How do magnets work?

For centuries, people have been mystified by magnets and wondered how they worked. In this video, Fermilab’s Dr. Don tells us how.

How Einstein saved magnet theory:

Fermilab physics 101:

Fermilab home page:

[wayneyadams]

2:15 One correction to Dr. Dan's narrative. Electrons are not FOUND INSIDE CLOUDS, they are most likely to be found in volumes of space that have different cloud shapes. There are no empty clouds into which electrons are located, the electrons themselves form clouds.

4:51 Unfortunately the term "electron spin" misleads people into thinking electrons are tiny particles spinning like tops or gyroscopes. Electrons exhibit a property similar to that which they would have if they did spin, but electrons DO NOT SPIN! In atoms the electron spin is the fourth quantum number for the electron and has values of +1/2 and -1/2, which we simplify this by saying up and down spin. Each orbital cannot be made up of two electrons with the same spin which limits each orbital to two electrons, one with spin +1/2 (up) and one with spin -1/2 (down).

The ability to retain magnetism after the magnetic field has been removed is called spontaneous or remanent magnetization. There are four elements that exhibit this attribute, Iron (Fe), Cobalt (Co), Nickel (Ni), Atomic numbers 26, 27, 28 as well as Gadolinium (Gd) atomic number 64. Iron, Cobalt, and Nickel all get their magnetism from 3d orbitals having four (4), three (3) and two (2) unpaired 3d electrons respectively.

Looking at Iron (Fe) on the periodic table we see that it has partially filled d orbitals. Iron has six (6) electrons forming d orbitals in the third energy level (3d) There are five (5) d orbitals each composed of two electrons. The rule is that all five orbitals must be formed by one electron before pairing occurs. Since there are six (6) electrons, one orbital has a pair of electrons leaving four (4) unpaired electrons. Cobalt (Co) has one more pair (one less unpaired), and Nickel has two more pairs (2 less unpaired).

Gadolinium is different with the electron configuration, [Xe] 4f⁷ 5d¹ 6s², having seven (7) unpaired electrons in 4f orbitals as well as a single unpaired electron in the 5d orbital.

We have all heard that neodymium magnets are the strongest magnets available, but they are not made of the element Neodymium (Nd) alone but are actually made of Nd2Fe14B (Neodymium, Iron, Boron).

[TaylorShockey]

After 37 years, you've filled a major gap in my understanding of physics. Your explainations are truely gifts that benefit all of humanity. From the bottom of my heart, thank you.❤

[alvinmick]

That was the clearest answer that I’ve heard to the question about why there are magnets. Thank you

[McKaySavage]

The step-wise explanation from small to larger of what has to happen for something to be a magnet was so helpful! That really cleared up the concept for me. I really wish schooling and even universities could use such clear conceptual explanations

[PhillStone]

Back in the day people were hatin' on ICP for asking the question, Magnets, how do they work? But its a fair question. Decade later and we still need fermilab to lay it down for us. Great video!

[fifferfiffer]

3:02 i like that he has the courage to say that nobody knows why the electrone behaves like a magnet on its own

the electron has a spin which makes is magnetic, but no one actually knows a whats a spin physically, they can only represent what they measre, so if you want to read about electron you will find a lot a description how does it behave, but what is it - no one knows.

i think the biggest issue here is that we should measure what happens inside an electron, but as its an elementary particle it does not have any internal structure, and cannot be probed inside, if if that cannot be measured we might never know the answer.

[jonathannetherton]

I for one feel they're even more magical now - my understanding has passed from caution out of a sense of separateness from mystery into a sense of connection from wonder. Figuring out the universe seems to make it come even more alive to me. Thank you for the explainer!

[RichardT]

The magic is really in Part 1 - why/how electrons are magnets. Great explanation of the rest!

[BOBMAN]

Every time I see a video like this--or an earnest answer from a physicist to a truly vexing question--I think about how everyone dissed ICP for asking (in a song), "Magnets. How do they work?!"

[daveangels]

I can't say how many times I've wondered about this, thank you for the simple explanation 🎉

[classicaudioadventures]

There's another video in which Richard Feynman is asked the same question, but his philosophical answer left me somewhat unsatisfied. I appreciate your ability to explain material like this elegantly and in terms that a casual person like me can understand. Thank you, Dr. Lincoln!

[starlightCataclysm]

I actually feel like I have a pretty good grasp on how magnets work now, an excellent video as always Dr. Don! What was once utterly opaque has been rendered transparent (much like the universe ;D )

[willeykev]

Thanks so much Dr. Don for that explanation!! Like many others, I can now understand the basic concepts of how a magnet works at the atomic level. I do have another question though: now that we understand how magnets generate their fields, can you please make a short video on EXACTLY how the magnet performs the action of attraction to other Ferro-metals? Thanks again for all you do!!

[dimension]

❤Doc Lincoln Rules.
Nicely done closed captions. Love he admits no one knows why electrons are magnetic. In 2023 we have so much to learn about physics.

[Qermaq]

As a Juggalo, I appreciate the thorough explanation.

[ollywright]

Thankyou. I have an additional question: when one permanent magnet is placed in the magnetic field of a second permanent magnet, it aligns. Where does the kinetic energy for that alignment come from? It doesn't come from the permanent magnet I assume (or it wouldn't be permanent). Does it only come from the kinetic energy used to move it into the field, creating a field potential that then becomes kinetic energy?

[jorispattyn]

There is one question I think is important (people have wondered for ages ...)which remains largely unanswered in this video. If we have to make iron magnets by putting them under a very strong magnetic field, in order to align the domains, then how was magnetic iron formed naturally? Already the ancient Greeks knew how to find natural magnets, so, how was this formed? By what kind of natural magnetism?

[majorrgeek]

how magnets work is an interesting question, because no one knows what magnetic force really is including Fermilab

[odizzido]

This is by far the best video I've seen on the topic. Excellent job.

[frankkolmann]

The best part that I love most is where you say 'No one knows'.