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Speaker 1: Unraveling the nature of the universe is a bit like

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Speaker 1: solving a murder mystery. You have to look very carefully

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Speaker 1: at all the clues. You have to pull really hard

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Speaker 1: on any thread that looks weird it's unexplained, because any

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Speaker 1: of them might be the key that solves the whole mystery.

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Speaker 1: Throughout history, whenever we've seen something we didn't understand, it's

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Speaker 1: often turned out to be a big screaming clue about

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Speaker 1: the next deeper layer of understanding reality. When we saw

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Speaker 1: patterns in the periodic table, they were obvious but unexplained

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Speaker 1: for many years until we were able to dig deeper

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Speaker 1: and discover that they all came out of how electrons

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Speaker 1: arranged themselves in shells around the nucleus. The similarity of

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Speaker 1: the shape of the coastlines of Africa and South America

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Speaker 1: a big clue that over millions of years, the continents

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Speaker 1: themselves were in motion, and these two had once been joined.

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Speaker 1: So amazing realizations can come from refusing to ignore little

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Speaker 1: time clues that bother you at night. So every time

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Speaker 1: we see something that doesn't make sense, we should dig

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Speaker 1: deeper and look for a reason. And that's especially true

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Speaker 1: when there's something that we don't understand about the whole

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Speaker 1: universe when we think it should has balance, but instead

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Speaker 1: it's out of balance. Why is there more matter than antimatter?

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Speaker 1: Why are some forces weaker than others? Particle physics is

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Speaker 1: filled with these kinds of mysteries, and today on the podcast,

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Speaker 1: we'll be digging deep into one unexplained choice. The universe

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Speaker 1: seems to have made billions of years ago between being

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Speaker 1: righty or lefty. Life is left handed. Particles prefer to

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Speaker 1: be left handed, though most humans are right handed. Today,

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Speaker 1: on the podcast, we'll be asking was the Big Bang

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Speaker 1: also left handed? Welcome to Daniel and Kelly's Extraordinary left

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Speaker 1: Handed Universe.

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Speaker 2: Hello. I'm Kelly Wienersmith. I study parasites, and my family

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Speaker 2: is fifty percent left handed and fifty percent right handed.

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Speaker 3: Hi.

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Speaker 1: I'm Daniel. I'm a particle physicist, and I'd give my

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Speaker 1: right hand to be ambidextros.

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Speaker 2: Well, Okay, that doesn't really make sense the more I

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Speaker 2: think about it, but I would love to be ambidextris too.

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Speaker 2: How does it fall out in your family?

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Speaker 1: We have one lefty, a bunch of righty's, and my

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Speaker 1: mom was ambidextris. She could write with both hands, and

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Speaker 1: some things she'd liked to do with her left hand,

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Speaker 1: like cutting with scissors, and other things she liked to

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Speaker 1: do with her right hand, like stirring a bowl of soup.

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Speaker 2: Interesting, I don't do anything with either hand well, like

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Speaker 2: pipe petting didn't go well. My writing's illegible from either hand,

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Speaker 2: but you know I can type, okay?

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Speaker 1: And who in your family is left handed?

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Speaker 2: Zach? And we think ben so.

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Speaker 1: Zach's a member of the Secret Society of Left Handers.

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Speaker 2: And the Secret Society of Red headed People. Yes, he's

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Speaker 2: involved in lots of secret societies, maybe in charge of everything.

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Speaker 1: I wouldn't mind having cartoonists be in charge of most stuff.

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Speaker 1: I think that would be a great way to run

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Speaker 1: the world. What's the name for that, you have democracy, oligarchy, cartoonocracy?

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Speaker 2: Yeah, I don't know, but I can tell you that

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Speaker 2: he doesn't run the household because he might not be

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Speaker 2: confident to do that. And so I don't know that

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Speaker 2: we should give him too much more power. And I

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Speaker 2: don't think he wants more power. So I think maybe

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Speaker 2: rule by the cartoonists, this one in particular, is maybe

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Speaker 2: not a great idea. What would it be like if

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Speaker 2: the world were ruled by physicists, we.

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Speaker 1: Would spend a lot more money on particle colliders. Oh

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Speaker 1: my gosh, Yes, we would know so much more about

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Speaker 1: the universe, but.

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Speaker 2: We'd spend less money on soap.

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Speaker 1: Sorry, fair, fair, Nobody in office would be wearing a suit,

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Speaker 1: that's for sure.

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Speaker 2: That's for sure. That's a world I can get behind.

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Speaker 1: Well, we seek to find balance between the physicists and

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Speaker 1: the cartoonists, and the left handiers and the right handers

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Speaker 1: and everything in the universe, which is why on today's

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Speaker 1: podcast we're gonna be talking about symmetry and balance and

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Speaker 1: imbalance in the universe.

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Speaker 2: So I'm super interested in this topic because I only

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Speaker 2: had a chance to sort of like realize that it

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Speaker 2: existed back when we were writing Souonish, because we wrote

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Speaker 2: a little note of bene on George Church, who is

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Speaker 2: trying to make organisms where every one of their molecules

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Speaker 2: is the opposite handedness as it is now. And the

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Speaker 2: ultimate goal, as I understood it, was that if you

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Speaker 2: had a human of opposite handedness, no pathogens or parasites

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Speaker 2: could recognize our receptors and they would never be able

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Speaker 2: to infect us, and so you would be free from

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Speaker 2: all infection.

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Speaker 1: But you also wouldn't have a microbiome, so you couldn't

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Speaker 1: digest any food, right.

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Speaker 2: So your microbiome would also have to be made opposite handed,

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Speaker 2: and then all of your foods would have to be

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Speaker 2: made opposite handed, and that just seems like way too

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Speaker 2: much work for the trade off and all. So like,

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Speaker 2: if a global supply chain problem popped up, could you

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Speaker 2: never feed anyone because they need the opposite handedness bread?

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Speaker 2: It was complicated, But I remember when I was doing

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Speaker 2: the research thinking why is there such a trend in

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Speaker 2: handedness for molecules? Like what caused that? And then I

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Speaker 2: got too busy and so I never dug in, And

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Speaker 2: today we get to find out about that.

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Speaker 1: That's right, So it'll be super fascinating when there's an

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Speaker 1: asymmetry in the universe, when the universe seems to have

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Speaker 1: made one choice, because then you got to ask, like,

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Speaker 1: why not the other choice? What does it mean? Is

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Speaker 1: it random? Is there a reason? Could it have been

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Speaker 1: the other way? Are there other universes out there where

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Speaker 1: another choice was made? And does that explain my whole childhood? Basically?

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Speaker 2: Wow, whoa it got deep?

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Speaker 1: And so this stretches from the mathematics of handedness, to

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Speaker 1: the handedness of life, to the handedness of particles, and

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Speaker 1: even the handedness of the whole universe and the origin

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Speaker 1: of the universe itself. So I went out there and

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Speaker 1: I asked folks what they knew about this topic, if

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Speaker 1: they thought the Big Bang could have been left handed,

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Speaker 1: If you'd like to play for future episodes of the podcast,

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Speaker 1: please don't be shy right to us two questions at

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Speaker 1: Danielandkelly dot org. So think about it for a moment.

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Speaker 1: Do you think the Big Bang could have been left handed?

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Speaker 1: Here's what people had to say.

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Speaker 4: Okay, this has to do with chirality, But I don't

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Speaker 4: think kyality is at the fundamental particle level that it

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Speaker 4: wouldn't be manifested there, you know, because you've got flavor, spin, charge,

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Speaker 4: flavor color, but you definitely don't have chirality built into

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Speaker 4: the core properties. Now, it does come up in chemistry.

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Speaker 4: I know that all chemistry on Earth is a certain

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Speaker 4: kiral and I can't remember if it's left right, but

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Speaker 4: it's one type. And if we get a meteor that

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Speaker 4: comes that has a different type, that shows some type

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Speaker 4: of organic biological life, then we would know that it's

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Speaker 4: that it's alien and not something you know that came

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Speaker 4: from Earth.

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Speaker 5: Let's see, in molecules, you can have handedness based on

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Speaker 5: the arrangement of the atoms in the same way your

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Speaker 5: hands are left handed and right handed based on the

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Speaker 5: arrangement of fingers. But in a soup of particles like protons,

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Speaker 5: surely there's no way their arrangement can be left handed

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Speaker 5: or right handed.

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Speaker 3: Considering the Big Bang was everywhere all at once, and

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Speaker 3: we ended up in a universe with both right and

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Speaker 3: left handed fundamental force particles, then maybe it was both.

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Speaker 2: So I feel like the intuition here from the answers

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Speaker 2: tends to be that folks think the Big Bang was

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Speaker 2: probably not left handed and produced an equal amount approximately

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Speaker 2: of left and right handed molecules. That totally matches my

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Speaker 2: intuition as well, but is not actually the answer, right.

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Speaker 1: Yeah, it reveals something about our prejudice, what we think

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Speaker 1: is natural, what makes sense, And I think it's super

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Speaker 1: fascinating in science what answers people will accept without further

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Speaker 1: explanation because it aligns with their intuition and they're like, oh, yeah,

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Speaker 1: that makes sense, And what answers require more explanation, and

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Speaker 1: for a lot of people hearing oh it was symmetric,

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Speaker 1: it was a balance between left and right handed, and

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Speaker 1: then like, yeah, cool, of course it was. That doesn't

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Speaker 1: require any more explanation. But if you tell them no,

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Speaker 1: it's left handed, or no it was right handed, then

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Speaker 1: to ask why. And I think all the possible outcomes

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Speaker 1: need a why. You know, why should it be symmetric?

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Speaker 1: But we have this innate preference for symmetry for balance

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Speaker 1: in the universe, which I think says something about us,

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Speaker 1: but I'm not sure exactly what it says.

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Speaker 2: I think I would like to have you on the

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Speaker 2: next panel that judges my grants. I like the way

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Speaker 2: you think about this stuff.

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Speaker 1: It all needs answers, It all needs answers exactly every

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Speaker 1: question is worth asking.

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Speaker 2: But yeah, it does make me wonder what questions we

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Speaker 2: should be asking that would like have amazing impacts on

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Speaker 2: how we view the world, but we just don't think

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Speaker 2: to ask them because our gut says they make sense.

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Speaker 1: Exactly to me. This tendency suggests that there probably are

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Speaker 1: questions we should be digging into more deeply, or it's

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Speaker 1: just accepting the answers because they seem right to us

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Speaker 1: without really understanding what's going on, and maybe in one

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Speaker 1: hundred years or maybe when the aliens come, they're going

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Speaker 1: to be like, why didn't you think about that more deeply?

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Speaker 1: We would be like, I don't know, it just made sense.

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Speaker 2: Set right, right, man, exactly? Yeah?

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Speaker 5: All right.

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Speaker 2: Well, I think for anyone who hasn't thought of this

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Speaker 2: concept yet, or anyone who was lucky enough to not

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Speaker 2: have to go through chemistry, is maybe a little confused

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Speaker 2: about what we mean by this handedness thing. So let's

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Speaker 2: start at the beginning. What does it mean for something

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Speaker 2: to have a handedness?

