Expanding Universes, Space Elevators & the Enigma of Gale Crater

WEBVTT

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Andrew Dunkley: Hello again. This is Space Nuts. It's a Q and

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A edition. This is where we take questions

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from the audience, throw them in the bin and

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discuss other things amongst ourselves. No,

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we do answer questions from the audience and

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we've got a bunch. Um, we've got a question

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about the uh, naming of the

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increase in the expansion of the universe

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rate. Although last episode, if you

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were listening, that might not be happening,

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but we will still try and tackle it. Uh,

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there's a question about space elevators.

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We've got uh, a question about an object that

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has been getting a lot of attention

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TOI6894B. And

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a very different kind of question, I

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will say, uh, regarding Gale Crater.

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That's all coming up on this, uh, edition of

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space nuts. 15 seconds. Guidance is

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internal. 10, 9.

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Ignition sequence start.

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Jonti Horner: Space nuts. 5, 4, 3, 2.

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Andrew Dunkley: 1. 2, 3, 4, 5, 5, 4, 3,

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2, 1. Space nuts. Astronauts report

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it feels good. He's back again for

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more. He is Jonti Horner, professor of

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Astrophysics at the University of Southern

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Queensland. Jonti, hello.

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Jonti Horner: Good afternoon. How are you going?

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Andrew Dunkley: I'm well, I'm very well.

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Uh, we've got a lot of questions and this

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very first one, we'll jump straight in. Comes

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from Rusty in Donnybrook in Western

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Australia.

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Andrew Dunkley: Johnny and Andrew. G'.

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Jonti Horner: Day.

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Andrew Dunkley: It's Rusty in Donnybrook and I'm wondering

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what the, the term um, for

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an increase in the acceleration

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rate for the expansion of the universe is.

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We've known about. Well we've had this

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concept for quite a few years now. And

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recently we um, we're now looking at

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a reduction in the acceleration of the

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expansion rate of the universe as well. So

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there's a positive and a negative aspect to

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this. And um, since we've had all this time,

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someone may have come up with ah, a better

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term than jolt or jerk, which seem

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to apply to very short term changes

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and not very gradual changes that

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we theorize uh, in the expansion of the

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universe. Thank you.

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Andrew Dunkley: Thanks Rusty. Always good to hear from you.

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Uh, he's always got a

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curveball type question, has Rusty. Although

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we might have been able to curve the ball

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back to him because last uh, episode we

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were talking about this very subject, the

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expand, increasing rate of the

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expansion of the universe. And uh, he wants

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to know what it should be called. But um, the

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expansion of the universe theory might be

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tipped on its head because of the research we

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were talking about last time. So if you

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haven't listened to the previous

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episode573, go back and have a Listen to

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the last story because it, it's

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suggesting that, uh, things may not be as

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they seem. Jonti.

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Jonti Horner: Absolutely. And it's, you know, this advert

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brought to you by the developing nature of

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science. Essentially it, uh, is how science

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evolves. You know, we get new observations

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and we revisit our theories. It's a really

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good question and it's a really good point. I

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have never actually heard any

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nickname or any kind of easy roll off

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the tongue phrase to talk about the

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accelerating expansion of the universe.

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Cosmologists talk about things in the context

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of the lambda CDM model. And, um, I don't

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really understand what that is because I'm

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not a cosmologist, but that is not an easy

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roll off the tongue nickname. Now, if you go

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back to the very, very, very, very early

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youth of the universe, there was

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a period where there was this incredibly

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accelerated expansion that is hypothesized

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called inflation. And, um, that was

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very, very, very early on. That's called the

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inflationary period. That's a little bit

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different. What Russ is talking about here is

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the, uh, evidence which won the Nobel

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Prize in 1998, I think, for the fact that,

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that the universe may be expanding at an

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accelerating rate. So in other words, the

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expansion is getting quicker rather than

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slowing down. And if gravity was winning,

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you'd expect the expansion to slow down over

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time as gravity pulls back on the expansion.

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So this was the great evidence for the

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existence of dark energy, which people

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hypothesize contributes something like

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68% of all that there is in the universe.

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It's basically we're a dark energy universe

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with a fair chunk of dark matter and a tiny

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little bit of normal matter on the side, like

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less than 2%. That,

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as we talked about in the previous episode,

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may be a paradigm that is about to change.

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There's growing evidence that the universe is

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perhaps a bit more complex than that. But in

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terms of Rusty's question, I have never come

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across a simple term or nickname

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or something like that for this theory.

