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Speaker 1: Hey, Daniel, is there still more stuff to discover out

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Speaker 1: there in space? Oh?

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Speaker 2: My gosh, so much more stuff. Are you looking forward

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Speaker 2: to some more new discoveries?

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Speaker 1: Well, I just kind of hope I'm not too.

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Speaker 2: Late, too late for what?

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Speaker 1: What do you mean, too late to get to name

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Speaker 1: one of these crazy things?

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Speaker 2: Do you have a particularly good idea for a name?

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Speaker 1: Well, I feel like scientists needs some new material like quasar, pulsar, blazar, masar, magnetar.

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Speaker 1: We need a new direction, we need some freshness.

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Speaker 2: All right, I'm terrified to hear what you have in mind.

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Speaker 1: I was thinking something like the Katie Orb. That has

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Speaker 1: a nice ring to it.

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Speaker 2: Right, all right, I'll send that in. But are you

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Speaker 2: as sured that's what you want? I mean, what if

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Speaker 2: we discover something gross, like a planet made of slime

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Speaker 2: and it gets called the Katie Orb?

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Speaker 1: Daniel, I would be honored.

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Speaker 2: Be careful what you wish for. Hi. I'm Daniel, I'm

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Speaker 2: a particle physicist and a professor at UC Irvine, and

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Speaker 2: I do want to discover a planet made of slime.

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Speaker 1: I am Katie Golden. I'm stepping in for Jorge. I

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Speaker 1: typically do a podcast on animals, but I love talking

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Speaker 1: about planets because they're kind of like big animals, but

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Speaker 1: round and.

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Speaker 2: Weird planets out there might have weird animals on it. Right.

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Speaker 2: Have you thought about starting a podcast on exozoology?

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Speaker 1: I feel like I would need a pretty good spaceship first,

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Speaker 1: and recording equipment that could span quite a bit of

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Speaker 1: broadcast distance.

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Speaker 2: Well, I'm sure as soon as we discover planets filled

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Speaker 2: with slime and the creatures swimming around in them named

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Speaker 2: the Katie Orb, of course somebody will jump on the

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Speaker 2: podcast opportunity a podcast all about these weird, slimy aliens.

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Speaker 1: It'll just be called a blobcast.

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Speaker 2: The slime Cast. Well, welcome to our podcast, Daniel and

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Speaker 2: Jorge Explain the Universe, a production of iHeartRadio, in which

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Speaker 2: we cast our minds out into the universe to think

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Speaker 2: about planets made of slime, planets made of diamonds, planets

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Speaker 2: made of all sorts of weird things, to wonder about

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Speaker 2: whether there are planets out there like ours, or whether

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Speaker 2: our planet is weird and unusual. We think about all

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Speaker 2: the strange stuff that's out there in the universe and

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Speaker 2: all the strange stuff we find here on Earth. The

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Speaker 2: quantum particles, frothing up between our toes all the way

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Speaker 2: up to the hearts of galaxies and the mammoth black

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Speaker 2: holes that live in them. We try to understand the

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Speaker 2: entire universe and explain it all to you while keeping

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Speaker 2: you laughing.

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Speaker 1: All right, I'm ready to learn about the entire universe

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Speaker 1: in about an hour.

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Speaker 2: My usual friend and co host Orge can't be here,

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Speaker 2: but we are very happy to have Katie along for

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Speaker 2: the ride to learn about weird stuff in outer space.

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Speaker 1: I love weird stuff in outer space. I always like

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Speaker 1: to imagine there's some kind of giant space whale out

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Speaker 1: there making its way slowly towards us.

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Speaker 2: See. I knew you think about the universe and space

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Speaker 2: in terms of critters, right Who is out there? Who

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Speaker 2: is swimming through space? Who is jumping through an ocean

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Speaker 2: of slime?

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Speaker 1: It's hard not to anthropomorphize the universe otherwise it feels

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Speaker 1: very lonely. So I like to think that there's stuff

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Speaker 1: out there wriggling and slimming it up, and when you meet.

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Speaker 2: These space wheels, you're going to give them like a

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Speaker 2: nice slimy hug.

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Speaker 1: Exactly.

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Speaker 2: Well, there is something fascinating about space and the universe

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Speaker 2: because it's such a vast frontier. We are trapped here

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Speaker 2: on this tiny little planet, looking up at the sky,

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Speaker 2: wondering about what's out there in space, and knowing that

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Speaker 2: it is chok full of discoveries waiting to be made.

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Speaker 2: Every time we look up at the sky and invent

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Speaker 2: some new kind of eyeball for peering further out, or

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Speaker 2: hearing in a new frequency, or listening to a new

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Speaker 2: kind of particle, we always find something shocking, something weird,

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Speaker 2: something unexpected. Because space really is the final frontier. It's

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Speaker 2: a place to explore and to discover and to learn

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Speaker 2: what's out there in the universe, which of course is

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Speaker 2: the first step to understanding it.

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Speaker 1: I do think it's an interesting way to look at things,

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Speaker 1: because there's this feeling sometimes I get of, well, science

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Speaker 1: has progressed pretty far, what more do we really have

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Speaker 1: to discover? But then when you try to think about

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Speaker 1: all of these unknown things about the universe, it becomes

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Speaker 1: pretty apparent that we know actually very little about the universe.

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Speaker 1: Our understanding of the universe is very it is a

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Speaker 1: fraction of what is actually out there.

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Speaker 2: Absolutely, we know very little about how the universe works,

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Speaker 2: and part of that is because we have seen very

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Speaker 2: little of the universe. We have not significantly left the

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Speaker 2: Earth or its neighborhood. Right. Everything we have learned about

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Speaker 2: the way that stars form and galaxies come together in

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Speaker 2: the history of the universe, and dark matter and all

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Speaker 2: these big mysteries have come just from observing the universe

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Speaker 2: from Earth, which means we're limited to capturing photons and

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Speaker 2: other particles that happen to make their way to Earth.

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Speaker 2: And because things are very very far away, a lot

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Speaker 2: of the stuff gets missed. So if you think about

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Speaker 2: like the fraction of the Milky Way that we have

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Speaker 2: studied in detail, it's a tiny little tea spoon of

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Speaker 2: all the stuff that's out there. And the most interesting stuff,

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Speaker 2: of course, is the weird stuff, the rare stuff. So

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Speaker 2: as we continue to build our capabilities and develop new

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Speaker 2: techniques for looking out into the universe, we're going they

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Speaker 2: keep stumbling over weird cases, things that we thought were

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Speaker 2: impossible or that we never imagine we're out there in

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Speaker 2: the universe. Take an analogy from particle physics about learning

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Speaker 2: things from rare examples. When we smash protons together, we

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Speaker 2: make Higgs bosons sometimes but not very often. It takes

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Speaker 2: like trillions of collisions to make one Higgs boson. So

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Speaker 2: now apply that to astronomy. How many stars do you

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Speaker 2: have to look at until you find that one that

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Speaker 2: reveals something deep and true about the universe.

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Speaker 1: I think that's also very unique because in a lot

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Speaker 1: of science, the key is looking at things that are replicable,

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Speaker 1: things that happen commonly, and it's not so much looking

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Speaker 1: at the extreme extraordinary cases. But I love that when

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Speaker 1: we look at the universe and the science of the universe,

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Speaker 1: like looking at these extreme cases can teach us so

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Speaker 1: much about the universe in general.

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Speaker 2: Absolutely, And one really valuable clue we have when we

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Speaker 2: look at the night sky is how it changes. And

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Speaker 2: humans have been doing this for thousands of years, the Mayans,

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Speaker 2: the Chinese, the Indians, the Greeks, the even the Babylonians.

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Speaker 2: We're looking up at the sky and noticing, of course

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Speaker 2: how it changes with the seasons, and learning from changes

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Speaker 2: in the sky, how things worked out there, how the

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Speaker 2: planets remove mo and all this kind of stuff. And

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Speaker 2: modern astronomy does the same thing. We look at the

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Speaker 2: night sky and we look for things changing, because things

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Speaker 2: changing are clues, their hints. When the star explodes, you

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Speaker 2: have an incredible opportunity to learn something about the life

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Speaker 2: cycle of a star, or if a new star appears.

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Speaker 2: Anything that's flickering or changing in the night sky is

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Speaker 2: literally sending you a message that something exciting is going on.

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Speaker 1: The night sky. It's interesting because it has this feeling

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Speaker 1: of something permanent, right, Yes, it does. As we rotate

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Speaker 1: around the Sun and as we spin on our own axis,

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Speaker 1: the sky also will change. But the idea that there

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Speaker 1: are actual changes happening to the stars in the sky,

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Speaker 1: I think it's something that is somewhat unexpected, right because

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Speaker 1: you look at the sky and you think, like, well,

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Speaker 1: sky's going to be the same, those stars are going

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Speaker 1: to be their stars are permanent, but they're not. They

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Speaker 1: can have their own lifespan. And then sometimes we're lucky

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Speaker 1: enough to actually see changes in the stars themselves during

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Speaker 1: their lifespans exactly.

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Speaker 2: And it's a really important clue about the nature of

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Speaker 2: deep time. It gives us this different perspective. We know

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Speaker 2: actually that the universe is quite chaotic and quite dynamic.

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Speaker 2: You know, even our Solar system. The planets move in

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Speaker 2: and out and migrate. We used to have another big

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Speaker 2: planet that got ejected when Saturn and Jupiter came into

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Speaker 2: the Inner Solar System and then went back out to

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Speaker 2: where we find them. Now we know that the whole

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Speaker 2: galaxy is histories of collisions with other galaxies. Everything is changing,

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Speaker 2: it's just doing it on a much, much, much longer timescale.

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Speaker 2: And we are used to thinking about not seconds, not minutes,

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Speaker 2: not days, not hundreds of years, but sometimes millions of years.

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Speaker 2: So when we are lucky enough to see something change

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Speaker 2: in the night sky, we're looking at a very rare moment,

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Speaker 2: a transition between periods that might last millions of years.

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Speaker 2: So thinking about the night sky changing is really fun

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Speaker 2: because it helps you get that deep time perspective to

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Speaker 2: realize that the universe looks very different when you found forward.

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Speaker 1: So when you say that these things take a lot

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Speaker 1: of time, are most of these changes very slow or

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Speaker 1: are there certain changes with stars that we can actually

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Speaker 1: see happening in real time, like an explosion or something

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Speaker 1: seems like it might actually be something that you see

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Speaker 1: over the course of minutes or hours or days. So

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Speaker 1: do we actually get to see things that happen rapidly

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Speaker 1: even though it took you know, an unfathomable amount of

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Speaker 1: time to get to that point.

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Speaker 2: Yeah, we do. Sometimes it's really exciting. There are things

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Speaker 2: like supernova that happen over minutes or days or months,

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Speaker 2: and you can actually find records of these. In ancient astronomy,

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Speaker 2: the Chinese were keeping track of what they called guest stars,

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Speaker 2: which are comments, and supernova's all the way back to

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Speaker 2: you know, a thousand BC. It's really incredible how long

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Speaker 2: their records go back. And so these are the moments

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Speaker 2: when we can really learn something about the night sky,

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Speaker 2: things that do happen on our time scale. Things we

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Speaker 2: can observe change in minutes or hours or even months,

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Speaker 2: and so that's a really fascinating opportunity to learn something

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Speaker 2: about the night sky. And today that's exactly what we're

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Speaker 2: going to talk about. An accidental discovery by an undergraduate

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Speaker 2: student of something very weird in the night sky, something

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Speaker 2: different from anything we have ever seen before.

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Speaker 1: Flying slime monster visitor.

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Speaker 2: From the Katie Orb. Today on the podcast, we'll be

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Speaker 2: asking the question, what's the weird thing in space that's

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Speaker 2: pulsing every twenty minutes.

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Speaker 1: You're telling me this isn't about a giant slime monster.

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Speaker 2: Though I'm saying, we don't know, I'm not ruling it out.

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Speaker 2: You know, maybe there is a giant slime monster out

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Speaker 2: there that burps every twenty minutes, and that's going to

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Speaker 2: be the answer, right. That's the joy of science is

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Speaker 2: not knowing the answer going in. So this is a

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Speaker 2: fairly recent result and one that astronomers have been puzzling over.

