WEBVTT - Why does the Universe have antiparticles?

0:00:08.480 --> 0:00:11.879
<v Speaker 1>Hey, Daniel, are you glad our universe has antimatter?

0:00:12.840 --> 0:00:16.400
<v Speaker 2>No, I'm definitely pro our universe. So I guess I'm

0:00:16.440 --> 0:00:17.920
<v Speaker 2>not anti antimatter.

0:00:18.160 --> 0:00:21.520
<v Speaker 1>That means your pro matter. But I guess the question is,

0:00:21.520 --> 0:00:23.919
<v Speaker 1>would you miss antimatter if we didn't have it?

0:00:24.160 --> 0:00:26.480
<v Speaker 2>I mean, I like things the way they are, so

0:00:26.760 --> 0:00:30.000
<v Speaker 2>if we lost antimatter, the universe would be pretty different

0:00:30.080 --> 0:00:33.560
<v Speaker 2>and maybe worse. But what if it's better, or maybe

0:00:33.560 --> 0:00:36.199
<v Speaker 2>it couldn't exist without antimatter and it would disappear in

0:00:36.280 --> 0:00:38.800
<v Speaker 2>a puff of mathematical contradictions.

0:00:38.960 --> 0:00:42.320
<v Speaker 1>Okay, then I would be anti antimatter. I would not

0:00:42.360 --> 0:00:43.320
<v Speaker 1>be pro antimatter.

0:00:43.600 --> 0:01:00.279
<v Speaker 2>I'm just saying it matters. Hi.

0:01:00.320 --> 0:01:03.160
<v Speaker 1>I'm Boria mccartoonist and the creator of PhD Comics.

0:01:03.440 --> 0:01:06.440
<v Speaker 2>Hi. I'm Daniel. I'm a particle physicist and a professor

0:01:06.520 --> 0:01:09.000
<v Speaker 2>at UC Irvine, and I love all the kinds of

0:01:09.040 --> 0:01:11.560
<v Speaker 2>matter out there, the matter and the antimatter and the

0:01:11.600 --> 0:01:12.160
<v Speaker 2>pro matter.

0:01:12.480 --> 0:01:17.440
<v Speaker 1>What about the meh matter? Not pro, not anti, It's

0:01:17.600 --> 0:01:18.640
<v Speaker 1>it's just kind of there.

0:01:18.480 --> 0:01:20.360
<v Speaker 2>You know. I will admit that there are some particles

0:01:20.400 --> 0:01:22.720
<v Speaker 2>I think they're exciting. In other particles, I'm like, yeah,

0:01:22.760 --> 0:01:23.600
<v Speaker 2>that's just a mess.

0:01:23.800 --> 0:01:28.039
<v Speaker 1>About your favorite kind of matter is chocolate matters certainly

0:01:28.080 --> 0:01:31.120
<v Speaker 1>better than vanilla matter, karp matter, But anyways, welcome to

0:01:31.200 --> 0:01:34.080
<v Speaker 1>our podcast, Daniel and Jorge Explain the Universe, a production

0:01:34.200 --> 0:01:35.679
<v Speaker 1>of iHeartRadio.

0:01:35.200 --> 0:01:37.920
<v Speaker 2>In which we dig deep into all kinds of matter

0:01:38.000 --> 0:01:40.280
<v Speaker 2>out there that matters. We talk about the things that

0:01:40.319 --> 0:01:42.200
<v Speaker 2>make you up. We talk about the things that make

0:01:42.319 --> 0:01:45.039
<v Speaker 2>nothing up, and things that seem to exist for which

0:01:45.080 --> 0:01:48.200
<v Speaker 2>we do not yet understand. The whole universe is like

0:01:48.240 --> 0:01:51.440
<v Speaker 2>a jigsaw puzzle with lots of weirdly shaped pieces, and

0:01:51.480 --> 0:01:53.480
<v Speaker 2>our goal is to find all those pieces, fit them

0:01:53.520 --> 0:01:56.840
<v Speaker 2>together to tell the whole story of our universe. And

0:01:56.920 --> 0:01:58.960
<v Speaker 2>on this podcast we'd like to do that and try

0:01:58.960 --> 0:02:00.560
<v Speaker 2>to explain all of it to you.

0:02:00.840 --> 0:02:03.720
<v Speaker 1>That's right. It is a vast and complicated universe, full

0:02:03.760 --> 0:02:06.960
<v Speaker 1>of all kinds of crazy and interesting kinds of matter

0:02:07.040 --> 0:02:10.000
<v Speaker 1>and energy and concepts and mathematics that we like to

0:02:10.040 --> 0:02:12.720
<v Speaker 1>explore as human beings and ask questions about and then

0:02:12.760 --> 0:02:15.000
<v Speaker 1>explain it to you, or at least ask you the question,

0:02:15.400 --> 0:02:16.320
<v Speaker 1>what's the matter with you?

0:02:18.800 --> 0:02:21.320
<v Speaker 2>We study all of these particles, we try to understand them,

0:02:21.360 --> 0:02:24.400
<v Speaker 2>and sometimes we even taste them to see if they're delicious.

0:02:24.760 --> 0:02:26.560
<v Speaker 2>But I wasn't joking when I said that some of

0:02:26.600 --> 0:02:29.040
<v Speaker 2>the particles out there are a little crazier and harder

0:02:29.080 --> 0:02:31.400
<v Speaker 2>to think about than others. I mean, there are so

0:02:31.560 --> 0:02:34.360
<v Speaker 2>many particles discovered in the era of the particle Zoo

0:02:34.520 --> 0:02:37.160
<v Speaker 2>that we almost ran out of silly Greek letters to

0:02:37.280 --> 0:02:38.320
<v Speaker 2>use to name all of them.

0:02:38.440 --> 0:02:40.639
<v Speaker 1>Oh boy, what happens when you run out of Greek letters?

0:02:40.800 --> 0:02:44.120
<v Speaker 2>Then you start using Hebrew letters? Okay, like the Gimmel

0:02:44.200 --> 0:02:48.120
<v Speaker 2>particle on the aleph particle. H interesting, But we've discovered

0:02:48.160 --> 0:02:51.239
<v Speaker 2>so many weird masons and baryons that we had to

0:02:51.320 --> 0:02:53.679
<v Speaker 2>use some of those weird Greek letters that nobody even

0:02:53.720 --> 0:02:55.080
<v Speaker 2>really knows how to write down.

0:02:55.320 --> 0:02:57.160
<v Speaker 1>I guess we have done a pretty good job of

0:02:57.280 --> 0:03:00.000
<v Speaker 1>kind of looking out into the universe and basically talent

0:03:00.240 --> 0:03:02.560
<v Speaker 1>up all the different kinds of matter, all the different

0:03:02.639 --> 0:03:05.280
<v Speaker 1>kinds of particles that can't exist out there, because there

0:03:05.320 --> 0:03:07.040
<v Speaker 1>are a lot. As you're saying, there are.

0:03:06.960 --> 0:03:09.079
<v Speaker 2>A lot, and it's sort of a two step process

0:03:09.120 --> 0:03:11.960
<v Speaker 2>to understand the universe. Like number one, just look out

0:03:12.000 --> 0:03:15.520
<v Speaker 2>and see what's there. Gather together all the puzzle pieces.

0:03:15.960 --> 0:03:18.359
<v Speaker 2>Number two, try to click them together to tell the

0:03:18.400 --> 0:03:21.680
<v Speaker 2>whole story. Are there pieces missing, do they fit together

0:03:21.720 --> 0:03:24.279
<v Speaker 2>into a puzzle or is it just a weird, disjointed

0:03:24.360 --> 0:03:25.600
<v Speaker 2>pile of confusion.

0:03:25.800 --> 0:03:27.760
<v Speaker 1>Yeah, And I guess the history of it is that

0:03:27.840 --> 0:03:29.640
<v Speaker 1>we used to think that we knew what the building

0:03:29.680 --> 0:03:32.480
<v Speaker 1>blocks of the universe was, right. We thought the elements

0:03:32.560 --> 0:03:35.360
<v Speaker 1>of the periodic table were like the basic lego pieces

0:03:35.400 --> 0:03:38.080
<v Speaker 1>of the universe. But actually those turned to be made

0:03:38.120 --> 0:03:40.280
<v Speaker 1>of other things. And then those some of those things

0:03:40.280 --> 0:03:41.800
<v Speaker 1>turn to be made of other things.

0:03:42.000 --> 0:03:45.200
<v Speaker 2>That's right. We revealed this sort of hierarchical structure of matter,

0:03:45.560 --> 0:03:48.320
<v Speaker 2>things made of smaller things, made of smaller things, but

0:03:48.360 --> 0:03:50.800
<v Speaker 2>the path to understand them in the history of science

0:03:50.880 --> 0:03:54.040
<v Speaker 2>was not so straightforward. We sort of like drilled down

0:03:54.160 --> 0:03:56.440
<v Speaker 2>and then got wider and weirder, and then drilled down

0:03:56.480 --> 0:03:59.360
<v Speaker 2>again and got wider and weirder. For example, when we

0:03:59.400 --> 0:04:02.880
<v Speaker 2>wanted to understand the nucleus, when we wanted to understand

0:04:02.920 --> 0:04:05.840
<v Speaker 2>protons and neutrons and what's inside them, we'd build bigger

0:04:05.880 --> 0:04:09.680
<v Speaker 2>atom smashers and higher energy colliders, but we didn't immediately

0:04:09.680 --> 0:04:12.640
<v Speaker 2>find out what was inside the proton. Instead, first we

0:04:12.680 --> 0:04:15.160
<v Speaker 2>discovered all sorts of weird other kinds of particles that

0:04:15.200 --> 0:04:18.680
<v Speaker 2>don't exist inside the atom, chaons and pions and rope

0:04:18.720 --> 0:04:21.479
<v Speaker 2>particles and omega particles and all sorts of other Greek letters.

0:04:21.520 --> 0:04:24.479
<v Speaker 2>I don't even know how to pronounce. Things got weird

0:04:24.880 --> 0:04:26.400
<v Speaker 2>before they got clearer.

0:04:26.720 --> 0:04:28.520
<v Speaker 1>Yeah, no, I understand. It's all Greek to me.

0:04:30.000 --> 0:04:32.280
<v Speaker 2>In the same way that we want to understand what's

0:04:32.320 --> 0:04:35.120
<v Speaker 2>inside the quarks that make up the proton, but first

0:04:35.120 --> 0:04:38.120
<v Speaker 2>we found more quarks along the way. Instead of figuring

0:04:38.120 --> 0:04:40.880
<v Speaker 2>out what's inside the upcork and the down cork, we

0:04:40.920 --> 0:04:42.840
<v Speaker 2>found the charm and the strange, and the top and

0:04:42.920 --> 0:04:45.480
<v Speaker 2>the bottom. So the universe gives us a big pile

0:04:45.560 --> 0:04:48.400
<v Speaker 2>of clues before it reveals its deepest secrets.

0:04:48.680 --> 0:04:51.280
<v Speaker 1>Yeah, it is a weird universe full of surprises. And

0:04:51.360 --> 0:04:54.039
<v Speaker 1>one of the weirdest things about matter in the universe

0:04:54.160 --> 0:04:57.000
<v Speaker 1>is that it seems to have an opposite to it.

0:04:57.040 --> 0:04:59.960
<v Speaker 1>There seems to be a lot of antimatter in the universe.

0:05:00.200 --> 0:05:02.839
<v Speaker 2>Every particle out there seems to have its weird twin.

0:05:02.920 --> 0:05:04.719
<v Speaker 2>And we don't know if this is a detour in

0:05:04.760 --> 0:05:08.440
<v Speaker 2>our path to finally understanding what is the fundamental nature

0:05:08.480 --> 0:05:11.880
<v Speaker 2>of matter, or if it's a crucial side quest to

0:05:11.960 --> 0:05:15.000
<v Speaker 2>get a clue that will help us unlock the deepest mystery.

0:05:15.480 --> 0:05:17.839
<v Speaker 2>We don't know if and of matter is necessary, we

0:05:17.920 --> 0:05:20.400
<v Speaker 2>don't know what role it plays, We don't really know

0:05:20.560 --> 0:05:23.720
<v Speaker 2>what clue it's giving us about the nature of the universe.

0:05:23.920 --> 0:05:25.920
<v Speaker 1>And so to the other podcast, we'll be asking the

0:05:26.040 --> 0:05:34.720
<v Speaker 1>question why do we have anti particles? Feel like that's

0:05:34.760 --> 0:05:39.400
<v Speaker 1>a weird double negative question, like why don't we have particles?

0:05:40.360 --> 0:05:43.200
<v Speaker 1>Or why do we have anti particles? What's the correct

0:05:43.240 --> 0:05:44.839
<v Speaker 1>grammar here or is it in Greek?

0:05:46.120 --> 0:05:48.279
<v Speaker 2>I think why do we have anti particles? Is the

0:05:48.279 --> 0:05:50.719
<v Speaker 2>deep question? You know, every time we see something in

0:05:50.760 --> 0:05:53.279
<v Speaker 2>the universe, we wonder like, hmmm, did it have to

0:05:53.320 --> 0:05:56.520
<v Speaker 2>be this way? Is this necessary? Is this a clue

0:05:56.640 --> 0:05:59.039
<v Speaker 2>as to the fundamental nature of the universe or just

0:05:59.040 --> 0:06:00.520
<v Speaker 2>sort of like a random accident.

0:06:00.839 --> 0:06:02.839
<v Speaker 1>Well, so, as usual, we were wondering how many people

0:06:02.839 --> 0:06:05.480
<v Speaker 1>out there had thought about this question or have any

0:06:05.520 --> 0:06:08.440
<v Speaker 1>ideas about why we have anti particles.