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People just talk about the accelerating

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expansion rate of the universe. So

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unfortunately, Rusty, I can't help you there.

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To the best of my knowledge, there is no

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really snappy roll off your tongue thing. I.

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The model that tries to explain it, like,

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say, is a lambda CDM model. But that is

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not a snappy, um,

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public article, BBC documentary

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type name that will capture people's

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imaginations. That's just a working

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terminology in the industry kind of thing.

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Yeah.

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Andrew Dunkley: Well, while you've been talking, I asked

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Chatgpt what we

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should call it. It came up with a whole

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bunch, uh, accelerating universe hypothesis,

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uh, cosmic expansion theory, uh,

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inflation continuum theory, dark energy

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paradigm. You use that word. Uh,

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that's a more scientific style. But uh, it

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came up with some, uh, conceptual names. The

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great unbinding, uh,

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external expansion

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hypothesis, uh, runaway cosmos

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model, uh, the horizon drift

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theory. I like that one. Metric

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unfolding principle, the lambda drive and the

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everflight theory. That's what ChatGPT's come

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up with. Probably just found stuff that

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people have published.

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Jonti Horner: I think a lot of those are things that are

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linked to this but are other hypotheses and

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stuff like that. Yeah, I mean I have to admit

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that I didn't really want to Google things

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there because I wasn't all that keen on

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seeing the Google autocorrect coming back

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saying, did you mean expanding wasteland?

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Andrew Dunkley: Yeah, it does come up with some. Really what

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I hate is when I know exactly what I'm

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searching for. I put it in, I've uh, spelled

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it right and an autocorrect and finds me

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something else. Yeah, that's not what I asked

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for. I told you to look for, you know,

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lemonade, not lemons. Anyway,

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thanks Rusty. Uh, maybe you've got a name you

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can send through to us or maybe um, somebody

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could pose the question on the Facebook group

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or the podcast group on Facebook and uh,

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come up with some names. I'd be interested to

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see what you think of.

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Uh, our next question comes from Barry. Uh,

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Barry said, I, uh, recently read a sci fi

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book called First Ascent. Based on a space

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element. The elevator had six stations, one

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being Earth, uh, two at 300 kilometers, five

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at 6200 kilometers and six being

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geostationary orbit at

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35,786 kilometers. I

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know the International Space Station's about

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400 kilometers and the crew are in free

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fall. This is due to the forward motion of

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the iss, which is constantly falling and is

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in orbit. In the book they discuss that at

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Station 1 at 300 km the travellers are still

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at about 1G. Station 5, uh,

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at 6200 km they're at 1 quarter G,

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they're on the moon, they be at 1/6 and free

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fall, weightless, is at station 6,

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35,000 and a bit kilometers. Can you

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discuss with accuracy of feeling

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gravity if and when a space elevator is

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built? Of course, this is totally

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hypothetical for at least the next few

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hundred or thousand years. Yes it is. It's

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not something we can do yet. And even if we

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could, I don't know if it would be the

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Logical way to do things. But you know, we

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don't know what reasons in the future we

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might need one. So um, we'll just leave it

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hanging in the air. Boom.

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Jonti Horner: Boom.

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Andrew Dunkley: Um, so, uh, yeah. So can you discuss the

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accuracy of feeling gravity if and when a

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space.

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Jonti Horner: Uh, elevator is built?

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Yeah, it's a fabulous question. And it does

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sound like this book is hard sci fi in

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the sense that it's based on real world

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physics is what I'd say. It sounds like the

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numbers are right to me. Now the argument is

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that a space elevator, once you can get it

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built, it's an incredibly challenging thing

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to do beyond us at the minute. But once

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you've got it, it's suddenly it makes it much

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easier to access space. And part of the

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argument there is that we will be extracting

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resources off Earth. And so it's likely that

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there'll be more stuff coming down the

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elevator than going up. So effectively you

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can ride up for free, just, you know, as a

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side effect of it. So it's one of those

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things that has become a staple of kind of

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relatively near futureish science fiction.