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Speaker 1: Yeah, left or right handedness really is a mathematical thing.

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Speaker 1: It's a geometric thing and super fascinating. So let's start

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Speaker 1: in two dimensional space. Imagine that you take two arrows right,

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Speaker 1: so you know they have a tip and a tail,

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Speaker 1: and then stick their tails together and have their tips

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Speaker 1: be ninety degrees apart. So now you have like two

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Speaker 1: arrows that are pointing perpendicular to each other. Right now,

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Speaker 1: in two dimensional space, just like on a sheet, any

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Speaker 1: pair of arrows you make are always going to be

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Speaker 1: essentially equivalent, And by equivalent, I mean that you could

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Speaker 1: line them up on top of each other, like move

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Speaker 1: them and spin them and put them on top of

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Speaker 1: each other. They're always going to line up perfectly. There's

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Speaker 1: no way to make a pair of arrows to follow

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Speaker 1: those rules where they're perpendicular to each other, where you

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Speaker 1: can't then line them up. So that's two dimensional space, right,

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Speaker 1: there's no handedness. But if you label one of the

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Speaker 1: arrows X and the other one y, so they're no

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Speaker 1: longer two totally symmetrical identical vectors, but they have these

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Speaker 1: labels on them. Now there are two ways to arrange

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Speaker 1: these two arrows, Like if the X arrow is straight

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Speaker 1: up in front of you, then the Y arrow can

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Speaker 1: be to its left or to its right. And because

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Speaker 1: you have these labels, there's now no way to spin

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Speaker 1: the left version of it to make it look like

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Speaker 1: the right version. To do that, to have one lay

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Speaker 1: on top of each other, so the x is align

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Speaker 1: and the ys align, you'd have to flip it over

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Speaker 1: essentially reflect it, make a mirror image, go from left

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Speaker 1: to right. It's analogous to notions of clockwise and counterclockwise

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Speaker 1: on the surface of a clock. Also two dimensional. Now

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Speaker 1: expand our universe, add a third dimension above and below

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Speaker 1: the plane and add another arrow. Take your two arrows

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Speaker 1: that are perpendicular to each other. You could think of

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Speaker 1: them as like the X axis and the y axis,

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Speaker 1: or you could think of them as like your thumb

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Speaker 1: and your pointy finger right, that are perpendicularly to each other.

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Speaker 1: And now add a third arrow that comes out from

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Speaker 1: where the first two were joined. Now you have to

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Speaker 1: make a choice. Do you go up above the plane

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Speaker 1: or down below the plane? And you might think, oh,

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Speaker 1: it doesn't matter if I stick it above the plane,

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Speaker 1: I can just rotate it to make it below the plane, right,

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Speaker 1: But it actually does matter. If you choose the arrow

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Speaker 1: that goes up above the plane, and then you rotate

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Speaker 1: the whole thing so the arrow goes below the plane,

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Speaker 1: you'll find that the other two don't line up to

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Speaker 1: the first two. There's no way to take that set

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Speaker 1: where the arrow is above the plane and rotate it

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Speaker 1: to match the arrow those below the plane. You can

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Speaker 1: see this very easily with your hands. Your hands on

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Speaker 1: his left handed when it's right handed. That's why we

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Speaker 1: call them that. If you take your thumb and your

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Speaker 1: pointy finger and you make them ninety degrees apart, then

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Speaker 1: you have your middle finger stick perpendicular to your pal

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Speaker 1: so it's perpendicular to the other two. Then you have

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Speaker 1: like an X, Y, Z axis, but there's no way

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Speaker 1: to orient them, so they line up on top of

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Speaker 1: each other. Is one is left handed and one is

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Speaker 1: right handed?

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Speaker 2: All right, So I get that. But when I think

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Speaker 2: of handedness, I feel like I'm thinking of my hands

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Speaker 2: and the X and the Y direction and not the

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Speaker 2: Z direction. Yeah, it still doesn't work in those two dimensions.

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Speaker 2: Is the point that, Kelly, your hands are actually three dimensional.

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Speaker 2: You're an idiot. Stop thinking about this like they're two dimensional.

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Speaker 1: No, you're not an idiot. Your hands are three dimensional.

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Speaker 1: You're exactly right. And the reason that you're like, make

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Speaker 1: your hands flat, you're thinking, I make my hands flat,

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Speaker 1: I lay them on top of each other. They're still

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Speaker 1: not the same, right, even in sort of flat hand

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Speaker 1: two dimensional world. The thing is that you're right. They're

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Speaker 1: not two dimensional, and if they were, you could make

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Speaker 1: them line on top of each other and be exactly

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Speaker 1: the same. The reason that they can't is because they

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Speaker 1: have a top and a bottom, right, they have a thickness.

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Speaker 1: If you try to put your hands together, then you

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Speaker 1: meet your palms together. Then they're inverted in that third dimension,

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Speaker 1: so you still are working in a three dimensional world.

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Speaker 1: If you squeezed your hands in a hydraulic press so

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Speaker 1: they were infinitely flat, then you could make them identical

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Speaker 1: and lay them on top of each other.

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Speaker 2: I don't think it's worth it for this purpose.

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Speaker 1: That's why we have thought experiments. You don't have to

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Speaker 1: actually do it. You could just think of it that way.

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Speaker 1: So that's what handedness is, and that's where it comes from.

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Speaker 1: It comes from our hands. Right, one hand is left handed,

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Speaker 1: one hand is right handed. Amazingly, these words actually make

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Speaker 1: sense and the technical definition lines up with your knowledge.

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Speaker 2: Another example of how humans sort of take the way

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Speaker 2: that we see and experience the world and overlay it

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Speaker 2: on our science.

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Speaker 1: Yeah, exactly right. And what would aliens call this kind.

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Speaker 2: Of stuff tentaicleness.

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Speaker 1: It's fascinating because this is a basic property of geometry, right,

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Speaker 1: and it's totally arbitrary. There's nothing special but left handed

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Speaker 1: or right handed right. It's just how do you orient

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Speaker 1: these three vectors? And it would be really weird if

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Speaker 1: the universe for some reason preferred one or the other. Mathematically,

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Speaker 1: they're totally equivalent, they're completely symmetrical. There's no reason for

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Speaker 1: one to be more fundamental or more basic. There's just

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Speaker 1: two choices to make here, and not everything in the

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Speaker 1: universe has a handedness, right, we're talking about this combination

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Speaker 1: of three vectors, or your three fingers have a handedness.

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Speaker 1: But take a sphere, for example. A sphere has no handedness.

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Speaker 1: There's no choices to make. There a way you can

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Speaker 1: tell something as handedness is put it in front of

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Speaker 1: a mirror. A mirror flips the handedness. Like if you

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Speaker 1: put your left hand in front of a mirror, it

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Speaker 1: looks like a right hand. If you put your right

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Speaker 1: hand in front of a mirror, it looks like a

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Speaker 1: left hand. Put a sphere in front of a mirror,

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Speaker 1: what do you get a sphere? Right, There's no handedness

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Speaker 1: to a sphere. So some things have handedness and some

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Speaker 1: things don't have handedness. So that's the sort of mathematics

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Speaker 1: of handedness. And you might imagine a perfect universe everything

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Speaker 1: would be symmetric. There's no reason to choose one or

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Speaker 1: the other. But as we already talked about in this episode,

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Speaker 1: nobody is really symmetric. Like I use my right hand right,

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Speaker 1: I am right handed, it's a part of me that

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Speaker 1: breaks this symmetry that for so reason prefers to use

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Speaker 1: my right hand to need doe and to write doodles

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Speaker 1: and to point at things and all sorts of stuff.

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Speaker 1: And some people are left handed. So the symmetry is

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Speaker 1: broken sort of two levels, right. One level is every

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Speaker 1: individual person prefers one or the other, and the population

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Speaker 1: has way more righties than lefties. So this symmetry is

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Speaker 1: already broken even from the place where you've defined it.

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Speaker 2: Fun fact, this happens in the animal kingdom too. I

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Speaker 2: remember a talk, Oh my gosh, this was two decades ago,

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Speaker 2: but they were looking at blind kfish and they put

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Speaker 2: them in an environment with legos in the middle, and

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Speaker 2: it was a circular tank, and the fish to explore

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Speaker 2: the environment, they like get you know, the vibrations or

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Speaker 2: the water currents, they feel them on one side of

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Speaker 2: their body to figure out where things are. And so

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Speaker 2: they'd swim around, and you could tell that they had

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Speaker 2: figured out like what their environment was like because they

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Speaker 2: eventually slowed down and like stopped swimming. But as soon

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Speaker 2: as you moved the legos in a different configuration, they'd

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Speaker 2: start swimming around again. A lot, they could tell the

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Speaker 2: environment had changed and they wanted to understand how it

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Speaker 2: had changed. And they specifically would swim with one side

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Speaker 2: of their body facing the legos because they had a

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Speaker 2: body side that they preferred to collect information on, and

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Speaker 2: so like even fish exhibits something like a preference for

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Speaker 2: one side over the other. Anyway, I always remembered that

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Speaker 2: it was like amazing that blind cavefish were responding to

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Speaker 2: changes in their environments. Animals are incredible.

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Speaker 1: We've noticed that our dog seems to have a preference,

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Speaker 1: Like when we ride in the car, he will stick

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Speaker 1: his head fully out the window, but only on the

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Speaker 1: right side. On the left side, he will stick his

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Speaker 1: nose out the window, but he won't like all the

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Speaker 1: way climb up on the armrest and get his whole

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Speaker 1: shoulders out the window. So he seems to prefer the

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Speaker 1: wind on the right side of the car. And that

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Speaker 1: makes me wonder, like, is he more comfortable with his

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Speaker 1: right paw and looking out that window requires more strength

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Speaker 1: from that leg or something, or is he fundamentally a

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Speaker 1: righty I mean, have we done a lot of experiments

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Speaker 1: on animals to determine, you know, if they're right left handed? Like,

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Speaker 1: do chimpanzees use their right or left hand?

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Speaker 4: More?

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Speaker 1: Do you know?

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Speaker 2: I don't know. I think we need to get Katie

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Speaker 2: Golded on the show from Creature Feature and she'll let

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Speaker 2: us know. But I do not know the answer to that.

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Speaker 2: So the left side is the side that the other

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Speaker 2: cars are coming from. I wonder if it just feels

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Speaker 2: safer to stick your head out farther on the opposite

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Speaker 2: side than like towards incoming traffic.

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Speaker 1: Oh, we'll have to do some experiments with folks in

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Speaker 1: England to see if their dogs prefer the opposite side.

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Speaker 2: There you go, that's a good experiment.

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Speaker 1: We're doing the natural experiment right here on Earth, folks.

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Speaker 1: So you see that pop up in your daily life

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Speaker 1: and in your own experience and in your family. But

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Speaker 1: it turns out to also be important in the biochemistry

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Speaker 1: of life and later on more fundamentally, in physics itself.