0:06:08.520 --> 0:06:10.800
<v Speaker 2>So thank you very much to everybody who answers these

0:06:10.920 --> 0:06:13.960
<v Speaker 2>questions for this fun segment of our podcast. If you

0:06:13.960 --> 0:06:16.679
<v Speaker 2>would like to play along next time, please don't be shy.

0:06:16.960 --> 0:06:20.080
<v Speaker 2>Write to me two questions at Danielandjorge dot Com.

0:06:20.120 --> 0:06:21.919
<v Speaker 1>So think about it for a second. Why do you

0:06:21.960 --> 0:06:25.280
<v Speaker 1>think we have anti particles? Here's what people had to say.

0:06:25.640 --> 0:06:30.760
<v Speaker 3>In general, antiparticles exist because particles exist and there's some

0:06:30.800 --> 0:06:33.600
<v Speaker 3>sort of balance that was broken at.

0:06:33.200 --> 0:06:34.280
<v Speaker 1>The Big Bang.

0:06:34.720 --> 0:06:38.240
<v Speaker 4>I don't know, but the universe seems to like symmetry,

0:06:38.960 --> 0:06:45.520
<v Speaker 4>and somehow antiparticles had to exist for some kind of

0:06:45.560 --> 0:06:49.840
<v Speaker 4>symmetry to be to be fulfilled. But I don't know.

0:06:50.120 --> 0:06:51.679
<v Speaker 4>It's kind of crazy.

0:06:51.920 --> 0:06:54.240
<v Speaker 1>I think anti particles exist for the same reason you

0:06:54.240 --> 0:06:55.919
<v Speaker 1>don't get monopole magnets.

0:06:56.040 --> 0:06:58.600
<v Speaker 2>But I'm got clear, so we'll say with me, well

0:06:58.640 --> 0:06:59.000
<v Speaker 2>maybe not.

0:06:59.160 --> 0:07:02.360
<v Speaker 3>I feel like you need the antiparticles like cancel it out,

0:07:02.720 --> 0:07:06.520
<v Speaker 3>because you can't have like something from nothing. You need

0:07:06.560 --> 0:07:10.000
<v Speaker 3>to have something and then the opposite of it, so

0:07:10.040 --> 0:07:13.160
<v Speaker 3>that like overall nothing has changed.

0:07:13.360 --> 0:07:17.040
<v Speaker 5>Any particles are probably like the ying and yang. For

0:07:17.120 --> 0:07:20.840
<v Speaker 5>every particle, there has to exist an anti particle in

0:07:20.920 --> 0:07:24.720
<v Speaker 5>order to balance the forces in the universe, similar to

0:07:25.240 --> 0:07:26.920
<v Speaker 5>matter and anti matter.

0:07:27.120 --> 0:07:31.679
<v Speaker 6>I think the reason why antiparticles exist is because everything

0:07:31.680 --> 0:07:34.160
<v Speaker 6>in nature and physics seems to be balanced. So if

0:07:34.160 --> 0:07:38.600
<v Speaker 6>you sum up everything, it comes off like zero. But yeah,

0:07:38.640 --> 0:07:40.760
<v Speaker 6>for everything that exists, there needs to be an anti

0:07:40.840 --> 0:07:42.600
<v Speaker 6>thing Somemari like Ying and Young.

0:07:42.840 --> 0:07:46.360
<v Speaker 1>All right, some very philosophical answers here, some of them

0:07:46.440 --> 0:07:46.920
<v Speaker 1>kind of zen.

0:07:47.400 --> 0:07:50.120
<v Speaker 2>Yeah, there's a lot of philosophy in these questions, you know,

0:07:50.200 --> 0:07:53.520
<v Speaker 2>wondering whether the universe could have multiple explanations or just

0:07:53.520 --> 0:07:57.520
<v Speaker 2>one explanation, or whether it has any explanation at all,

0:07:57.720 --> 0:08:00.520
<v Speaker 2>whether it makes sense, and whether it's sensible to human minds.

0:08:00.720 --> 0:08:03.080
<v Speaker 2>All that stuff is tied up in this quest to

0:08:03.160 --> 0:08:04.200
<v Speaker 2>understand the universe.

0:08:04.920 --> 0:08:07.800
<v Speaker 1>Do you think maybe there are anti particle scientists out

0:08:07.840 --> 0:08:11.480
<v Speaker 1>there and or cartoonists we're wondering why do we have particles?

0:08:11.680 --> 0:08:12.760
<v Speaker 1>What is this weird stuff?

0:08:12.920 --> 0:08:15.600
<v Speaker 2>I don't know, but humans are capable of developing science

0:08:15.680 --> 0:08:18.480
<v Speaker 2>as well as antiscience. More recently, I'm.

0:08:18.360 --> 0:08:20.960
<v Speaker 1>Just antiphysics, I like all the other sciences.

0:08:21.240 --> 0:08:23.680
<v Speaker 2>Are you antiphysics or are you anti physicists?

0:08:23.880 --> 0:08:27.840
<v Speaker 1>I'm anti answering that question and that's an answer to

0:08:27.880 --> 0:08:33.000
<v Speaker 1>that a position there. Well, let's dig into it, Daniel Water,

0:08:33.120 --> 0:08:35.760
<v Speaker 1>anti particles is it like antimatter exactly?

0:08:35.800 --> 0:08:39.680
<v Speaker 2>Anti particles are what make up anti matter. So matter

0:08:39.800 --> 0:08:41.720
<v Speaker 2>is the stuff that we find around us that you

0:08:41.720 --> 0:08:43.760
<v Speaker 2>were made of. That I am made out of everything

0:08:43.760 --> 0:08:46.320
<v Speaker 2>you have ever eaten is made out of particles that

0:08:46.360 --> 0:08:49.760
<v Speaker 2>we call matter particles. So you and I are made

0:08:49.760 --> 0:08:53.040
<v Speaker 2>out of protons, neutrons, and electrons, and those protons and

0:08:53.080 --> 0:08:57.040
<v Speaker 2>neutrons are made up of quarks. Anti matter is made

0:08:57.120 --> 0:09:00.319
<v Speaker 2>up of anti particles, so you could have, for example,

0:09:00.480 --> 0:09:04.080
<v Speaker 2>anti hydrogen is made of an anti proton and an

0:09:04.120 --> 0:09:07.120
<v Speaker 2>anti electron, where the anti proton is then made of

0:09:07.240 --> 0:09:10.079
<v Speaker 2>anti quarks. So there's a close connection, of course between

0:09:10.120 --> 0:09:12.440
<v Speaker 2>anti matter and anti particles.

0:09:12.600 --> 0:09:16.000
<v Speaker 1>I see. So particles are the little things that we're

0:09:16.040 --> 0:09:18.840
<v Speaker 1>all made out of, and some of them have anti

0:09:19.040 --> 0:09:22.200
<v Speaker 1>versions of them. Do all particles have anti versions or

0:09:22.240 --> 0:09:24.360
<v Speaker 1>only some of them? Like do the force particles have

0:09:24.440 --> 0:09:26.199
<v Speaker 1>anti force particles?

0:09:26.600 --> 0:09:29.760
<v Speaker 2>Great question, sort of yes and no. All the particles

0:09:29.880 --> 0:09:33.040
<v Speaker 2>have anti particles, but some of them are their own

0:09:33.080 --> 0:09:35.840
<v Speaker 2>anti particles, so I'm not sure if that counts as

0:09:36.000 --> 0:09:39.640
<v Speaker 2>having an anti particle. So, for example, the electron has

0:09:39.679 --> 0:09:43.680
<v Speaker 2>an antiparticle the positron, and the muon has an anti

0:09:43.720 --> 0:09:47.040
<v Speaker 2>particle the anti muon, and the quarks have antiparticles the

0:09:47.120 --> 0:09:50.040
<v Speaker 2>anti quarks. Those are different particles, or you could think

0:09:50.080 --> 0:09:52.240
<v Speaker 2>of them as two parts of the same pair. But

0:09:52.480 --> 0:09:55.720
<v Speaker 2>they are distinct states. But then particles, like you said,

0:09:55.720 --> 0:09:59.240
<v Speaker 2>the force carrying particles like the photon, the photon is

0:09:59.400 --> 0:10:02.640
<v Speaker 2>its own anti particle, and so you might also say

0:10:02.679 --> 0:10:04.839
<v Speaker 2>it doesn't have an anti particle. But I'd like to

0:10:04.840 --> 0:10:07.000
<v Speaker 2>think about it as one particle playing two roles.

0:10:07.200 --> 0:10:09.400
<v Speaker 1>What about some of the other force particles, do they

0:10:09.400 --> 0:10:10.280
<v Speaker 1>have anti versions?

0:10:10.400 --> 0:10:13.000
<v Speaker 2>Well, there are two w bosons, and they are each

0:10:13.040 --> 0:10:15.560
<v Speaker 2>other's antiparticles. So you have the W plus and the

0:10:15.720 --> 0:10:19.120
<v Speaker 2>W minus for example. So those two force particles are

0:10:19.200 --> 0:10:21.560
<v Speaker 2>each other's anti particles, which is why we have two

0:10:21.559 --> 0:10:25.280
<v Speaker 2>of them. The Z boson is its own antiparticle, and

0:10:25.320 --> 0:10:29.040
<v Speaker 2>the gluon is actually eight gluons, all of different colors,

0:10:29.040 --> 0:10:31.600
<v Speaker 2>and some of them are each other's antiparticles. So you

0:10:31.640 --> 0:10:35.240
<v Speaker 2>can have like a red anti green gluon, which is

0:10:35.280 --> 0:10:38.800
<v Speaker 2>the antiparticle to the anti red green gluon. It gets

0:10:38.880 --> 0:10:40.680
<v Speaker 2>really colorful with gluons.

0:10:41.600 --> 0:10:43.360
<v Speaker 1>Well, I feel bad for those particles that are their

0:10:43.400 --> 0:10:45.839
<v Speaker 1>own anti versions of themselves. It's like they're their own

0:10:45.880 --> 0:10:47.080
<v Speaker 1>worst enemies.

0:10:47.840 --> 0:10:50.520
<v Speaker 2>Or maybe they're lonely. Right, one is the loneliest number.

0:10:50.559 --> 0:10:52.160
<v Speaker 1>After all, this should hang out together.

0:10:53.880 --> 0:10:57.679
<v Speaker 2>Some people confuse anti matter with dark matter, And there's

0:10:57.760 --> 0:11:00.640
<v Speaker 2>lots of mysteries in particle physics, right, lots of things

0:11:00.640 --> 0:11:03.440
<v Speaker 2>that we don't understand about the universe, But those are

0:11:03.440 --> 0:11:07.520
<v Speaker 2>two separate mysteries. Dark matter is the invisible matter that's

0:11:07.600 --> 0:11:09.880
<v Speaker 2>out there in the universe that we know is holding

0:11:09.920 --> 0:11:13.360
<v Speaker 2>galaxies together and shaping the whole development of the large

0:11:13.400 --> 0:11:15.679
<v Speaker 2>scale structure of the universe. We don't know what it is,

0:11:15.720 --> 0:11:18.760
<v Speaker 2>and if it's made of particles, that's a different idea

0:11:18.840 --> 0:11:22.240
<v Speaker 2>from antimatter. Antimatter is a real thing that we can make,

0:11:22.280 --> 0:11:24.800
<v Speaker 2>that we can study. We've seen it in our detectors.

0:11:24.800 --> 0:11:27.560
<v Speaker 2>We know for sure that it exists and it's made

0:11:27.600 --> 0:11:28.839
<v Speaker 2>of anti particles.

0:11:29.080 --> 0:11:31.240
<v Speaker 1>Well, I guess maybe the question now is how do

0:11:31.280 --> 0:11:34.160
<v Speaker 1>you make antimatter? Can you make it or does it

0:11:34.200 --> 0:11:36.880
<v Speaker 1>exist in nature or is it just a matter of

0:11:36.920 --> 0:11:40.600
<v Speaker 1>like flipping the sign on some quantum property of regular particles.

0:11:40.679 --> 0:11:43.600
<v Speaker 2>So sort of all of the above. Antimatter isn't very common.

0:11:43.640 --> 0:11:47.199
<v Speaker 2>The universe is almost entirely made of matter, meaning it's

0:11:47.200 --> 0:11:51.560
<v Speaker 2>made of particles instead of anti particles, but sometimes antimatter

0:11:51.679 --> 0:11:54.280
<v Speaker 2>is produced, though it doesn't last very long because it

0:11:54.360 --> 0:11:58.480
<v Speaker 2>runs into normal particles and annihilates but for example, the

0:11:58.559 --> 0:12:01.640
<v Speaker 2>discovery of anti I mapps, which led to the nineteen

0:12:01.760 --> 0:12:06.920
<v Speaker 2>thirty three Nobel Prize, was from naturally produced antimatter. So

0:12:07.080 --> 0:12:10.760
<v Speaker 2>a positron the opposite particle to an electron produced in

0:12:11.000 --> 0:12:15.480
<v Speaker 2>cosmic rays, meaning high energy collisions of particles from space

0:12:15.640 --> 0:12:19.560
<v Speaker 2>hitting the upper atmosphere and creating antimatter which then showered

0:12:19.600 --> 0:12:21.120
<v Speaker 2>down to the surface of the Earth.

0:12:21.320 --> 0:12:23.160
<v Speaker 1>So when was this When was the first time we

0:12:23.240 --> 0:12:24.120
<v Speaker 1>saw antimatter?

0:12:24.440 --> 0:12:27.040
<v Speaker 2>So it was first observed in the late nineteen twenties.