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The numbers here about the acceleration that

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you'd feel are accurate. So there's two ways

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that you can get gravity if you're on a space

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elevator. One is that you would feel

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a pseudo gravity based on the acceleration

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of the lift going upwards. And you

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get this when your lift goes up or when it

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falls. If you're in a building that has one

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of those ultra fast lifts, you feel a little

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bit more weightless. If it's going down, you

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feel a little bit heavier when it's pulling

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up initially because the flow will be

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accelerating up to meet you or

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accelerating down away from you. And that

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will mean that you will get a change to the

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gravity you would otherwise feel if you were

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stationary at that altitude. So

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some sci fi books I've seen with kind of far

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future type technology have

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your space elevator, uh, able to accelerate,

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ah, or in excess of 1g, very hard

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acceleration. And what they do is they

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accelerate slowly going up through the

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atmosphere and then speed up once you're in

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vacuum with the acceleration

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offsetting the drop in gravity you get as you

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get higher, keeping you at a comfortable

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level of gravity. And then when you're

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halfway to the end point, it turns around,

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you have a brief period of pseudo

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weightlessness and then you accelerate in the

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other direction, slow down. So that's one way

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that you could get kind of constant gravity

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throughout almost the entire trip. And that

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will get you to your uh, End point pretty

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quickly. So if you're accelerating at 1G, you

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actually accelerate very quickly. And that's

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why you wait till you're out of the

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atmosphere to do that. But the other thing

259
00:10:15.380 --> 00:10:17.780
is, as you ride up on a space elevator, the

260
00:10:17.780 --> 00:10:20.780
higher you get, you will still feel gravity

261
00:10:20.780 --> 00:10:22.540
pulling you down through the soles of your

262
00:10:22.540 --> 00:10:25.070
feet, but the strength of the gravitational

263
00:10:25.070 --> 00:10:27.950
pull you feel will weaken. Now,

264
00:10:27.950 --> 00:10:30.790
when you're at the end point, which is

265
00:10:30.790 --> 00:10:33.590
a space station in geostationary orbit, you

266
00:10:33.590 --> 00:10:35.750
are moving around the Earth, ah, at orbital

267
00:10:35.750 --> 00:10:38.230
velocity. And, um, the space station around

268
00:10:38.230 --> 00:10:39.910
you is moving around the Earth at orbital

269
00:10:39.910 --> 00:10:42.150
velocity. So that's why you'd be weightless,

270
00:10:42.150 --> 00:10:44.270
because you're accelerating at exactly the

271
00:10:44.270 --> 00:10:46.710
same rate as your surroundings.

272
00:10:47.430 --> 00:10:50.070
So compared to you, there is no acceleration

273
00:10:50.070 --> 00:10:51.950
pulling you down because the flow's falling

274
00:10:51.950 --> 00:10:54.290
away at exactly the speed that you're falling

275
00:10:54.290 --> 00:10:56.890
down effectively. So that's what you'd

276
00:10:56.890 --> 00:10:58.450
experience very briefly if you were in an

277
00:10:58.450 --> 00:11:01.090
elevator on Earth and the wires were cut when

278
00:11:01.090 --> 00:11:03.250
you started to fall, you'd be weightless, but

279
00:11:03.250 --> 00:11:05.010
you wouldn't be enjoying the experience. No,

280
00:11:05.010 --> 00:11:06.610
not much worrying about what happens at the

281
00:11:06.610 --> 00:11:09.250
bottom. Although, thanks to a very, very

282
00:11:09.250 --> 00:11:12.210
silly TV series that's quite swearing

283
00:11:12.210 --> 00:11:14.690
offensive called Archer, my understanding is

284
00:11:14.690 --> 00:11:17.570
that lifts, uh, have been designed in such a

285
00:11:17.570 --> 00:11:19.370
way that if the cables break, there are

286
00:11:19.370 --> 00:11:21.330
safety mechanisms in so you won't just splat

287
00:11:21.330 --> 00:11:23.200
at the bottom. There was a whole episode

288
00:11:23.200 --> 00:11:24.600
based where they were stuck in the lift and

289
00:11:24.600 --> 00:11:26.320
they were worried about that. It's bizarre

290
00:11:26.320 --> 00:11:28.160
what you learn from random TV cartoons.