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Speaker 2: Yes, we said chemistry, but stick with us. This is exciting,

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Speaker 2: all right, So we're back. We've talked about handedness, and

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Speaker 2: I remember from organic chemistry and biokam that organic molecules

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Speaker 2: are left handed in right handed And actually, when we

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Speaker 2: were researching studish, Zach discovered that spearment and care away,

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Speaker 2: which are very different tastes, are molecules with opposite handedness.

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Speaker 2: Whoa and so like those, opposite handedness results in completely

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Speaker 2: different ways that it interacts with our body. So anyway,

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Speaker 2: molecules have handedness and our chirrol and why.

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Speaker 1: Yeah, So we don't fundamentally know the answer, and you

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Speaker 1: might be wondering, like, what does handedness mean for a molecule, Well,

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Speaker 1: it just means that if you put it in front

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Speaker 1: of a mirror, you don't get the same molecules. So

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Speaker 1: a molecule is more like the three first fingers on

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Speaker 1: your hand or the xyz axis than it is like

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Speaker 1: a sphere. Right, They're not symmetric. They have a handedness

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Speaker 1: to them, so you can't just like spin a left

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Speaker 1: handed version of amino acids into a right handed version

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Speaker 1: of methane. It's like fundamentally a diff molecule. You can

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Speaker 1: tell which one is left and which one is right.

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Speaker 1: And as Kelly mentioned earlier, life is built out of

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Speaker 1: only one of these things. Life has chosen one of these.

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Speaker 1: We are all built out of left handed amino acids,

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Speaker 1: the things that make up all living creatures on earth,

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Speaker 1: including the microbes that infect us are all made out

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Speaker 1: of one of these things and not the other one,

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Speaker 1: which is really peculiar.

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Speaker 2: Yeah, wouldn't we have a lot more options for the

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Speaker 2: kinds of amino acids and stuff we could make if

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Speaker 2: we had both kiralities. But I guess we already could

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Speaker 2: make more amino acids than are typically used by organisms,

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Speaker 2: So maybe we don't need that many more amino acids.

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Speaker 1: Yeah, because the different chiralities don't work together, like these

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Speaker 1: things have to fit together really precisely. I think of

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Speaker 1: these little molecules as little machines, you know, that do

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Speaker 1: something biochemically. This one builds that, and this one builds

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Speaker 1: the other thing, and this one rotates this thing. They're

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Speaker 1: all like, you know, I imagine little legos in my

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Speaker 1: head because I'm not very good chemistry, and they have

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Speaker 1: to have their particular arrangement to do their job. You

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Speaker 1: can't just replace it with the opposite kirality and expect

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Speaker 1: it to do the same thing, especially if everybody else

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Speaker 1: is the different kirality. It might work if you flipped

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Speaker 1: all of it right. You took all of life from

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Speaker 1: left to right, and you can make a right handed version.

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Speaker 1: I think That's one of the questions Eric Church was

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Speaker 1: hoping to answer, like is it really arbitrary? Could life

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Speaker 1: work if everything was right handed? It seems like it should,

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Speaker 1: But it's fascinating that you can't mix them right like

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Speaker 1: a left handed person can't eat right handed food, or

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Speaker 1: couldn't have a baby with a right handed person, you know,

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Speaker 1: like their biochemistries just don't interact. It's fascinating.

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Speaker 2: Yeah, you said Eric Church, but I think you met

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Speaker 2: George Church. Oh sorry, yeah, that's all right. So is

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Speaker 2: this kind of like if you have a iPhone you

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Speaker 2: can't use the apps made for Android? Could it just

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Speaker 2: be that life sort of started in one direction and

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Speaker 2: then some piece of machinery for life came into existence

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Speaker 2: that was really good, but only the right handed molecules

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Speaker 2: could be used with that piece of machinery. And that's

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Speaker 2: just it got the ball rolling and the left handed

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Speaker 2: ones could never compete. Sorry, Android users, And that's why

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Speaker 2: we have this preference for one. It was like some

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Speaker 2: early machinery used one chirality and not the other.

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Speaker 1: Yeah, so we actually don't know the answer to that question.

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Speaker 1: We don't know like does it have to be this way?

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Speaker 1: Is there something about left handed molecules that are better

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Speaker 1: at forming life, or something fundamentally by the biochemistry of

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Speaker 1: life that prefers left handedness. That would be weird, right,

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Speaker 1: because there isn't really a difference, it's just reflection. Fundamentally,

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00:21:29,359 --> 00:21:32,480
Speaker 1: the universe shouldn't prefer one or the other, but it

435
00:21:32,560 --> 00:21:34,760
Speaker 1: kind of seems to And you're right that once you

436
00:21:34,840 --> 00:21:37,880
Speaker 1: choose one, you're stuck. Right. It's sort of like everybody

437
00:21:37,920 --> 00:21:40,560
Speaker 1: sits down at a dinner party. Are you taking the

438
00:21:40,600 --> 00:21:42,960
Speaker 1: silverware that's on your left or on your right. Once

439
00:21:43,080 --> 00:21:45,840
Speaker 1: somebody takes one, everybody's gonna make the same choice, or

440
00:21:45,880 --> 00:21:48,800
Speaker 1: you get clashes, right, Or as you say, once you're

441
00:21:48,840 --> 00:21:51,480
Speaker 1: in the Apple ecosphere, then you got to have all

442
00:21:51,520 --> 00:21:54,160
Speaker 1: Apple devices where they don't work together. So we think

443
00:21:54,200 --> 00:21:56,359
Speaker 1: that once you choose one, you're stuck with it. We

444
00:21:56,400 --> 00:21:58,399
Speaker 1: don't know if it was just like a random choice,

445
00:21:58,440 --> 00:22:01,280
Speaker 1: like that first living thing could have been left or right,

446
00:22:01,320 --> 00:22:04,159
Speaker 1: and it was just randomly left and now we're all

447
00:22:04,160 --> 00:22:06,480
Speaker 1: stuck left, or if there's a reason it has to

448
00:22:06,520 --> 00:22:09,240
Speaker 1: be left or more likely to be left, and just

449
00:22:09,320 --> 00:22:10,840
Speaker 1: everything has followed from that.

450
00:22:11,400 --> 00:22:14,119
Speaker 2: Yeah, but it feels to me like there's no reason

451
00:22:14,160 --> 00:22:16,240
Speaker 2: why you couldn't have had a branch of life that

452
00:22:16,320 --> 00:22:19,800
Speaker 2: started right and that a branch of life that started left.

453
00:22:20,160 --> 00:22:22,440
Speaker 2: Like you know, the same trick could have been come

454
00:22:22,520 --> 00:22:25,480
Speaker 2: upon for both kyalities and then you sort of radiate

455
00:22:25,480 --> 00:22:26,680
Speaker 2: out from there, and then.

456
00:22:26,600 --> 00:22:28,840
Speaker 1: There was an epic battle right versus left.

457
00:22:29,880 --> 00:22:32,440
Speaker 2: Yeah, I'm sure the right handed would win.

458
00:22:33,600 --> 00:22:35,840
Speaker 1: But this is not something we even knew until like

459
00:22:35,840 --> 00:22:38,280
Speaker 1: one hundred and fifty years ago, and it was Louis

460
00:22:38,320 --> 00:22:42,480
Speaker 1: Pasteur who discovered this. He was studying this byproduct of

461
00:22:42,480 --> 00:22:46,080
Speaker 1: wine fermentation, tartaric acid, and he noticed that there were

462
00:22:46,119 --> 00:22:48,760
Speaker 1: two types of crystals that were made. There were mirror

463
00:22:48,800 --> 00:22:51,719
Speaker 1: images of each other. So he was trying to synthesize

464
00:22:51,800 --> 00:22:53,960
Speaker 1: this thing, because you can synthesize these chemicals and you

465
00:22:54,000 --> 00:22:56,280
Speaker 1: can make right or left, but then you discover out

466
00:22:56,320 --> 00:22:59,440
Speaker 1: in a natural world you only ever find left. So

467
00:22:59,480 --> 00:23:01,480
Speaker 1: he discovered, oh, this is a difference if I make

468
00:23:01,520 --> 00:23:04,600
Speaker 1: it myself in the lab versus if I like find

469
00:23:04,640 --> 00:23:07,439
Speaker 1: it from nature. And he was able to pin this

470
00:23:07,560 --> 00:23:10,760
Speaker 1: down using polarized light to figure out what the chemical

471
00:23:10,760 --> 00:23:13,160
Speaker 1: structure of these things were. So this is something we've

472
00:23:13,200 --> 00:23:15,439
Speaker 1: only known about for one hundred and fifty years and

473
00:23:15,440 --> 00:23:17,439
Speaker 1: people have been trying to figure out, like what is

474
00:23:17,480 --> 00:23:19,920
Speaker 1: the cause of it for much longer than that. There

475
00:23:19,920 --> 00:23:23,159
Speaker 1: are some speculative answers. I read a paper that suggested

476
00:23:23,240 --> 00:23:26,760
Speaker 1: that there could be something about how magnets formed in

477
00:23:26,840 --> 00:23:30,840
Speaker 1: the Earth that prefers left handed chirality, like the magnetic

478
00:23:30,920 --> 00:23:34,440
Speaker 1: field of the Earth generates some preference for the left

479
00:23:34,440 --> 00:23:37,760
Speaker 1: handed versions versus the right handed versions. But it's very speculative,

480
00:23:38,080 --> 00:23:41,000
Speaker 1: and this is super cool. We just learned from an

481
00:23:41,040 --> 00:23:44,600
Speaker 1: amazing mission that went out and sampled an asteroid Bendu

482
00:23:45,080 --> 00:23:48,199
Speaker 1: brought stuff back to Earth we could study it. In

483
00:23:48,240 --> 00:23:51,480
Speaker 1: that sample, there are equal mixtures of left and right

484
00:23:51,520 --> 00:23:55,720
Speaker 1: handed organic chemicals, So huge clue because life on Earth

485
00:23:55,840 --> 00:23:59,320
Speaker 1: prefers the left handed ones, but the basic ingredients for

486
00:23:59,440 --> 00:24:02,200
Speaker 1: left or right handed life seem to be out there

487
00:24:02,240 --> 00:24:03,080
Speaker 1: in the universe.

488
00:24:03,640 --> 00:24:07,320
Speaker 2: So when you do industrial processes like Pastura was doing,

489
00:24:07,680 --> 00:24:11,080
Speaker 2: you get both kinds? Do you get both kinds evenly?

490
00:24:11,119 --> 00:24:14,439
Speaker 2: Because if so, it feels like the magnet's answer doesn't work.