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Speaker 2: And if you listeners sent it to me and said,

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Speaker 2: what's going going on here? Can you explain it? And

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Speaker 2: I love digging into recent science discoveries to help people

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Speaker 2: understand the context of them, what we've learned, what really

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Speaker 2: is mysterious about it, and what the various possible explanations are.

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Speaker 2: And this one's especially fun because we get to talk

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Speaker 2: about all the things in the sky that pulse. But

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Speaker 2: before we dig in, of course, I wanted to know

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Speaker 2: if people already had heard about this and had ideas

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Speaker 2: for what might be pulsing in the sky every twenty minutes.

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Speaker 2: So thank you very much to our group of volunteers

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Speaker 2: who answer these questions. If you would like to join them,

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Speaker 2: please don't be shy. Everybody is welcome. Just write to

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Speaker 2: me too questions at Danielandjorge dot com. You can record

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Speaker 2: the answers in the privacy of your own living room

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Speaker 2: and then just delete them before sending to me if

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Speaker 2: you don't like so, think about it for a moment

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Speaker 2: before you hear these answers. Do you know what kind

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Speaker 2: of things in the sky can pulse every twenty minutes?

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Speaker 2: Here's what people had to say.

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Speaker 3: What pulses every twenty minutes? It can't be a pulsar,

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Speaker 3: because that's way too easy of a question for you guys.

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Speaker 3: But I believe that there's a heavenly body out there

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Speaker 3: that is producing a radio wave every eighty six seconds,

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Speaker 3: which I seem to believe is about twenty minutes, And

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Speaker 3: it was the little Green Man signal.

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Speaker 2: What object pulses every twenty minutes?

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Speaker 4: Well, I believe that pulsars pulse much more rapidly than that,

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Speaker 4: so I'm going I guessed, and might be something more

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Speaker 4: like a quasar. Pulsing makes me think of pulsars, so

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Speaker 4: spinning neutron stars, that's my guess. But I feel that

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Speaker 4: they can pulse they pose much faster than that, so

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Speaker 4: I'm not sure it.

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Speaker 3: Is a pulsar that blips every time. Jeff Basos earns

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Speaker 3: one million.

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Speaker 1: Dollars, so I'm somewhat surprised that only one person mentioned

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Speaker 1: the idea of this being like the doings of aliens

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Speaker 1: or the handiwork of some organical life form.

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Speaker 2: Well, that's interesting. Is organic life typically that regular? I mean,

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Speaker 2: I know that humans can sense signals that pulse very

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Speaker 2: regularly because it's part of our sort of like digital

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Speaker 2: technological civilization. But are there examples in nature of things

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Speaker 2: that like pulse very regularly every twenty minutes?

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Speaker 1: Well, maybe not every twenty minutes, although there are some

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Speaker 1: animals that have very slow rates of this. But our

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Speaker 1: heart beats or something that makes me think of something

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Speaker 1: with a very regular pulsating mechanism. But yeah, something that

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Speaker 1: pulsates with this sort of regularity does actually make me

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Speaker 1: think of biological processes. They may not be exact down

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Speaker 1: to the nanosecond, but there are a lot of biological

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Speaker 1: processes where you have a sort of pulsing I'm not

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Speaker 1: sure what animal would have a heartbeat that is once

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Speaker 1: every twenty minutes, but some animals can slow down their

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Speaker 1: heart rates quite a bit when they go into a

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Speaker 1: sort of a state of torpore.

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Speaker 2: Well, isn't heart rate connected to body mass like the

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Speaker 2: larger you are, the slower your heart rate.

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Speaker 1: Generally speaking, it can also be dependent on your metabolism.

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Speaker 1: So like a small thing like a wood frog that

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Speaker 1: freezes itself in the winter can slow its heart rate

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Speaker 1: down quite a bit, whereas a large thing that's running

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Speaker 1: is going to have a really fast heart rate. So

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Speaker 1: it has to do with your metabolism, which may have

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Speaker 1: something to do with your species or your size. Often

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Speaker 1: large things do have slower metabolisms, but it can also

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Speaker 1: depend on the state that you are in. So if

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Speaker 1: you're exercising, your heart rate's going to be pretty quick.

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Speaker 1: If you're a wood frog and you've frozen yourself in

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Speaker 1: the winter to kind of hibernate, then your heartbeat is

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Speaker 1: going to be really really slow.

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Speaker 2: Well, the direction I was thinking was, you know, a

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Speaker 2: little mouse has its heart rate very very fast, and

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Speaker 2: a human is slower, and a big whale is even slower.

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Speaker 2: So I was wondering, like, how big of a space

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Speaker 2: whale do you have to have to have a twenty

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Speaker 2: minute heartbeat? Maybe it's a planet sized slimeball space whale.

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Speaker 1: I like where this is going.

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Speaker 2: Yes, we don't know, of course, whether this is an

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Speaker 2: actual alien slime whale or not. But we do know

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Speaker 2: that there are things in the night sky that pulse,

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Speaker 2: and lots of our listeners mentioned one of them pulsars

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Speaker 2: that we're going to dig into in a moment. But

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Speaker 2: there might be more things in the night sky that

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Speaker 2: pulse and that vary and that change than you might expect.

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Speaker 2: A lot of people look up for the night sky

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Speaker 2: and think that it's static, that it doesn't change, but

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Speaker 2: actually all stars have cycles. They're not just like static

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Speaker 2: burning balls of gas. They vary, they get brighter, they

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Speaker 2: get dimmer. Even our Sun, for example, changes its brightness

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Speaker 2: over an eleven year cycle.

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Speaker 1: They're like huge and sort of deadly lava lamps.

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Speaker 2: That's exactly right, because there are these big balls of plasma.

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Speaker 2: They're not just fire the way we have like a campfire.

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Speaker 2: There's fusion going on, and there's all sorts of convection

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Speaker 2: and lots of complicated processes that we still do not

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Speaker 2: really understand very well. Our own star, the Sun, has

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Speaker 2: this weird eleven year cycle where it's magnetic field flips

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Speaker 2: every eleven years with crazy regularity as far as we

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Speaker 2: can tell, going back a very long time. And this

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Speaker 2: has to do with the currents of plasma inside the

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Speaker 2: Sun like flopping over on top of each other. You

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Speaker 2: can think of these things like big spaghetti noodles and

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Speaker 2: they get bound up by magnetic fields and then they

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Speaker 2: snap and twist. So something is going on inside our sun.

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Speaker 2: That's like a clock. It's like a universe clock. And

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Speaker 2: every eleven years the Sun flips its magnetic field, and

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Speaker 2: it also changes its brightness, not that much, like zero

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Speaker 2: point one percent over eleven year cycles, but it does change.

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Speaker 2: It is variable.

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Speaker 1: So this big bright spaghetti clock you were talking about currents,

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Speaker 1: it sounds like it has like these complex almost weather

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Speaker 1: patterns that follow a sort of timeline.

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Speaker 2: Yeah, they have these big plasma tubes inside the sun,

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Speaker 2: these currents of these hot protons and electrons that are flowing,

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Speaker 2: and that helps make the magnetic field. Remember, the fields

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Speaker 2: come from moving charges, and the Sun is basically just

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Speaker 2: ionized hydrogen. You take the proton and the electron and

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Speaker 2: you give them so much energy that they don't want

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Speaker 2: to hang out together anymore. They want to be free,

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Speaker 2: so they are just flying around all of these charges

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Speaker 2: and then they flow in these big tubes and that's

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Speaker 2: what makes magnetic fields. But they like slip and slide

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Speaker 2: on top of each other, and sometimes they snap and

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Speaker 2: break and relax in various modes. It's extraordinarily complicated. We

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Speaker 2: don't have the technology to model the inside of the

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Speaker 2: sun very well because it is very complicated each of

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Speaker 2: the particles. Not only does it have location and momentum,

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Speaker 2: but you also have to think about their electromagnetic forces

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Speaker 2: between each other. These things can get very turbulent and

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Speaker 2: very chaotic, meaning that like a very small change in

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Speaker 2: one electron can cascade into a big effect for other electrons.

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Speaker 2: So you make a little mistake and it becomes very

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Speaker 2: quickly a big mistake. That's one of the things that

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Speaker 2: makes the Sun hard to model. It can be very

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Speaker 2: chaotic on its insides, and that's a weak point in

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Speaker 2: our science that sometimes we can simulate things because we

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Speaker 2: understand the fundamental rules, like we know electromagnetism, but we

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Speaker 2: can't necessarily model a lot of them all at once,

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Speaker 2: And the Sun is a lot of electrons to model.

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Speaker 1: So you mentioned that it's very chaotic, but it also

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Speaker 1: may follow a sort of eleven year cycle. How do

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Speaker 1: you get things like cycles or regularity out of such

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Speaker 1: chaotic processes.

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Speaker 2: Yeah, they're chaotic in the sense that a small change

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Speaker 2: in the initial conditions can lead to a large change,

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Speaker 2: and that's a problem often for our simulations, that if

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Speaker 2: we don't get things exactly right, then our simulations go wrong.

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Speaker 2: Inside the star, the process can be quite stable. Actually,

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Speaker 2: there are things that keep it on track, you know,

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Speaker 2: the magnetic field configuration of these plasma tubes have energetic

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Speaker 2: minimums that they like to settle into. But then the

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Speaker 2: magnetic fields get stretched and twisted, and then there's a

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Speaker 2: new energetic minimum that forms and they snap over into that.

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Speaker 2: And so that's the kind of thing that can give

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Speaker 2: you these regular processes. And our star is pretty constant

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Speaker 2: when it comes to this, but other stars are much

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Speaker 2: more dramatic. There's stars out there in the universe that

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Speaker 2: are very dramatically pulsating. They swell in size and they

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Speaker 2: also shrink, they get like bigger and smaller. Some of

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Speaker 2: these things pulse with a fairly regular frequency, or sometimes

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Speaker 2: multiple frequencies that can be either very regular or stochastic.

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Speaker 2: A classic example of these is very famous the cephids.

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Speaker 2: These are the ones that Hubble use to discover that

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Speaker 2: the universe is expanding because it's a very clever trick

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Speaker 2: to figuring out how far away these stars are by

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Speaker 2: how they are pulsating. It turns out if you measure

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Speaker 2: the period of their variation, like as they get brighter

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Speaker 2: and dimmer and brighter and dimmer, the time between being

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Speaker 2: bright and dim allows you to know the true brightness

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Speaker 2: of the star, Like there's a relationship there, whereas stars

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Speaker 2: that are pulsating faster might be brighter and stars that

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Speaker 2: are pulsating slower might be dimmer. And then you can

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Speaker 2: know how far away the star is because you can

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Speaker 2: measure the brightness here on Earth compared to the brightness

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Speaker 2: you know to be the case that you got from

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Speaker 2: the pulsation from the periodicity of the star, and that

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Speaker 2: tells you how far away it is. That was very

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Speaker 2: important early on for understanding the expansion of the universe,

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Speaker 2: because we just looked out of the sky and we

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Speaker 2: didn't know how far away are all these dots. Some

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Speaker 2: of them might be closer, some of them might be further.

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Speaker 2: It's not always easy to tell. So the variability of

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Speaker 2: the night skies actually are very important handbills scientifically for

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Speaker 2: understanding like the three D structure of what we're.

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Speaker 1: Looking at so these sephids that were studied, we found

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Speaker 1: that they were starting to get demmer, so they were

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Speaker 1: starting to get further from Earth, showing that there was

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Speaker 1: an expansion of the universe.

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Speaker 2: So for the cephids, we can measure their velocity relative

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Speaker 2: to Earth because we look at the light from them

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Speaker 2: and we see how it's shifted. Stars that are moving

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Speaker 2: away from Earth are red shifted. The wavelengths of their

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Speaker 2: light has been extended because they're moving away from us.