291
00:11:28.160 --> 00:11:31.160
Anyway, so you have,

292
00:11:31.320 --> 00:11:34.040
at the upper limit, effectively

293
00:11:34.280 --> 00:11:37.080
zero G, you are weightless. You're actually,

294
00:11:37.240 --> 00:11:39.520
you are experiencing the Earth's gravity, but

295
00:11:39.520 --> 00:11:40.880
so is the space station around you. When

296
00:11:40.880 --> 00:11:42.840
you're falling together, just like mentioned

297
00:11:42.840 --> 00:11:44.360
with the International Space Station

298
00:11:45.880 --> 00:11:48.680
at, uh, that point, if you had some way of

299
00:11:49.350 --> 00:11:51.550
sitting stationary in space, so in other

300
00:11:51.550 --> 00:11:54.190
words, you were not orbiting the Earth, you

301
00:11:54.190 --> 00:11:56.070
were motionless, but you had a rocket holding

302
00:11:56.070 --> 00:11:58.070
you up. You would still feel the Earth's

303
00:11:58.070 --> 00:12:00.670
gravity pulling you down because the rocket

304
00:12:00.670 --> 00:12:02.070
would be pushing up against your feet

305
00:12:02.070 --> 00:12:04.590
essentially, and you'd feel the strength of

306
00:12:04.590 --> 00:12:06.950
gravity there. You're, uh, at

307
00:12:06.950 --> 00:12:09.710
36,000 kilometers, which means you're 42,000

308
00:12:09.710 --> 00:12:11.350
kilometers from the center of the earth,

309
00:12:11.670 --> 00:12:13.870
which means you're seven times further from

310
00:12:13.870 --> 00:12:15.490
the middle of the Earth, uh, than we are

311
00:12:15.490 --> 00:12:17.930
here. The strength of gravity falls off as 1

312
00:12:17.930 --> 00:12:20.654
over distance squared. So you'd feel about 1

313
00:12:20.726 --> 00:12:23.610
50th of a G there. So if

314
00:12:23.610 --> 00:12:25.130
you were able to sit still rather than

315
00:12:25.130 --> 00:12:26.730
falling with the Space station, you would

316
00:12:26.730 --> 00:12:28.890
feel a little bit of gravity there, but it

317
00:12:28.890 --> 00:12:31.850
wouldn't be that intense at the lower

318
00:12:31.850 --> 00:12:34.810
altitudes. The effect

319
00:12:34.810 --> 00:12:36.970
is dominated not by your rotation movement,

320
00:12:36.970 --> 00:12:38.730
because you're going much slower than orbital

321
00:12:38.730 --> 00:12:41.410
speed, but by the fact that gravity is

322
00:12:41.410 --> 00:12:43.790
pulling you down, but the

323
00:12:43.950 --> 00:12:45.950
lift is being winched upwards.

324
00:12:46.990 --> 00:12:49.710
So if you lifted your space elevator up and

325
00:12:49.710 --> 00:12:52.270
you stopped at one of these stops, and that's

326
00:12:52.270 --> 00:12:54.630
why they talk about the stops, I suspect if

327
00:12:54.630 --> 00:12:57.270
you stopped at 300 km at a station just above

328
00:12:57.270 --> 00:12:59.070
the atmosphere, attached to the tether,

329
00:12:59.710 --> 00:13:02.310
moving around at the same speed the Earth's

330
00:13:02.310 --> 00:13:05.110
rotating underneath you, you'd feel an

331
00:13:05.110 --> 00:13:07.190
acceleration due to gravity that is a little

332
00:13:07.190 --> 00:13:08.870
bit smaller than that we feel at the surface

333
00:13:08.870 --> 00:13:11.080
of the Earth. Now, if you're at the top of

334
00:13:11.080 --> 00:13:13.000
Mount Everest, technically you feel a

335
00:13:13.000 --> 00:13:14.880
slightly lower acceleration due to gravity

336
00:13:14.880 --> 00:13:17.640
than you do at the sea level because

337
00:13:17.640 --> 00:13:19.320
you're further from the center of the Earth.

338
00:13:19.400 --> 00:13:22.320
So that one over R squared component in

339
00:13:22.320 --> 00:13:25.280
the acceleration due to gravity equation is

340
00:13:25.280 --> 00:13:27.480
a slightly bigger number on the R squared,

341
00:13:27.480 --> 00:13:29.200
which means your acceleration due to gravity

342
00:13:29.200 --> 00:13:31.360
is a slightly smaller number. But that's

343
00:13:31.360 --> 00:13:33.240
imperceptible to humans. But we can measure

344
00:13:33.240 --> 00:13:35.720
it with instrumentation. That, incidentally,

345
00:13:35.720 --> 00:13:38.320
is why, if you really wanted to, to,

346
00:13:38.540 --> 00:13:41.480
um, lose weight, um, but

347
00:13:41.480 --> 00:13:43.760
you're being lazy. If you want to get weighed

348
00:13:43.760 --> 00:13:45.480
in the place where you will wear the least on

349
00:13:45.480 --> 00:13:47.800
the Earth, you go to the top of that mountain

350
00:13:47.800 --> 00:13:49.880
near the equator. Is it anaconda? I think it

351
00:13:49.880 --> 00:13:52.000
is. Which is a point on the Earth that is

352
00:13:52.000 --> 00:13:54.320
furthest from the Earth's core. Because

353
00:13:54.320 --> 00:13:55.920
you've got the bulge of the Earth's equator

354
00:13:55.920 --> 00:13:58.640
on top of the height of the mountain.