491
00:24:14,680 --> 00:24:16,920
Speaker 1: You're right. But I think the idea is that there

492
00:24:16,960 --> 00:24:20,280
Speaker 1: could be these magnetic surfaces essentially that are made that

493
00:24:20,440 --> 00:24:23,119
Speaker 1: better bind to the left handed bits, and then essentially

494
00:24:23,200 --> 00:24:25,480
Speaker 1: bring them together, gather them together so that they can

495
00:24:25,520 --> 00:24:28,760
Speaker 1: make more complex molecules. So you might get more complex

496
00:24:28,840 --> 00:24:32,800
Speaker 1: left handed structures faster than you get complex right handed structures,

497
00:24:32,840 --> 00:24:36,080
Speaker 1: even if you have the same relative abundance of the precursors.

498
00:24:36,200 --> 00:24:39,399
Speaker 1: That basically it creates a playground where the lefty bits

499
00:24:39,560 --> 00:24:42,680
Speaker 1: come together to make the complex structures you need for life.

500
00:24:42,800 --> 00:24:44,040
Speaker 2: I mean that feels testable.

501
00:24:44,400 --> 00:24:46,359
Speaker 1: Yes, this is totally testable. And I read an article

502
00:24:46,440 --> 00:24:48,840
Speaker 1: from Science in twenty twenty three where they do experiments

503
00:24:48,880 --> 00:24:52,000
Speaker 1: and they can produce this kind of effect. That doesn't

504
00:24:52,000 --> 00:24:54,639
Speaker 1: mean that it's the reason why life is left handed.

505
00:24:54,680 --> 00:24:58,040
Speaker 1: It's just like there is in some sense something that

506
00:24:58,080 --> 00:25:02,360
Speaker 1: prefers left handed chemistry to right handed chemistry right, and

507
00:25:02,400 --> 00:25:04,640
Speaker 1: we do see other hints of that in the universe,

508
00:25:04,680 --> 00:25:06,600
Speaker 1: like there are other parts of the universe that seem

509
00:25:06,680 --> 00:25:11,600
Speaker 1: to prefer left handedness over right handedness, like particle physics.

510
00:25:11,920 --> 00:25:15,840
Speaker 1: Particle physics has a basic preference for left handedness over

511
00:25:15,920 --> 00:25:18,560
Speaker 1: right handedness, And after we dig into it, we can

512
00:25:18,600 --> 00:25:21,160
Speaker 1: come back and make the connection. People think that maybe

513
00:25:21,320 --> 00:25:24,960
Speaker 1: high speed particles from space could have influenced the left

514
00:25:25,040 --> 00:25:27,159
Speaker 1: or right handedness of life, on Earth.

515
00:25:27,520 --> 00:25:30,679
Speaker 2: We talked about amino acids being left handed. Amino acids

516
00:25:30,680 --> 00:25:34,119
Speaker 2: come together to form proteins. Are there other things that

517
00:25:34,160 --> 00:25:38,960
Speaker 2: are important to biology that also have a handedness?

518
00:25:39,160 --> 00:25:41,159
Speaker 1: Well, I think the left handed nature of the amino

519
00:25:41,280 --> 00:25:45,400
Speaker 1: acids means that the sugars they make are right handed,

520
00:25:45,720 --> 00:25:47,520
Speaker 1: because that's the kind of thing that a left handed

521
00:25:47,480 --> 00:25:51,600
Speaker 1: amino acid will make. So those bits are sort of complementary.

522
00:25:51,880 --> 00:25:54,359
Speaker 1: So there are some parts of our life biochemistry that

523
00:25:54,400 --> 00:25:57,159
Speaker 1: are right handed that the amino acids are all left handed,

524
00:25:57,200 --> 00:26:00,240
Speaker 1: so we call it left handed, if that makes sense.

525
00:26:00,240 --> 00:26:04,000
Speaker 2: The amino acids are the building blocks. You expect the

526
00:26:04,040 --> 00:26:07,760
Speaker 2: things that the amino acids make, like proteins and sugars,

527
00:26:08,520 --> 00:26:11,920
Speaker 2: to be the opposite handedness because of how they all

528
00:26:11,920 --> 00:26:12,639
Speaker 2: get put together.

529
00:26:13,200 --> 00:26:15,719
Speaker 1: Yeah, exactly, Okay, And you can actually exploit that, as

530
00:26:15,720 --> 00:26:20,080
Speaker 1: you were talking about earlier with flavors. Some artificial sweeteners

531
00:26:20,320 --> 00:26:23,480
Speaker 1: exploit this fact. Despite being a sugar and tasting sweet,

532
00:26:23,480 --> 00:26:26,240
Speaker 1: they can go through your body without being metabolized because

533
00:26:26,240 --> 00:26:28,840
Speaker 1: they have the wrong handedness. So that's kind of cool.

534
00:26:29,119 --> 00:26:31,399
Speaker 2: That is kind of cool. I feel like there's a

535
00:26:31,440 --> 00:26:34,240
Speaker 2: little voice in the back of my head saying wasn't

536
00:26:34,240 --> 00:26:35,920
Speaker 2: there a study about how maybe they're not so good

537
00:26:35,920 --> 00:26:38,560
Speaker 2: for your body? But I'm not an expert on that. Anyway,

538
00:26:38,560 --> 00:26:39,479
Speaker 2: it might be worth looking up.

539
00:26:39,560 --> 00:26:42,080
Speaker 1: And we are not making any medical recommendations here, folks.

540
00:26:42,200 --> 00:26:46,119
Speaker 2: Amen, All right, So we've discussed that amino acids are

541
00:26:46,160 --> 00:26:49,560
Speaker 2: building blocks of other things, and that the left handed

542
00:26:49,560 --> 00:26:53,600
Speaker 2: building blocks produce right handed other things. So let's go

543
00:26:53,720 --> 00:26:57,479
Speaker 2: down another level before amino acids, or maybe multiple levels

544
00:26:57,520 --> 00:27:00,879
Speaker 2: before amino acids, down to particles. I knew that amino

545
00:27:00,920 --> 00:27:03,359
Speaker 2: acids were left handed. Could you predict the handedness of

546
00:27:03,359 --> 00:27:05,560
Speaker 2: particles because it alternates between levels.

547
00:27:05,720 --> 00:27:07,760
Speaker 1: Oh, it's a great question. We don't know the answer

548
00:27:07,800 --> 00:27:09,360
Speaker 1: to that. And we knew one hundred and fifty years

549
00:27:09,359 --> 00:27:13,080
Speaker 1: ago that amino acids were left handed. But physicists were

550
00:27:13,240 --> 00:27:16,520
Speaker 1: confident that the universe fundamentally at the particle level had

551
00:27:16,560 --> 00:27:19,840
Speaker 1: to be balanced, that it would be crazy if the

552
00:27:19,920 --> 00:27:22,640
Speaker 1: universe itself was left handed in some way, like why

553
00:27:22,680 --> 00:27:26,280
Speaker 1: would it prefer one direction over the other? That was nonsense,

554
00:27:26,640 --> 00:27:28,960
Speaker 1: And people did some tests early on, like let's see

555
00:27:28,960 --> 00:27:32,440
Speaker 1: if electromagnetism is symmetric, is there any preference for photons

556
00:27:32,480 --> 00:27:34,280
Speaker 1: to go in one direction? Or the other and they're

557
00:27:34,280 --> 00:27:37,119
Speaker 1: like no. And they did tests on another force as well,

558
00:27:37,200 --> 00:27:39,560
Speaker 1: the strong force, but people were very confident that the

559
00:27:39,640 --> 00:27:43,080
Speaker 1: universe didn't prefer left or right handed. And when we

560
00:27:43,080 --> 00:27:44,639
Speaker 1: talk about particles, we have to be a little bit

561
00:27:44,680 --> 00:27:47,160
Speaker 1: careful what we mean by left or right handed particles

562
00:27:47,200 --> 00:27:49,880
Speaker 1: because the definition we gave earlier, you have like three directions.

563
00:27:49,880 --> 00:27:52,960
Speaker 1: That makes sense for building molecules. Right, you're putting these

564
00:27:52,960 --> 00:27:55,439
Speaker 1: things together. You can imagine like balls and sticks, and

565
00:27:55,480 --> 00:27:58,239
Speaker 1: you're making something which doesn't reflect in the mirror. But

566
00:27:58,359 --> 00:28:00,920
Speaker 1: particles we don't think about is having extent. Right, they're

567
00:28:00,960 --> 00:28:03,520
Speaker 1: just like dots. So what do we mean by left

568
00:28:03,600 --> 00:28:06,919
Speaker 1: or right handed when it comes to particles, Well, particles

569
00:28:06,960 --> 00:28:10,000
Speaker 1: don't have an extent, but they do have two different arrows.

570
00:28:10,600 --> 00:28:12,920
Speaker 1: You can have particles that can be moving in one direction,

571
00:28:13,080 --> 00:28:15,879
Speaker 1: so that's the momentum of the particle. Right, imagine an

572
00:28:15,880 --> 00:28:18,399
Speaker 1: electron is flying through space. You could put an arrow

573
00:28:18,840 --> 00:28:21,760
Speaker 1: from where it was to where it's going. That's one arrow.

574
00:28:22,200 --> 00:28:25,119
Speaker 1: The other arrow of the particle is its spin. Electrons

575
00:28:25,119 --> 00:28:27,560
Speaker 1: can be spin up or spin down, so you can

576
00:28:27,600 --> 00:28:30,160
Speaker 1: think of that as another little arrow, and that arrow

577
00:28:30,200 --> 00:28:32,480
Speaker 1: can either be aligned with its motion, in which case

578
00:28:32,520 --> 00:28:35,720
Speaker 1: we call it a right handed electron or not aligned,

579
00:28:35,800 --> 00:28:39,040
Speaker 1: so pointing away from the direction it's moving. So if

580
00:28:39,040 --> 00:28:41,880
Speaker 1: your two arrows of your spin and your momentum point

581
00:28:41,920 --> 00:28:44,160
Speaker 1: in the same direction, we call you a right handed particle,

582
00:28:44,600 --> 00:28:46,480
Speaker 1: and if they're not aligned, we call you a left

583
00:28:46,520 --> 00:28:47,280
Speaker 1: handed particle.

584
00:28:47,720 --> 00:28:50,000
Speaker 2: Does it change the way we think about this when

585
00:28:50,040 --> 00:28:53,040
Speaker 2: we think about electrons as waves instead of particles.