0:12:27.080 --> 0:12:30.880
<v Speaker 2>It was predicted by Paul Durack, the quantum physicist, who

0:12:30.920 --> 0:12:33.520
<v Speaker 2>saw the mathematical need for them in his equations, and

0:12:33.559 --> 0:12:36.040
<v Speaker 2>he said, hm, my equations predict there should be electrons

0:12:36.080 --> 0:12:39.400
<v Speaker 2>and should also be another particle with the opposite charge

0:12:39.440 --> 0:12:41.679
<v Speaker 2>as the electron. So he predicted it, and then Carl

0:12:41.720 --> 0:12:44.360
<v Speaker 2>Anderson saw it. We have a whole fun podcast episode

0:12:44.360 --> 0:12:47.240
<v Speaker 2>about the discovery of antimatter and the twists and turns

0:12:47.280 --> 0:12:50.240
<v Speaker 2>and the egos involved. It's a really fun story. Check

0:12:50.320 --> 0:12:52.480
<v Speaker 2>that out. We've known about it for almost one hundred

0:12:52.600 --> 0:12:53.240
<v Speaker 2>years now.

0:12:53.400 --> 0:12:56.080
<v Speaker 1>It sort of involves cloud chambers, right, which is something

0:12:56.120 --> 0:12:58.680
<v Speaker 1>you can usually find in most science museums.

0:12:58.800 --> 0:13:02.320
<v Speaker 2>Yeah, early particle physics didn't have fancy digital electronics and

0:13:02.720 --> 0:13:05.600
<v Speaker 2>the complicated detectors we have now. They had to use

0:13:05.640 --> 0:13:09.000
<v Speaker 2>techniques to observe the paths of these particles with the

0:13:09.000 --> 0:13:11.600
<v Speaker 2>technology they had. And one thing you can do to

0:13:11.800 --> 0:13:15.199
<v Speaker 2>illuminate what particles are flying through the air around you

0:13:15.480 --> 0:13:17.959
<v Speaker 2>is to create clouds of water vapor. If you have

0:13:18.120 --> 0:13:21.480
<v Speaker 2>air that's super saturated with water, meaning it actually has

0:13:21.640 --> 0:13:24.080
<v Speaker 2>more water in it than it likes to have, then

0:13:24.080 --> 0:13:27.120
<v Speaker 2>it's very easy to knock that water out of the air,

0:13:27.400 --> 0:13:29.959
<v Speaker 2>and a passing charge particle will do just that and

0:13:30.000 --> 0:13:33.000
<v Speaker 2>will create a string of droplets in the air. You

0:13:33.040 --> 0:13:35.320
<v Speaker 2>can actually create cloud chambers at home. Check out lots

0:13:35.320 --> 0:13:37.600
<v Speaker 2>of YouTube videos for how to do this. You can

0:13:37.640 --> 0:13:39.560
<v Speaker 2>build one in your garage. You can see them at

0:13:39.600 --> 0:13:43.040
<v Speaker 2>science museums and so you can see high energy particles

0:13:43.120 --> 0:13:45.640
<v Speaker 2>streaming through the air around you, muons and all sorts

0:13:45.679 --> 0:13:48.040
<v Speaker 2>of stuff. Carl Anderson proved that a fraction of these

0:13:48.040 --> 0:13:51.079
<v Speaker 2>are actually anti matter particles, and he did that by

0:13:51.080 --> 0:13:54.480
<v Speaker 2>showing how they curve differently in magnetic fields. Because magnetic

0:13:54.480 --> 0:13:57.600
<v Speaker 2>fields will change the path of a charge particle depending

0:13:57.760 --> 0:14:00.280
<v Speaker 2>on the charge. A positive charge will be in it

0:14:00.280 --> 0:14:02.920
<v Speaker 2>one way. A negative charge will bend it the other way.

0:14:03.280 --> 0:14:06.200
<v Speaker 2>So he saw particles that had the same mass as electrons,

0:14:06.200 --> 0:14:07.520
<v Speaker 2>but bend in the other.

0:14:07.400 --> 0:14:13.120
<v Speaker 1>Direction like a positively charged electron. Is that basically what

0:14:13.200 --> 0:14:16.160
<v Speaker 1>an anti electron is, Just an electron with a charge flip.

0:14:16.720 --> 0:14:20.360
<v Speaker 2>Yeah, that's what antiparticles are. They're just like their particle counterparts,

0:14:20.480 --> 0:14:23.920
<v Speaker 2>but they have the opposite charges, so the opposite electric charge,

0:14:24.000 --> 0:14:27.640
<v Speaker 2>the opposite weak charges, and the opposite color charges. So

0:14:27.680 --> 0:14:30.640
<v Speaker 2>in the case of the electron, it's basically a positively

0:14:30.720 --> 0:14:32.200
<v Speaker 2>charged electron.

0:14:31.880 --> 0:14:34.080
<v Speaker 1>Right, because I guess an electron doesn't have the weak

0:14:34.200 --> 0:14:36.520
<v Speaker 1>charge and it doesn't have the strong charge.

0:14:36.600 --> 0:14:39.360
<v Speaker 2>Right, Electrons do have the weak charge. Actually, remember, the

0:14:39.360 --> 0:14:43.160
<v Speaker 2>weak force is actually unified with electromagnetism into one force

0:14:43.200 --> 0:14:46.520
<v Speaker 2>we call electro week, and electrons can interact via the

0:14:46.520 --> 0:14:49.400
<v Speaker 2>weak force. They can emit w's for example, that's how

0:14:49.480 --> 0:14:52.560
<v Speaker 2>beta decay happens. So electrons interact with the weak force.

0:14:52.600 --> 0:14:55.440
<v Speaker 2>In fact, every particle we've ever seen interacts with a

0:14:55.520 --> 0:14:58.360
<v Speaker 2>weak force, which is fascinating because the other forces are

0:14:58.400 --> 0:15:02.040
<v Speaker 2>not so democratic. The strong force only interacts with quarks

0:15:02.080 --> 0:15:06.240
<v Speaker 2>and not at all with electrons or neutrinos, and electromagnetism

0:15:06.320 --> 0:15:09.440
<v Speaker 2>doesn't interact with neutrinos. But we've never found a particle

0:15:09.480 --> 0:15:12.280
<v Speaker 2>that doesn't have any kind of weak charge. Every particle

0:15:12.320 --> 0:15:15.520
<v Speaker 2>out there so far we discovered interacts with the weak force.

0:15:15.840 --> 0:15:17.640
<v Speaker 1>Wait, what's the name of the week charge? If you

0:15:17.680 --> 0:15:19.480
<v Speaker 1>have a week charge, what is that called?

0:15:19.600 --> 0:15:22.280
<v Speaker 2>Well, there's actually two different week charges. One of them

0:15:22.360 --> 0:15:24.480
<v Speaker 2>is called weak isospin and the other one is called

0:15:24.520 --> 0:15:27.200
<v Speaker 2>weak hypercharge. But you can combine them actually to make

0:15:27.240 --> 0:15:31.400
<v Speaker 2>electromagnetic charge. So there's two different charges for the electro

0:15:31.520 --> 0:15:34.440
<v Speaker 2>weak force, but one of them is really from electromagnetism.

0:15:34.600 --> 0:15:38.080
<v Speaker 1>I'll pretend I totally understood that. But I guess when

0:15:38.120 --> 0:15:40.200
<v Speaker 1>you're trying to make an anti electron, which one do

0:15:40.240 --> 0:15:43.000
<v Speaker 1>you flip? Do you flip the electromagnetic charge like the

0:15:43.160 --> 0:15:44.960
<v Speaker 1>you know, plus and minds that we're all familiar with,

0:15:45.080 --> 0:15:47.520
<v Speaker 1>or do you flip one of these other sub charges?

0:15:47.960 --> 0:15:49.440
<v Speaker 1>And if you do, do I mean there are several

0:15:49.560 --> 0:15:50.920
<v Speaker 1>versions of an anti electron.

0:15:51.040 --> 0:15:53.160
<v Speaker 2>Now you flip all the charges. So there's only one

0:15:53.240 --> 0:15:56.280
<v Speaker 2>version of a positron, and it has a positive electric charge.

0:15:56.320 --> 0:15:58.600
<v Speaker 2>It also has both of its weak charges flipped.

0:15:58.640 --> 0:16:00.600
<v Speaker 1>But what if you flip one and the other you

0:16:00.600 --> 0:16:02.880
<v Speaker 1>can't do that, man, don't do that. They'll tell you

0:16:02.920 --> 0:16:05.520
<v Speaker 1>why not to do, tell you why I can't do it.

0:16:05.640 --> 0:16:07.720
<v Speaker 1>Then I can choose whether or not I can't.

0:16:07.920 --> 0:16:10.800
<v Speaker 2>I will do it. It's not me, man, it's the

0:16:10.880 --> 0:16:13.640
<v Speaker 2>laws of the universe. No, we do not see particles

0:16:13.640 --> 0:16:15.920
<v Speaker 2>where only one charge is flipped and the other one

0:16:16.040 --> 0:16:16.280
<v Speaker 2>is not.

0:16:16.840 --> 0:16:17.120
<v Speaker 1>Why not.

0:16:17.480 --> 0:16:20.640
<v Speaker 2>Yeah, that's a very cool question, imagining particles that are

0:16:20.760 --> 0:16:24.040
<v Speaker 2>particles according to one force and anti particles according to

0:16:24.080 --> 0:16:27.760
<v Speaker 2>another force. Remember, we recently answered a question about whether

0:16:27.800 --> 0:16:30.880
<v Speaker 2>it even matters whether you're calling something matter or antimatter,

0:16:31.200 --> 0:16:34.240
<v Speaker 2>and turns out that's totally an arbitrary distinction. So it

0:16:34.240 --> 0:16:37.480
<v Speaker 2>doesn't really matter if one force considers a particle matter

0:16:37.560 --> 0:16:39.920
<v Speaker 2>and the other one considers a particle the anti matter.

0:16:40.040 --> 0:16:42.760
<v Speaker 2>But the forces do have to be consistent, and in

0:16:42.800 --> 0:16:45.840
<v Speaker 2>the case of the weak force and electromagnetism, for example,

0:16:46.040 --> 0:16:48.800
<v Speaker 2>they are tightly linked, so you can't just flip one

0:16:49.000 --> 0:16:51.400
<v Speaker 2>and not the other. The charges of the two forces

0:16:51.680 --> 0:16:54.440
<v Speaker 2>really are connected by the structure of the theory.

0:16:54.840 --> 0:16:57.000
<v Speaker 1>I think what you're what you're saying, is this matter

0:16:57.120 --> 0:17:01.200
<v Speaker 1>anti matter distinction is really kind of arbitrary kind of right,

0:17:01.320 --> 0:17:03.160
<v Speaker 1>Like it's not as clear cut, like maybe there are

0:17:03.200 --> 0:17:05.960
<v Speaker 1>shades of gray or shades of antiness.

0:17:06.080 --> 0:17:08.600
<v Speaker 2>Yeah, we definitely don't claim to understand everything there is

0:17:08.640 --> 0:17:11.040
<v Speaker 2>to know about antimatter. But I think you're right A

0:17:11.080 --> 0:17:12.600
<v Speaker 2>lot of this comes down to just like what do

0:17:12.640 --> 0:17:15.040
<v Speaker 2>you call matter and what do you call antimatter. A

0:17:15.119 --> 0:17:17.600
<v Speaker 2>crucial idea is that there are these symmetries that you

0:17:17.600 --> 0:17:21.360
<v Speaker 2>can flip these charges and the equations still work, that

0:17:21.400 --> 0:17:24.480
<v Speaker 2>the universe can do both of these things, and so

0:17:24.560 --> 0:17:27.119
<v Speaker 2>it does in some cases. We have like multiple ways

0:17:27.119 --> 0:17:29.800
<v Speaker 2>to categorize what is matter and what is antimatter.

0:17:30.040 --> 0:17:32.520
<v Speaker 1>Well, I think the thing that most people probably remember

0:17:32.600 --> 0:17:36.399
<v Speaker 1>about antimatter, and that maybe is relevant here, is that

0:17:36.560 --> 0:17:39.800
<v Speaker 1>like a matter particle and it's antimatter particle, if they touch,

0:17:39.880 --> 0:17:43.080
<v Speaker 1>then they annihilate. They become pure energy. Right, We've talked

0:17:43.119 --> 0:17:45.880
<v Speaker 1>about that before they explode. That's one of the things

0:17:45.920 --> 0:17:47.360
<v Speaker 1>about antimatter.

0:17:47.280 --> 0:17:51.520
<v Speaker 2>Particles and their antiparticles can annihilate into a force particle.

0:17:51.560 --> 0:17:54.159
<v Speaker 2>So for example, an electron and a positron can come

0:17:54.200 --> 0:17:57.800
<v Speaker 2>together to make a photon or a z boson and

0:17:57.880 --> 0:18:00.360
<v Speaker 2>a and an anti quark can come together to make

0:18:00.400 --> 0:18:03.040
<v Speaker 2>a glue on, and the opposite can happen. Also, a

0:18:03.080 --> 0:18:06.879
<v Speaker 2>photon can turn into a matter antimatter pair, or a

0:18:06.960 --> 0:18:10.920
<v Speaker 2>z boson can decay into a muon and its anti particle.

0:18:11.160 --> 0:18:13.439
<v Speaker 1>But then I guess if anti nus is kind of

0:18:13.920 --> 0:18:16.679
<v Speaker 1>relative or there's a gray area there, or how does

0:18:16.720 --> 0:18:19.399
<v Speaker 1>that affect the annihilation? Like if I take a cork

0:18:19.400 --> 0:18:21.960
<v Speaker 1>and an antiquark, but I flip some other other signs,

0:18:22.400 --> 0:18:23.400
<v Speaker 1>do they still annihilate?

