple.m.wikipedia.org/wiki/Maxwell%27s_equations
The potential energy between two magnets exists in the magnetic field wiki.
This energy does not “run out” unless it gets converted into another form (conservation of energy) such as kinetic energy, gravitational energy, heat, sound, etc. So if you fix two magnets in place they will never stop pulling on each other assuming nothing chemically changes within them (which would likely release heat energy instead).
As an analogy, if you fix an object a certain distance above the Earth, will gravity “run out” of energy to make it fall? No, the energy is stored as gravitational potential energy until it can be converted into another form of energy.
Alright so others have explained the physics of magnetic fields pretty well – but I’ll do my best to explain “what magnetism is” in ELI5 terms.
Go to ptable.com to follow along. Stay with me through the intro because it all does come back to magnets I swear.
First: atoms are made of three (simplified) things – protons (positively charged), neutrons (no charge), and electrons (negative charge). Protons and neutrons occupy the center [nucleus] – the number of protons in the nucleus determine which element the atom is (Hydrogen has one proton, helium has two protons, lithium has three protons, and there it goes down the line). Electrons occupy different distinct “clouds”/”shells” that surround and orbit the nucleus. Every atom in its native state has an equal number of protons and electrons to balance the total charge of the atom.
Every electron has its own orientation (“spin”) that either points up or down – and the quantum mechanics of it works out that two electrons “want” to pair with each other in a one-up-one-down orientation more than either want to be off on their own. This electron pairing is literally what all chemical covalent bonds are and is like THE fundamental concept of chemistry.
So as we go down the periodic table – you’ll see all the really important biological elements towards the top right. After the first two rows (periods) you’ll see a big gap populated that wasn’t there in the previous two rows. These are the “transition metals” – and now the quantum mechanics of it work out so that electrons don’t get paired off but start to go off on their own all with their own spin (all aligned in the same direction). That maximizes at iron (Fe, #26) with 5 total unpaired electrons in its outermost shell. All of those electrons are all aligned in the same direction.
Unpaired electrons in any atom dictate the strength of that atom’s magnetic (and electric) field. When you apply an external magnetic field to those unpaired electrons – they will all align in the same direction. If a US Nickel was made from pure iron it would have about 60,000,000,000,000,000,000,000 iron atoms in it. All those unpaired electrons in the nickel (while incredibly weak on their own) once aligned they’ll stay locked in that orientation and will then try to bring other external electrons in the same direction as the nickel’s. That’s what the average layman would describe as magnetism.
Congratulations if you’ve made it this far and kind of get – you have a very basic introduction to quantum mechanics! Pretty sweet right!?
This is also a series of gross oversimplifications – but I think I got the core ideas across.