586
00:28:53,600 --> 00:28:55,520
Speaker 1: Yeah, that's a great question, and we should always keep

587
00:28:55,520 --> 00:28:58,240
Speaker 1: in our minds that electrons are not tiny little balls

588
00:28:58,320 --> 00:29:01,720
Speaker 1: or even dots, but they are guided by the wave function. Right,

589
00:29:01,760 --> 00:29:05,200
Speaker 1: So what happens to a particle is determined by this

590
00:29:05,320 --> 00:29:09,040
Speaker 1: wave its outcome, which makes some of this stuff probabilistic. Right, Like,

591
00:29:09,080 --> 00:29:11,760
Speaker 1: an electron might not have a definan spin. It might

592
00:29:11,800 --> 00:29:15,080
Speaker 1: be maybe this or maybe that right. But some processes

593
00:29:15,200 --> 00:29:18,080
Speaker 1: have to produce left or right handed electrons, which means

594
00:29:18,080 --> 00:29:20,400
Speaker 1: you know in advance, like this one doesn't have a

595
00:29:20,400 --> 00:29:22,120
Speaker 1: probability to be left or right. It has to be

596
00:29:22,200 --> 00:29:23,960
Speaker 1: left or it has to be right in order to

597
00:29:23,960 --> 00:29:27,240
Speaker 1: balance with other bits. So, for example, if you have

598
00:29:27,400 --> 00:29:30,479
Speaker 1: two electrons produced opposite each other, you know their momenta

599
00:29:30,520 --> 00:29:33,120
Speaker 1: point opposite to each other, and you know, their spin

600
00:29:33,240 --> 00:29:36,040
Speaker 1: also have to be opposite to each other, which means

601
00:29:36,040 --> 00:29:39,280
Speaker 1: they're either both right handed or they're both left handed,

602
00:29:39,320 --> 00:29:40,840
Speaker 1: and you might not know that in advance. So in

603
00:29:40,840 --> 00:29:42,640
Speaker 1: that case, for example, your electron is going to be

604
00:29:42,680 --> 00:29:45,720
Speaker 1: fifty percent left handed and fifty percent right handed, but

605
00:29:45,760 --> 00:29:47,959
Speaker 1: they have to be the same right if they're produced

606
00:29:47,960 --> 00:29:50,320
Speaker 1: the same. So yeah, the wave nature gives you a

607
00:29:50,320 --> 00:29:52,920
Speaker 1: probabilistic aspect to all these particles for sure.

608
00:29:53,080 --> 00:29:54,080
Speaker 2: All right, got it?

609
00:29:54,320 --> 00:29:56,520
Speaker 1: And so this is what we call handedness for particles.

610
00:29:56,600 --> 00:29:59,760
Speaker 1: Sometimes they call it helicity. And one important caveat here

611
00:29:59,840 --> 00:30:03,400
Speaker 1: is that this isn't actually something that's exact, because the

612
00:30:03,480 --> 00:30:06,680
Speaker 1: momentum of a particle depends on your velocity. Like you

613
00:30:06,720 --> 00:30:10,440
Speaker 1: can imagine flipping the direction of a particle by zooming

614
00:30:10,480 --> 00:30:13,320
Speaker 1: past it in a spaceship. So now instead of moving

615
00:30:13,360 --> 00:30:15,479
Speaker 1: one direction, it looks like it's moving the other direction

616
00:30:15,800 --> 00:30:19,200
Speaker 1: that basically flips its momentum. So we actually only talk

617
00:30:19,240 --> 00:30:22,800
Speaker 1: about the handedness of particles that have no mass or

618
00:30:23,040 --> 00:30:26,760
Speaker 1: very very very low mass, precisely because then you can't

619
00:30:26,920 --> 00:30:29,440
Speaker 1: pass them in a spaceship. To be very technical, this

620
00:30:29,480 --> 00:30:32,760
Speaker 1: handedness is actually an internal label it's not a physical thing.

621
00:30:33,280 --> 00:30:35,360
Speaker 1: So the direction of the two arrows, it's like an

622
00:30:35,360 --> 00:30:38,240
Speaker 1: approximate way to think about the handedness of the particles.

623
00:30:38,400 --> 00:30:41,080
Speaker 1: But fundamentally it's some internal label we don't understand the

624
00:30:41,120 --> 00:30:44,000
Speaker 1: way like charge is. So now I just think about

625
00:30:44,040 --> 00:30:46,080
Speaker 1: these particles as having like a little label on them.

626
00:30:46,120 --> 00:30:47,600
Speaker 1: Some of them have an L and some of them

627
00:30:47,600 --> 00:30:49,560
Speaker 1: have an R. And we thought for a long time,

628
00:30:49,680 --> 00:30:52,200
Speaker 1: like the universe shouldn't predict either one, Like if you

629
00:30:52,280 --> 00:30:55,320
Speaker 1: have some particle physics process, it should make the same

630
00:30:55,400 --> 00:30:58,800
Speaker 1: number of right and left handed electrons in the early universe.

631
00:30:58,880 --> 00:31:00,880
Speaker 1: You should have gotten an equal mixture, right in the

632
00:31:00,880 --> 00:31:03,959
Speaker 1: same way we talked earlier about preferring symmetry. And then

633
00:31:04,000 --> 00:31:06,360
Speaker 1: it was in the nineteen sixties that people realized, hey,

634
00:31:06,800 --> 00:31:09,920
Speaker 1: you know, we think that the universe is balanced. We

635
00:31:10,000 --> 00:31:12,800
Speaker 1: think that there is a symmetry here, and we've checked

636
00:31:12,800 --> 00:31:15,000
Speaker 1: it for a couple of things, but nobody's actually gone

637
00:31:15,040 --> 00:31:17,640
Speaker 1: and done the test to see if the weak nuclear

638
00:31:17,680 --> 00:31:21,720
Speaker 1: force prefers left or right handed particles equally or not.

639
00:31:22,320 --> 00:31:24,120
Speaker 2: I'm just going to point out that the biologist had

640
00:31:24,160 --> 00:31:26,840
Speaker 2: figured out the importance of this one hundred years earlier. Apparently.

641
00:31:28,560 --> 00:31:30,560
Speaker 2: I'm glad you guys caught up though, So go ahead.

642
00:31:31,200 --> 00:31:33,840
Speaker 1: That's right. Physics is always one hundred years behind biology.

643
00:31:33,880 --> 00:31:38,360
Speaker 1: That's the way it works. So there was this exciting

644
00:31:38,400 --> 00:31:41,280
Speaker 1: moment in the late fifties where people realized, oh my gosh,

645
00:31:41,320 --> 00:31:45,080
Speaker 1: nobody's tested this before, and it's not actually that hard

646
00:31:45,120 --> 00:31:48,280
Speaker 1: to do. So then this amazing scientist, chan hin Wu

647
00:31:48,960 --> 00:31:53,120
Speaker 1: realized in the late fifties, actually this wasn't difficult to test.

648
00:31:53,680 --> 00:31:56,000
Speaker 1: This is something you could figure out. So she decided

649
00:31:56,040 --> 00:31:59,440
Speaker 1: to skip her Christmas holiday, she sent her husband on

650
00:31:59,480 --> 00:32:01,080
Speaker 1: along and say, I'm going to stay in the lab

651
00:32:01,080 --> 00:32:03,160
Speaker 1: and figure this out. You know when you get like

652
00:32:03,200 --> 00:32:06,480
Speaker 1: excited about something. And she put the experiment together. She

653
00:32:06,600 --> 00:32:08,960
Speaker 1: got a bunch of cobalt atoms to spin only in

654
00:32:09,000 --> 00:32:11,880
Speaker 1: one direction, and then she measured the angles that the

655
00:32:11,880 --> 00:32:14,520
Speaker 1: electrons came out. And this was a great test of

656
00:32:14,560 --> 00:32:17,840
Speaker 1: whether the universe preferred one direction or another because the

657
00:32:17,840 --> 00:32:20,320
Speaker 1: electrons were made purely by the weak force. And she

658
00:32:20,400 --> 00:32:23,040
Speaker 1: discovered not only was it out of balance, but it

659
00:32:23,120 --> 00:32:25,920
Speaker 1: was completely out of balance. It wasn't like the electrons

660
00:32:25,920 --> 00:32:28,520
Speaker 1: were fifty one forty nine one direction. It was like

661
00:32:28,560 --> 00:32:32,000
Speaker 1: one hundred zero, like the electrons would only go in

662
00:32:32,080 --> 00:32:35,280
Speaker 1: one direction. It turns out that the weak force only

663
00:32:35,320 --> 00:32:39,120
Speaker 1: makes and interacts with left handed particles. It like completely

664
00:32:39,200 --> 00:32:42,560
Speaker 1: doesn't play with right handed particles at all. So all

665
00:32:42,600 --> 00:32:46,840
Speaker 1: the other forces don't care. Electromagnetism, the strong force no preference,

666
00:32:46,840 --> 00:32:50,080
Speaker 1: but the weak force only plays with left handed particles.

667
00:32:50,400 --> 00:32:52,480
Speaker 1: This was a really shocking discovery.

668
00:32:52,640 --> 00:32:54,760
Speaker 2: And after the break we are going to one hundred

669
00:32:54,760 --> 00:33:14,680
Speaker 2: percent explain to you why that is. And we're back

670
00:33:14,880 --> 00:33:18,120
Speaker 2: just kidding. We never have one hundred percent explanations for anything.

671
00:33:18,280 --> 00:33:21,600
Speaker 2: What is our current state of not understanding this phenomenon, Danniel.

672
00:33:23,320 --> 00:33:25,880
Speaker 1: It's not something that we understand, it's something that we describe,

673
00:33:25,960 --> 00:33:28,920
Speaker 1: something we see in the universe. We can incorporate it

674
00:33:28,920 --> 00:33:32,120
Speaker 1: into the mathematics of our theory, like the standard model

675
00:33:32,160 --> 00:33:35,120
Speaker 1: of particle physics that describes how particles interact and how

676
00:33:35,120 --> 00:33:37,680
Speaker 1: they're created and all. This kind of stuff naturally has

677
00:33:37,760 --> 00:33:40,440
Speaker 1: left and right handed particles, and the mathematics of the

678
00:33:40,440 --> 00:33:44,200
Speaker 1: weak force allow it to only interact with left handed particles.

679
00:33:44,200 --> 00:33:46,840
Speaker 1: But again we don't know why that is. You know,

680
00:33:46,880 --> 00:33:50,320
Speaker 1: the other forces treat the particles completely equally, and the

681
00:33:50,400 --> 00:33:54,400
Speaker 1: Higgs force unifies these things, Like the Higgs force combines

682
00:33:54,720 --> 00:33:57,960
Speaker 1: the left handed and right handed version of particles into

683
00:33:58,040 --> 00:34:00,560
Speaker 1: one that we see and know and love and has mass.

684
00:34:00,760 --> 00:34:03,720
Speaker 2: Where does it get the right handed versions if it's

685
00:34:03,760 --> 00:34:05,920
Speaker 2: combining them. So it gets the right handed versions from

686
00:34:05,960 --> 00:34:08,160
Speaker 2: other forces and combines them.

687
00:34:08,320 --> 00:34:11,400
Speaker 1: Okay, yeah, so you can make right handed electrons. You

688
00:34:11,440 --> 00:34:13,279
Speaker 1: just can't use the weak force to do it. You

689
00:34:13,320 --> 00:34:16,000
Speaker 1: can use the electromagnetic force to make right handed electrons,

690
00:34:16,040 --> 00:34:19,359
Speaker 1: no problem. Oh, but those will not interact with W

691
00:34:19,520 --> 00:34:23,040
Speaker 1: bosons and z bosons and stuff like that. It's really weird.