0:18:23.600 --> 0:18:26.360
<v Speaker 2>They can annihilate if there is a particle that carries

0:18:26.800 --> 0:18:30.439
<v Speaker 2>their combined charges. So for example, an electron and a

0:18:30.480 --> 0:18:33.840
<v Speaker 2>positron can annihilate because in total they have zero electric

0:18:33.920 --> 0:18:37.160
<v Speaker 2>charge and the photon has zero electric charge. That's why

0:18:37.160 --> 0:18:40.080
<v Speaker 2>an electron cannot annihilate with another electron, because then you'd

0:18:40.080 --> 0:18:42.560
<v Speaker 2>have to have a particle with a minus two charge

0:18:42.720 --> 0:18:46.120
<v Speaker 2>in order to conserve electric charge. So the same thing

0:18:46.160 --> 0:18:47.440
<v Speaker 2>goes for the other charges.

0:18:47.720 --> 0:18:49.920
<v Speaker 1>So like if I have a green cork and an

0:18:49.920 --> 0:18:54.200
<v Speaker 1>anti green cork, but a given different you know, regular charges,

0:18:54.760 --> 0:18:56.800
<v Speaker 1>what's gonna happen? Are they going to annihilate or repel

0:18:56.800 --> 0:18:58.480
<v Speaker 1>each other? Or what I'm just trying to get at,

0:18:58.800 --> 0:19:00.760
<v Speaker 1>Like what it means to be anti mime. Is it

0:19:00.800 --> 0:19:03.800
<v Speaker 1>depending on this annihilation thing or is it kind of random.

0:19:03.880 --> 0:19:05.720
<v Speaker 2>It's a little bit more complicated for the color charge

0:19:05.760 --> 0:19:09.720
<v Speaker 2>because gluons themselves are colored. You know, the photons don't

0:19:09.760 --> 0:19:12.080
<v Speaker 2>have any charge for example, right, so it's simple plus

0:19:12.119 --> 0:19:15.120
<v Speaker 2>and minus annihilate to zero charge photons. In the case

0:19:15.200 --> 0:19:18.240
<v Speaker 2>of gluons, gluons do carry color. In fact, they carry

0:19:18.280 --> 0:19:21.840
<v Speaker 2>two colors, which is even more confusing. So for example,

0:19:21.880 --> 0:19:25.640
<v Speaker 2>a red anti green quark can combine to make red

0:19:25.680 --> 0:19:28.639
<v Speaker 2>anti green gluon. The glue on itself carries two of

0:19:28.680 --> 0:19:32.000
<v Speaker 2>those colors, but the gluons don't carry electric charge, so

0:19:32.040 --> 0:19:35.440
<v Speaker 2>this can only happen for quarks that have opposite electric

0:19:35.600 --> 0:19:38.959
<v Speaker 2>charges that can balance out to zero electric charge. So

0:19:39.119 --> 0:19:41.320
<v Speaker 2>one way to think about how to pair particles and

0:19:41.320 --> 0:19:46.200
<v Speaker 2>antiparticles is whether they can annihilate into these force particles.

0:19:46.640 --> 0:19:49.480
<v Speaker 1>I see, So maybe one particle can have multiple anti

0:19:49.560 --> 0:19:50.400
<v Speaker 1>versions of itself.

0:19:50.480 --> 0:19:53.040
<v Speaker 2>There are definitely multiple different versions of quarks that an

0:19:53.040 --> 0:19:57.359
<v Speaker 2>individual quark can annihilate with to create a gluon. Because

0:19:57.400 --> 0:20:00.480
<v Speaker 2>there are so many different kinds of gluons, they always

0:20:00.520 --> 0:20:03.800
<v Speaker 2>have to have opposite electric charges. Because the gluons don't

0:20:03.800 --> 0:20:06.919
<v Speaker 2>have electric charge, So yeah, it gets really complicated when

0:20:06.960 --> 0:20:10.200
<v Speaker 2>you're talking about the color charges because there's multiple different

0:20:10.200 --> 0:20:12.879
<v Speaker 2>color charges and the gluons carry them themselves, and so

0:20:12.920 --> 0:20:14.080
<v Speaker 2>the whole thing is a big mess.

0:20:14.359 --> 0:20:17.440
<v Speaker 1>Is that how you end every physics paper? YadA YadA,

0:20:17.520 --> 0:20:19.600
<v Speaker 1>YadA YadA, And it's all a big mess.

0:20:19.720 --> 0:20:21.840
<v Speaker 2>It's a big mess, and it's a glorious puzzle and

0:20:21.880 --> 0:20:24.919
<v Speaker 2>we're still working to try to figure it out. Yeah.

0:20:24.960 --> 0:20:27.760
<v Speaker 1>Cool, Well, I guess the big question is still why

0:20:27.800 --> 0:20:30.159
<v Speaker 1>do we have anti particles at all? Why do they

0:20:30.240 --> 0:20:32.959
<v Speaker 1>exist in the universe? And so let's dig into that

0:20:33.119 --> 0:20:37.600
<v Speaker 1>question and some of the other open questions about antimatter.

0:20:38.000 --> 0:20:52.880
<v Speaker 1>But first let's take a quick break. All right, we're

0:20:52.880 --> 0:20:56.560
<v Speaker 1>talking about antimatter antiparticles and why do we need them

0:20:56.560 --> 0:20:59.480
<v Speaker 1>at all? Which sounds like a very insensitive question.

0:21:00.000 --> 0:21:02.200
<v Speaker 2>What the deepest question we ask when we see something

0:21:02.200 --> 0:21:04.320
<v Speaker 2>in the universe, We ask like, why is it this

0:21:04.400 --> 0:21:06.879
<v Speaker 2>way and not some other way? Does it have to

0:21:06.880 --> 0:21:10.080
<v Speaker 2>be this way? Is the universe parsimonious, like it only

0:21:10.119 --> 0:21:12.520
<v Speaker 2>contains things that have to happen? Or is it sort

0:21:12.520 --> 0:21:14.560
<v Speaker 2>of like baroque that has all sorts of flourishes that

0:21:14.600 --> 0:21:16.720
<v Speaker 2>it doesn't really need, and it's just sort of beautiful.

0:21:16.880 --> 0:21:18.919
<v Speaker 2>We tend to think of the universe as parsimonious. We

0:21:18.960 --> 0:21:21.000
<v Speaker 2>try to take every piece that we find and fit

0:21:21.080 --> 0:21:23.760
<v Speaker 2>it into the puzzle to explain why the universe works

0:21:23.800 --> 0:21:24.280
<v Speaker 2>this way.

0:21:25.240 --> 0:21:27.159
<v Speaker 1>Well, I guess one of the reasons we as we

0:21:27.240 --> 0:21:29.720
<v Speaker 1>talked about last time, that we call some things matter

0:21:29.760 --> 0:21:33.000
<v Speaker 1>and something's antimatter, is that we mostly see matter out

0:21:33.000 --> 0:21:34.840
<v Speaker 1>there in the universe, at least as far as we know.

0:21:35.359 --> 0:21:38.080
<v Speaker 1>Our planet, our Solar System, our galaxy is made out

0:21:38.080 --> 0:21:41.160
<v Speaker 1>of regular matter, and there's a big mystery about why

0:21:41.200 --> 0:21:44.080
<v Speaker 1>there isn't as much antimatter in the universe. But maybe

0:21:44.160 --> 0:21:46.879
<v Speaker 1>one question that you can ask is, like, is matter

0:21:46.920 --> 0:21:50.880
<v Speaker 1>and antimatter made at the same rate in the universe.

0:21:50.920 --> 0:21:53.560
<v Speaker 1>Like if you run a particle collision experiment and you

0:21:53.600 --> 0:21:57.200
<v Speaker 1>create some energy and some particles spill out to matter,

0:21:57.240 --> 0:22:00.199
<v Speaker 1>particles get made as much as antimatter particles.

0:22:00.200 --> 0:22:01.719
<v Speaker 2>A little bit on what you start from. I mean,

0:22:01.760 --> 0:22:04.359
<v Speaker 2>if you start from particles of matter, then you're going

0:22:04.400 --> 0:22:07.800
<v Speaker 2>to get more matter particles than antimatter particles. If you

0:22:07.840 --> 0:22:10.639
<v Speaker 2>start from antimatter particles, then you're going to get more antimatter,

0:22:10.680 --> 0:22:13.040
<v Speaker 2>and we actually ran a whole collider that smashed matter

0:22:13.200 --> 0:22:17.080
<v Speaker 2>versus antimatter. Now, was the collider outside Chicago, the Tevatron,

0:22:17.160 --> 0:22:21.080
<v Speaker 2>collided protons with anti protons, and so there we got

0:22:21.119 --> 0:22:25.440
<v Speaker 2>even splits of matter and antimatter. Whereas the collider at Cerne,

0:22:25.480 --> 0:22:29.840
<v Speaker 2>the Large Hadron Collider, smashes protons with protons because antimatter

0:22:30.040 --> 0:22:32.560
<v Speaker 2>was such a big headache to produce for the other collider,

0:22:32.960 --> 0:22:35.760
<v Speaker 2>And so there we get more matter produced than antimatter

0:22:35.760 --> 0:22:38.919
<v Speaker 2>because we're starting from matter. But most of these processes

0:22:39.000 --> 0:22:39.680
<v Speaker 2>are symmetric.

0:22:39.760 --> 0:22:39.879
<v Speaker 4>Right.

0:22:39.880 --> 0:22:41.840
<v Speaker 2>If you just have a big pile of photons and

0:22:41.920 --> 0:22:44.120
<v Speaker 2>you wait for them to decay, they will produce an

0:22:44.160 --> 0:22:46.960
<v Speaker 2>equal number of positrons and electrons.

0:22:47.640 --> 0:22:49.640
<v Speaker 1>I see. So I guess the big mystery is that

0:22:49.720 --> 0:22:53.080
<v Speaker 1>it sounds kind of like the universe is able to

0:22:53.119 --> 0:22:55.679
<v Speaker 1>make equal amounts of both kinds of matter, but what

0:22:55.720 --> 0:22:57.840
<v Speaker 1>we see in the universe is mostly only one kind

0:22:57.840 --> 0:22:58.200
<v Speaker 1>of matter.

0:22:58.320 --> 0:23:01.280
<v Speaker 2>Yeah, we suspect that the very early universe, matter and

0:23:01.320 --> 0:23:03.879
<v Speaker 2>antimatter were created at the same rates that as the

0:23:03.960 --> 0:23:07.560
<v Speaker 2>universe cooled down from the frothing pile of quantum fields

0:23:07.920 --> 0:23:10.400
<v Speaker 2>and things got cold and isolated enough that you could

0:23:10.440 --> 0:23:14.719
<v Speaker 2>call things particles, that the particles and anti particles existed

0:23:14.720 --> 0:23:16.720
<v Speaker 2>at basically the same level. Then there was a huge

0:23:16.760 --> 0:23:19.480
<v Speaker 2>amount of annihilation, as you can imagine, and most of

0:23:19.520 --> 0:23:22.280
<v Speaker 2>the matter and antimatter went away and turned into radiation.

0:23:22.520 --> 0:23:25.199
<v Speaker 2>But a little bit more matter is left over than antimatter,

0:23:25.240 --> 0:23:28.400
<v Speaker 2>and we don't understand the source of that discrepancy, even

0:23:28.440 --> 0:23:32.240
<v Speaker 2>though it's the reason why we have matter galaxies and matter,

0:23:32.320 --> 0:23:36.040
<v Speaker 2>stars and matter, people and matter chocolate and not anti matter.

0:23:36.480 --> 0:23:40.560
<v Speaker 2>The universe seems to have some preference for matter over antimatter.

0:23:40.160 --> 0:23:44.240
<v Speaker 1>Which makes me ask the question, is anti chocolate vanilla

0:23:44.359 --> 0:23:46.360
<v Speaker 1>or white chocolate or is it a case of having

0:23:46.440 --> 0:23:47.960
<v Speaker 1>multiple antiversities?

0:23:48.720 --> 0:23:50.600
<v Speaker 2>I hope so, because neither of those things should be

0:23:50.680 --> 0:23:51.760
<v Speaker 2>categorized with chocolate.

0:23:51.840 --> 0:23:54.800
<v Speaker 1>You're just pro chocolate. You just anti everything that's.

0:23:55.119 --> 0:23:57.560
<v Speaker 2>I'm just anti calling things chocolate that aren't chocolate. Even

0:23:57.600 --> 0:24:00.240
<v Speaker 2>calling them anti chocolate somehow groups them to get they're

0:24:00.280 --> 0:24:02.479
<v Speaker 2>in that chocolate category where they don't belong.

0:24:02.760 --> 0:24:05.680
<v Speaker 1>What about vegan chocolate, not chocolate.

0:24:05.400 --> 0:24:07.480
<v Speaker 2>No, totally chocolate. It comes from the cocoa bean.

0:24:07.560 --> 0:24:11.040
<v Speaker 1>Yeah, absolutely, all right, Well, the big question is why

0:24:11.080 --> 0:24:14.560
<v Speaker 1>does it exist? At all. Why do we have antimatter,

0:24:14.680 --> 0:24:17.480
<v Speaker 1>Like is it something that the equations of the universe

0:24:17.600 --> 0:24:21.000
<v Speaker 1>requires or is it just something that seems to happen.

0:24:21.800 --> 0:24:23.040
<v Speaker 1>That's the big question, right.

0:24:22.960 --> 0:24:25.520
<v Speaker 2>That's the question, and the short answer is we don't know.

0:24:26.200 --> 0:24:30.199
<v Speaker 2>But what's really fascinating is that without antimatter, some of

0:24:30.240 --> 0:24:33.600
<v Speaker 2>our basic theories of physics don't work very well together.