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Speaker 2: It's like a Doppler effect. So we can measure the

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Speaker 2: velocity of these stars. And then Hubble also was able

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Speaker 2: to measure the distance to these stars. He was able

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Speaker 2: to tell which ones were closer and which ones were

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Speaker 2: further away using this trick where he measured how they pulsed.

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Speaker 2: How they pulsed told him how bright they were, which

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Speaker 2: tells him how far away they are. So if he

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Speaker 2: knows how far away they are and he knows their velocity,

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Speaker 2: then he can compare those two things. And what Hubble

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Speaker 2: noticed was that stars that are further away seemed to

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Speaker 2: be moving away from us faster, and stars that are

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Speaker 2: closer by are moving away less fast. And what that

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Speaker 2: tells you is that the universe is expanding, that everything

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Speaker 2: is moving away from us, and things further away are

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Speaker 2: moving away faster. And that's the original Hubble's law, and

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Speaker 2: Hubble's constant relates these two things. How fast things are

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Speaker 2: expanding relative to how far away they are.

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Speaker 1: Wow. So that's like we're able to tell things about

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Speaker 1: our universe just from the movement of stars. And because

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Speaker 1: these stars are pulsating, that gave us enough information to

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Speaker 1: be able to measure distance and velocity, which was the

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Speaker 1: key to understanding the.

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Speaker 2: Yeah. And also this other great mind blowing moment of

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Speaker 2: understanding because we didn't know until then that there were

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Speaker 2: other galaxies in the universe. We thought we just had

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Speaker 2: this one galaxy and it was a bunch of stars

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Speaker 2: and that was it. And we saw these other little

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Speaker 2: smudges up in the sky that we now know are

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Speaker 2: other full galaxies, but we didn't know that at the time.

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Speaker 2: They couldn't tell how far away they are, so they

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Speaker 2: thought they were just little clouds of gas that were

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Speaker 2: inside our galaxy. They didn't realize they were mammoth collections

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Speaker 2: of other stars much much further away until Hubble measured

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Speaker 2: their distance using these variable stars. Using these things pulsating

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Speaker 2: in those other galaxies, and he could tell, oh my gosh,

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Speaker 2: these things are super far away. We totally got this wrong,

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Speaker 2: and all of a sudden instantly your whole mental picture

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Speaker 2: of the universe expands from we have this one galaxy

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Speaker 2: floating in space to while the universe is littered with galaxies.

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Speaker 2: It's a complete mind blowing moment to realize that the

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Speaker 2: universe has so many more galaxies than just ours.

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Speaker 1: It is also kind of wild that we once thought

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Speaker 1: we were the only galaxy. I find that somewhat I

439
00:23:07,200 --> 00:23:11,080
Speaker 1: guess egocentric. I'm not really sure I get it. I mean,

440
00:23:11,119 --> 00:23:13,520
Speaker 1: at one point we thought Earth was the center of

441
00:23:13,560 --> 00:23:16,520
Speaker 1: the universe, so to think we're the only galaxy kind

442
00:23:16,560 --> 00:23:19,320
Speaker 1: of makes sense too. But also it is a little

443
00:23:19,440 --> 00:23:21,560
Speaker 1: bit We're a little bit full of ourselves here in

444
00:23:21,560 --> 00:23:22,600
Speaker 1: the Milky Way, aren't we.

445
00:23:22,720 --> 00:23:24,439
Speaker 2: It can be really hard to put yourself in the

446
00:23:24,520 --> 00:23:27,880
Speaker 2: mindset of people who made assumptions one hundred years ago

447
00:23:28,040 --> 00:23:30,480
Speaker 2: or five hundred years ago. It seemed totally natural to

448
00:23:30,560 --> 00:23:33,080
Speaker 2: them at the time, and now to us seemed kind

449
00:23:33,080 --> 00:23:35,959
Speaker 2: of bonkers and obvious. It really goes to show you

450
00:23:36,000 --> 00:23:40,439
Speaker 2: how much our intuition is informed by science. You know,

451
00:23:40,480 --> 00:23:43,320
Speaker 2: what we think is obvious and natural has changed over

452
00:23:43,440 --> 00:23:46,119
Speaker 2: time as we've learned about the universe. And so that

453
00:23:46,160 --> 00:23:50,800
Speaker 2: tells you really shouldn't trust your intuition at all. It's

454
00:23:50,880 --> 00:23:53,600
Speaker 2: totally biased by what you've been told and how things

455
00:23:53,600 --> 00:23:54,600
Speaker 2: have been described to you.

456
00:23:54,880 --> 00:23:57,520
Speaker 1: So I shouldn't be trusting my intuition. That's saying it's

457
00:23:57,520 --> 00:23:58,400
Speaker 1: time for a nap break.

458
00:23:58,960 --> 00:24:00,440
Speaker 2: No, there you are on.

459
00:24:13,000 --> 00:24:15,760
Speaker 1: All right. So we are back and we are talking

460
00:24:15,800 --> 00:24:21,080
Speaker 1: about the dynamic stars out there that pulse and change

461
00:24:21,760 --> 00:24:24,879
Speaker 1: and things that we can actually measure. So we talked

462
00:24:24,920 --> 00:24:30,119
Speaker 1: about these stars, the sephids that they're pulsating. Were the

463
00:24:30,280 --> 00:24:33,679
Speaker 1: pulsating of the sephids told us a lot about the

464
00:24:33,760 --> 00:24:36,959
Speaker 1: nature of the universe that it was expanding. It allowed

465
00:24:37,040 --> 00:24:39,960
Speaker 1: us to measure the distance to these stars. What are

466
00:24:40,160 --> 00:24:44,760
Speaker 1: other examples of stars changing that we can observe here

467
00:24:44,800 --> 00:24:45,160
Speaker 1: on Earth?

468
00:24:45,320 --> 00:24:48,360
Speaker 2: So pulsating stars are not the only example of stars

469
00:24:48,480 --> 00:24:50,880
Speaker 2: changing out there in the universe. We see all sorts

470
00:24:50,920 --> 00:24:53,320
Speaker 2: of things changing, and every time this happens, we try

471
00:24:53,359 --> 00:24:56,240
Speaker 2: to understand it, like what's going on? You know, people

472
00:24:56,320 --> 00:24:59,120
Speaker 2: have been working on understanding sephids for a long time.

473
00:24:59,160 --> 00:25:01,919
Speaker 2: Because we'd like to know, so, what's going on inside stars?

474
00:25:01,960 --> 00:25:05,000
Speaker 2: How does the energy dynamics work. In the case of stephids,

475
00:25:05,000 --> 00:25:07,560
Speaker 2: we have sort of an idea. People think that, like

476
00:25:07,880 --> 00:25:11,359
Speaker 2: something inside the star might become opaque so that the

477
00:25:11,480 --> 00:25:14,399
Speaker 2: radiation basically can't escape, and that makes the star a

478
00:25:14,440 --> 00:25:16,960
Speaker 2: little bit darker. And then the star puffs up because

479
00:25:17,000 --> 00:25:20,119
Speaker 2: it's absorbing that radiation instead of emitting it. It puffs

480
00:25:20,119 --> 00:25:22,360
Speaker 2: it up, and then it collapses again due to gravity.

481
00:25:22,440 --> 00:25:24,560
Speaker 2: So there's some sort of cycle there. But these stars

482
00:25:24,600 --> 00:25:26,720
Speaker 2: just go to do this thing over and over again.

483
00:25:26,800 --> 00:25:29,879
Speaker 2: There are other kinds of stars that are much more dramatic,

484
00:25:29,960 --> 00:25:33,200
Speaker 2: where you have like huge amounts of material blown out

485
00:25:33,320 --> 00:25:36,640
Speaker 2: of the star, called like flare stars. Some of these

486
00:25:36,680 --> 00:25:39,560
Speaker 2: things can get very dramatic, Like the star can grow

487
00:25:39,640 --> 00:25:43,040
Speaker 2: in brightness by a factor of five or six in

488
00:25:43,240 --> 00:25:45,879
Speaker 2: just like thirty minutes. So imagine you're like sitting on

489
00:25:45,920 --> 00:25:48,919
Speaker 2: a planet near one of these stars, your sun bathing nicely,

490
00:25:49,160 --> 00:25:51,440
Speaker 2: and all of a sudden, the star is like six

491
00:25:51,560 --> 00:25:53,840
Speaker 2: times as bright as it was just a half an

492
00:25:53,880 --> 00:25:54,479
Speaker 2: hour ago.

493
00:25:54,600 --> 00:25:59,240
Speaker 1: It's like that black Hole Sun music video, which gives

494
00:25:59,280 --> 00:26:02,160
Speaker 1: me a migraine I watch it is this a repeating

495
00:26:02,200 --> 00:26:05,200
Speaker 1: pattern or does it just happen one and once and done.

496
00:26:05,320 --> 00:26:08,560
Speaker 2: These things are unpredictable. They're not like very regular. So

497
00:26:08,600 --> 00:26:10,600
Speaker 2: you'll be watching the star and all of a sudden,

498
00:26:10,640 --> 00:26:13,399
Speaker 2: it'll get much much brighter, very briefly, and then it'll

499
00:26:13,400 --> 00:26:15,680
Speaker 2: dim back down again, and they think it might be

500
00:26:15,920 --> 00:26:19,040
Speaker 2: something going on inside the star that's blowing out a

501
00:26:19,119 --> 00:26:21,440
Speaker 2: huge amount of material, and then it's settled down again.

502
00:26:21,520 --> 00:26:25,040
Speaker 2: There must be something chaotic happening inside these stars. But

503
00:26:25,080 --> 00:26:26,760
Speaker 2: this is not the kind of thing we expect our

504
00:26:26,880 --> 00:26:29,399
Speaker 2: son to do. Most of the flare stars that are

505
00:26:29,440 --> 00:26:32,040
Speaker 2: out there tend to be of the red dwarf variety.

506
00:26:32,800 --> 00:26:35,920
Speaker 2: And remember that red dwarfs are much more common kind

507
00:26:35,960 --> 00:26:38,760
Speaker 2: of star than ours. Our stars kind of unusual in

508
00:26:38,800 --> 00:26:41,040
Speaker 2: the universe, and most of the flare stars that we've

509
00:26:41,040 --> 00:26:45,720
Speaker 2: observed are these red dwarfs. And that's actually one hypothesis

510
00:26:45,920 --> 00:26:49,800
Speaker 2: for why life evolves around the not most common star,

511
00:26:50,040 --> 00:26:52,400
Speaker 2: because you might imagine, if red dwarfs are the most

512
00:26:52,400 --> 00:26:54,760
Speaker 2: common star in the universe, why is it that we

513
00:26:54,840 --> 00:26:57,760
Speaker 2: evolved around a weird star? And it might be that

514
00:26:57,800 --> 00:26:59,879
Speaker 2: red dwarfs are common, but they're just sort of like

515
00:27:00,080 --> 00:27:02,960
Speaker 2: inhospitable to life because it takes a lot of sunscreen

516
00:27:03,040 --> 00:27:06,439
Speaker 2: to survive. Your star getting six times as bright all

517
00:27:06,480 --> 00:27:07,840
Speaker 2: of a sudden, unpredictably.

518
00:27:08,080 --> 00:27:11,640
Speaker 1: That's really interesting. So if most stars out there are

519
00:27:11,720 --> 00:27:14,879
Speaker 1: red dwarves, what kind of star is our sun?

520
00:27:15,119 --> 00:27:17,120
Speaker 2: Our star is one of the category that they call

521
00:27:17,160 --> 00:27:20,040
Speaker 2: an F or G type star, So it's a bigger star,

522
00:27:20,160 --> 00:27:22,800
Speaker 2: and it's yellower, and so it tends to burn brighter.

523
00:27:22,840 --> 00:27:26,760
Speaker 2: Remember that smaller stars are cooler, which is why smaller

524
00:27:26,800 --> 00:27:31,040
Speaker 2: stars are redder, because red indicates longer wavelengths, which means

525
00:27:31,119 --> 00:27:35,000
Speaker 2: lower surface temperatures. And our sun is more yellow, it's

526
00:27:35,040 --> 00:27:37,760
Speaker 2: a little bit hotter than the typical red type of star,

527
00:27:37,960 --> 00:27:40,159
Speaker 2: So we live on an unusually hot kind.