692
00:34:23,120 --> 00:34:25,960
Speaker 1: And if we didn't have the weak force, we never

693
00:34:26,000 --> 00:34:29,400
Speaker 1: would have discovered that our universe for some reason, seems

694
00:34:29,440 --> 00:34:31,560
Speaker 1: to be left handed at a particle level.

695
00:34:31,800 --> 00:34:34,880
Speaker 2: If you were to like rank the forces in terms

696
00:34:34,880 --> 00:34:37,560
Speaker 2: of like how common they are in the universe, I

697
00:34:37,560 --> 00:34:39,239
Speaker 2: actually don't know the right way to rank these, Like

698
00:34:39,520 --> 00:34:41,000
Speaker 2: how important is the weak force?

699
00:34:42,719 --> 00:34:46,120
Speaker 1: Amazing question? Well, you know, the most powerful force is

700
00:34:46,160 --> 00:34:49,000
Speaker 1: a strong force, and then electromagnetism, then the weak force,

701
00:34:49,120 --> 00:34:51,880
Speaker 1: then gravity if it's a force at all. But the

702
00:34:51,880 --> 00:34:54,480
Speaker 1: weak force, in some way is so much more complex

703
00:34:54,520 --> 00:34:57,480
Speaker 1: and fascinating than any of the other forces. It's got

704
00:34:57,560 --> 00:35:01,319
Speaker 1: extra particles like it has the W and the Z particles,

705
00:35:01,640 --> 00:35:04,480
Speaker 1: all these particles needed to do its stuff, and it's

706
00:35:04,480 --> 00:35:08,240
Speaker 1: so much more complicated, and it's responsible for the Higgs boson.

707
00:35:08,840 --> 00:35:12,239
Speaker 1: So it's pretty important and weird, and in that sense

708
00:35:12,239 --> 00:35:14,800
Speaker 1: it's valuable because it gives us insight into the nature

709
00:35:14,840 --> 00:35:17,320
Speaker 1: of the universe. You know, it does. It's weird stuff.

710
00:35:17,320 --> 00:35:19,920
Speaker 1: If everything was simple and clean, that we wouldn't learn

711
00:35:19,960 --> 00:35:22,680
Speaker 1: as much about the universe. It's the ugly messes that

712
00:35:22,760 --> 00:35:25,520
Speaker 1: teach us something about how the universe is actually working.

713
00:35:25,719 --> 00:35:27,719
Speaker 2: I feel like that's a lesson for my life somehow.

714
00:35:27,760 --> 00:35:29,560
Speaker 2: But go ahead.

715
00:35:30,640 --> 00:35:32,799
Speaker 1: There's just such a shocking discovery that the theorist that

716
00:35:32,920 --> 00:35:35,719
Speaker 1: suggested it won the Nobel Prize, just like a couple

717
00:35:35,760 --> 00:35:39,200
Speaker 1: of years later. Unfortunately, chinchin Wu, who did the experiment,

718
00:35:39,520 --> 00:35:42,160
Speaker 1: she didn't get the Nobel Prize. Another example of the

719
00:35:42,160 --> 00:35:46,640
Speaker 1: Nobel not treating lady scientists equally. Unfortunately, there's an imbalance

720
00:35:46,680 --> 00:35:46,880
Speaker 1: for you.

721
00:35:47,360 --> 00:35:49,200
Speaker 2: Yeah, that sucks. She's still alive.

722
00:35:49,400 --> 00:35:51,400
Speaker 1: She is no longer alive, but we're gonna have a

723
00:35:51,400 --> 00:35:54,000
Speaker 1: whole episode about her next year, and we're going to

724
00:35:54,080 --> 00:35:56,440
Speaker 1: talk to her granddaughter, who I grew.

725
00:35:56,280 --> 00:35:58,960
Speaker 2: Up with Oh fantastic, all right, I'm looking forward to that.

726
00:35:59,320 --> 00:36:04,000
Speaker 2: So the weak force produces left handed electrons, and then

727
00:36:04,000 --> 00:36:07,319
Speaker 2: somehow we end up with left handed amino acids. Let's

728
00:36:07,320 --> 00:36:09,640
Speaker 2: talk about the intermediate scale there. How do we think

729
00:36:09,680 --> 00:36:14,240
Speaker 2: scale up between left handed electrons and left handed amino acids.

730
00:36:14,320 --> 00:36:17,400
Speaker 1: Yeah, we don't know. There's a lot of speculation because

731
00:36:17,440 --> 00:36:20,560
Speaker 1: this smells like a weird coincidence, Like, how is it

732
00:36:21,080 --> 00:36:24,440
Speaker 1: that the universe produces more left handed particles and right

733
00:36:24,480 --> 00:36:27,320
Speaker 1: handed particles and life is made out of left handed

734
00:36:27,480 --> 00:36:30,280
Speaker 1: amino acids? Is that a coincidence or is there a reason?

735
00:36:30,520 --> 00:36:34,600
Speaker 1: So there's a theory that particles from space when they

736
00:36:34,719 --> 00:36:38,280
Speaker 1: smash into the atmosphere cosmic rays, they produce a shower

737
00:36:38,280 --> 00:36:41,600
Speaker 1: of particles, and the weak force is involved, which means

738
00:36:41,640 --> 00:36:44,600
Speaker 1: that it makes more left handed particles than right handed particles.

739
00:36:45,239 --> 00:36:47,560
Speaker 1: And then dot dot dot a bunch of stuff that's

740
00:36:47,600 --> 00:36:50,920
Speaker 1: not really plausible. Maybe that makes more left handed amino acids.

741
00:36:51,120 --> 00:36:53,399
Speaker 1: And you know, there are papers I've read about this

742
00:36:53,520 --> 00:36:55,759
Speaker 1: and I always come away from them going like, I

743
00:36:55,800 --> 00:36:59,520
Speaker 1: don't think. So it's like a real effort to draw

744
00:36:59,560 --> 00:37:02,560
Speaker 1: a line between these things, because it's hard to imagine

745
00:37:02,560 --> 00:37:06,239
Speaker 1: how a left handed muon is going to somehow make

746
00:37:06,440 --> 00:37:09,960
Speaker 1: more amino acids that are left handed. Like, yes, the

747
00:37:10,080 --> 00:37:12,080
Speaker 1: muons come in and they smash into stuff, and there's

748
00:37:12,080 --> 00:37:14,840
Speaker 1: still an important part of life today, you know, breaking

749
00:37:14,880 --> 00:37:17,920
Speaker 1: amino acids and creating mutations and all sorts of stuff

750
00:37:18,080 --> 00:37:21,440
Speaker 1: is important for evolution. But we don't have a microphysical

751
00:37:21,480 --> 00:37:25,600
Speaker 1: explanation for why having more left handed muons could create

752
00:37:25,640 --> 00:37:28,120
Speaker 1: more left handed amino acids or encourage them to form

753
00:37:28,239 --> 00:37:31,759
Speaker 1: life or whatever make them more resilient. I don't know,

754
00:37:32,040 --> 00:37:34,480
Speaker 1: because the weak force is very, very weak. You know,

755
00:37:34,520 --> 00:37:36,520
Speaker 1: most of the time when a muon interacts with you,

756
00:37:36,640 --> 00:37:40,080
Speaker 1: it's interacts electromagnetically, so it would be a very subtle

757
00:37:40,120 --> 00:37:43,080
Speaker 1: effect if it even did exist. So really still an

758
00:37:43,080 --> 00:37:47,080
Speaker 1: open question. We don't understand whether there's any connection between

759
00:37:47,360 --> 00:37:50,960
Speaker 1: the fundamental left handed preference of the weak force and

760
00:37:51,040 --> 00:37:52,960
Speaker 1: the left handed nature of life on Earth.

761
00:37:53,320 --> 00:37:56,440
Speaker 2: Okay, so there's an important question that one of our

762
00:37:56,480 --> 00:37:59,799
Speaker 2: listeners can answer, one of our young listeners. Okay, so

763
00:38:00,000 --> 00:38:02,560
Speaker 2: we know we have handedness in some cases, we don't

764
00:38:02,640 --> 00:38:05,600
Speaker 2: know why we have it. We don't know the implications,

765
00:38:05,600 --> 00:38:10,560
Speaker 2: as you scale, is there important symmetry in other areas

766
00:38:10,560 --> 00:38:11,400
Speaker 2: that gets broken.

767
00:38:11,640 --> 00:38:14,120
Speaker 1: Yeah, so great question. This inspires us to look for

768
00:38:14,239 --> 00:38:17,000
Speaker 1: violations of symmetry elsewhere in the universe. Right, and we

769
00:38:17,080 --> 00:38:20,880
Speaker 1: know already that the universe isn't always in balance, like,

770
00:38:20,920 --> 00:38:23,319
Speaker 1: for example, we know that there are two different kinds

771
00:38:23,360 --> 00:38:27,120
Speaker 1: of matter in the universe, matter and antimatter. Antimatter is

772
00:38:27,160 --> 00:38:30,320
Speaker 1: like the reflection of matter, where everything has the opposite charge.

773
00:38:30,560 --> 00:38:33,160
Speaker 1: So we have electrons. We can also make positrons, which

774
00:38:33,160 --> 00:38:35,719
Speaker 1: are just like electrons, but they have the opposite charge.

775
00:38:35,920 --> 00:38:38,680
Speaker 1: And you can make anti protons and anti neutrons and

776
00:38:38,840 --> 00:38:42,000
Speaker 1: there's nothing really anti about them except that they're not

777
00:38:42,200 --> 00:38:45,359
Speaker 1: our kind of matter. So you know, you could we think,

778
00:38:45,520 --> 00:38:49,560
Speaker 1: maybe build life out of anti electrons and anti protons

779
00:38:49,560 --> 00:38:52,600
Speaker 1: to make anti people or whatever. We don't really know

780
00:38:52,680 --> 00:38:54,719
Speaker 1: that for sure, but the laws of physics so far

781
00:38:55,080 --> 00:38:58,160
Speaker 1: suggest that that's possible. But the universe has made more

782
00:38:58,200 --> 00:38:59,680
Speaker 1: of matter than antimatter.

783
00:39:00,000 --> 00:39:03,560
Speaker 2: I watched too many sci fi movies. I'm under the

784
00:39:03,560 --> 00:39:07,040
Speaker 2: impression that if matter and antimatter interact, they explode or

785
00:39:07,280 --> 00:39:09,880
Speaker 2: consume each other in some way, Like could both of

786
00:39:09,920 --> 00:39:11,839
Speaker 2: these things exist in the same universe? Or does one

787
00:39:11,880 --> 00:39:12,759
Speaker 2: have to win.

788
00:39:13,160 --> 00:39:16,600
Speaker 1: They can't exist near each other because they interact very strongly.