0:24:33.760 --> 0:24:37.120
<v Speaker 2>Like we have relativity and we have quantum mechanics, both

0:24:37.160 --> 0:24:40.359
<v Speaker 2>things that we think make sense in the universe, but

0:24:40.480 --> 0:24:43.280
<v Speaker 2>when we try to bring them together, we get some conflicts.

0:24:43.560 --> 0:24:46.919
<v Speaker 2>And it turns out that antimatter resolves those conflicts and

0:24:47.040 --> 0:24:51.200
<v Speaker 2>lets us bring special relativity and quantum mechanics together into

0:24:51.280 --> 0:24:51.959
<v Speaker 2>one theory.

0:24:52.119 --> 0:24:54.680
<v Speaker 1>Wait, I thought those two things didn't like each other.

0:24:54.840 --> 0:24:58.360
<v Speaker 2>So we have two different theories of relativity, special relativity,

0:24:58.520 --> 0:25:01.080
<v Speaker 2>which tells us about what happens and things move really

0:25:01.160 --> 0:25:04.640
<v Speaker 2>really fast near the speed of light, and then general relativity,

0:25:04.800 --> 0:25:08.160
<v Speaker 2>which tells us how space bends in the presence of mass.

0:25:08.480 --> 0:25:11.240
<v Speaker 2>General relativity and quantum mechanics we do not know how

0:25:11.280 --> 0:25:14.200
<v Speaker 2>to combine into a theory of quantum gravity. That's something

0:25:14.240 --> 0:25:16.720
<v Speaker 2>for a future physicist, maybe one of our listeners, to

0:25:16.840 --> 0:25:19.760
<v Speaker 2>figure out, but special relativity and quantum mechanics we do

0:25:19.880 --> 0:25:22.120
<v Speaker 2>know how to combine, and we've had that for many,

0:25:22.160 --> 0:25:26.520
<v Speaker 2>many decades. So that's basically relativistic quantum mechanics, and that

0:25:26.680 --> 0:25:28.800
<v Speaker 2>is something that we know how to do thinking about

0:25:28.880 --> 0:25:31.280
<v Speaker 2>quantum particles and moving near the speed of light, and

0:25:31.320 --> 0:25:33.560
<v Speaker 2>we do that all the time in our particle colliders, right,

0:25:33.560 --> 0:25:37.120
<v Speaker 2>it happens all the time that we have high speed particles.

0:25:37.200 --> 0:25:41.600
<v Speaker 2>So relativistic quantum mechanics we can do bend space, curved space.

0:25:41.680 --> 0:25:43.280
<v Speaker 2>Quantum mechanics we don't know how to do.

0:25:44.160 --> 0:25:48.840
<v Speaker 1>Interesting. Okay, So you're saying somehow antimatter and antiparticles somehow

0:25:48.960 --> 0:25:52.520
<v Speaker 1>make quantum mechanics and special relativity work together. What does

0:25:52.560 --> 0:25:52.840
<v Speaker 1>that mean?

0:25:52.920 --> 0:25:55.600
<v Speaker 2>So it all has to do with preserving causality, and

0:25:55.640 --> 0:25:59.520
<v Speaker 2>special relativity makes it really hard to think about causality,

0:25:59.640 --> 0:26:02.720
<v Speaker 2>to think about the order that things happen in the universe,

0:26:02.960 --> 0:26:05.159
<v Speaker 2>because it forces us to think about the order of

0:26:05.200 --> 0:26:08.440
<v Speaker 2>events in a very different way than like Newton thought

0:26:08.440 --> 0:26:11.080
<v Speaker 2>about things, and the way that we intuitively think about things.

0:26:11.200 --> 0:26:13.640
<v Speaker 2>You probably think about the universe happening as if there's

0:26:13.680 --> 0:26:16.479
<v Speaker 2>like a giant clock and the whole universe like ticks

0:26:16.520 --> 0:26:19.040
<v Speaker 2>forward and then the next thing happens, and the universe

0:26:19.080 --> 0:26:21.080
<v Speaker 2>ticks forward and the next thing happens. But you can

0:26:21.119 --> 0:26:23.439
<v Speaker 2>think of the whole universe as having like one clock,

0:26:23.720 --> 0:26:26.400
<v Speaker 2>so you can tell like one story about what happened

0:26:26.440 --> 0:26:29.840
<v Speaker 2>in the universe. Special relativity tells us that that's not

0:26:30.080 --> 0:26:33.800
<v Speaker 2>actually true, that there's lots of different clocks in the universe,

0:26:34.119 --> 0:26:37.560
<v Speaker 2>and how fast they tick depends on where you are

0:26:37.800 --> 0:26:40.240
<v Speaker 2>and how fast they're moving relative to you, So you

0:26:40.240 --> 0:26:43.000
<v Speaker 2>can actually tell lots of different stories about what happened

0:26:43.040 --> 0:26:46.720
<v Speaker 2>in the universe, even stories that conflict with each other,

0:26:46.920 --> 0:26:50.639
<v Speaker 2>that contradict each other about the order in which events happen.

0:26:51.040 --> 0:26:53.560
<v Speaker 1>Yeah, I know. We've talked about this before and include

0:26:53.600 --> 0:26:56.159
<v Speaker 1>it in our book. It's kind of this idea that

0:26:56.200 --> 0:26:59.080
<v Speaker 1>if two people run a race, you think that whoever

0:26:59.119 --> 0:27:01.399
<v Speaker 1>wins would be clear, but it sort of depends on

0:27:02.560 --> 0:27:06.200
<v Speaker 1>how fast they're moving and how fast the judges moving,

0:27:06.280 --> 0:27:08.280
<v Speaker 1>or how fast you're moving as an observer.

0:27:08.119 --> 0:27:11.040
<v Speaker 2>Right, Imagine two people running a race, but instead of

0:27:11.080 --> 0:27:13.760
<v Speaker 2>running alongside each other on a track the way people

0:27:13.760 --> 0:27:16.199
<v Speaker 2>typically do, imagine them starting in the same place but

0:27:16.280 --> 0:27:19.520
<v Speaker 2>running opposite directions. This makes it easier to think about

0:27:19.680 --> 0:27:22.040
<v Speaker 2>because they end up far apart from each other. If

0:27:22.080 --> 0:27:24.240
<v Speaker 2>you're standing at the starting line and you're not moving

0:27:24.720 --> 0:27:27.920
<v Speaker 2>relative to the starting line, imagine these two runners run

0:27:27.920 --> 0:27:30.320
<v Speaker 2>at the same speed relative to you. You call it

0:27:30.320 --> 0:27:32.240
<v Speaker 2>a tie. But if somebody else is flying along in

0:27:32.280 --> 0:27:35.119
<v Speaker 2>a spaceship alongside one of these runners, they see the

0:27:35.119 --> 0:27:38.359
<v Speaker 2>two runners moving at different speeds relative to them, and

0:27:38.520 --> 0:27:42.000
<v Speaker 2>moving clocks run slow, which means they see one of

0:27:42.040 --> 0:27:45.199
<v Speaker 2>these runners in slow motion relative to the other one,

0:27:45.359 --> 0:27:47.800
<v Speaker 2>So they'll think one of the runners wins the race

0:27:48.000 --> 0:27:50.760
<v Speaker 2>and the other one is slower. But another judge going

0:27:50.760 --> 0:27:53.399
<v Speaker 2>the opposite direction sees the same thing, but flipped. He

0:27:53.480 --> 0:27:56.680
<v Speaker 2>sees the first runner's clock running slow, so he thinks

0:27:56.680 --> 0:27:59.480
<v Speaker 2>the second runner wins the race. So who you think

0:27:59.520 --> 0:28:03.320
<v Speaker 2>wins the race depends on the speed you're going relative

0:28:03.400 --> 0:28:07.199
<v Speaker 2>to the runners. Like people can honestly disagree about the

0:28:07.320 --> 0:28:09.520
<v Speaker 2>order of events, did the first runner reach the finish

0:28:09.600 --> 0:28:12.000
<v Speaker 2>line first or did the second runner reach the finish

0:28:12.040 --> 0:28:14.359
<v Speaker 2>line first. This is not a case of like people

0:28:14.400 --> 0:28:18.560
<v Speaker 2>being confused or mistaken or getting things wrong. It means

0:28:18.560 --> 0:28:22.000
<v Speaker 2>that there are multiple true stories about what happened. In

0:28:22.040 --> 0:28:24.160
<v Speaker 2>the universe that conflict with each other.

0:28:24.680 --> 0:28:28.080
<v Speaker 1>Well, there's sort of one story, right, It's just when

0:28:28.119 --> 0:28:31.399
<v Speaker 1>you transform it between points of views, the order of

0:28:31.440 --> 0:28:32.240
<v Speaker 1>events changes.

0:28:32.359 --> 0:28:34.720
<v Speaker 2>Yeah. That sounds to me like multiple stories. But you're

0:28:34.800 --> 0:28:38.000
<v Speaker 2>right that we can link them together. Special relativity tells

0:28:38.080 --> 0:28:42.000
<v Speaker 2>us how to predict what any observer will see. And

0:28:42.040 --> 0:28:45.040
<v Speaker 2>what special relativity says is that different observers will see

0:28:45.080 --> 0:28:47.920
<v Speaker 2>the order in different events. The laws of physics are

0:28:47.960 --> 0:28:51.360
<v Speaker 2>consistent from frame to frame, and they predict the observers

0:28:51.360 --> 0:28:53.640
<v Speaker 2>tell different stories. Yeah, so you can think about that

0:28:53.680 --> 0:28:55.960
<v Speaker 2>as like one coherent understanding.

0:28:56.360 --> 0:28:59.160
<v Speaker 1>Yeah, that's what I mean. It's not like there's two realities.

0:28:59.360 --> 0:29:03.080
<v Speaker 1>Nobody can ever figure this out. It's more like, you know,

0:29:03.520 --> 0:29:06.840
<v Speaker 1>everyone has to agree on which observer they're measuring your

0:29:06.880 --> 0:29:07.280
<v Speaker 1>race by.

0:29:07.400 --> 0:29:09.160
<v Speaker 2>Right, that's right. It means that the order of events

0:29:09.200 --> 0:29:12.040
<v Speaker 2>is not universal, right, that it's dependent on the observer.

0:29:12.280 --> 0:29:14.400
<v Speaker 1>Well, or it is universal, as you said, it changes

0:29:14.520 --> 0:29:16.760
<v Speaker 1>depending on what you ask.

0:29:17.040 --> 0:29:19.120
<v Speaker 2>Yeah, it depends on the observer. Right, It's not something

0:29:19.160 --> 0:29:22.239
<v Speaker 2>everybody agrees on will happen from their point of view. Right,

0:29:22.240 --> 0:29:24.720
<v Speaker 2>Different points of view will see a different order of events,

0:29:25.120 --> 0:29:27.800
<v Speaker 2>and that's very confusing when you think about causality because

0:29:27.840 --> 0:29:30.480
<v Speaker 2>you think, like you know, there should be an order

0:29:30.520 --> 0:29:33.000
<v Speaker 2>two events, Like you can't finish the race before you

0:29:33.080 --> 0:29:36.400
<v Speaker 2>start it, you can't receive a message before you send it.

0:29:36.760 --> 0:29:39.080
<v Speaker 2>You can't die before you're born. There are some things

0:29:39.120 --> 0:29:43.000
<v Speaker 2>send in the universe where there's a causal link between them, right,

0:29:43.440 --> 0:29:45.560
<v Speaker 2>and so they have to happen in a certain order.

0:29:45.680 --> 0:29:48.719
<v Speaker 1>All right, Well, what does that mean for causality and antimatter?

0:29:48.760 --> 0:29:51.280
<v Speaker 2>Then well, you might think that this makes the universe nonsense,

0:29:51.680 --> 0:29:55.360
<v Speaker 2>because if different people can see events order different ways,

0:29:55.680 --> 0:29:57.680
<v Speaker 2>does not just break causality. Does that mean you can

0:29:57.720 --> 0:29:59.760
<v Speaker 2>eat an apple before it's grown? Does that mean you

0:29:59.800 --> 0:30:02.920
<v Speaker 2>can get a message before it's sent? This kind of stuff, Well,

0:30:02.920 --> 0:30:06.400
<v Speaker 2>special relativity has some protection built in for that, right,

0:30:06.440 --> 0:30:08.960
<v Speaker 2>It says this can only happen for things that are really,

0:30:09.000 --> 0:30:12.240
<v Speaker 2>really far apart, things that are so far apart that

0:30:12.360 --> 0:30:16.040
<v Speaker 2>light can't pass between them. We call these space like

0:30:16.080 --> 0:30:20.360
<v Speaker 2>events instead of timelike events. And so you can reorder

0:30:20.400 --> 0:30:23.240
<v Speaker 2>events that are really really far apart because they're already

0:30:23.320 --> 0:30:26.520
<v Speaker 2>not causally connected. If two things are so far apart

0:30:26.520 --> 0:30:29.400
<v Speaker 2>that light couldn't pass between them, then there's no way

0:30:29.480 --> 0:30:31.600
<v Speaker 2>for them to have a causal connection. You can't like

0:30:31.840 --> 0:30:34.720
<v Speaker 2>send a message from one to the other. And so

0:30:34.920 --> 0:30:39.280
<v Speaker 2>things that are already causally not connected. Those things you

0:30:39.320 --> 0:30:42.560
<v Speaker 2>can reorder by traveling at some crazy speed. Things that

0:30:42.600 --> 0:30:45.719
<v Speaker 2>are causally connected, Like if you turn on a flashlight

0:30:45.920 --> 0:30:48.840
<v Speaker 2>and then the beam arrive somewhere else, there's enough time

0:30:48.880 --> 0:30:50.920
<v Speaker 2>for light to get from one to the other. You

0:30:51.000 --> 0:30:54.240
<v Speaker 2>can't reorder those events just by going faster or.

