They are not touching. So what is pushing?
Eve can say this.
They are not touching. So what is pushing? Flip one magnet. Feel the space. Try two fridge magnets with a grown-up.
Words Eve says
They are not touching. So what is pushing? Flip one magnet. Feel the space. Try two fridge magnets with a grown-up.
Two fridge magnets
Use ordinary fridge magnets. Strong rare-earth magnets can pinch skin, wreck phones, and interfere with medical devices. Keep those in a drawer.
Take two ordinary fridge magnets. Press the same sides together. Feel the gap that will not close.
Slide them slowly apart. Notice how fast the push dies.
Flip one. Now they grab. Same objects. One change.
What else sits in a field you cannot see?
Look closer
Notice
Same ends face each other and the magnets refuse to meet. There is a gap you can feel.
Flip one magnet and the gap collapses. They snap together.
The push lives in the space around the magnet, not only on its painted ends.
What do you think will happen?
If you slide the two magnets farther apart, what happens to the push?
Change distance, and which ends face each other.
Keep looking
What must be true?
A magnet changes the space around it. That changed space can push or pull another magnet.
The effect is strongest close in, and falls off quickly as the gap grows.
The lines we draw are a map of that space. They are not threads floating in the air.
The map has a name.
We call the map a magnetic field. A field is a way of saying “the push is already in the space, even before the second magnet arrives.” Same ends push. Opposite ends pull. The magnet does not throw invisible strings. It changes the space.
Two magnets hover apart. They are not touching. So what is pushing? The magnet changes the space around it. That changed space can push, or pull, another magnet. The lines we draw are only a map of that space. Not threads in the air. Flip one magnet. Feel what the space does.
Words Eve says
Two magnets hover apart. They are not touching. So what is pushing? The magnet changes the space around it. That changed space can push, or pull, another magnet. The lines we draw are only a map of that space. Not threads in the air. Flip one magnet. Feel what the space does.
Faraday’s map
In the 1830s, Michael Faraday sprinkled iron filings around a magnet and watched them line up.
The filings were not the field. They were dust following a map.
Faraday was a bookbinder’s apprentice who taught himself in the hours after work. The field idea was argued over for decades. It stayed because it predicted what the next magnet would do.
- NIST: Magnetic fields · What a magnetic field is, and how it is measured.
- NASA: Earth’s magnetosphere · Earth itself is a magnet. The same kind of field, scaled up.