528
00:27:40,000 --> 00:27:43,960
Speaker 1: Of star, and so our sun doesn't have these sort

529
00:27:43,960 --> 00:27:48,119
Speaker 1: of star sneezes like these red dwarves have, and so

530
00:27:48,200 --> 00:27:54,000
Speaker 1: that protects us from having suddenly needing one hundred spf

531
00:27:54,240 --> 00:27:55,359
Speaker 1: every so often.

532
00:27:55,400 --> 00:27:58,560
Speaker 2: Not entirely though, right our sun does have little sneezes,

533
00:27:58,640 --> 00:28:02,520
Speaker 2: you know. These coronal mass ejections can be fairly dramatic events,

534
00:28:02,560 --> 00:28:05,040
Speaker 2: where like loops of plasma get ejected, and some of

535
00:28:05,080 --> 00:28:07,760
Speaker 2: them can even bathe the Earth we had this event

536
00:28:07,800 --> 00:28:10,400
Speaker 2: in the eighteen hundreds where like all wires on Earth

537
00:28:10,400 --> 00:28:13,760
Speaker 2: were suddenly electrified because of the crazy magnetic and electric

538
00:28:13,800 --> 00:28:16,680
Speaker 2: fields that were coming from these events. So they do happen.

539
00:28:16,720 --> 00:28:19,440
Speaker 2: They're not neatly as dramatic as flare stars. But even

540
00:28:19,480 --> 00:28:21,520
Speaker 2: our sun can burp in our direction.

541
00:28:21,840 --> 00:28:25,680
Speaker 1: Oh dear, uh oh what if Twitter goes down? Oh no,

542
00:28:26,000 --> 00:28:27,679
Speaker 1: that would be so bad.

543
00:28:28,119 --> 00:28:30,080
Speaker 2: Blame the sun, not elon Musk.

544
00:28:31,600 --> 00:28:36,040
Speaker 1: So we've got pulsating stars like the sephids, We've got

545
00:28:36,080 --> 00:28:40,760
Speaker 1: the red dwarfs who have their explosive sneezes. What other

546
00:28:40,920 --> 00:28:44,400
Speaker 1: kinds of star pulsating do we have?

547
00:28:44,720 --> 00:28:46,840
Speaker 2: One of my favorite and the kind that was mentioned

548
00:28:46,880 --> 00:28:50,160
Speaker 2: by listeners when we ask them about this, are pulsars.

549
00:28:50,600 --> 00:28:53,600
Speaker 2: These are a very very cool kind of star and

550
00:28:53,640 --> 00:28:57,040
Speaker 2: they represent the end of the life of many stars.

551
00:28:57,200 --> 00:28:59,960
Speaker 2: So you know, stars form from having a huge block

552
00:29:00,200 --> 00:29:04,280
Speaker 2: of cold gas and dust that gravity gathers together until

553
00:29:04,280 --> 00:29:07,360
Speaker 2: eventually it's hot enough and dense enough that fusion can start.

554
00:29:07,720 --> 00:29:10,880
Speaker 2: And then fusion is fighting back against gravity. If we

555
00:29:10,960 --> 00:29:13,000
Speaker 2: only had gravity and then a blob of gas and

556
00:29:13,080 --> 00:29:15,680
Speaker 2: dust would just form a black hole straight away. But

557
00:29:15,720 --> 00:29:18,440
Speaker 2: because it starts to burn it emits radiation that's like

558
00:29:18,680 --> 00:29:21,560
Speaker 2: puffing back up against gravity, and it keeps it in

559
00:29:21,680 --> 00:29:25,880
Speaker 2: balance for millions or billions or trillions of years, depending

560
00:29:26,200 --> 00:29:29,560
Speaker 2: on the size of the star. Smaller stars burn longer

561
00:29:29,640 --> 00:29:33,200
Speaker 2: because they burn cooler. Bigger stars burn shorter and faster

562
00:29:33,360 --> 00:29:36,040
Speaker 2: and hotter and don't last for very long. And the

563
00:29:36,160 --> 00:29:39,360
Speaker 2: mass of the star also sort of determines what happens

564
00:29:39,400 --> 00:29:41,719
Speaker 2: to it. Like a star that's smaller, like less than

565
00:29:41,760 --> 00:29:44,680
Speaker 2: eight times the mass of our Sun, will eventually turn

566
00:29:44,720 --> 00:29:47,720
Speaker 2: into a red giant. It puffs up and then eventually

567
00:29:47,760 --> 00:29:50,400
Speaker 2: collapses and you get like maybe a white dwarf at

568
00:29:50,400 --> 00:29:53,400
Speaker 2: its core, which is just like a hot leftover blob

569
00:29:53,760 --> 00:29:55,440
Speaker 2: of the stuff that fusion produced.

570
00:29:55,640 --> 00:29:58,120
Speaker 1: I knew blob monsters were out there. I knew it.

571
00:29:58,920 --> 00:30:01,160
Speaker 2: And that's probably the phase of our star. It's going

572
00:30:01,200 --> 00:30:03,040
Speaker 2: to become a red giant and puff out all of

573
00:30:03,080 --> 00:30:05,560
Speaker 2: its material and eventually just be left as a white

574
00:30:05,640 --> 00:30:08,160
Speaker 2: dwarf which will cool over trillions of years to a

575
00:30:08,160 --> 00:30:10,480
Speaker 2: black dwarf. But if you have more stuff in that

576
00:30:10,560 --> 00:30:13,600
Speaker 2: initial scoop of matter, then you have like a massive

577
00:30:13,640 --> 00:30:16,320
Speaker 2: star that can become a red super giant. And when

578
00:30:16,320 --> 00:30:19,880
Speaker 2: that collapses, you've got a supernova, which can leave a

579
00:30:19,920 --> 00:30:22,880
Speaker 2: neutron star or a black hole, and a neutron star

580
00:30:22,960 --> 00:30:25,800
Speaker 2: is what forms a pulsar. A neutron star is a

581
00:30:25,840 --> 00:30:29,160
Speaker 2: blob of mass so dense that the electrons and the

582
00:30:29,200 --> 00:30:31,880
Speaker 2: protons that used to be in the hydrogen have gotten

583
00:30:31,960 --> 00:30:35,920
Speaker 2: squeezed together to form neutrons. Usually it goes the other way.

584
00:30:36,240 --> 00:30:39,520
Speaker 2: Neutrons like to decay into a proton and an electron,

585
00:30:39,760 --> 00:30:41,880
Speaker 2: but if you push them together hard enough, they will

586
00:30:41,880 --> 00:30:46,200
Speaker 2: actually reverse that process and make neutrons. So neutron stars

587
00:30:46,240 --> 00:30:49,200
Speaker 2: are some of the densest things in the universe, and

588
00:30:49,200 --> 00:30:52,680
Speaker 2: they're like the last step before gravity finally takes over

589
00:30:52,720 --> 00:30:55,880
Speaker 2: and collapses this thing into a black hole. So they're

590
00:30:56,040 --> 00:31:00,320
Speaker 2: very weird, very interesting things. Scientifically, we don't really underderstand

591
00:31:00,360 --> 00:31:03,360
Speaker 2: what's going on inside a neutron star, how it all works,

592
00:31:03,400 --> 00:31:06,520
Speaker 2: but they do something really really fascinating, which is that

593
00:31:06,640 --> 00:31:10,160
Speaker 2: they send us these regular pulses from space.

594
00:31:10,640 --> 00:31:13,240
Speaker 1: So I imagine if I wanted to scoop like a

595
00:31:13,280 --> 00:31:17,600
Speaker 1: tea spoon of neutron star, it would be pretty heavy.

596
00:31:17,800 --> 00:31:19,560
Speaker 2: It would not be good for your diet to eat

597
00:31:19,560 --> 00:31:21,640
Speaker 2: even a tea spoon of neutron star.

598
00:31:22,080 --> 00:31:26,000
Speaker 1: It's a little too rich. So are these still emitting light?

599
00:31:26,520 --> 00:31:29,600
Speaker 1: What is pulsing for these neutron stars?

600
00:31:29,640 --> 00:31:32,200
Speaker 2: So these things are not undergoing fusion, right, They're not

601
00:31:32,280 --> 00:31:35,080
Speaker 2: glowing the way that other stars are. And Jorge Make,

602
00:31:35,160 --> 00:31:37,120
Speaker 2: for example, quibble about whether we should call it a

603
00:31:37,160 --> 00:31:39,640
Speaker 2: star or not. And so these things are not glowing

604
00:31:39,680 --> 00:31:41,160
Speaker 2: in that sense. You can't look up at the night's

605
00:31:41,160 --> 00:31:43,040
Speaker 2: side and see a bright dot and say, oh, that's

606
00:31:43,040 --> 00:31:45,800
Speaker 2: a neutron star. We can see them sometimes because they

607
00:31:45,960 --> 00:31:49,120
Speaker 2: emit X rays, but the best way to discover neutron

608
00:31:49,200 --> 00:31:53,120
Speaker 2: stars is through their pulses. Because neutron stars are also

609
00:31:53,240 --> 00:31:56,400
Speaker 2: spinning really really fast. They have to spin because the

610
00:31:56,440 --> 00:31:59,360
Speaker 2: original blob of stuff that made them was spinning, and

611
00:31:59,400 --> 00:32:03,000
Speaker 2: now they've gotten really really small. Neutron stars are like

612
00:32:03,120 --> 00:32:06,560
Speaker 2: a few kilometers in size, but they have the mass

613
00:32:06,600 --> 00:32:08,960
Speaker 2: of like the sun or five times the sun.

614
00:32:09,280 --> 00:32:11,760
Speaker 1: That kind of sounds like an ice skater, like a

615
00:32:11,800 --> 00:32:14,960
Speaker 1: figure skater. They can start a spin and then when

616
00:32:14,960 --> 00:32:17,960
Speaker 1: they collapse, like they kind of go into a ball,

617
00:32:18,040 --> 00:32:19,400
Speaker 1: they can spin even faster.

618
00:32:19,680 --> 00:32:22,760
Speaker 2: That's exactly right, And they have to spin faster because

619
00:32:22,800 --> 00:32:25,680
Speaker 2: they're smaller and so to maintain the angular momentum, you

620
00:32:25,720 --> 00:32:29,040
Speaker 2: have to spin faster with a smaller radius. That's just

621
00:32:29,080 --> 00:32:31,720
Speaker 2: because the law of angular momentum is conserved in the

622
00:32:31,840 --> 00:32:34,560
Speaker 2: universe and it forces these things to spin faster as

623
00:32:34,560 --> 00:32:38,800
Speaker 2: they get smaller. Now that's spinning also makes a magnetic field, right,

624
00:32:38,800 --> 00:32:41,080
Speaker 2: because again you got charge particles in there and things

625
00:32:41,080 --> 00:32:43,120
Speaker 2: are spinning, so you get a magnetic field, and that

626
00:32:43,200 --> 00:32:46,920
Speaker 2: magnetic field will funnel some charge particles up towards the

627
00:32:47,000 --> 00:32:49,440
Speaker 2: pole the same way that like on Earth, we have

628
00:32:49,480 --> 00:32:52,920
Speaker 2: a magnetic field and it protects us from charge particles

629
00:32:52,920 --> 00:32:55,800
Speaker 2: from space. If an electron hits the Earth, it doesn't

630
00:32:55,800 --> 00:32:57,680
Speaker 2: just go all the way down into the Earth. The

631
00:32:57,760 --> 00:33:00,480
Speaker 2: magnetic field will funnel it up to the pole, which

632
00:33:00,480 --> 00:33:03,360
Speaker 2: is why you see like northern lights and southern lights.