355
00:13:59.120 --> 00:14:00.600
And you will feel a slightly smaller

356
00:14:00.600 --> 00:14:02.160
acceleration due to gravity there because

357
00:14:02.160 --> 00:14:04.310
you're further from the Earth's core. So at

358
00:14:04.310 --> 00:14:07.190
300km up, you've only changed your distance

359
00:14:07.190 --> 00:14:10.030
from the center of the earth by about 5%. And

360
00:14:10.030 --> 00:14:11.390
so you've probably changed the acceleration

361
00:14:11.390 --> 00:14:13.430
due to gravity by less than 10%. It's

362
00:14:13.430 --> 00:14:15.070
probably enough that you'd be able to notice

363
00:14:15.070 --> 00:14:17.470
it. Walking around would feel slightly

364
00:14:17.470 --> 00:14:20.069
unusual, but it wouldn't be a problem. The

365
00:14:20.390 --> 00:14:22.230
station number five that is mentioned here,

366
00:14:22.230 --> 00:14:25.110
at 6200km, that means

367
00:14:25.110 --> 00:14:27.150
you're nearly twice as far away from the

368
00:14:27.150 --> 00:14:29.350
center of the Earth now as we are on the

369
00:14:29.350 --> 00:14:30.980
surface of the Earth. Surface of the Earth,

370
00:14:30.980 --> 00:14:33.780
we're about 6,380 kilometers from the middle.

371
00:14:34.020 --> 00:14:35.780
Varies a little depending on your altitude

372
00:14:35.780 --> 00:14:37.140
above sea level and where you are on the

373
00:14:37.140 --> 00:14:39.650
globe. Yeah. Add another 6200

374
00:14:39.790 --> 00:14:42.180
km, you've effectively doubled the distance,

375
00:14:42.740 --> 00:14:45.500
which means 1 upon r squared is 1 over 2

376
00:14:45.500 --> 00:14:48.140
times 1 over 2 is 1 over 4. So the

377
00:14:48.140 --> 00:14:50.860
acceleration is a quarter of a g. So we've

378
00:14:50.860 --> 00:14:52.740
dropped the strength of gravitude field by a

379
00:14:52.740 --> 00:14:54.820
factor of four. And at that point that is

380
00:14:54.820 --> 00:14:57.770
hugely noticeable. It's a little bit stronger

381
00:14:57.770 --> 00:14:59.610
gravity than you'd have on the moon, but not

382
00:14:59.610 --> 00:15:02.010
by much. Now, I guess this is the kind of

383
00:15:02.010 --> 00:15:03.850
thing where you could, if you were sending

384
00:15:03.850 --> 00:15:06.370
people to Mars and you wanted them to

385
00:15:06.850 --> 00:15:09.850
experience Martian gravity and see if they

386
00:15:09.850 --> 00:15:11.690
could cope with it, you know, you had a

387
00:15:11.690 --> 00:15:13.690
training and a testing program and anybody

388
00:15:13.690 --> 00:15:15.370
that got too travel sick or whatever and

389
00:15:15.370 --> 00:15:17.330
couldn't adapt was bumped out of the program.

390
00:15:17.730 --> 00:15:19.890
What you do is you take this space elevator,

391
00:15:20.290 --> 00:15:22.490
you figure out exactly at what height above

392
00:15:22.490 --> 00:15:24.490
the ground, you would emulate Martian gravity

393
00:15:24.490 --> 00:15:26.600
perfectly and you build a training station

394
00:15:26.600 --> 00:15:28.440
there. Because at the end of the day, if

395
00:15:28.440 --> 00:15:29.880
you've got a space elevator, you know, you

396
00:15:29.880 --> 00:15:32.720
may as well put an extra level on it. Um, and

397
00:15:32.720 --> 00:15:34.120
that way you can train people up for Mars.