0:30:54.200 --> 0:30:57.480
<v Speaker 1>Slower, all right, So then how does that figure into antimatter?

0:30:57.800 --> 0:31:00.520
<v Speaker 2>So these events that you can't reorder, those are things

0:31:00.520 --> 0:31:03.560
<v Speaker 2>we call inside our light cone. Light cone are things

0:31:03.560 --> 0:31:06.000
<v Speaker 2>that we can affect in our future, and there's things

0:31:06.040 --> 0:31:09.520
<v Speaker 2>that affected us from the past. So that special relativity,

0:31:09.560 --> 0:31:12.320
<v Speaker 2>and it has this nice causal connection for things inside

0:31:12.320 --> 0:31:14.760
<v Speaker 2>your light cone. Things outside your light cone, they can

0:31:14.800 --> 0:31:18.080
<v Speaker 2>get reordered by things going fast or slow. Quantum mechanics, however,

0:31:18.400 --> 0:31:22.840
<v Speaker 2>doesn't naturally obey this rule. Quantum mechanics has weird limitations

0:31:23.080 --> 0:31:27.239
<v Speaker 2>on how much you can know about objects momentums, and velocities. So,

0:31:27.280 --> 0:31:31.200
<v Speaker 2>for example, you measure a particle really really specifically. The

0:31:31.240 --> 0:31:35.120
<v Speaker 2>Heisenbergen certainty principle tells you you can't know anything about

0:31:35.200 --> 0:31:39.000
<v Speaker 2>its velocity, how fast it's going. So in principle, quantum

0:31:39.000 --> 0:31:42.800
<v Speaker 2>mechanics allows things to go faster than the speed of light.

0:31:43.080 --> 0:31:46.080
<v Speaker 2>That allows particles to move from one place to another

0:31:46.520 --> 0:31:49.680
<v Speaker 2>outside the light cone because they could be going faster

0:31:49.800 --> 0:31:52.640
<v Speaker 2>than the speed of light. Quantum mechanics doesn't have the

0:31:52.680 --> 0:31:55.960
<v Speaker 2>speed of light built into it naturally, it allows particles

0:31:56.040 --> 0:31:59.400
<v Speaker 2>to violate this speed limit. WHOA well.

0:32:01.520 --> 0:32:04.760
<v Speaker 1>On they think quantum mechanics can break the speed of light.

0:32:04.800 --> 0:32:06.920
<v Speaker 1>That sounds a little bit too much, Daniel. I think

0:32:06.960 --> 0:32:10.080
<v Speaker 1>you mean maybe, like our math allows it to, but

0:32:10.200 --> 0:32:12.560
<v Speaker 1>we don't know if in reality it can go faster

0:32:12.600 --> 0:32:13.760
<v Speaker 1>than light. Doing If you just.

0:32:13.760 --> 0:32:16.680
<v Speaker 2>Start from sort of low speed quantum mechanics, the original

0:32:16.720 --> 0:32:20.840
<v Speaker 2>quantum mechanics that was developed right, non relativistic quantum mechanics

0:32:20.840 --> 0:32:24.520
<v Speaker 2>for slow moving particles, then that theory with the Heisenberg

0:32:24.600 --> 0:32:28.040
<v Speaker 2>uncertainty principle doesn't respect the speed limit of the universe.

0:32:28.360 --> 0:32:30.360
<v Speaker 2>It's only when you try to bring quantum mechanics and

0:32:30.400 --> 0:32:34.160
<v Speaker 2>special relativity together to make a theory of relativistic high

0:32:34.160 --> 0:32:37.480
<v Speaker 2>speed particles that you have to answer this question like, uh, oh,

0:32:37.520 --> 0:32:40.800
<v Speaker 2>what happens if particles that quantum mechanics predicts can go

0:32:40.880 --> 0:32:43.040
<v Speaker 2>faster than the speed of light. What does special relativity

0:32:43.080 --> 0:32:45.360
<v Speaker 2>say about that? So it's you know, in trying to

0:32:45.480 --> 0:32:48.240
<v Speaker 2>bring the mathematics in harmony with the universe, that we

0:32:48.320 --> 0:32:50.240
<v Speaker 2>run into this problem. We're like, hold on a second.

0:32:50.600 --> 0:32:54.080
<v Speaker 2>Quantum mechanics has this problem with causality. It allows things

0:32:54.440 --> 0:32:58.960
<v Speaker 2>to move outside your light cone. What's going on and between?

0:32:59.000 --> 0:33:02.320
<v Speaker 2>You bring these two things together, that antiparticles save the

0:33:02.400 --> 0:33:05.479
<v Speaker 2>day and allow you to bring quantum mechanics and special

0:33:05.480 --> 0:33:07.920
<v Speaker 2>relativity together in a way that makes perfect sense.

0:33:08.880 --> 0:33:11.600
<v Speaker 1>I think maybe what you mean is that antimatter says

0:33:11.640 --> 0:33:17.000
<v Speaker 1>physicism because their original theory made no sense.

0:33:17.240 --> 0:33:20.040
<v Speaker 2>Yeah, you cannot bring quantum mechanics and special relativity together

0:33:20.160 --> 0:33:22.080
<v Speaker 2>without anti particles.

0:33:21.800 --> 0:33:24.760
<v Speaker 1>Right, It's like the limitations of the theory would allow

0:33:24.840 --> 0:33:28.400
<v Speaker 1>things to move faster than light, but probably in reality

0:33:28.440 --> 0:33:28.840
<v Speaker 1>they don't.

0:33:29.000 --> 0:33:30.880
<v Speaker 2>That's right. We think special relativity is the law of

0:33:30.920 --> 0:33:33.720
<v Speaker 2>the universe. Nothing moves faster than light. Original old school

0:33:33.760 --> 0:33:36.480
<v Speaker 2>quantum mechanics has this problem that allows things to move

0:33:36.520 --> 0:33:39.840
<v Speaker 2>faster than the speed of light, potentially breaking causality. And

0:33:39.840 --> 0:33:41.880
<v Speaker 2>you're right, we don't think that happens in reality, So

0:33:41.920 --> 0:33:44.480
<v Speaker 2>we need to patch up the theory, and it turns

0:33:44.480 --> 0:33:46.920
<v Speaker 2>out that we need antimatter in order to do that.

0:33:47.200 --> 0:33:50.760
<v Speaker 1>All right, well, let's dig into how antimatter saves the day.

0:33:51.000 --> 0:33:52.840
<v Speaker 1>It's sort of like a plot to is the villain

0:33:53.040 --> 0:33:54.920
<v Speaker 1>actually turns out to be the good guy. So let's

0:33:54.920 --> 0:33:57.160
<v Speaker 1>dig into that, and what does it mean about our

0:33:57.320 --> 0:34:00.239
<v Speaker 1>understanding of matter, antimatter and all kinds of matters or

0:34:00.320 --> 0:34:03.280
<v Speaker 1>in the universe. But first, let's take another quick break.

0:34:15.600 --> 0:34:18.640
<v Speaker 1>All right, we're talking about antimatter antiparticles. Why do we

0:34:18.680 --> 0:34:20.879
<v Speaker 1>have them? Why do we need them? It turns out

0:34:20.880 --> 0:34:26.520
<v Speaker 1>that they're useful in making our theories work, which is

0:34:26.560 --> 0:34:28.440
<v Speaker 1>not really I guess an answer to the question.

0:34:28.239 --> 0:34:28.480
<v Speaker 4>Is it?

0:34:28.520 --> 0:34:30.520
<v Speaker 2>Well, it's sort of an answer to the question. You know.

0:34:30.600 --> 0:34:34.000
<v Speaker 2>It says that the universe needs this to be consistent,

0:34:34.080 --> 0:34:36.560
<v Speaker 2>or our theories need this in order to be consistent

0:34:36.600 --> 0:34:38.160
<v Speaker 2>description of the universe.

0:34:38.320 --> 0:34:41.920
<v Speaker 1>Okay, so then you're saying that it somehow helps reconcile

0:34:41.960 --> 0:34:44.480
<v Speaker 1>special relativity and quantum mechanics. How does it do that?

0:34:44.560 --> 0:34:47.799
<v Speaker 2>So let's think about how quantum mechanics breaks causality. Right,

0:34:47.800 --> 0:34:50.799
<v Speaker 2>Imagine you have like a particle that you emit right

0:34:50.840 --> 0:34:53.759
<v Speaker 2>here at this moment, and quantum mechanics predicts that it

0:34:53.800 --> 0:34:57.040
<v Speaker 2>has a probability to end up like in Andromeda ten

0:34:57.120 --> 0:35:00.160
<v Speaker 2>seconds from now. That would break causality because if be

0:35:00.200 --> 0:35:02.360
<v Speaker 2>outside your leg cone, it would be like getting to

0:35:02.520 --> 0:35:05.680
<v Speaker 2>Andromeda faster than the speed of light. Nothing that we

0:35:05.760 --> 0:35:09.120
<v Speaker 2>do right now should be able to affect Andromeda until

0:35:09.120 --> 0:35:12.360
<v Speaker 2>millions of years into the future, because Andromeda is millions

0:35:12.440 --> 0:35:13.440
<v Speaker 2>of light years away.

0:35:13.600 --> 0:35:15.680
<v Speaker 1>I think you're saying, the quantum mechanics, we have a

0:35:15.680 --> 0:35:19.520
<v Speaker 1>description of a particle here, and because there's uncertainty about

0:35:19.520 --> 0:35:22.279
<v Speaker 1>where it can be, there's a certain probability that in

0:35:22.320 --> 0:35:25.600
<v Speaker 1>the next second it can be right where it is now,

0:35:25.719 --> 0:35:28.200
<v Speaker 1>or it can be a meter away or two meters away.

0:35:28.440 --> 0:35:31.120
<v Speaker 1>And there's a very very very small possibility that in

0:35:31.160 --> 0:35:34.799
<v Speaker 1>the next two seconds, according to the quantum mechanics, it

0:35:34.840 --> 0:35:37.800
<v Speaker 1>can then be in Andromeda. That's kind of how you

0:35:37.840 --> 0:35:38.520
<v Speaker 1>would describe it.

0:35:38.600 --> 0:35:41.319
<v Speaker 2>Yeah, exactly if you have a lot of uncertainty on

0:35:41.400 --> 0:35:44.720
<v Speaker 2>its momentum, because you've narrowed down its position super duper well,

0:35:45.080 --> 0:35:48.040
<v Speaker 2>and Heisenbergen certainty principle tells you can't know both things

0:35:48.080 --> 0:35:50.160
<v Speaker 2>at the same time. So if you know the position

0:35:50.239 --> 0:35:52.960
<v Speaker 2>really really well, you don't know the momentum, and therefore

0:35:53.000 --> 0:35:56.840
<v Speaker 2>there's a possibility that it has some crazy high momentum

0:35:56.840 --> 0:35:59.279
<v Speaker 2>would be faster than the speed of light, getting it

0:35:59.320 --> 0:36:03.000
<v Speaker 2>too Andrama in just ten seconds instead of the millions

0:36:03.040 --> 0:36:04.960
<v Speaker 2>of years it should take. And this would be a

0:36:05.000 --> 0:36:09.439
<v Speaker 2>problem for causality because those two events are spacelike. It's

0:36:09.480 --> 0:36:12.600
<v Speaker 2>outside of our light cone, which means that somebody flying

0:36:12.640 --> 0:36:14.600
<v Speaker 2>by in a spaceship could see them happen. In the

0:36:14.640 --> 0:36:18.200
<v Speaker 2>other order, could see this particle arrive in Andromeda before

0:36:18.239 --> 0:36:22.280
<v Speaker 2>it leaves our galaxy, which is nonsense. Right, So anything

0:36:22.320 --> 0:36:25.560
<v Speaker 2>that moves faster than the speed of light breaks causality.

0:36:25.560 --> 0:36:27.719
<v Speaker 2>That's one reason why we don't think things can move

0:36:27.760 --> 0:36:29.799
<v Speaker 2>faster than the speed of light, because it would allow

0:36:29.800 --> 0:36:33.279
<v Speaker 2>you to reorder events that are causally linked. Right, so

0:36:33.800 --> 0:36:35.320
<v Speaker 2>make the universe nonsense.

0:36:35.480 --> 0:36:37.760
<v Speaker 1>Well, it sort of sounds like quantum mechanics just breaks

0:36:37.760 --> 0:36:42.440
<v Speaker 1>causality anyways, right. Quantum mechanics say that particles can just

0:36:42.480 --> 0:36:46.080
<v Speaker 1>pop out of nowhere without any cause, So like quantum

0:36:46.080 --> 0:36:48.800
<v Speaker 1>mechanics says that a particle can suddenly disappear here and

0:36:48.840 --> 0:36:49.600
<v Speaker 1>appear in Andromeda.

0:36:50.200 --> 0:36:53.759
<v Speaker 2>Why not now, I wouldn't say that quantum mechanics necessarily

0:36:53.800 --> 0:36:56.840
<v Speaker 2>breaks causality. It makes a different description of the universe.

0:36:56.840 --> 0:37:00.560
<v Speaker 2>It makes the universe probabilistic instead of deterministic. It says

0:37:00.840 --> 0:37:03.279
<v Speaker 2>weird things can happen, like a photon can turn into

0:37:03.320 --> 0:37:06.320
<v Speaker 2>an electron and a positron, or it could do something else.