633
00:33:03,640 --> 00:33:07,280
Speaker 2: Those are cosmic rays, charged particles from space that have

634
00:33:07,360 --> 00:33:09,880
Speaker 2: been swept up to the northern and the southern parts

635
00:33:09,880 --> 00:33:12,520
Speaker 2: of the Earth by our magnetic field. And so the

636
00:33:12,560 --> 00:33:15,280
Speaker 2: same thing can happen on these neutron stars. They have

637
00:33:15,400 --> 00:33:18,160
Speaker 2: charged particles that are swept up to the poles and

638
00:33:18,160 --> 00:33:21,560
Speaker 2: then emitted, so you get these very powerful beams being

639
00:33:21,600 --> 00:33:24,440
Speaker 2: emitted from the north and south poles of this planet,

640
00:33:24,520 --> 00:33:27,040
Speaker 2: because the magnetic field is sort of like focused it

641
00:33:27,080 --> 00:33:29,640
Speaker 2: instead of just like shooting particles off in every direction,

642
00:33:30,000 --> 00:33:32,760
Speaker 2: it shoots them up in these two beams, one north

643
00:33:32,840 --> 00:33:33,640
Speaker 2: and one south.

644
00:33:33,880 --> 00:33:37,280
Speaker 1: Now, if you could stand on this neutron star, which

645
00:33:37,280 --> 00:33:42,000
Speaker 1: I'm assuming you can't without being grievously hurt, when you

646
00:33:42,040 --> 00:33:44,680
Speaker 1: look up at one of the poles, would you see

647
00:33:44,680 --> 00:33:49,520
Speaker 1: something like an aurora before you're presumably squished or tossed

648
00:33:49,520 --> 00:33:50,160
Speaker 1: off the planet.

649
00:33:50,320 --> 00:33:52,640
Speaker 2: Well, the scale of these things is ridiculous. I mean,

650
00:33:53,000 --> 00:33:55,880
Speaker 2: the gravity is so strong on a neutron star that,

651
00:33:56,040 --> 00:33:58,760
Speaker 2: like the tallest mountain on a neutron star is about

652
00:33:58,760 --> 00:34:01,880
Speaker 2: a millimeter, and the atmosphere of the neutron star is

653
00:34:01,920 --> 00:34:04,560
Speaker 2: like a few more millimeters. So you'd have to be

654
00:34:04,640 --> 00:34:07,880
Speaker 2: like ant sized to be looking up from a neutron

655
00:34:07,920 --> 00:34:11,640
Speaker 2: star and see any atmosphere above you. It'd be pretty tough. Also,

656
00:34:11,680 --> 00:34:13,320
Speaker 2: you'd have to be like an Olympic strong man or

657
00:34:13,360 --> 00:34:15,120
Speaker 2: strong woman to be able to stand up on a

658
00:34:15,160 --> 00:34:18,400
Speaker 2: neutron star without being crushed or pulled apart by its

659
00:34:18,480 --> 00:34:19,280
Speaker 2: tidal forces.

660
00:34:19,440 --> 00:34:21,880
Speaker 1: I mean, good news is on a neutron star, I

661
00:34:21,880 --> 00:34:25,640
Speaker 1: could scale the tallest mountain bad news. All my bones

662
00:34:25,680 --> 00:34:26,719
Speaker 1: would be jelly.

663
00:34:28,320 --> 00:34:31,520
Speaker 2: Exactly. So you have this neutron star and it's spinning,

664
00:34:31,680 --> 00:34:35,120
Speaker 2: and you have this magnetic field which accelerates any protons

665
00:34:35,160 --> 00:34:38,040
Speaker 2: and electrons on the surface into these beams which shoot

666
00:34:38,080 --> 00:34:41,120
Speaker 2: out into space. And the fascinating thing is that sometimes

667
00:34:41,160 --> 00:34:44,560
Speaker 2: the magnetic field is not aligned with the spin of

668
00:34:44,600 --> 00:34:47,800
Speaker 2: the star, so you have like the star itself is spinning.

669
00:34:47,960 --> 00:34:50,560
Speaker 2: Now you have this beam shooting off the surface. But

670
00:34:50,600 --> 00:34:53,279
Speaker 2: the beam is not shooting on the spin axis. It's

671
00:34:53,280 --> 00:34:56,080
Speaker 2: shooting a little bit off, which means the beam is

672
00:34:56,120 --> 00:35:00,040
Speaker 2: like sweeping around through space. It's like forming a cone

673
00:35:00,520 --> 00:35:03,719
Speaker 2: of light and it sweeps around. And so these pulsars

674
00:35:03,760 --> 00:35:07,640
Speaker 2: are not actually variable in that sense. Their beam is constant,

675
00:35:07,719 --> 00:35:10,520
Speaker 2: but if the beam sweeps by you, it seems variable

676
00:35:10,680 --> 00:35:12,880
Speaker 2: because it sweeps over you and then it passes you

677
00:35:12,960 --> 00:35:14,960
Speaker 2: and then it comes back again. So it's sort of

678
00:35:15,000 --> 00:35:17,719
Speaker 2: like that figure Skaters holding a flashlight and as she

679
00:35:17,840 --> 00:35:20,640
Speaker 2: turns she blinds you once every revolution.

680
00:35:20,880 --> 00:35:23,000
Speaker 1: I hate it when they do that at the Olympics.

681
00:35:23,080 --> 00:35:27,880
Speaker 1: But yeah, no, I mean it sounds like an intergalactic lighthouse.

682
00:35:28,160 --> 00:35:30,600
Speaker 2: It's exactly right, just like a lighthouse. And when they

683
00:35:30,600 --> 00:35:33,080
Speaker 2: were first discovered. It was super fascinating. The first one

684
00:35:33,120 --> 00:35:36,280
Speaker 2: to be discovered had a period of about one point

685
00:35:36,320 --> 00:35:39,000
Speaker 2: thirty three seconds, one in a third second. So they

686
00:35:39,000 --> 00:35:41,400
Speaker 2: were looking up at the night sky and actually listening

687
00:35:41,440 --> 00:35:43,719
Speaker 2: for other stuff, and they saw this signal that went

688
00:35:43,800 --> 00:35:48,560
Speaker 2: like beep beep beep, very very regular and so of

689
00:35:48,600 --> 00:35:52,080
Speaker 2: course the first astronomer is to see this. Jocelyn Bell Burnell,

690
00:35:52,200 --> 00:35:54,839
Speaker 2: who unfortunately was overlooked for the Nobel Prize for this,

691
00:35:55,239 --> 00:35:58,560
Speaker 2: she at first thought, maybe this is aliens, giant space

692
00:35:58,600 --> 00:36:01,880
Speaker 2: whales or something else us a message because we didn't

693
00:36:01,920 --> 00:36:04,560
Speaker 2: expect the night sky to pulse and to pulse with

694
00:36:04,680 --> 00:36:08,920
Speaker 2: such regularity. It seemed artificial, it seemed technological.

695
00:36:09,280 --> 00:36:12,560
Speaker 1: Yeah, that is interesting. As humans, we love a pattern,

696
00:36:13,000 --> 00:36:16,640
Speaker 1: and I think that patterns to us seem to signal

697
00:36:16,680 --> 00:36:21,520
Speaker 1: some intention. I guess like it's very easy to anthropomorphize

698
00:36:21,680 --> 00:36:25,000
Speaker 1: a pattern because we think of well, if something acts

699
00:36:25,000 --> 00:36:27,520
Speaker 1: in a regular pattern, it's got some kind of volition,

700
00:36:27,680 --> 00:36:31,200
Speaker 1: it's got some sort of consciousness because it is acting

701
00:36:31,239 --> 00:36:34,279
Speaker 1: in this pattern. But of course patterns can exist in

702
00:36:34,320 --> 00:36:39,120
Speaker 1: ways that have nothing to do with being alive or

703
00:36:39,360 --> 00:36:42,759
Speaker 1: having a brain. Like when we notice patterns, we have

704
00:36:42,880 --> 00:36:45,759
Speaker 1: this sense, and I think there have been some psychology

705
00:36:45,760 --> 00:36:49,960
Speaker 1: studies on this. When people see things like inanimate objects

706
00:36:50,000 --> 00:36:52,279
Speaker 1: like a marble or something and that's sort of doing

707
00:36:52,320 --> 00:36:55,400
Speaker 1: some kind of patterned behavior, they perceive it as having

708
00:36:55,800 --> 00:36:59,680
Speaker 1: sort of a like it desires, or having its own

709
00:37:00,000 --> 00:37:05,160
Speaker 1: sort of consciousness. But yeah, it's not necessarily indicative of

710
00:37:05,520 --> 00:37:07,680
Speaker 1: as much as I would like it to be a

711
00:37:07,920 --> 00:37:13,440
Speaker 1: giant space whale spouting its space spout, but it feels

712
00:37:13,440 --> 00:37:15,920
Speaker 1: that way very much. I think patterns feel very human,

713
00:37:15,960 --> 00:37:17,680
Speaker 1: they feel very intentional.

714
00:37:17,800 --> 00:37:19,880
Speaker 2: But I suspect this is just human bias.

715
00:37:20,000 --> 00:37:20,160
Speaker 4: You know.

716
00:37:20,200 --> 00:37:23,560
Speaker 2: We imagine that like nature is messy and doesn't form

717
00:37:23,640 --> 00:37:27,920
Speaker 2: things like perfect circles and perfect pulses and squares, because

718
00:37:27,920 --> 00:37:29,480
Speaker 2: that's the kind of thing that we like to make,

719
00:37:29,520 --> 00:37:32,120
Speaker 2: and we imagine that differentiates us. But you know, there

720
00:37:32,160 --> 00:37:35,680
Speaker 2: are like squares in nature. You can find weird formations

721
00:37:35,680 --> 00:37:38,480
Speaker 2: of rock that are like almost perfect cubes or whatever.

722
00:37:38,600 --> 00:37:40,319
Speaker 2: So I imagine that when we do get to an

723
00:37:40,400 --> 00:37:43,360
Speaker 2: alien planet sometime we will be tripped up by this

724
00:37:43,520 --> 00:37:47,520
Speaker 2: expectation that things that form straight lines or geometric patterns

725
00:37:47,800 --> 00:37:51,560
Speaker 2: must be artificial and technological and intelligent, and maybe not right.

726
00:37:51,640 --> 00:37:54,600
Speaker 2: Maybe those aliens are messy slobs and their cities don't

727
00:37:54,600 --> 00:37:56,879
Speaker 2: look anything like all of this, right, And there are

728
00:37:56,920 --> 00:38:00,000
Speaker 2: of course examples in the universe when things are very

729
00:38:00,120 --> 00:38:03,279
Speaker 2: regular and yet not artificial, and these pulsars are a

730
00:38:03,280 --> 00:38:06,720
Speaker 2: great example. And because they spin so fast, their pulses

731
00:38:06,760 --> 00:38:10,360
Speaker 2: are very very short. You know, on a cosmological time scale,

732
00:38:10,360 --> 00:38:14,040
Speaker 2: these things are super fast. Right, we expect stars to

733
00:38:14,160 --> 00:38:16,680
Speaker 2: pulse to vary on the scale of millions or billions

734
00:38:16,719 --> 00:38:19,120
Speaker 2: of years. These things are pulsing at like seconds, and

735
00:38:19,160 --> 00:38:22,240
Speaker 2: some of them are spinning so fast millisecond. Pulsars pulse

736
00:38:22,360 --> 00:38:27,200
Speaker 2: literally every millisecond and with extraordinary regularity. You know, they

737
00:38:27,200 --> 00:38:30,839
Speaker 2: are more precise, more accurate, more repeatable at least than

738
00:38:30,920 --> 00:38:32,800
Speaker 2: our best atomic clocks.

739
00:38:33,080 --> 00:38:36,200
Speaker 1: There's something that's hard for me to kind of visualize

740
00:38:36,200 --> 00:38:40,480
Speaker 1: with that, because when I think of space and you know, stars,

741
00:38:40,680 --> 00:38:45,520
Speaker 1: I think of very slow movements. But something that is

742
00:38:45,560 --> 00:38:49,719
Speaker 1: spinning that fast and flashing that fast, it's hard to

743
00:38:49,880 --> 00:38:51,440
Speaker 1: conceive of on that scale.