398
00:15:34.120 --> 00:15:35.680
And I could almost imagine a future where

399
00:15:35.680 --> 00:15:37.560
they have one for the moon as well. You know,

400
00:15:37.880 --> 00:15:39.640
go up there, spend a few weeks training in

401
00:15:39.640 --> 00:15:41.880
lunar gravity and see if you can hack it on

402
00:15:41.880 --> 00:15:43.200
the surface of the M moon. And anybody who

403
00:15:43.200 --> 00:15:45.680
can't, no shame. We all have slightly

404
00:15:45.680 --> 00:15:47.840
different balance systems and all the rest of

405
00:15:47.840 --> 00:15:50.000
it, if you can't adjust, that's fine, you can

406
00:15:50.000 --> 00:15:52.890
work on Earth, no problem. But so it

407
00:15:52.890 --> 00:15:55.810
does sound like the science in this

408
00:15:55.810 --> 00:15:58.450
book is robust. In other words, it's hard,

409
00:15:58.530 --> 00:15:59.450
hard sci fi.

410
00:15:59.450 --> 00:16:01.530
It's based on our current understanding of

411
00:16:01.530 --> 00:16:03.690
physics and that's how it would work on space

412
00:16:03.690 --> 00:16:05.370
elevator. So hopefully that makes sense. And

413
00:16:05.370 --> 00:16:08.330
it is a really good example of how you can

414
00:16:08.330 --> 00:16:10.610
use a science fiction book to t to teach

415
00:16:10.610 --> 00:16:11.730
people science fact.

416
00:16:12.370 --> 00:16:14.710
Andrew Dunkley: Yeah, absolutely. Yeah. Thanks, Barry. Um,

417
00:16:14.930 --> 00:16:17.920
just a side question, Jonti. Do you think

418
00:16:17.920 --> 00:16:19.880
we ever will build such a thing?

419
00:16:21.320 --> 00:16:23.400
Jonti Horner: I'd be a fool to say no on it. I really hope

420
00:16:23.400 --> 00:16:26.400
that we do. And um, given the impact we've

421
00:16:26.400 --> 00:16:29.080
seen both good and bad, from the

422
00:16:29.240 --> 00:16:31.400
advent of reusable spacecraft and the growth

423
00:16:31.400 --> 00:16:33.760
of commercial space, that's dropped the cost

424
00:16:33.760 --> 00:16:36.160
of launching kilogram of material to space by

425
00:16:36.160 --> 00:16:38.560
between a factor of 10 and factor of 100. And

426
00:16:38.560 --> 00:16:40.880
it's been revolutionary. If you could drop

427
00:16:40.880 --> 00:16:43.760
that cost to essentially nothing. What

428
00:16:43.760 --> 00:16:46.680
that enables is an enormous expansion in

429
00:16:46.680 --> 00:16:49.040
our use of space. It also enables the kind of

430
00:16:49.040 --> 00:16:51.680
space tourism type stuff because if you

431
00:16:52.000 --> 00:16:54.880
have a docking station at geostationary

432
00:16:54.880 --> 00:16:57.520
orbit, you've Already done a hell of a lot of

433
00:16:57.520 --> 00:16:59.440
the work of getting out of Earth's gravity.

434
00:17:00.160 --> 00:17:02.680
So it's much easier to launch to Mars or the

435
00:17:02.680 --> 00:17:05.640
moon or pick your tourist destination from

436
00:17:05.640 --> 00:17:08.040
there. Pick your research destination, you

437
00:17:08.040 --> 00:17:10.880
hugely reduce the cost of doing

438
00:17:10.880 --> 00:17:13.040
both. Research, commerce, tourism.

439
00:17:13.920 --> 00:17:15.720
By getting people up to that altitude. You

440
00:17:15.720 --> 00:17:17.080
don't have to get through the atmosphere, but

441
00:17:17.080 --> 00:17:19.920
you also don't have to burn your rocket to

442
00:17:19.920 --> 00:17:21.960
get up, uh, through that hardest, steepest

443
00:17:21.960 --> 00:17:24.720
part of Earth's gravity well. So once it is

444
00:17:24.720 --> 00:17:27.280
technologically feasible, I suspect what

445
00:17:27.280 --> 00:17:28.800
you'll have is it'll become technologically

446
00:17:28.800 --> 00:17:31.400
feasible. Then not too long after that, it

447
00:17:31.400 --> 00:17:33.600
will become commercially feasible. And that's

448
00:17:33.600 --> 00:17:35.490
the point people look at doing it. And, uh,

449
00:17:35.560 --> 00:17:37.930
the big caveat there would be, is it actually

450
00:17:37.930 --> 00:17:40.050
ever going to be technologically feasible?

