Placeholder Image

Subtitles section Play video

  • Pretty much everything in the universe is made out of matter - the earth, air, you and

  • me, stars, interstellar dust - all matter. By which we mean that these things are made

  • out of electrons and quarks - and very occasionally other rarer matter particles like muons, tauons,

  • and neutrinos.

  • All of these particles are, at their fundamental level, excitations in everywhere-permeating

  • quantum fields. But, as the famous quote goes, “for every particle, there is an equal and

  • opposite antiparticle - an opposite excitation in the everywhere permeating quantum field

  • that has all of the exact same properties as that particle - except opposite charge.”

  • And since these antiparticles are opposite excitations of the quantum field, when a particle

  • and antiparticle meet, they annihilate and destroy each other!

  • Which is pretty much exactly like how the equation x^2=4 has two solutions: 2 and -2,

  • with the same value but opposite sign. And when they meet, they annihilate!

  • Every fundamental particle has an antiparticle: there are antiquarks, antineutrinos, antimuons,

  • antitauons, and of course antielectrons - though we call them positrons.

  • Since antimatter particles are essentially identical to regular matter other than the

  • opposite charge thing, they can combine together in essentially identical ways to form antiprotons,

  • anti-atoms, anti-molecules, and, in principle, anything from anti-ants to anti-matterhorns.

  • Except because every particle of antimatter annihilates with regular matter upon meeting, it’s really

  • hard to make anything big out of antimatter - at this point were still only able to

  • contain a few hundred antihydrogen atoms at one time. But we can also make the really

  • cool positronium atom - it’s like hydrogen, except instead of an electron orbiting a proton,

  • it’s an electron orbiting a POSITRON. Until they annihilate each other in under a nanosecond.

  • And when they annihilate, the energy of particle and antiparticle has to go somewhere, which

  • is why matter/antimatter annihilations have been proposed as bombs. But naturally-occuring

  • antimatter is hard to come by. So, unlike a uranium fission bomb, which allow us to

  • release the bottled energy of the supernovas that forged the uranium in the first place,

  • you’d have to put all the energy into an antimatter bomb yourself by making antimatter.

  • Which you do by agitating empty space into pairs of matter and antimatter excitations.

  • Kind of like hitting zero with a hammer to get out 2 and minus 2, except instead of a

  • hammer, you use a particle accelerator or high-energy photons of light.

  • Photons, incidentally, have zero charge and so are their OWN antiparticles, in the same

  • way that zero is equal to negative zero!

  • In fact, mathematics has always been closely tied to antimatter: the mathematics of relativisitic

  • quantum mechanics predicted the existence of antimatter before any had ever been discovered.

  • The fact that there’s so little antimatter around in the universe TO discover is both

  • an obvious thing (because if it were around, it would have destroyed us), a good thing

  • (because it can’t destroy us), and a puzzling thing - if matter and antimatter are basically

  • identicalmirrorimages of one another, why did the big bang produce so much more

  • matter than antimatter?

  • No one knows - though to physicists, the answer matters.

Pretty much everything in the universe is made out of matter - the earth, air, you and

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it