744
00:38:51,560 --> 00:38:53,560
Speaker 2: It is really amazing. And there's another sort of time

745
00:38:53,600 --> 00:38:56,200
Speaker 2: scale for pulsars, which is that they do slow down,

746
00:38:56,480 --> 00:38:59,120
Speaker 2: like as we watch them, they seem very very regular,

747
00:39:00,160 --> 00:39:02,880
Speaker 2: can't spin and emit light forever, right, that would be

748
00:39:02,880 --> 00:39:05,800
Speaker 2: like an infinite energy source. This rotation and this beam

749
00:39:05,880 --> 00:39:09,080
Speaker 2: actually SAPs energy from the star and eventually they do

750
00:39:09,200 --> 00:39:11,759
Speaker 2: slow down. We think that it takes like ten to

751
00:39:11,840 --> 00:39:15,000
Speaker 2: one hundred million years for a pulsar to basically give

752
00:39:15,120 --> 00:39:18,040
Speaker 2: up its energy by beaming it out into space. And

753
00:39:18,280 --> 00:39:20,359
Speaker 2: that's actually kind of a short amount of time. Right.

754
00:39:20,400 --> 00:39:24,200
Speaker 2: Pulsars don't last very long, which means that like most

755
00:39:24,200 --> 00:39:26,879
Speaker 2: of the pulsars in the history of the universe are

756
00:39:26,920 --> 00:39:30,239
Speaker 2: now quiet. They did their pulse, they spread their lighthouse

757
00:39:30,280 --> 00:39:33,680
Speaker 2: information through the universe, and now they're dead. They're quiet.

758
00:39:33,719 --> 00:39:35,880
Speaker 2: So in something like ninety nine percent of the pulsars

759
00:39:35,880 --> 00:39:37,960
Speaker 2: that ever pulse are no longer pulsing.

760
00:39:38,239 --> 00:39:41,120
Speaker 1: What happens to them after they stop pulsing? Do they

761
00:39:41,160 --> 00:39:45,520
Speaker 1: just remain a neutron star or do they turn into

762
00:39:45,520 --> 00:39:46,040
Speaker 1: something else?

763
00:39:46,160 --> 00:39:49,320
Speaker 2: We hope they have a long career as emeritus stars.

764
00:39:49,560 --> 00:39:53,840
Speaker 2: You know, they continue to participate in the galactics discussions. No, exactly,

765
00:39:53,840 --> 00:39:57,080
Speaker 2: then they're just neutron stars. Right, there's still hot blobs

766
00:39:57,120 --> 00:39:59,919
Speaker 2: of neutrons, they're just not emitting anymore. They're not spin

767
00:40:00,360 --> 00:40:01,040
Speaker 2: as fast.

768
00:40:01,280 --> 00:40:04,080
Speaker 1: I see. Well, the glory days are over for them,

769
00:40:04,320 --> 00:40:07,839
Speaker 1: maybe they can retire. Well, I'm gonna try to do

770
00:40:08,120 --> 00:40:11,600
Speaker 1: some spinning around to see if I can see what

771
00:40:11,640 --> 00:40:15,160
Speaker 1: it feels like to be a neutron star, and we

772
00:40:15,200 --> 00:40:31,120
Speaker 1: will be right back. So I just got really dizzy

773
00:40:31,480 --> 00:40:35,160
Speaker 1: trying to method act as a neutron star spinning around.

774
00:40:35,400 --> 00:40:39,600
Speaker 1: I feel nauseous, and I guess that's how these neutrons

775
00:40:39,600 --> 00:40:41,920
Speaker 1: stars feel too, if they can feel things. And I

776
00:40:42,239 --> 00:40:43,799
Speaker 1: sympathize and mentioned I.

777
00:40:43,800 --> 00:40:45,839
Speaker 2: Like that you're trying to get in the head of

778
00:40:45,880 --> 00:40:49,279
Speaker 2: your giant spinning space whale. That's really very empathetic of you.

779
00:40:49,400 --> 00:40:51,279
Speaker 2: And when they do come to visit, I think that's

780
00:40:51,320 --> 00:40:52,880
Speaker 2: going to make you sort of like last on the

781
00:40:52,920 --> 00:40:53,680
Speaker 2: list of people to.

782
00:40:53,640 --> 00:40:57,520
Speaker 1: Be eaten exactly. I think ahead, I plan for the

783
00:40:57,560 --> 00:40:58,120
Speaker 1: long game.

784
00:40:58,239 --> 00:41:00,800
Speaker 2: My point is that it sounds like you're being altruistic

785
00:41:01,040 --> 00:41:03,839
Speaker 2: and empathetic, but really it's cynical, right, You're just really

786
00:41:03,880 --> 00:41:05,400
Speaker 2: looking at it for Katie.

787
00:41:05,000 --> 00:41:07,080
Speaker 1: Like I'm hedging all my bets when it comes to

788
00:41:07,200 --> 00:41:12,560
Speaker 1: giant space whales. So I apologize for nothing. So we

789
00:41:12,680 --> 00:41:17,440
Speaker 1: just talked about pulsars, these neutron stars that's been incredibly

790
00:41:17,520 --> 00:41:20,560
Speaker 1: fast and sort of has that flash it like almost

791
00:41:20,560 --> 00:41:25,400
Speaker 1: like auroras that can flash really quickly, which kind of

792
00:41:25,400 --> 00:41:28,200
Speaker 1: blows my mind. So is this is have we gone

793
00:41:28,239 --> 00:41:32,120
Speaker 1: through all of the methods of pulsing in the universe.

794
00:41:31,840 --> 00:41:33,920
Speaker 2: Yet those are the primary methods of pulsing. There are

795
00:41:33,920 --> 00:41:37,000
Speaker 2: other things like supernovas that do change in the night sky,

796
00:41:37,520 --> 00:41:39,840
Speaker 2: but really these are the biggest categories of things we

797
00:41:39,920 --> 00:41:43,960
Speaker 2: expect to see flare stars, Sephid's pulsating stars, and then

798
00:41:44,040 --> 00:41:47,840
Speaker 2: pulsars themselves. But of course there's always the opportunity to

799
00:41:47,960 --> 00:41:51,120
Speaker 2: discover something new. And I was so excited to read

800
00:41:51,160 --> 00:41:54,520
Speaker 2: this paper for so many reasons, not just because they

801
00:41:54,560 --> 00:41:57,000
Speaker 2: found something new that we don't understand in the universe,

802
00:41:57,080 --> 00:42:01,200
Speaker 2: but because how the discovery was made. This discovery was

803
00:42:01,239 --> 00:42:05,200
Speaker 2: made by an undergraduate physics student who is looking through

804
00:42:05,320 --> 00:42:08,680
Speaker 2: old data that had been sitting on disc for years

805
00:42:09,160 --> 00:42:12,560
Speaker 2: and nobody had looked at in this way. He was like, well,

806
00:42:12,600 --> 00:42:15,200
Speaker 2: looking for a research opportunity, found a professor and the

807
00:42:15,200 --> 00:42:17,640
Speaker 2: professor said, hey, I have this data. Why don't you

808
00:42:17,680 --> 00:42:20,080
Speaker 2: look through this and see if you can find something weird.

809
00:42:20,320 --> 00:42:23,360
Speaker 2: So he's analyzed this data looking to see if you

810
00:42:23,400 --> 00:42:26,880
Speaker 2: could find things that pulsed at rates that were longer

811
00:42:26,920 --> 00:42:28,360
Speaker 2: than anybody looked at before.

812
00:42:28,600 --> 00:42:31,000
Speaker 1: This is a lesson to all undergraduates when you are

813
00:42:31,040 --> 00:42:34,160
Speaker 1: given what you think seems like busy work just to

814
00:42:34,200 --> 00:42:37,520
Speaker 1: get you out of the hair of some professor. Maybe not,

815
00:42:37,680 --> 00:42:39,319
Speaker 1: maybe you'll discover something new.

816
00:42:39,560 --> 00:42:42,239
Speaker 2: And this is not the first time undergraduates looking through

817
00:42:42,280 --> 00:42:45,400
Speaker 2: old data have found something dramatic that has taught us

818
00:42:45,440 --> 00:42:48,240
Speaker 2: something about the universe. Check out our episode on fast

819
00:42:48,360 --> 00:42:51,680
Speaker 2: radio bursts. It's also something very similar and interesting. And

820
00:42:51,719 --> 00:42:54,200
Speaker 2: the lesson here also is sometimes you have to know

821
00:42:54,239 --> 00:42:56,560
Speaker 2: what to look for when you're looking through the data.

822
00:42:56,600 --> 00:42:58,319
Speaker 2: Like you can't just stare up at the night sky

823
00:42:58,400 --> 00:43:00,560
Speaker 2: and say, Universe, tell me what's out there.

824
00:43:00,760 --> 00:43:03,319
Speaker 1: Wait, I've been doing, Mattgan, Well.

825
00:43:03,239 --> 00:43:05,040
Speaker 2: You have to ask a question, and you have to say,

826
00:43:05,120 --> 00:43:07,759
Speaker 2: you know, are there big pulses in radio bursts or

827
00:43:08,160 --> 00:43:12,080
Speaker 2: are there things that pulse very very long periods, Because

828
00:43:12,080 --> 00:43:13,640
Speaker 2: the kind of things we know of that are out

829
00:43:13,640 --> 00:43:17,640
Speaker 2: there pulsars, and they're very magnetic versions magnetars tend to

830
00:43:17,719 --> 00:43:21,239
Speaker 2: pulse on seconds or faster. And so this guy went

831
00:43:21,280 --> 00:43:23,680
Speaker 2: into the data and looked for things that pulsed with

832
00:43:23,880 --> 00:43:28,560
Speaker 2: longer time scales, and surprise, surprise, surprise, he found one.

833
00:43:28,920 --> 00:43:31,839
Speaker 2: His undergrad's name is PJ. Hancock, and he was looking

834
00:43:31,880 --> 00:43:35,600
Speaker 2: through data from the Australian Murchison wide field Array.

835
00:43:35,960 --> 00:43:39,359
Speaker 1: So when we talk about arrays, are these these are

836
00:43:39,800 --> 00:43:43,200
Speaker 1: big fields of detection equipment.

837
00:43:43,280 --> 00:43:45,759
Speaker 2: Yeah, exactly. The Murchison whitefield Array is not the kind

838
00:43:45,760 --> 00:43:48,359
Speaker 2: of telescope you find imagine where you're like looking through

839
00:43:48,360 --> 00:43:50,920
Speaker 2: an eyepiece up at the universe. It's actually just a

840
00:43:50,960 --> 00:43:54,440
Speaker 2: bunch of antennas. There are four thou ninety six sort

841
00:43:54,480 --> 00:43:58,719
Speaker 2: of like spider like antennas that all just receive radio messages.

842
00:43:58,840 --> 00:44:01,160
Speaker 2: Each one is just like an intent to listen to radio,

843
00:44:01,239 --> 00:44:04,560
Speaker 2: but instead of listening to you know, Kiss FM or whatever,

844
00:44:04,640 --> 00:44:07,560
Speaker 2: it's listening to messages from space. And you have this

845
00:44:07,640 --> 00:44:10,800
Speaker 2: big array of antennas, which helps you, number one, capture

846
00:44:10,840 --> 00:44:14,120
Speaker 2: more signals and also tell where the signals came from,

847
00:44:14,200 --> 00:44:16,479
Speaker 2: because if you see the signal first on one side

848
00:44:16,480 --> 00:44:19,120
Speaker 2: of the array, then it like sweeps over the array,

849
00:44:19,400 --> 00:44:21,000
Speaker 2: then you can tell where you're in the sky it

850
00:44:21,080 --> 00:44:22,000
Speaker 2: might have come from.

851
00:44:22,400 --> 00:44:25,720
Speaker 1: I love how we reverse engineer things that you find

852
00:44:26,000 --> 00:44:30,040
Speaker 1: in nature in terms of like detection. Animals that have

853
00:44:30,160 --> 00:44:35,600
Speaker 1: really good sensory organs that can really pinpoint where something

854
00:44:35,680 --> 00:44:38,960
Speaker 1: is coming from usually have this spatial element to it.