451
00:17:40.610 --> 00:17:42.650
But it's near enough future science that

452
00:17:42.650 --> 00:17:44.730
people have already had suggestions about the

453
00:17:44.730 --> 00:17:47.650
kind of materials you could use to make

454
00:17:47.970 --> 00:17:50.490
the cable. Because that's a big

455
00:17:50.490 --> 00:17:53.350
constraint is actually making the cable, um,

456
00:17:53.350 --> 00:17:55.050
would need to be a lot stronger than spider

457
00:17:55.050 --> 00:17:57.410
silk, for example. But it is

458
00:17:58.370 --> 00:18:01.370
not so far beyond what we can make now that

459
00:18:01.370 --> 00:18:03.610
people think it's impossible. Rather, people

460
00:18:03.610 --> 00:18:05.330
think it could be feasible, but we don't know

461
00:18:05.330 --> 00:18:07.660
how yet. And in that kind of context, we're

462
00:18:07.660 --> 00:18:09.780
incredibly good at doing the impossible and

463
00:18:09.780 --> 00:18:12.780
the improbable as a species. So, uh, so long

464
00:18:12.780 --> 00:18:15.380
as we don't wipe each other out, so long as

465
00:18:15.380 --> 00:18:18.060
the shutdown eventually ends, then perhaps

466
00:18:18.060 --> 00:18:20.780
we'll be able to figure this out. And, you

467
00:18:20.780 --> 00:18:23.100
know, probably not in our lifetime, but may

468
00:18:23.100 --> 00:18:24.780
well not be as far beyond that as you'd

469
00:18:24.780 --> 00:18:25.060
think.

470
00:18:25.540 --> 00:18:27.540
Andrew Dunkley: Well, uh, if you go back 200 years and tell

471
00:18:27.540 --> 00:18:29.540
people, hey, I, you know, where I come from,

472
00:18:29.540 --> 00:18:31.220
we've been to the moon, they'd think you were

473
00:18:31.790 --> 00:18:34.510
a witch. They just wouldn't believe

474
00:18:34.510 --> 00:18:37.070
it. So, uh, who knows what's possible in 200

475
00:18:37.070 --> 00:18:37.630
years time?

476
00:18:37.870 --> 00:18:39.590
Jonti Horner: Yeah, the thing that makes my head hurt with

477
00:18:39.590 --> 00:18:41.830
that, uh, is we're almost at the point. In

478
00:18:41.830 --> 00:18:43.470
fact, I think we possibly are at the point

479
00:18:43.470 --> 00:18:45.590
now where it is longer since the first

480
00:18:45.590 --> 00:18:48.550
moonwalk than that moonwalk was from the

481
00:18:48.550 --> 00:18:49.550
first powered flight.

482
00:18:49.550 --> 00:18:51.630
Andrew Dunkley: I know. Isn't it amazing?

483
00:18:52.430 --> 00:18:54.750
It's incredible how far we've come in such a

484
00:18:54.750 --> 00:18:57.440
short period of time. M thank you, Barry. Um,

485
00:18:57.470 --> 00:18:58.190
great question.

486
00:18:58.510 --> 00:19:00.790
Uh, our next question coming up in a moment

487
00:19:00.790 --> 00:19:02.110
on Space Nuts.

488
00:19:06.810 --> 00:19:09.250
Space Nuts. And you're with Andrew Dunkley

489
00:19:09.250 --> 00:19:11.690
and John T. Horner. Um, this one comes from

490
00:19:11.690 --> 00:19:14.250
Casey in Colorado. I was hoping that you

491
00:19:14.250 --> 00:19:16.970
could Please explain why TOI

492
00:19:17.530 --> 00:19:20.330
6894B is such a big deal

493
00:19:20.650 --> 00:19:23.010
and what it means for our understanding of

494
00:19:23.010 --> 00:19:24.610
the universe. Love the show, and I hope

495
00:19:24.610 --> 00:19:25.450
you're both well.

496
00:19:25.530 --> 00:19:26.010
Jonti Horner: Thanks.

497
00:19:26.010 --> 00:19:28.130
Andrew Dunkley: Thank you, Casey. Yeah. So I did a bit of

498
00:19:28.130 --> 00:19:30.770
research on this, uh, particular planet,

499
00:19:30.770 --> 00:19:33.770
TOI 6894. It's a massive,

500
00:19:34.010 --> 00:19:36.790
massive gas giant planet. But what makes it

501
00:19:36.790 --> 00:19:39.270
unusual is that its star

502
00:19:39.510 --> 00:19:41.990
is, um, a bit of a mouse.

