Explain to a 4-year-old how magnets work

Question

My 4-year-old daughter would like to know: "How do magnets magnet onto things?"

How can I explain this at a level she can understand?

(I'm asking this here rather than on physics.SE because this is fundamentally a how-to-explain-to-my-children question rather than a physics question. I'm not asking how magnets work, I'm asking how to explain to a 4-year-old how magnets work).

A friend has referred me to this Feynman video: https://m.youtube.com/watch?v=wMFPe-DwULM which is great, but my 4-year-old wouldn't understand it.

So any suggestions? Any advance on my current 4-year-old interpretation of the Feynman video, which is "They Just Do"?

Answer 1

say "let's find out together". Then collect some different magnets, some magnetic and non magnetic items, something the magnetism can be transferred to (screw driver or pin). Some type of compass building items would be nice too. Metal shaving would be nice for showing the magnetic field.

Then do experiments, when possible have your child guess the outcome ahead of time and suggest things to try with the items you have on hand.

Have fun, it is great that your child is asking questions about the physical mechanics of how the world around them works.

Answer 2

The first thing I'd do is read up on magnetism myself. I seem to recall that it is a relativistic effect of electric currents, but that's about it. In spite of what I said in my comment, I would try to give as good and exact an answer as I can. (Talk about atoms, electrons going in circles -- oh my, what an oversimplification....) In my experience children are very open to funny ideas like bending space, and they have next to no use from (wrong) simplifications. And as I said in the comment, building practical knowledge is always great, so I concur with Eric. Build a compass, proceed to Vikings.

Answer 3

First of all, the answers by @Eric and Peter Schneider are already good. Instead of always explaining stuff by words, let the kids try to find it out as much as possible by themselves, if possible. Guide them, encourage them to try this and this, and if they claim an idea about it, let them prove it. That's just how real science works, too (without the guidance, of course). And if the kids want to know more, explain it on a level they understand - though underlying mechanisms are often hard to understand, even by adults.

Sometimes, there are intermediate explanations as the example of the slippery ice from Feynman's video, which can be explained by a thin film of water, melted from the ice under pressure. But the next step, why water behaves like that, while other substances do not, is already more complicated.

Sometimes, there is also no good intermediate step. One of the most head questions is "Why is the sky blue?", where most adults don't have an answer for. As physicist, I know it's about Raman and Rayleigh scattering of sunlight in the atmosphere, but I really have no idea how to explain this to an adult, or even a child. I can just say that sunlight is scattered, and that this happens more to blue than other colors... which is not very satisfying.

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Back to magnets, I would explain it as follows:

The kid should already have found out, that a magnet has a north and a south pole , and that poles can repel or attract each other, and that this already works from some distance.

Now, a magnet consists of many many, very tiny mini-magnets, which are all aligned into the same direction, and can not move / rotate.
One prove for this is to break a magnet into two pieces, which each on it's own are perfect magnets with north and south pole.

Iron also contains this mini-magnets, but they are not aligned and have random orientations. When a magnet is placed near to iron, the mini-magnets start to rotate and align into the direction of the magnet. This is because the poles of the magnet attract the counter-poles of the mini-magnets. The iron becomes magnetic, and attracts the magnet (and vice-versa). If the magnet is removed, each of the mini-magnets start to move to a random orientation again, and the iron looses its magnetic property.

Inside steel, the mini-magnets can't rotate that easily, they only do it when there is a magnet near to them. As consequence, they remain in their orientation, even when the magnet is removed. The steel becomes a (weak) magnet itself.

Other materials may not contain any mini-magnets, or those mini-magnets are not aligned and absolutely unable to rotate.

However, this does not explain what this mini magnets are or why they / magnetic fields exist. (And there's also no fundamental answer why magnetism itself exists.)

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By the way: Did you ever notice that earths north pole actually is a magnetic south pole? A compass needle is a magnet, and its north pole is marked with an N. So, this side is attracted by a magnetic south pole, which must be at the geographic north pole.