855
00:44:39,360 --> 00:44:43,280
Speaker 1: And I love that we have created as humans basically

856
00:44:43,320 --> 00:44:47,359
Speaker 1: all these sensory antenna on our Earth to turn our

857
00:44:47,400 --> 00:44:52,120
Speaker 1: Earth into like a giant et all detecting things out

858
00:44:52,120 --> 00:44:52,840
Speaker 1: in the universe.

859
00:44:53,239 --> 00:44:54,919
Speaker 2: Well, I hope the space whales don't like to eat

860
00:44:54,920 --> 00:44:56,160
Speaker 2: beetles when they come here.

861
00:44:57,840 --> 00:45:01,200
Speaker 1: It's a big space bird been. We're in trouble.

862
00:45:01,400 --> 00:45:04,000
Speaker 2: So he found this thing in the data that releases

863
00:45:04,440 --> 00:45:07,560
Speaker 2: big bursts of energy kind of like a pulsar. But

864
00:45:08,000 --> 00:45:11,760
Speaker 2: the weird thing is that it pulses every twenty minutes. Actually,

865
00:45:11,800 --> 00:45:15,800
Speaker 2: it's even weirder. It pulses every eighteen point eighteen minutes.

866
00:45:15,960 --> 00:45:19,040
Speaker 2: And this is a very long frequency for something in space,

867
00:45:19,120 --> 00:45:22,040
Speaker 2: Like we don't have models for magnetars or pulsars that

868
00:45:22,120 --> 00:45:24,919
Speaker 2: pulse this long. And in seconds, this is like one

869
00:45:25,600 --> 00:45:28,880
Speaker 2: ninety one seconds. And when it does pulse, it pulses

870
00:45:28,880 --> 00:45:31,960
Speaker 2: for like thirty to sixty seconds at a time, sometimes

871
00:45:32,080 --> 00:45:34,799
Speaker 2: with shorter bursts. If you look inside the paper, it's

872
00:45:34,840 --> 00:45:37,480
Speaker 2: really fascinating. They have like a sketch of all the

873
00:45:37,560 --> 00:45:40,239
Speaker 2: different pulses that they captured. Once they found a few

874
00:45:40,280 --> 00:45:42,480
Speaker 2: examples of this. They went back into the data and

875
00:45:42,560 --> 00:45:46,040
Speaker 2: scanned more deeply and they found a bunch of these examples.

876
00:45:46,200 --> 00:45:49,040
Speaker 2: So they have like seventy one pulses from this thing

877
00:45:49,440 --> 00:45:52,319
Speaker 2: over like a three month period when this telescope was

878
00:45:52,320 --> 00:45:54,360
Speaker 2: observing data in just the right direction.

879
00:45:54,680 --> 00:45:57,360
Speaker 1: Now I'm not a medical doctor, but if this was

880
00:45:57,480 --> 00:46:02,520
Speaker 1: the heart rate for someone, I would be concerned, because, yeah,

881
00:46:02,520 --> 00:46:05,480
Speaker 1: this looks this is a lot like there's a big

882
00:46:05,960 --> 00:46:07,880
Speaker 1: kind of spike and then there's a lot of little

883
00:46:07,920 --> 00:46:09,239
Speaker 1: spikes going on.

884
00:46:10,560 --> 00:46:12,640
Speaker 2: You're like, this thing needs a pacemaker.

885
00:46:13,360 --> 00:46:16,200
Speaker 1: Please help. My star is very sick.

886
00:46:16,360 --> 00:46:18,080
Speaker 2: Well, we don't know, right, maybe this is a very

887
00:46:18,120 --> 00:46:20,720
Speaker 2: healthy signature for a giant space whale, but it's definitely

888
00:46:20,760 --> 00:46:24,960
Speaker 2: something very weird for a pulsar. Again, pulsars tend to

889
00:46:25,000 --> 00:46:28,399
Speaker 2: be much much faster. And so when they found this thing,

890
00:46:28,520 --> 00:46:33,120
Speaker 2: this undergrad took it to his advisor, astrophysicist Natasha Hurley Walker,

891
00:46:33,280 --> 00:46:36,120
Speaker 2: and she dug in more deeply. But she said, quote,

892
00:46:36,239 --> 00:46:39,720
Speaker 2: I was concerned that it was aliens when he brought

893
00:46:39,719 --> 00:46:42,319
Speaker 2: it to her. And I have so many questions about that, like,

894
00:46:42,320 --> 00:46:45,279
Speaker 2: what do you mean concerned? Why are you concerned?

895
00:46:45,440 --> 00:46:49,120
Speaker 1: Not elated? And not ready to show them how you've

896
00:46:49,160 --> 00:46:52,240
Speaker 1: been trying to empathize with them by spinning around really fast.

897
00:46:52,719 --> 00:46:54,759
Speaker 1: This is why I plan exactly.

898
00:46:54,840 --> 00:46:56,960
Speaker 2: So they dug into this to try to understand, like,

899
00:46:57,000 --> 00:46:59,560
Speaker 2: what is this thing? Where is it coming from? And

900
00:46:59,560 --> 00:47:01,160
Speaker 2: one of the first things they had to do was

901
00:47:01,200 --> 00:47:04,080
Speaker 2: to understand the period of the pulses. But they noticed

902
00:47:04,120 --> 00:47:06,880
Speaker 2: the pulses didn't actually line up in a very nice period,

903
00:47:06,920 --> 00:47:10,400
Speaker 2: like the separation between the pulses wasn't perfect. And that

904
00:47:10,520 --> 00:47:13,200
Speaker 2: turned out to me because this thing is not coming

905
00:47:13,280 --> 00:47:16,640
Speaker 2: from our solar system. It's coming from something much much

906
00:47:16,680 --> 00:47:19,800
Speaker 2: further away. And as the Earth goes around the Sun,

907
00:47:20,200 --> 00:47:23,760
Speaker 2: it changes the frequency with which we observe these things.

908
00:47:23,880 --> 00:47:26,440
Speaker 2: So once they corrected for the Earth moving around the

909
00:47:26,480 --> 00:47:29,399
Speaker 2: Sun and like not capturing the signal at the same

910
00:47:29,440 --> 00:47:31,720
Speaker 2: place in our orbit as we go around, they found

911
00:47:31,719 --> 00:47:34,719
Speaker 2: a much more precise fit. So that tells us, Okay,

912
00:47:34,719 --> 00:47:37,600
Speaker 2: it is really very regular, and it's coming from somewhere

913
00:47:37,640 --> 00:47:40,640
Speaker 2: far away. It's not like, you know, behind Jupiter or

914
00:47:40,680 --> 00:47:43,360
Speaker 2: something like that. This thing is outside of our solar system.

915
00:47:43,360 --> 00:47:45,560
Speaker 2: It's not also orbiting our Sun.

916
00:47:45,960 --> 00:47:48,799
Speaker 1: I mean, that's kind of comforting. I'm glad that this

917
00:47:49,120 --> 00:47:52,880
Speaker 1: pulsating mystery object isn't just hiding behind Jupiter ready to

918
00:47:53,200 --> 00:47:55,759
Speaker 1: jump out at us. So we don't We don't even

919
00:47:55,800 --> 00:47:58,520
Speaker 1: know what it is. We don't know if it's like

920
00:47:58,600 --> 00:48:01,279
Speaker 1: a neutron star. We don't, like, what do we know

921
00:48:01,440 --> 00:48:05,720
Speaker 1: about it other than it has this weird twenty minute

922
00:48:05,840 --> 00:48:08,600
Speaker 1: ish interval and it's super far away.

923
00:48:08,880 --> 00:48:10,839
Speaker 2: We don't really know. We know that it's about four

924
00:48:10,920 --> 00:48:14,040
Speaker 2: thousand light years away, and they can use another trick

925
00:48:14,080 --> 00:48:15,759
Speaker 2: to tell the distance, which is how the light of

926
00:48:15,800 --> 00:48:19,320
Speaker 2: different frequencies is arriving on Earth. It doesn't all travel

927
00:48:19,400 --> 00:48:21,759
Speaker 2: through the universe at the same velocity, even though of

928
00:48:21,800 --> 00:48:24,520
Speaker 2: course light always has the same speed in a vacuum.

929
00:48:24,760 --> 00:48:28,080
Speaker 2: Space itself is not a perfect vacuum. There are electrons

930
00:48:28,120 --> 00:48:30,880
Speaker 2: all over the place, and that tends to effectively slow

931
00:48:30,960 --> 00:48:32,920
Speaker 2: light down, but just so at a different rate for

932
00:48:32,960 --> 00:48:37,319
Speaker 2: different frequencies. This is called dispersion. So the dispersion of

933
00:48:37,400 --> 00:48:40,880
Speaker 2: the signal tells us how far it's gone through this

934
00:48:41,120 --> 00:48:45,000
Speaker 2: like electron gas that's filling space, because we know something

935
00:48:45,040 --> 00:48:47,520
Speaker 2: about the density of the electron gas, so sort of

936
00:48:47,520 --> 00:48:50,560
Speaker 2: reverse engineering that you can tell by the dispersion that

937
00:48:50,600 --> 00:48:54,080
Speaker 2: it's about four thousand light years away from Earth, which

938
00:48:54,120 --> 00:48:57,040
Speaker 2: means that it is in our galaxy. It's not in

939
00:48:57,160 --> 00:49:00,000
Speaker 2: like another galaxy, which would be millions of light years.

940
00:49:00,520 --> 00:49:03,120
Speaker 1: Okay, so we do have to share the galaxy with

941
00:49:03,239 --> 00:49:07,080
Speaker 1: whatever this is. So I do want to understand it better,

942
00:49:07,200 --> 00:49:10,239
Speaker 1: so if it ever decides to visit, it knows I'm

943
00:49:10,239 --> 00:49:12,080
Speaker 1: on its team. What else do we know about this?

944
00:49:12,360 --> 00:49:14,520
Speaker 2: So we know that it's kind of got a broad signal,

945
00:49:14,600 --> 00:49:19,040
Speaker 2: meaning that it admits not just at a single radio wavelength, right,

946
00:49:19,080 --> 00:49:22,640
Speaker 2: And this convinces some people that it's not aliens. People think,

947
00:49:22,719 --> 00:49:24,520
Speaker 2: if we're going to get a message from aliens, it's

948
00:49:24,520 --> 00:49:26,440
Speaker 2: going to be at like one frequency, the way that

949
00:49:26,480 --> 00:49:29,040
Speaker 2: we tend to send radio messages, you know, kiss FM

950
00:49:29,200 --> 00:49:31,400
Speaker 2: is different from another frequency, like you know one to

951
00:49:31,440 --> 00:49:34,520
Speaker 2: one point one rocking from the eighties or whatever. All

952
00:49:34,560 --> 00:49:37,960
Speaker 2: your different stations are different frequencies, and so people imagine,

953
00:49:37,960 --> 00:49:39,239
Speaker 2: if we're going to get a message, it's going to

954
00:49:39,239 --> 00:49:41,360
Speaker 2: be at one frequency, and this one is sort of broad.

955
00:49:41,719 --> 00:49:43,880
Speaker 1: I don't know though, because like what if the aliens

956
00:49:43,960 --> 00:49:47,000
Speaker 1: want to really reach out to whoever, so they're trying

957
00:49:47,040 --> 00:49:50,160
Speaker 1: to send it out as on as many frequencies as

958
00:49:50,239 --> 00:49:54,080
Speaker 1: possible to make it more likely someone picks it up.

959
00:49:54,160 --> 00:49:56,560
Speaker 2: Yeah, exactly, We don't know, right, It's another case of

960
00:49:56,719 --> 00:50:00,720
Speaker 2: like anthromorphizing, how aliens might send their messages. So another

961
00:50:00,760 --> 00:50:03,600
Speaker 2: thing to look at is the potential magnetic field of

962
00:50:03,640 --> 00:50:06,960
Speaker 2: this object, if it's a pulsar or a magnetar, which

963
00:50:07,040 --> 00:50:09,760
Speaker 2: is just a pulsar with a very large magnetic field

964
00:50:09,920 --> 00:50:12,439
Speaker 2: that affects the kind of light that comes from it.