0:37:06.719 --> 0:37:09.240
<v Speaker 2>It says that the laws of the universe only predict

0:37:09.280 --> 0:37:12.520
<v Speaker 2>what might happen instead of what does actually happen. But

0:37:12.600 --> 0:37:15.160
<v Speaker 2>there is still causality, Like in quantum mechanics, the wave

0:37:15.160 --> 0:37:17.680
<v Speaker 2>function right now is determined by the wave function in

0:37:17.719 --> 0:37:21.240
<v Speaker 2>the past. Right The wave function itself doesn't specify exactly

0:37:21.320 --> 0:37:24.360
<v Speaker 2>what will happen, only to probabilities, but the wave function

0:37:24.440 --> 0:37:26.960
<v Speaker 2>is still determined by the past wave function, so there

0:37:26.960 --> 0:37:29.759
<v Speaker 2>should still be logic in quantum mechanics.

0:37:30.560 --> 0:37:32.560
<v Speaker 1>I guess that's weird because if you're saying that anything

0:37:32.680 --> 0:37:33.520
<v Speaker 1>might happen, I.

0:37:33.480 --> 0:37:36.400
<v Speaker 2>Would say anything might happen, you know quantum mechanics, as

0:37:36.560 --> 0:37:39.200
<v Speaker 2>is the probability for things to happen. Some things are

0:37:39.239 --> 0:37:43.320
<v Speaker 2>impossible even in quantum mechanics, like you can't violate conservation

0:37:43.400 --> 0:37:46.759
<v Speaker 2>of electric charge right, Electrons have no probability to turn

0:37:46.800 --> 0:37:51.040
<v Speaker 2>into positrons directly, because I would violate conservation of electric charge,

0:37:51.040 --> 0:37:53.760
<v Speaker 2>which is built into our quantum mechanical theories.

0:37:54.640 --> 0:37:57.719
<v Speaker 1>But haven't we talked about how like, according to quantum mechanics,

0:37:58.080 --> 0:38:01.600
<v Speaker 1>a pink elephant could certainly you're out of nowhere outside

0:38:01.640 --> 0:38:03.400
<v Speaker 1>of the Earth's orbit, right in space.

0:38:03.680 --> 0:38:06.320
<v Speaker 2>Yeah, that's not impossible. That doesn't break any of the rules.

0:38:06.360 --> 0:38:07.920
<v Speaker 1>But then we have no cause would it.

0:38:08.239 --> 0:38:10.600
<v Speaker 2>Well, the cause would be that there's a distribution of

0:38:10.640 --> 0:38:14.200
<v Speaker 2>probabilities for what those particles in the vacuum could do.

0:38:14.320 --> 0:38:16.640
<v Speaker 2>They could sit there and do nothing. They could create

0:38:16.680 --> 0:38:19.760
<v Speaker 2>one electron, they could create ten electrons, they could create

0:38:20.000 --> 0:38:23.240
<v Speaker 2>forty two trillion electrons. They could create a Boltzmann brain,

0:38:23.600 --> 0:38:26.760
<v Speaker 2>they could create a pink elephant. Those things are probabilities.

0:38:26.800 --> 0:38:29.960
<v Speaker 2>What does our universe choose one particular probability and not another?

0:38:30.280 --> 0:38:32.600
<v Speaker 2>What does it choose one that's like really unlikely, like

0:38:32.600 --> 0:38:35.359
<v Speaker 2>a pink elephant in space, and not another that's more

0:38:35.480 --> 0:38:38.280
<v Speaker 2>likely that we don't understand. That's like a deep question

0:38:38.520 --> 0:38:41.440
<v Speaker 2>in quantum philosophy, whether all of them happen at once

0:38:41.520 --> 0:38:45.040
<v Speaker 2>in different universes, whether the universe collapses these wave functions

0:38:45.040 --> 0:38:47.960
<v Speaker 2>to choose one. Whether it even is truly random, That

0:38:48.080 --> 0:38:50.279
<v Speaker 2>is definitely not something we know. But I wouldn't say

0:38:50.320 --> 0:38:53.480
<v Speaker 2>there's no cause there's still like a distribution of probabilities

0:38:53.480 --> 0:38:54.440
<v Speaker 2>for what might happen.

0:38:54.680 --> 0:38:57.520
<v Speaker 1>Well, let's get back to the antimatter particle. How does

0:38:57.520 --> 0:38:59.560
<v Speaker 1>that antimatter particle fit into this scenario.

0:38:59.600 --> 0:39:01.480
<v Speaker 2>Then it turns out if you do these calculations, and

0:39:01.480 --> 0:39:04.120
<v Speaker 2>you calculate like, okay, what's the probability for my particle

0:39:04.200 --> 0:39:06.080
<v Speaker 2>to appear in and Drama in ten seconds from now,

0:39:06.480 --> 0:39:11.080
<v Speaker 2>and you include antimatter, then those probabilities vanish. Because the

0:39:11.120 --> 0:39:14.160
<v Speaker 2>probability for you to see a particle go to Andrama

0:39:14.200 --> 0:39:18.040
<v Speaker 2>in ten seconds, there's another probability for a particle to

0:39:18.080 --> 0:39:21.840
<v Speaker 2>go from Andromeda to here in ten seconds, for an

0:39:21.880 --> 0:39:26.040
<v Speaker 2>antimatter particle to come the opposite direction. And because matter

0:39:26.120 --> 0:39:29.359
<v Speaker 2>and antimatter have all the opposite properties, those two things

0:39:29.480 --> 0:39:33.719
<v Speaker 2>quantum mechanically cancel each other out. So the antimatter nonsense

0:39:34.080 --> 0:39:39.040
<v Speaker 2>cancels out the matter nonsense to make no nonsense. Whoa, whoa, whoa.

0:39:39.120 --> 0:39:41.560
<v Speaker 1>Wait, we had this scenario of having one particle here

0:39:41.600 --> 0:39:44.879
<v Speaker 1>that suddenly appears in Andromeda in ten seconds. You're saying,

0:39:44.880 --> 0:39:49.080
<v Speaker 1>there's a different scenario in which an anti particle the

0:39:49.160 --> 0:39:54.080
<v Speaker 1>exact antiparticle of my particle is where my particle would appear.

0:39:54.880 --> 0:39:58.440
<v Speaker 1>That one disappears and appears where my current particle is

0:39:58.840 --> 0:40:01.680
<v Speaker 1>at the same time, and somehow that cancels it out.

0:40:01.840 --> 0:40:04.960
<v Speaker 1>But what are the chances that there's an antiparticle exactly

0:40:04.960 --> 0:40:07.040
<v Speaker 1>where my particle would go.

0:40:07.200 --> 0:40:09.680
<v Speaker 2>Well, all of this stuff is very unlikely. But when

0:40:09.719 --> 0:40:12.160
<v Speaker 2>you do a quantum mechanical calculation, you sum over all

0:40:12.239 --> 0:40:15.960
<v Speaker 2>the possibilities, and these equations are wave equations, so you

0:40:16.000 --> 0:40:19.719
<v Speaker 2>can get like constructive interference and destructive interference and things

0:40:19.760 --> 0:40:22.399
<v Speaker 2>where the probabilities cancel out, those things just don't happen.

0:40:22.560 --> 0:40:25.320
<v Speaker 2>Like in the Devil's Slight experiment. You see interference places

0:40:25.320 --> 0:40:28.520
<v Speaker 2>where lots of particles and places with no particles, the

0:40:28.520 --> 0:40:31.160
<v Speaker 2>places where no particles land, and the interference on the

0:40:31.200 --> 0:40:35.360
<v Speaker 2>screen is because there's been destructive interference among the probabilities.

0:40:35.640 --> 0:40:38.760
<v Speaker 2>So when the probabilities cancel out, those things just don't

0:40:38.760 --> 0:40:41.560
<v Speaker 2>happen in the universe, And so the probability for a

0:40:41.600 --> 0:40:45.400
<v Speaker 2>particle to break special relativity and appear in Andromeda is

0:40:45.440 --> 0:40:48.360
<v Speaker 2>canceled out by the probability for an antiparticle to do

0:40:48.440 --> 0:40:49.279
<v Speaker 2>the opposite.

0:40:49.360 --> 0:40:51.560
<v Speaker 1>Well, I guess what does it mean to cancel out

0:40:51.600 --> 0:40:53.720
<v Speaker 1>the probability? That means that it's never going to happen.

0:40:53.880 --> 0:40:56.319
<v Speaker 2>It means that it's never going to happen. And so

0:40:56.400 --> 0:41:00.200
<v Speaker 2>if you bring quantum mechanics and special relativity together, you

0:41:00.239 --> 0:41:04.040
<v Speaker 2>include anti particles, then it all clicks together perfectly and

0:41:04.080 --> 0:41:06.560
<v Speaker 2>you get no violations of causality.

0:41:06.800 --> 0:41:10.640
<v Speaker 1>But wait, the wouldn't that also cancel all movements like

0:41:10.680 --> 0:41:12.920
<v Speaker 1>even a meter distance?

0:41:13.080 --> 0:41:16.080
<v Speaker 2>Yeah, great question. It doesn't happen for things inside the

0:41:16.160 --> 0:41:19.400
<v Speaker 2>light cone because things inside the light cone everybody agrees

0:41:19.440 --> 0:41:22.160
<v Speaker 2>on the order, whereas things outside the light cone you

0:41:22.200 --> 0:41:25.359
<v Speaker 2>can reorder them. So, for example, if I say, well, look,

0:41:25.440 --> 0:41:28.160
<v Speaker 2>my particle left here and ended up in a drama

0:41:28.239 --> 0:41:31.600
<v Speaker 2>in ten seconds, that's outside my light cone. So somebody

0:41:31.640 --> 0:41:33.840
<v Speaker 2>else flying by in a spaceship might see them happen

0:41:33.920 --> 0:41:36.520
<v Speaker 2>in the opposite order. Right. Seeing it happen in the

0:41:36.520 --> 0:41:39.640
<v Speaker 2>opposite order is like seeing a particle go backwards in time,

0:41:39.920 --> 0:41:43.319
<v Speaker 2>which is equivalent to the anti matter particle. Right, So

0:41:43.880 --> 0:41:48.000
<v Speaker 2>both probabilities exist, the particle and anti particle version, because

0:41:48.040 --> 0:41:51.440
<v Speaker 2>you can reorder them because they are outside your light cone.

0:41:51.680 --> 0:41:54.879
<v Speaker 2>Things inside your light cone, you can't reorder them. Their

0:41:54.960 --> 0:41:57.680
<v Speaker 2>order is fixed. Only things outside the light cone where

0:41:57.719 --> 0:41:59.759
<v Speaker 2>you could reorder them, where somebody could see it as

0:41:59.760 --> 0:42:01.440
<v Speaker 2>a part article and the other person could see it

0:42:01.480 --> 0:42:04.440
<v Speaker 2>as an anti particle. Only those things cancel out.

0:42:04.640 --> 0:42:07.719
<v Speaker 1>It feels a little convenient, like maybe saying like, oh,

0:42:07.800 --> 0:42:10.719
<v Speaker 1>my theory breaks down after this limit. Let's just come

0:42:10.800 --> 0:42:13.759
<v Speaker 1>up with something totally different and ex sort it only

0:42:13.760 --> 0:42:16.240
<v Speaker 1>applies outside of this limit where my thing breaks.

0:42:16.480 --> 0:42:19.439
<v Speaker 2>Yeah. Well, it's sort of convenient and sort of spooky, right.

0:42:19.480 --> 0:42:22.000
<v Speaker 2>It's sort of like if you didn't know antiparticles existed

0:42:22.400 --> 0:42:24.800
<v Speaker 2>and you were trying to bring quantum mechanics and relativity

0:42:24.800 --> 0:42:28.440
<v Speaker 2>together into relativistic quantum mechanics, You're like, huh, this is

0:42:28.440 --> 0:42:31.520
<v Speaker 2>a problem. This could be solved if, for example, there

0:42:31.560 --> 0:42:34.560
<v Speaker 2>were the existence of antimatter hmm, and then you went

0:42:34.560 --> 0:42:36.360
<v Speaker 2>out in the universe and you found it, You'd be like, wow,

0:42:36.480 --> 0:42:38.400
<v Speaker 2>that was pretty cool. Here it's sort of works the

0:42:38.400 --> 0:42:41.839
<v Speaker 2>opposite direction. We're like, no antimatter exists, and we can

0:42:42.000 --> 0:42:44.640
<v Speaker 2>use it to help bring these two theories together. It

0:42:44.719 --> 0:42:47.200
<v Speaker 2>is very convenient, but that's sort of like a glorious

0:42:47.239 --> 0:42:49.920
<v Speaker 2>moment when you're like, oh wow, look these things. They

0:42:49.960 --> 0:42:52.080
<v Speaker 2>sort of need to exist for the universe to be

0:42:52.160 --> 0:42:52.960
<v Speaker 2>self consistent.

0:42:53.160 --> 0:42:55.280
<v Speaker 1>Now, you said something earlier that was kind of interesting.

0:42:55.320 --> 0:42:57.520
<v Speaker 1>You said, anti particles kind of go back in time.

0:42:57.560 --> 0:42:58.160
<v Speaker 1>What does that mean?

0:42:58.200 --> 0:43:00.920
<v Speaker 2>Well, mathematically you can look at it a particle moving

0:43:00.960 --> 0:43:04.480
<v Speaker 2>forwards in time, and it's equivalent to an antimatter particle

0:43:04.600 --> 0:43:06.919
<v Speaker 2>moving backwards in time. And you can sort of see

0:43:06.920 --> 0:43:09.799
<v Speaker 2>that in this example we're talking about, where like, my

0:43:09.920 --> 0:43:12.839
<v Speaker 2>particle goes from here to Andromeda, and it does it

0:43:12.920 --> 0:43:14.920
<v Speaker 2>faster than the speed of light. Right. If it does

0:43:14.960 --> 0:43:16.600
<v Speaker 2>it faster than the speed of light, that means that

0:43:16.719 --> 0:43:18.919
<v Speaker 2>somebody else going by in a spaceship they could see

0:43:18.920 --> 0:43:20.800
<v Speaker 2>it happen in the opposite order. They could see it

0:43:20.920 --> 0:43:25.319
<v Speaker 2>arrive in Andromeda before it leaves my house in the

0:43:25.320 --> 0:43:28.520
<v Speaker 2>milky way, right, which means that it's started in Andromeda.