789
00:39:16,760 --> 00:39:18,520
Speaker 1: And so for example, if you have an electron and

790
00:39:18,520 --> 00:39:20,799
Speaker 1: apostles near each other, they will attract each other and

791
00:39:20,800 --> 00:39:23,520
Speaker 1: they will annihilate and give you photons. And it's a

792
00:39:23,640 --> 00:39:28,680
Speaker 1: very efficient conversion of energy from mass to radiation. So

793
00:39:28,800 --> 00:39:30,920
Speaker 1: for example, if you have a gram of matter like

794
00:39:30,960 --> 00:39:34,279
Speaker 1: a raisin and a gram of antimatter like an anti raasin,

795
00:39:34,320 --> 00:39:36,439
Speaker 1: and you bring them together, you get about as much

796
00:39:36,560 --> 00:39:39,480
Speaker 1: energy as a nuclear bomb just out of two grams

797
00:39:39,520 --> 00:39:42,800
Speaker 1: of matter and antimatter. So yes, you can't have matter

798
00:39:42,840 --> 00:39:45,880
Speaker 1: based life and antimatter based life on the same planet,

799
00:39:46,040 --> 00:39:51,319
Speaker 1: but you could have, for example, matter galaxies and antimatter galaxies. Right,

800
00:39:51,360 --> 00:39:53,200
Speaker 1: they don't have to touch each other. That is floating

801
00:39:53,239 --> 00:39:56,440
Speaker 1: in space saying hi. But we're pretty sure that all

802
00:39:56,480 --> 00:39:59,560
Speaker 1: the galaxies in the universe are matter galaxies, not anti

803
00:39:59,600 --> 00:40:02,239
Speaker 1: matter g galaxies. And we can actually test this a

804
00:40:02,239 --> 00:40:06,239
Speaker 1: little bit because galaxies shoot out particles. All the stars

805
00:40:06,280 --> 00:40:09,640
Speaker 1: and the black holes are emitting radiation and they shoot

806
00:40:09,640 --> 00:40:12,800
Speaker 1: out electrons for example, and if there were anti galaxies,

807
00:40:12,840 --> 00:40:16,439
Speaker 1: they would shoot out anti electrons and where those meet

808
00:40:16,520 --> 00:40:18,719
Speaker 1: you would see these great flashes of light where the

809
00:40:18,719 --> 00:40:21,120
Speaker 1: electrons and the anti electrons were meeting, and we don't

810
00:40:21,120 --> 00:40:23,760
Speaker 1: see any of that. We don't see like huge curtains

811
00:40:23,760 --> 00:40:26,600
Speaker 1: of light between galaxies, which suggests that at least as

812
00:40:26,640 --> 00:40:29,000
Speaker 1: far as we can see, everything is made of matter.

813
00:40:29,360 --> 00:40:32,839
Speaker 1: So that's an important asymmetry in the universe, again, one

814
00:40:32,880 --> 00:40:36,400
Speaker 1: we don't understand. We think probably in the Big Bang

815
00:40:36,880 --> 00:40:39,839
Speaker 1: there was an equal amount of matter and antimatter, but

816
00:40:40,000 --> 00:40:42,799
Speaker 1: something preferred matter because otherwise it would have all just

817
00:40:42,880 --> 00:40:45,839
Speaker 1: gone away and turned into a universe filled with light

818
00:40:46,000 --> 00:40:49,040
Speaker 1: and no matter. So there's a preference there for matter.

819
00:40:49,080 --> 00:40:51,080
Speaker 1: It's just an example. We don't know that it's connected

820
00:40:51,080 --> 00:40:53,920
Speaker 1: to right or left handed. We call one matter and

821
00:40:53,960 --> 00:40:56,440
Speaker 1: the other antimatter. It's just an example of how the

822
00:40:56,560 --> 00:40:59,759
Speaker 1: universe sometimes seems to make one choice and not the

823
00:40:59,760 --> 00:41:01,840
Speaker 1: other for reasons we don't understand.

824
00:41:02,000 --> 00:41:03,560
Speaker 2: All right, Well, so first of all, I think it's

825
00:41:03,600 --> 00:41:06,160
Speaker 2: important to note that I'm on team anti Raisin.

826
00:41:07,840 --> 00:41:10,080
Speaker 1: That you like the golden raisins instead, I don't like

827
00:41:10,120 --> 00:41:10,840
Speaker 1: any raisins.

828
00:41:10,840 --> 00:41:14,399
Speaker 2: No raisins, no raisin. Okay, yeah, team anti Razin.

829
00:41:14,560 --> 00:41:16,400
Speaker 1: But how do you feel about grapes? You like grapes

830
00:41:16,440 --> 00:41:17,120
Speaker 1: but no raisins.

831
00:41:17,280 --> 00:41:19,000
Speaker 2: I'm pro grapes really interesting.

832
00:41:19,000 --> 00:41:20,800
Speaker 1: Are you anti dried fruit in general? No?

833
00:41:21,040 --> 00:41:22,439
Speaker 2: Dried mangoes? Those are great?

834
00:41:22,560 --> 00:41:24,080
Speaker 1: Oh man, we got to convert you.

835
00:41:24,400 --> 00:41:26,240
Speaker 2: This is really really important.

836
00:41:26,400 --> 00:41:28,800
Speaker 1: Is it just because you think raises ruined oatmeal cookies?

837
00:41:28,840 --> 00:41:29,920
Speaker 1: Because you'd be right about that.

838
00:41:30,160 --> 00:41:32,760
Speaker 2: Yeah, that's like ninety percent of why I have trust issues.

839
00:41:35,640 --> 00:41:37,560
Speaker 2: So the Big Bang had to have resulted in a

840
00:41:37,560 --> 00:41:39,520
Speaker 2: preference for one or the other, right, because otherwise it

841
00:41:39,520 --> 00:41:42,360
Speaker 2: would have all just like blown up at that point

842
00:41:42,360 --> 00:41:43,520
Speaker 2: when it was all compressed.

843
00:41:43,719 --> 00:41:47,800
Speaker 1: Well, either more matter was made in those early moments

844
00:41:47,960 --> 00:41:51,120
Speaker 1: than anti matter, and then when they annihilated, you get

845
00:41:51,120 --> 00:41:53,800
Speaker 1: the massive matter left over. So either there's some early

846
00:41:53,920 --> 00:41:57,160
Speaker 1: baked in preference for matter over antimatter, or it was

847
00:41:57,160 --> 00:41:59,960
Speaker 1: symmetric at the beginning and there's some process which then

848
00:42:00,120 --> 00:42:03,400
Speaker 1: prefers matter to antimatter. And we have a few clues.

849
00:42:03,440 --> 00:42:06,600
Speaker 1: We've discovered one or two little processes that prefer making

850
00:42:06,680 --> 00:42:09,680
Speaker 1: matter to antimatter, and that was sort of fascinating and

851
00:42:09,719 --> 00:42:12,319
Speaker 1: surprising and let to more Nobel prizes. These things are

852
00:42:12,360 --> 00:42:15,279
Speaker 1: called CP violation if anybody wants to dig deeper into them,

853
00:42:15,520 --> 00:42:17,720
Speaker 1: But they're not enough to explain it. They're like tiny

854
00:42:17,760 --> 00:42:20,160
Speaker 1: little effects. It can't explain the size to the effect

855
00:42:20,200 --> 00:42:22,560
Speaker 1: that we see in the universe. So this basic question,

856
00:42:22,680 --> 00:42:25,040
Speaker 1: this asymmetry in the universe, we still don't have an

857
00:42:25,080 --> 00:42:27,279
Speaker 1: answer to. But just to be clear again, it's not

858
00:42:27,680 --> 00:42:31,719
Speaker 1: directly connected to left handed versus right handed whether the

859
00:42:31,800 --> 00:42:34,520
Speaker 1: universe is symmetric. It's just whether the universe is symmetric

860
00:42:34,600 --> 00:42:37,000
Speaker 1: in a mirror. It's just another example of how the

861
00:42:37,080 --> 00:42:40,160
Speaker 1: universe doesn't have to be balanced right. It can pick

862
00:42:40,200 --> 00:42:42,279
Speaker 1: one or the other, we think, and we just don't

863
00:42:42,320 --> 00:42:45,359
Speaker 1: understand why it does or whether it did. But we

864
00:42:45,400 --> 00:42:47,560
Speaker 1: can think about whether the universe and the Big Bang

865
00:42:47,600 --> 00:42:51,080
Speaker 1: itself was symmetric from a left versus right handed point

866
00:42:51,080 --> 00:42:54,920
Speaker 1: of view, Like when we talk about making those three vectors,

867
00:42:54,960 --> 00:42:57,080
Speaker 1: is there something in the universe that really prefers those

868
00:42:57,480 --> 00:43:00,399
Speaker 1: fundamentally at the level of the structure of the universe self,

869
00:43:00,880 --> 00:43:04,320
Speaker 1: not just the particles or the amino acids or dogs

870
00:43:04,400 --> 00:43:06,439
Speaker 1: or this kind of stuff. And we can think about

871
00:43:06,440 --> 00:43:10,319
Speaker 1: this by looking at the relationships between galaxies. There's this

872
00:43:10,600 --> 00:43:14,120
Speaker 1: really amazing study people did last year where they basically

873
00:43:14,160 --> 00:43:17,880
Speaker 1: just looked at groups of four galaxies and decided whether

874
00:43:18,080 --> 00:43:20,680
Speaker 1: they would call them left handed or right handed. So

875
00:43:20,680 --> 00:43:23,560
Speaker 1: remember the example of your fingers, right, you have three fingers,

876
00:43:24,200 --> 00:43:27,080
Speaker 1: so three tips, and there's also the point where they

877
00:43:27,080 --> 00:43:29,920
Speaker 1: all meet, so you have sort of like four points there.

878
00:43:30,360 --> 00:43:32,520
Speaker 1: So if you have four points, you can say is

879
00:43:32,560 --> 00:43:36,439
Speaker 1: this a left handed grouping or right handed grouping? So

880
00:43:36,560 --> 00:43:39,080
Speaker 1: they looked at all the galaxies that they could find

881
00:43:39,239 --> 00:43:42,200
Speaker 1: over a million examples in this one study, and they

882
00:43:42,280 --> 00:43:45,480
Speaker 1: grouped them into clusters of four and then decided is

883
00:43:45,520 --> 00:43:48,319
Speaker 1: this a left handed grouping or right handed grouping? And

884
00:43:48,360 --> 00:43:51,560
Speaker 1: they figured like, hey, this is just galaxies strewn out

885
00:43:51,560 --> 00:43:54,520
Speaker 1: in the universe. We're just assigning left or right handed

886
00:43:54,560 --> 00:43:57,280
Speaker 1: to these clusters. It should be balanced, right, There should

887
00:43:57,280 --> 00:43:59,959
Speaker 1: be no reason why you would get like more right

888
00:44:00,040 --> 00:44:03,920
Speaker 1: handed or left handed clusters. But what they found is

889
00:44:04,040 --> 00:44:09,120
Speaker 1: a huge bias towards left handed clusters of galaxies when

890
00:44:09,160 --> 00:44:11,480
Speaker 1: you group these things together. I know, it makes no sense,

891
00:44:11,560 --> 00:44:14,400
Speaker 1: like why would you prefer one or the other, But

892
00:44:14,719 --> 00:44:17,120
Speaker 1: you know, they had groups check their results. This is

893
00:44:17,160 --> 00:44:19,560
Speaker 1: the kind of result you sort of hope for in science,

894
00:44:19,600 --> 00:44:21,400
Speaker 1: but then you're terrified of because then you're like, what,

895
00:44:21,680 --> 00:44:23,480
Speaker 1: this has got to be wrong. This has been delay

896
00:44:23,560 --> 00:44:24,080
Speaker 1: my paper.