965
00:50:12,520 --> 00:50:15,120
Speaker 2: Like the photons that come from these stars have a

966
00:50:15,160 --> 00:50:18,960
Speaker 2: different polarization based on the magnetic field, and this seems

967
00:50:19,000 --> 00:50:21,279
Speaker 2: to have a very strong magnetic field on it. It's

968
00:50:21,320 --> 00:50:24,319
Speaker 2: a very bright object, so that points toward it being

969
00:50:24,360 --> 00:50:27,600
Speaker 2: a magnetar, but it would be very strange because it's

970
00:50:27,640 --> 00:50:30,600
Speaker 2: a very long period magnetar. Like if you look at

971
00:50:30,640 --> 00:50:34,080
Speaker 2: the distribution of pulsars magnetars that we've seen so far,

972
00:50:34,320 --> 00:50:37,640
Speaker 2: they all clustered have very short periods. So this is

973
00:50:37,680 --> 00:50:40,560
Speaker 2: like a big outlier. This is like a very weird

974
00:50:40,680 --> 00:50:42,680
Speaker 2: one from the point of view of like how fast

975
00:50:42,719 --> 00:50:43,880
Speaker 2: it seems to be spinning.

976
00:50:44,560 --> 00:50:48,720
Speaker 1: What is something that could affect the speed of its spinning,

977
00:50:48,920 --> 00:50:51,640
Speaker 1: Like would that be size of it or something else.

978
00:50:51,880 --> 00:50:53,680
Speaker 2: It might be that it's just kind of old. Remember,

979
00:50:53,719 --> 00:50:57,480
Speaker 2: these things eventually do slow down because they are emitting radiation,

980
00:50:58,080 --> 00:51:00,440
Speaker 2: and so they last for tens or hundreds of millions

981
00:51:00,440 --> 00:51:02,720
Speaker 2: of years. So it might just be that we're seeing

982
00:51:02,800 --> 00:51:05,359
Speaker 2: one sort of at the last moment. But the weird

983
00:51:05,360 --> 00:51:07,360
Speaker 2: thing is that we've never seen one like this before,

984
00:51:07,360 --> 00:51:10,480
Speaker 2: and we've seen lots and lots of pulsars in the universe.

985
00:51:10,560 --> 00:51:12,399
Speaker 2: So either these things are rare and it just takes

986
00:51:12,480 --> 00:51:14,879
Speaker 2: a while of observation before we see one of these

987
00:51:15,000 --> 00:51:17,279
Speaker 2: kinds of things, you know, like there's a tale of

988
00:51:17,320 --> 00:51:19,560
Speaker 2: a distribution. You have most of them in the bulk

989
00:51:19,600 --> 00:51:22,080
Speaker 2: and a few very slow ones that are sort of

990
00:51:22,080 --> 00:51:24,319
Speaker 2: fading out, and you just have to keep looking for

991
00:51:24,360 --> 00:51:26,520
Speaker 2: a long time, the way we have to like collide

992
00:51:26,520 --> 00:51:29,040
Speaker 2: particles for a long time before we see a Higgs boson.

993
00:51:29,320 --> 00:51:31,399
Speaker 2: You have to keep looking before you see the rare ones,

994
00:51:31,440 --> 00:51:34,280
Speaker 2: and there's just now emerging because we've been paying attention

995
00:51:34,400 --> 00:51:36,439
Speaker 2: for so long. Or it might be a new kind

996
00:51:36,440 --> 00:51:38,480
Speaker 2: of thing, right, it might be something else out there,

997
00:51:38,680 --> 00:51:42,160
Speaker 2: not a magnetar, some new kind of astrophysical object that

998
00:51:42,200 --> 00:51:45,720
Speaker 2: has a different kind of behavior. And that's frankly my hope,

999
00:51:45,840 --> 00:51:48,440
Speaker 2: because that means that there's something new that the universe

1000
00:51:48,520 --> 00:51:52,280
Speaker 2: can do, right, and it's sending us literally sending us information.

1001
00:51:52,360 --> 00:51:54,680
Speaker 2: It says, be be beep, there's something going on here.

1002
00:51:54,840 --> 00:51:58,440
Speaker 1: I do like the sort of funny irony though, if

1003
00:51:58,440 --> 00:52:00,520
Speaker 1: it is just a grandpas star, just like.

1004
00:52:00,560 --> 00:52:02,200
Speaker 2: Oh, what's going on over there?

1005
00:52:02,800 --> 00:52:06,399
Speaker 1: Just gotta slow down a little bit, you know, and

1006
00:52:06,480 --> 00:52:08,480
Speaker 1: we think it's some new exciting thing, but it's just

1007
00:52:08,760 --> 00:52:12,279
Speaker 1: old star, old and slow. Somehow. That's cute to me

1008
00:52:12,400 --> 00:52:15,880
Speaker 1: that stars slow down when they get older, just like people.

1009
00:52:17,160 --> 00:52:19,600
Speaker 2: So people are trying to study this thing in further detail.

1010
00:52:19,640 --> 00:52:22,959
Speaker 2: They're like looking at it across a range of frequencies,

1011
00:52:23,120 --> 00:52:27,000
Speaker 2: understanding its X ray emissions because magnetars tend to be

1012
00:52:27,000 --> 00:52:29,560
Speaker 2: fairly quiet in the X rays. So they look for

1013
00:52:29,719 --> 00:52:31,600
Speaker 2: X rays from this thing and didn't see any, which

1014
00:52:31,640 --> 00:52:33,759
Speaker 2: is sort of consistent with being a magnetar, but not

1015
00:52:33,800 --> 00:52:36,480
Speaker 2: really a smoking gun because you're like not seeing a

1016
00:52:36,520 --> 00:52:39,600
Speaker 2: signature instead of seeing a signature. So what they're doing

1017
00:52:39,600 --> 00:52:41,400
Speaker 2: now is they're looking for more of these things, Like

1018
00:52:41,440 --> 00:52:43,920
Speaker 2: we have a bunch of data that nobody's analyzed that

1019
00:52:44,040 --> 00:52:47,440
Speaker 2: might have more examples. It might be like that data

1020
00:52:47,480 --> 00:52:51,040
Speaker 2: set that undergrad was looking at could have dozens of examples,

1021
00:52:51,200 --> 00:52:53,879
Speaker 2: or other radio telescopes around the world might have taken

1022
00:52:53,960 --> 00:52:57,200
Speaker 2: data with this in it and nobody else had noticed.

1023
00:52:57,320 --> 00:53:00,200
Speaker 2: So it's exciting that you can make discoveries like in

1024
00:53:00,200 --> 00:53:03,680
Speaker 2: the data that we already have like sitting on computers.

1025
00:53:03,920 --> 00:53:06,640
Speaker 1: Yeah, I mean, it seems that the key is knowing.

1026
00:53:07,040 --> 00:53:09,279
Speaker 1: Like you said earlier, the key is knowing what to

1027
00:53:09,560 --> 00:53:12,319
Speaker 1: look for. It's hard to spot a pattern if you

1028
00:53:12,440 --> 00:53:15,520
Speaker 1: don't even know what you're supposed to be focusing on,

1029
00:53:15,960 --> 00:53:18,080
Speaker 1: or like what timescale you should be looking at.

1030
00:53:18,160 --> 00:53:20,560
Speaker 2: Yeah, there's something really deep there about how we make

1031
00:53:20,600 --> 00:53:22,960
Speaker 2: discoveries and how we look out in the universe, what

1032
00:53:23,000 --> 00:53:25,560
Speaker 2: we notice and what we don't notice. Because the universe

1033
00:53:25,640 --> 00:53:28,680
Speaker 2: is like a tsunami of information, you can't pay attention

1034
00:53:28,760 --> 00:53:31,920
Speaker 2: to everything. You can't notice everything, so our brains tend

1035
00:53:32,000 --> 00:53:34,799
Speaker 2: to filter and pattern match. We can only really see

1036
00:53:34,800 --> 00:53:37,440
Speaker 2: a tiny fraction of what's out there in the universe,

1037
00:53:37,600 --> 00:53:40,759
Speaker 2: even just surrounding us. Right, people are very oblivious to

1038
00:53:40,800 --> 00:53:43,440
Speaker 2: obvious stuff if they're not looking for it. So what

1039
00:53:43,480 --> 00:53:45,759
Speaker 2: we see in the universe depends on what we look for,

1040
00:53:45,840 --> 00:53:48,480
Speaker 2: which means we might be missing all sorts of crazy

1041
00:53:48,520 --> 00:53:50,960
Speaker 2: stuff that's happening out there just because we haven't been

1042
00:53:51,000 --> 00:53:53,920
Speaker 2: asking the right questions and we didn't have patient undergrads

1043
00:53:53,960 --> 00:53:57,080
Speaker 2: to sift through the data in the right way. Right,

1044
00:53:57,160 --> 00:53:59,399
Speaker 2: and in one hundred years or five hundred years, people

1045
00:53:59,480 --> 00:54:02,520
Speaker 2: might laugh that how obvious these discoveries were to make

1046
00:54:02,560 --> 00:54:04,960
Speaker 2: if we'd only known to ask the right questions.

1047
00:54:05,160 --> 00:54:08,400
Speaker 1: That's why it's really important for people in academia to

1048
00:54:08,480 --> 00:54:11,000
Speaker 1: remember that undergrads are people too.

1049
00:54:12,280 --> 00:54:14,640
Speaker 2: And for you out there to remember that there's lots

1050
00:54:14,680 --> 00:54:18,279
Speaker 2: more things to discover in the universe, really basic, low

1051
00:54:18,360 --> 00:54:21,839
Speaker 2: hanging fruit that almost anybody could figure out if they

1052
00:54:21,880 --> 00:54:24,160
Speaker 2: have the interest and the patience. So if you have

1053
00:54:24,239 --> 00:54:28,000
Speaker 2: aspirations to become an astrophysicist one day, don't worry. This

1054
00:54:28,200 --> 00:54:30,839
Speaker 2: plenty of stuff for you to discover, all right. Thanks

1055
00:54:30,920 --> 00:54:33,200
Speaker 2: very much Katie for joining us on today's tour of

1056
00:54:33,320 --> 00:54:37,919
Speaker 2: pulsating space whales and slime orbs or maybe just magnetars.

1057
00:54:38,360 --> 00:54:40,719
Speaker 2: And thanks to our listeners for coming along another ride

1058
00:54:40,760 --> 00:54:42,879
Speaker 2: as we talk about the weird stuff that's out there

1059
00:54:42,960 --> 00:54:43,680
Speaker 2: in the universe.

1060
00:54:43,840 --> 00:54:45,839
Speaker 1: I'm going to do some more spinning to see if

1061
00:54:45,880 --> 00:54:49,960
Speaker 1: I can feel what it feels like to be this mysterious,

1062
00:54:50,000 --> 00:54:50,960
Speaker 1: pulsating object.

1063
00:54:51,200 --> 00:54:53,360
Speaker 2: And when they get here, they're not going to love you, Katie.

1064
00:54:53,400 --> 00:54:55,719
Speaker 2: I'm sorry, they just could eat you like everybody else.

1065
00:54:57,120 --> 00:54:59,400
Speaker 1: I don't know. If I'm so dizzy that I've thrown up,

1066
00:54:59,440 --> 00:55:00,560
Speaker 1: they may not to eat.

1067
00:55:00,400 --> 00:55:03,760
Speaker 2: Me, or maybe that makes you delicious. Either way, Thanks

1068
00:55:03,800 --> 00:55:15,040
Speaker 2: everybody for listening in tune in next time. Thanks for listening,

1069
00:55:15,040 --> 00:55:17,759
Speaker 2: and remember that Daniel and Jorge Explain the Universe is

1070
00:55:17,800 --> 00:55:22,399
Speaker 2: a production of iHeartRadio. For more podcasts from iHeartRadio, visit

1071
00:55:22,440 --> 00:55:26,520
Speaker 2: the iHeartRadio app, Apple Podcasts, or wherever you listen to

1072
00:55:26,600 --> 00:55:27,600
Speaker 2: your favorite shows.