And a last comment:
I don't know if you know who Richard Feynman from the video is. He is one of the greatest physicists of the 20th century and got the nobel prize for his work on quantum electro dynamics. This is very complicated stuff, and he managed to teach about it in the most clearest way possible. His Feynman diagramms are the standard to describe processes in particle and quantum physics. So, if you need someone explaining complicated stuff "for dummys", he's your man.

Answer 4

What she is really asking is not details about how it works - poles, relationship to distance, etc. These are things we understand about magnetism. But what we do not understand is the nature of magnetism. Feynman concludes that he cannot tell the interviewer why magnetism works, because we still do not know why magnetism works. We know magnetic forces are related to electrical forces, but we are still in the dark about what is at the nature of the electric or magnetic field. So I think the best answer is to be very clear that we, people, still do not know how magnets magnet. If it was my child (and I have had similar conversations with them), I would be clear about that, then go over what we do know, with experiments. Recently, my son and I got into a discussion about the nature of light, and we actually did the experiment where we split a laser beam with razor blades (cost of materials $3.50 at Walmart).

Also, I would be telling them the whole time that maybe they will be the ones to figure out how magnets magnet. If they are asking the question, that is the kind of inquisitiveness you want to encourage. It shows a bit of a scientist's mindset, so encourage it, but without pushing.

Answer 5

Going beyond "They just do" is a bit difficult when dealing with a four-year-old.

Think about some other substances with unusual properties.

• You can see through glass and plastic.
• Pumice floats in water/Helium balloons float.
• Mercury is liquid at room temperature.
• Metal bends, but glass shatters
• Rocks are heavy

Understanding these concepts takes different levels of scientific understanding. However, people generally just accept that those are how things are in everyday life.

Part of the video linked in the question does a nice job of illustrating this: Your arm doesn't fall through the armrest when you put it down. It's just part of how things work.

So, to advance your description, I would maybe go into a lesson about how some things just are that way. Rocks are hard. Water is see-through. Stars are in the sky. You may not be teaching a lesson about electromagnetism, but you will still be teaching a lesson about how the world works.

Now, based on personal experience, you could also teach about North/South Poles, or opposites. I taught my three-year-old (now four), when they wanted to know how their magnetic toys worked. I showed them that when the magnets push away from one another, they're the same Pole (North & North or South & South), but that they like to be with different Poles, so only North & South will stick together.

Although you may fall down a rabbit hole of "Why?", I found that my child was more than satisfied by that quick lesson, and five months later they recalled it well enough to explain to an adult relative.

Answer 6

For a 4 year old, I think it may be best to simply explain that a magnet will stick to an object if the object is made from steel. The child can go about the house identifying which things are made from steel, and which are not, by checking to see what the magnet will stick to. Children have a lot of fun doing this, and soon they will learn to identify which things are made of steel simply by the look or feel, even without the magnet.

If you have magnets with the poles labelled, you can also teach them about magnetic repulsion, and explain that the 'N' likes to stick to the 'S', but 2 N's, or 2 S's push away from each other.

I can't think of any way you could actually explain the "why" without the child just getting very confused.

The practical experimentation is really more fun, and more valuable to the child anyway.

disclaimer: As always with magnets and children, be very very careful! A four year old is still young enough to casually pop things in her mouth. You really have to re-enforce that a magnet must NEVER go in the mouth. It's particularly important to make sure she never plays with the tiny, and often very powerful, rare earth magnets.

Answer 7

I think to add to what a few people have said, I would do an experiment with things.

In very simple terms, show that magnets can't "stick" to everything.
At the same time you can do the same thing with tape, especially scotch tape. They can't see the adhesive on scotch tape, but they can feel it. But, tape can't stick everything. It can't stick to liquids or certain surfaces. Eventually that "stickiness" comes off too, like in water. A very simple comparison can be made with magnets. They can't "stick" to everything and we can't see the part of it that makes it "stick". We can't feel it either (which we can't feel the adhesive on the smooth side of tape but we know that its still tape). Some magnets will also eventually 'wear out' as well.

You can then also go into how everything has some "scientific" properties that you can classify and categorize each object. Some are heave, but different sizes, some are large, some are small, some are soft, some hard, etc. So magnetic or sticky could be one of those things.