897
00:44:24,080 --> 00:44:26,960
Speaker 2: Oh my gosh, did I pick the galaxies arbitrarily? I

898
00:44:27,000 --> 00:44:28,560
Speaker 2: feel like that it would have to be a hard

899
00:44:28,880 --> 00:44:29,680
Speaker 2: hard to pick them.

900
00:44:29,760 --> 00:44:32,719
Speaker 1: Yeah, exactly where they tried every combination, and out of

901
00:44:32,760 --> 00:44:37,080
Speaker 1: a million galaxies you get a trillion trillion combinations. They

902
00:44:37,120 --> 00:44:40,960
Speaker 1: make these pyramids, right, like four galaxies make this pyramid,

903
00:44:41,360 --> 00:44:43,120
Speaker 1: and you can decide whether it's a left or right

904
00:44:43,120 --> 00:44:46,680
Speaker 1: handed pyramid. And the chances of this being a random

905
00:44:46,680 --> 00:44:51,759
Speaker 1: fluctuation is one in three hundred billion. So either it's

906
00:44:51,800 --> 00:44:57,240
Speaker 1: a crazy fluctuation, or it suggests that there's something about

907
00:44:57,280 --> 00:45:01,279
Speaker 1: the universe, something about the topology, structure, the nature of

908
00:45:01,320 --> 00:45:05,080
Speaker 1: space and time itself that aligns these galaxies in a

909
00:45:05,120 --> 00:45:08,040
Speaker 1: more lefty way than a right handed way. It's really

910
00:45:08,080 --> 00:45:11,520
Speaker 1: a fascinating clue. And it's just like adds to the story,

911
00:45:11,600 --> 00:45:15,080
Speaker 1: like life is left handed, particles are left handed, something

912
00:45:15,120 --> 00:45:17,880
Speaker 1: about the structure of galaxies in the universe itself is

913
00:45:17,960 --> 00:45:18,560
Speaker 1: left handed.

914
00:45:18,719 --> 00:45:20,279
Speaker 2: No wonder Zach thinks he's so great.

915
00:45:21,120 --> 00:45:23,600
Speaker 1: It turns out he's right. Science has proved him right.

916
00:45:25,080 --> 00:45:27,520
Speaker 2: There's got to be something we don't understand in between there.

917
00:45:27,480 --> 00:45:31,160
Speaker 1: All right, reviewer number two over there, So this is

918
00:45:31,320 --> 00:45:34,800
Speaker 1: just like a collection of clues that all point towards

919
00:45:34,840 --> 00:45:38,880
Speaker 1: something that smells suggestive. But it could just be nothing.

920
00:45:39,400 --> 00:45:41,920
Speaker 1: It could just be here's a bunch of coincidences, you know,

921
00:45:42,040 --> 00:45:45,360
Speaker 1: left versus right. Whatever the universe just picks randomly. And

922
00:45:45,400 --> 00:45:48,320
Speaker 1: we live in a multiverse with all different kinds of universes,

923
00:45:48,360 --> 00:45:50,480
Speaker 1: and some of them have right handed life and right

924
00:45:50,480 --> 00:45:56,000
Speaker 1: handed particles and left handed galaxy structures. Or maybe there's

925
00:45:56,000 --> 00:46:00,480
Speaker 1: something deep in the mathematics which really prefers left handed

926
00:46:00,520 --> 00:46:03,880
Speaker 1: structures and can only work this way, and just we

927
00:46:03,960 --> 00:46:06,359
Speaker 1: haven't puzzled it out yet. We haven't found the connections

928
00:46:06,400 --> 00:46:10,799
Speaker 1: between these different layers of leftiness, and we haven't understood

929
00:46:10,960 --> 00:46:13,440
Speaker 1: what about the nature of the universe requires things to

930
00:46:13,440 --> 00:46:16,040
Speaker 1: be left handed. It's a fascinating puzzle and the kind

931
00:46:16,040 --> 00:46:18,400
Speaker 1: of thing I think in one hundred years, I hope

932
00:46:18,440 --> 00:46:19,839
Speaker 1: we have much more clarity on.

933
00:46:20,000 --> 00:46:22,359
Speaker 2: Are we currently at the just like scratching our head

934
00:46:22,400 --> 00:46:24,279
Speaker 2: and pulling out our hair phase, or are they're like

935
00:46:24,800 --> 00:46:28,480
Speaker 2: four competing hypotheses and we're just waiting for the LHC

936
00:46:28,640 --> 00:46:30,960
Speaker 2: to give us the answer, Like where are we right now?

937
00:46:31,200 --> 00:46:33,920
Speaker 1: I think we're in between those two different outcomes. We

938
00:46:34,040 --> 00:46:38,200
Speaker 1: have some crazy ideas, like people think maybe the thing

939
00:46:38,280 --> 00:46:42,680
Speaker 1: that came before that early moment of hot density, you know,

940
00:46:42,760 --> 00:46:45,600
Speaker 1: the inflation and the infloton field and sort of pre

941
00:46:45,719 --> 00:46:49,520
Speaker 1: Big Bang theories and everything that's pre Big bang very speculative,

942
00:46:49,680 --> 00:46:52,399
Speaker 1: and that doesn't mean worthless, right, it just means like, hey,

943
00:46:52,400 --> 00:46:54,440
Speaker 1: we don't really know. We're still in the building phase.

944
00:46:54,480 --> 00:46:58,120
Speaker 1: We're trying stuff out some of those Maybe we're seated

945
00:46:58,200 --> 00:47:02,080
Speaker 1: by something that prefers handedness, and people are trying to

946
00:47:02,080 --> 00:47:07,080
Speaker 1: build left handed ideas into that infloton field with varying success.

947
00:47:07,440 --> 00:47:09,960
Speaker 1: So we don't have solid predictions that we can use

948
00:47:10,280 --> 00:47:12,480
Speaker 1: to test any of these ideas. We're just sort of like,

949
00:47:12,920 --> 00:47:15,040
Speaker 1: maybe this is something, and maybe this is something we

950
00:47:15,040 --> 00:47:17,600
Speaker 1: should be building into our theories of the pre Big

951
00:47:17,640 --> 00:47:21,279
Speaker 1: Bang universe. We can try to look deeper into the

952
00:47:21,320 --> 00:47:24,000
Speaker 1: history of time to try to understand it, Like we

953
00:47:24,200 --> 00:47:28,480
Speaker 1: hope that gravitational waves from the very very early universe

954
00:47:28,760 --> 00:47:31,160
Speaker 1: will help illuminate what was going on. You know, we

955
00:47:31,160 --> 00:47:34,359
Speaker 1: can only see the early universe back to about three

956
00:47:34,440 --> 00:47:37,560
Speaker 1: hundred and eighty thousand years after that first understood moment

957
00:47:38,000 --> 00:47:41,080
Speaker 1: because that's the first time the universe was transparent, but

958
00:47:41,120 --> 00:47:43,040
Speaker 1: there's a lot of stuff going on before the universe

959
00:47:43,080 --> 00:47:46,160
Speaker 1: was transparent, when it's hot and dense and opaque, and

960
00:47:46,320 --> 00:47:49,040
Speaker 1: we hope that gravitational waves will give us a window

961
00:47:49,200 --> 00:47:52,279
Speaker 1: into those moments and maybe this can clue there and

962
00:47:52,360 --> 00:47:55,680
Speaker 1: the polarity of those gravitational waves to see if they

963
00:47:55,719 --> 00:47:58,800
Speaker 1: prefer left handed physics to right handed physics, or maybe

964
00:47:58,800 --> 00:48:02,200
Speaker 1: not right maybe they are perfectly in balance. So this

965
00:48:02,400 --> 00:48:05,960
Speaker 1: possibility that we could learn something, but that's very subtle physics,

966
00:48:06,000 --> 00:48:09,000
Speaker 1: and seeing gravitational waves from the very early univers is

967
00:48:09,080 --> 00:48:12,279
Speaker 1: notoriously tricky. There was an experiment by step two a

968
00:48:12,280 --> 00:48:14,319
Speaker 1: few years ago that thought it had seen them and

969
00:48:14,400 --> 00:48:16,799
Speaker 1: had evidence for inflation. Then it turned out to just

970
00:48:16,840 --> 00:48:17,280
Speaker 1: be dust.

971
00:48:17,480 --> 00:48:18,080
Speaker 3: Yeah.

972
00:48:18,160 --> 00:48:21,120
Speaker 2: Yeah, Oh, that's frustrating. It's always pigeon.

973
00:48:20,840 --> 00:48:26,680
Speaker 1: Poop or dust exactly. Science is hard, people, it's hard,

974
00:48:27,760 --> 00:48:30,919
Speaker 1: it is, but the mysteries are deep and they are fascinating,

975
00:48:30,960 --> 00:48:33,560
Speaker 1: and all of these clues tell us like, maybe this

976
00:48:33,600 --> 00:48:35,160
Speaker 1: is a thread we should pull on that's going to

977
00:48:35,239 --> 00:48:38,480
Speaker 1: unravel our whole understanding of the universe, or maybe it's

978
00:48:38,480 --> 00:48:40,560
Speaker 1: just a coin toss in beginning of the universe and

979
00:48:40,600 --> 00:48:42,320
Speaker 1: it means nothing, and people.

980
00:48:42,040 --> 00:48:44,239
Speaker 2: Will spend entire careers trying to figure it.

981
00:48:44,160 --> 00:48:46,680
Speaker 1: Out, and maybe one of you out there will be

982
00:48:46,680 --> 00:48:49,239
Speaker 1: the one to pull back the veil and help us

983
00:48:49,280 --> 00:48:51,200
Speaker 1: understand the nature of our own universe.

984
00:48:51,760 --> 00:48:52,440
Speaker 2: Please do that.

985
00:48:53,680 --> 00:48:56,200
Speaker 1: Soon, Please soon. I'd love to know the answer.

986
00:48:56,920 --> 00:48:57,120
Speaker 3: Yeah.

987
00:48:57,320 --> 00:49:08,280
Speaker 2: Same. Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio.

988
00:49:08,480 --> 00:49:11,000
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989
00:49:11,200 --> 00:49:13,920
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990
00:49:14,120 --> 00:49:15,800
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991
00:49:16,000 --> 00:49:18,960
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992
00:49:19,040 --> 00:49:22,120
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993
00:49:22,160 --> 00:49:22,359
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994
00:49:22,560 --> 00:49:26,080
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995
00:49:26,120 --> 00:49:29,160
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996
00:49:28,400 --> 00:49:30,440
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997
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998
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999
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1000
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