🌊 Quantum fields
Everything is fields
At the deepest level we know of, everything is made of invisible fields that fill all of space.
You’ve probably learned that everything is made of tiny balls…
…like atoms and electrons.
Go one level deeper and even those are ripples in fields.
The setup
An invisible sheet through all of space
A field is something invisible stretched through every scrap of space, including this room, the gap between stars and the inside of your hand. Where it lies flat, there’s nothing there. Where it bunches up into a ripple, that ripple is a particle, a wave in the field itself.
This is how physicists really describe particles today. Your turn: tap or drag on the sheet below and raise a few particles yourself.
Electrons made: 0
Every ripple you raise is one electron, in a different spot on the same sheet. There’s only one electron field, and every electron in you and in the furthest star is a ripple in it.
What you’re looking at: the teal sheet is the field, stretched through everywhere, even the parts that look empty. Where it’s flat there’s nothing there, and a lump is a particle. After a moment each lump fades back into flat field.
Your guess
What’s the most fundamental thing?
Picture the world zoomed right down, with particles and the space between them. Which do you think is the truly fundamental layer, the bedrock everything else is built on? Pick before you read on.
The bedrock of reality is…
The bedrock is the field, which is spread through every scrap of space, even where there’s “nothing”. A particle is a spot where the field is bunched up into a ripple. If you take the ripple away, the field is still there, lying flat. The field is what’s fundamental, and particles are something it does.
Poke the electron field and you get an electron.
Poke the light field and you get light.
The why
Different fields make different particles
If particles are ripples, then different kinds of particle are ripples in different fields. Space is full of these fields, all overlapping in the same place. Switch between two of them below and poke each one to see what you get.
Poke it. A ripple here is an electron, which is a lump in the electron field.
The electron field: it’s everywhere, and every electron anywhere is one of its ripples.
And if a particle is only a ripple…
…you can make one out of pure energy.
The why
Pour in energy, get a particle
If a particle is a ripple, then as well as finding particles, you can make them, by putting enough energy into a field to raise a ripple from flat. That turns energy into matter. Keep pressing the button until a particle appears.
Energy poured in
The field’s flat. Keep pouring in energy.
This is real. It’s called pair production, and it’s E = mc² working in reverse, with energy turning into mass. You always get a particle and its antimatter twin, because things like electric charge have to stay balanced. Physicists do this in colliders every day.
There’s only one electron field in the whole universe.
Think about what that means…
The consequence
Every electron is exactly the same
Because there’s only one electron field, and every electron is a ripple in it, every electron in the universe is identical. Each one has exactly the same mass and the same charge as every other. Make a few and try to find a difference.
Electrons made: 0 · Differences between any two: 0
Why they can’t differ: every electron is the same kind of ripple in the same field, so there’s nothing that could make one different from another. You could swap any electron in your body for one from the Sun and nothing would change at all.
There’s one more field to meet…
…which also fills all of space…
…and it gives the smallest particles their mass.
The Higgs field
The field that gives particles mass
The Higgs field also fills all of space, and particles that interact with it are harder to push. The more strongly a particle interacts with it, the harder that particle is to shove, and being hard to shove is exactly what mass is. Use the slider to go from a particle that doesn’t interact with the Higgs at all to the one that interacts with it most.
Photon
0
It doesn’t interact with the Higgs field at all, so it has no mass and always moves at the speed of light.
Two things to know. Physicists only confirmed the Higgs in 2012, so it’s the newest and least settled part of this picture. It also doesn’t give all mass. Most of your body’s weight comes from energy locked inside protons and neutrons, and the Higgs gives mass to basic particles like the electron.
You’re made of particles…
…and each one is a ripple, so you’re a pattern of ripples in fields that fill the universe.
Even the “empty” room around you is full of fields lying flat. When you move your hand, you’re moving ripples through those fields.
Pass it on
Next time someone talks about atoms as if they’re the smallest bits of everything, you can go one level deeper. Explain that a particle is a ripple in a field that fills all of space, and that every electron in existence is the same kind of ripple in the same field. See if you can get them to picture the empty room they’re standing in as full of fields. Nobody knows yet why the fields are there at all.