0:43:28.640 --> 0:43:30.920
<v Speaker 2>The first event is in Andromeda. So I could say, look,

0:43:31.000 --> 0:43:33.560
<v Speaker 2>this is a particle going forwards in time faster than

0:43:33.600 --> 0:43:36.000
<v Speaker 2>the speed of light. Somebody else could say, no, it

0:43:36.000 --> 0:43:38.640
<v Speaker 2>goes the other direction. They could say, no, it's going

0:43:38.640 --> 0:43:41.360
<v Speaker 2>from your future to your past. But I see it

0:43:41.400 --> 0:43:44.800
<v Speaker 2>as an antimatter particle because they could reorder the events,

0:43:44.800 --> 0:43:47.719
<v Speaker 2>and so they see it going from Andromeda to the

0:43:47.760 --> 0:43:50.640
<v Speaker 2>Milky Way, and they see it moving as an antimatter particle.

0:43:50.840 --> 0:43:53.560
<v Speaker 1>But I guess maybe in order to measure my particle

0:43:53.640 --> 0:43:56.040
<v Speaker 1>here and there, don't I need to measure the particle,

0:43:56.160 --> 0:43:58.879
<v Speaker 1>wouldn't they collapse the wave function and make this all

0:43:59.000 --> 0:44:00.520
<v Speaker 1>kind of not really applicable.

0:44:00.560 --> 0:44:03.160
<v Speaker 2>You would need to collapse the wave function absolutely, and

0:44:03.239 --> 0:44:05.920
<v Speaker 2>of course it wouldn't really happen, right. That probability is

0:44:05.960 --> 0:44:08.200
<v Speaker 2>actually zero. You can't collapse the wave function and make

0:44:08.280 --> 0:44:10.680
<v Speaker 2>this happen. What we're talking about really is just a

0:44:10.719 --> 0:44:14.319
<v Speaker 2>partial probability. There's another part to that calculation, the antimatter part,

0:44:14.360 --> 0:44:17.399
<v Speaker 2>that cancels it out. So you can't actually do this right.

0:44:17.440 --> 0:44:21.320
<v Speaker 2>You can't see a particle appear in Andromeda in ten seconds.

0:44:21.320 --> 0:44:23.120
<v Speaker 2>It would take millions of years to get there, and

0:44:23.160 --> 0:44:25.440
<v Speaker 2>the probability for that to happen is canceled out by

0:44:25.440 --> 0:44:27.960
<v Speaker 2>the anti matter version, So that's why it just doesn't happen.

0:44:28.280 --> 0:44:30.920
<v Speaker 1>Is this sort of like one of those virtual particle

0:44:30.960 --> 0:44:33.560
<v Speaker 1>scenarios where like just a matter of fact that something

0:44:33.600 --> 0:44:38.440
<v Speaker 1>else can happen, actually in a way happens canceling out

0:44:38.719 --> 0:44:40.000
<v Speaker 1>other effects that are happening.

0:44:40.120 --> 0:44:42.160
<v Speaker 2>Yeah, you can think about this the way other quantum

0:44:42.160 --> 0:44:46.319
<v Speaker 2>mechanical weirdness happens, where like particles can interfere with themselves.

0:44:46.400 --> 0:44:48.880
<v Speaker 2>Right again, like in the double slit experiment, if you

0:44:48.920 --> 0:44:51.239
<v Speaker 2>don't know which slit the particle went through, has a

0:44:51.280 --> 0:44:54.320
<v Speaker 2>probability to go through both, and those probabilities can actually

0:44:54.320 --> 0:44:58.680
<v Speaker 2>interfere with themselves, So single particle interferes with itself. This

0:44:58.800 --> 0:45:01.160
<v Speaker 2>is sort of the same deal. Like this single particle

0:45:01.200 --> 0:45:03.680
<v Speaker 2>that goes from here to Andromeda, you could also be

0:45:03.760 --> 0:45:06.440
<v Speaker 2>seen as an antimatter particle going the other direction, and

0:45:06.440 --> 0:45:10.400
<v Speaker 2>those two probabilities cancel, which is why it never actually happens.

0:45:10.640 --> 0:45:12.839
<v Speaker 1>All right, Well, then what is the I guess main

0:45:12.880 --> 0:45:16.719
<v Speaker 1>takeaway is it that quantum mechanics does work with special activity,

0:45:16.800 --> 0:45:21.759
<v Speaker 1>and it's because antimatter particles exist or are a possibility

0:45:21.760 --> 0:45:22.400
<v Speaker 1>in the universe.

0:45:22.440 --> 0:45:26.680
<v Speaker 2>That's exactly right. You need antimatter to bring quantum mechanics

0:45:26.760 --> 0:45:30.799
<v Speaker 2>and special relativity together and not break causality. If we

0:45:30.880 --> 0:45:33.560
<v Speaker 2>think the universe is causal, meaning that like there's a

0:45:33.600 --> 0:45:36.840
<v Speaker 2>logical flow to things, that the past influences the future

0:45:37.200 --> 0:45:40.160
<v Speaker 2>and not the deep past. Then you need antimatter in

0:45:40.280 --> 0:45:43.520
<v Speaker 2>order to have special relativity and quantum mechanics. We just

0:45:43.560 --> 0:45:45.520
<v Speaker 2>don't know how to do it without antimatter.

0:45:45.719 --> 0:45:49.400
<v Speaker 1>Cool. All right, well, you've commissed me. I'm pro antimatter

0:45:50.239 --> 0:45:51.680
<v Speaker 1>or I'm not anti antimatter.

0:45:51.800 --> 0:45:54.080
<v Speaker 2>Does that mean that you're pro anti vanilla, which means

0:45:54.120 --> 0:45:55.320
<v Speaker 2>you're willing to try some chocolate.

0:45:55.360 --> 0:45:57.239
<v Speaker 1>I am pro anything with the word vanilla in it.

0:46:00.120 --> 0:46:02.960
<v Speaker 2>Right, I'm part of the vanilla eradication project. How do

0:46:02.960 --> 0:46:03.239
<v Speaker 2>you feel?

0:46:03.440 --> 0:46:08.960
<v Speaker 1>Oh my god? And that is how this podcast got canceled. Daniel.

0:46:10.280 --> 0:46:13.360
<v Speaker 1>Thank you, it's been a nice run. We're done.

0:46:13.480 --> 0:46:15.480
<v Speaker 2>No, I love vanilla. Vanilla is wonderful.

0:46:15.760 --> 0:46:18.480
<v Speaker 1>We've gone the way of Scott Adams and Dilbert.

0:46:19.400 --> 0:46:22.640
<v Speaker 2>I'm not a flavorist. Okay, I'm definitely pro vanilla.

0:46:22.680 --> 0:46:24.880
<v Speaker 1>I'm just more we think they're flavorists.

0:46:24.920 --> 0:46:29.800
<v Speaker 2>Daniel, I need to go for some flavor sensitivity training.

0:46:29.840 --> 0:46:34.399
<v Speaker 1>It sounds like, thank you, maybe you should examine those

0:46:34.440 --> 0:46:35.040
<v Speaker 1>anti FeAs.

0:46:37.120 --> 0:46:39.239
<v Speaker 2>All right, well, between this and the next episode, I

0:46:39.239 --> 0:46:43.040
<v Speaker 2>will do a deep dive into my own internal flavor preferences.

0:46:43.400 --> 0:46:47.640
<v Speaker 1>There you go examine your own anti matter. All right, Well,

0:46:47.800 --> 0:46:50.480
<v Speaker 1>another interesting bit of how we're trying to figure out

0:46:50.480 --> 0:46:53.520
<v Speaker 1>how the universe works, and how sometimes it's interesting how

0:46:53.760 --> 0:46:56.080
<v Speaker 1>our theories of the universe actually kind of turn out

0:46:56.080 --> 0:46:58.240
<v Speaker 1>to be true, which is kind of surprising, right.

0:46:58.360 --> 0:47:02.040
<v Speaker 2>It is surprising sometimes, and that crazy little human brains

0:47:02.080 --> 0:47:04.840
<v Speaker 2>can come up with mathematical stories that do seem to

0:47:04.920 --> 0:47:08.080
<v Speaker 2>describe the universe, even in ways we didn't anticipate.

0:47:08.400 --> 0:47:10.480
<v Speaker 1>All right, Well, thanks for joining us. We hope you

0:47:10.560 --> 0:47:12.040
<v Speaker 1>enjoyed that. See you next time.

0:47:14.480 --> 0:47:16.920
<v Speaker 2>Hey, everyone, I want to take a moment and share

0:47:17.000 --> 0:47:20.359
<v Speaker 2>a personal message with you. When I record these podcasts,

0:47:20.400 --> 0:47:22.759
<v Speaker 2>there's no live audience here, and so I have no

0:47:22.880 --> 0:47:25.920
<v Speaker 2>idea really how they're going to be received. So I

0:47:25.960 --> 0:47:28.680
<v Speaker 2>love hearing that they have an impact on people's lives,

0:47:28.719 --> 0:47:31.600
<v Speaker 2>maybe inspiring you to think about the universe, or talk

0:47:31.600 --> 0:47:34.239
<v Speaker 2>to your kids about physics, or even just keep your

0:47:34.280 --> 0:47:37.600
<v Speaker 2>brain going on long drive or a boring shift at work.

0:47:38.080 --> 0:47:40.799
<v Speaker 2>That's what gives me the energy to keep making these

0:47:40.920 --> 0:47:43.120
<v Speaker 2>to put them out twice a week without fail for

0:47:43.239 --> 0:47:46.080
<v Speaker 2>five years now. So it really heartens me to hear

0:47:46.080 --> 0:47:48.160
<v Speaker 2>from you. But I realize that you all don't get

0:47:48.160 --> 0:47:51.360
<v Speaker 2>to know each other as much to hear about these experiences.

0:47:51.560 --> 0:47:53.160
<v Speaker 2>So I want to share a little bit with you,

0:47:53.239 --> 0:47:56.000
<v Speaker 2>including an example that made me smile and one that

0:47:56.040 --> 0:47:59.239
<v Speaker 2>frankly brought some tears to my eyes. First, a happy one,

0:47:59.360 --> 0:48:02.040
<v Speaker 2>someone writes and says, I don't have a question but

0:48:02.120 --> 0:48:04.200
<v Speaker 2>a compliment. Just wanted to let both of you know

0:48:04.280 --> 0:48:06.840
<v Speaker 2>that I greatly appreciate the way you both explain physics.

0:48:07.040 --> 0:48:09.480
<v Speaker 2>As a person who has no science background and barely

0:48:09.520 --> 0:48:12.919
<v Speaker 2>passed college algebra, it's refreshing to hear people explain things

0:48:12.960 --> 0:48:16.120
<v Speaker 2>without talking down to the listener. That's wonderful and it's

0:48:16.160 --> 0:48:19.040
<v Speaker 2>exactly what we're trying to do, make physics more accessible

0:48:19.080 --> 0:48:22.080
<v Speaker 2>to everybody without dumbing it down at all. But some

0:48:22.120 --> 0:48:24.120
<v Speaker 2>of the messages we get are a little bit harder

0:48:24.160 --> 0:48:26.640
<v Speaker 2>to hear. A woman wrote in that her brother is

0:48:26.680 --> 0:48:29.839
<v Speaker 2>a listener and an ultrarunner, but that at thirty nine

0:48:30.120 --> 0:48:33.440
<v Speaker 2>he had a massive stroke and faces a long recovery.

0:48:33.920 --> 0:48:36.759
<v Speaker 2>She writes that quote each night he makes sure his

0:48:36.840 --> 0:48:39.800
<v Speaker 2>phone is charged and loaded with enough Daniel and Jorgey

0:48:39.840 --> 0:48:42.560
<v Speaker 2>to get him through the night. It's without drama that

0:48:42.640 --> 0:48:45.120
<v Speaker 2>I say that your show is one of his lifelines,

0:48:45.200 --> 0:48:49.040
<v Speaker 2>right now, you guys are his intellectual support above all,

0:48:49.120 --> 0:48:51.200
<v Speaker 2>on behalf of our family. I want to thank you

0:48:51.239 --> 0:48:53.839
<v Speaker 2>for your podcast and being a comfort to him in

0:48:53.920 --> 0:48:59.120
<v Speaker 2>this season. Wow, it's hard to overstate how deeply that

0:48:59.280 --> 0:49:02.400
<v Speaker 2>touches me, and I want to send him our encouragement

0:49:02.480 --> 0:49:05.120
<v Speaker 2>on his road to recovery. I'm so glad that we

0:49:05.160 --> 0:49:08.080
<v Speaker 2>can be there to help in this small way, and

0:49:08.120 --> 0:49:10.040
<v Speaker 2>I want to say thank you to everyone out there,

0:49:10.120 --> 0:49:12.399
<v Speaker 2>those of you who are listening and writing back or

0:49:12.520 --> 0:49:15.600
<v Speaker 2>just enjoying silently. You're all the reason that I do this.

0:49:23.600 --> 0:49:26.400
<v Speaker 2>Thanks for listening, and remember that Daniel and Jorge explain

0:49:26.440 --> 0:49:30.400
<v Speaker 2>the Universe is a production of iHeartRadio. For more podcasts

0:49:30.480 --> 0:49:35.120
<v Speaker 2>from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever

0:49:35.200 --> 0:49:36.920
<v Speaker 2>you listen to your favorite shows.