503
00:19:42.630 --> 00:19:45.030
So they're trying to figure out how such a

504
00:19:45.030 --> 00:19:46.630
massive planet can exist

505
00:19:47.910 --> 00:19:50.630
next to such a tiny star. I think that's the

506
00:19:50.630 --> 00:19:51.589
guts of it, isn't it?

507
00:19:51.910 --> 00:19:54.630
Jonti Horner: It is. And it's a really good example, again,

508
00:19:54.870 --> 00:19:57.310
of the detective story side of

509
00:19:57.310 --> 00:20:00.190
astronomy, the way that we can't really

510
00:20:00.190 --> 00:20:01.910
do experiments, so we have to learn through

511
00:20:01.910 --> 00:20:03.670
observation. And so the interplay is not

512
00:20:03.670 --> 00:20:05.310
experiment and theory like it is in other

513
00:20:05.310 --> 00:20:07.030
disciplines, but it's observation and the.

514
00:20:07.490 --> 00:20:09.050
And, um, that leads to our science being

515
00:20:09.050 --> 00:20:11.810
different in subtle ways, even down to the

516
00:20:11.810 --> 00:20:13.130
structure of how we write and how we

517
00:20:13.130 --> 00:20:15.090
communicate. It's less about testing

518
00:20:15.090 --> 00:20:16.850
hypotheses than other disciplines. You know,

519
00:20:16.850 --> 00:20:19.170
there's a lot of complexity in that. Now,

520
00:20:19.650 --> 00:20:21.970
if you go back to when I was a kid and I was

521
00:20:22.210 --> 00:20:23.890
learning all about astronomy, we didn't know

522
00:20:23.890 --> 00:20:26.290
of any planet from any other star. And we

523
00:20:26.290 --> 00:20:27.850
thought we had a very good feeling of how the

524
00:20:27.850 --> 00:20:29.410
solar system formed and therefore, by

525
00:20:29.410 --> 00:20:31.170
extension, what kind of planets we would

526
00:20:31.170 --> 00:20:33.770
find. Yeah, and we expected that you'd find

527
00:20:33.770 --> 00:20:36.160
giant planets like Jupiter out beyond the

528
00:20:36.160 --> 00:20:38.000
snow line, you know, several astronomical

529
00:20:38.000 --> 00:20:39.720
units from their star, going around on orbits

530
00:20:39.720 --> 00:20:41.720
that are measured in decades, and rocky

531
00:20:41.720 --> 00:20:43.000
planets in the interior. And that's how

532
00:20:43.000 --> 00:20:44.760
planetary systems would form and the solar

533
00:20:44.760 --> 00:20:47.680
system would be typical. We then found

534
00:20:47.840 --> 00:20:50.840
51 Pegasi B, which is a planet comparable to

535
00:20:50.840 --> 00:20:52.480
Jupiter, going around its star every four

536
00:20:52.480 --> 00:20:55.280
days. And that kind of threw everything out.

537
00:20:55.280 --> 00:20:57.960
And we had to improve our theories. Now what

538
00:20:57.960 --> 00:21:00.400
it led to was a refinement of the theories of

539
00:21:00.560 --> 00:21:02.360
planets forming in disks rather than them

540
00:21:02.360 --> 00:21:04.080
being totally chucked out on something new.

541
00:21:04.820 --> 00:21:06.980
But that first discovery of a planet around a

542
00:21:06.980 --> 00:21:08.940
sun like star really set the scene for the

543
00:21:08.940 --> 00:21:11.740
fact that the diversity of planets we find

544
00:21:11.740 --> 00:21:14.340
around other stars is overwhelmingly

545
00:21:14.340 --> 00:21:16.260
greater than we could have ever imagined.

546
00:21:16.580 --> 00:21:18.700
Planets are ubiquitous. Every star has them.

547
00:21:18.700 --> 00:21:20.940
That's what we've learned. But the variety of

548
00:21:20.940 --> 00:21:22.380
planets is much greater than we could have

549
00:21:22.380 --> 00:21:25.140
imagined. And all of that data has been

550
00:21:25.460 --> 00:21:27.780
a fabulous resource for scientists trying to

551
00:21:27.780 --> 00:21:29.620
understand the process of planet formation

552
00:21:29.620 --> 00:21:32.240
and the variety of ways that that process can

553
00:21:32.240 --> 00:21:35.120
proceed effectively. Every planetary system

554
00:21:35.120 --> 00:21:37.560
will be unique in the same way every human's

555
00:21:37.560 --> 00:21:39.680
unique. You know, they're the product of the

556
00:21:39.680 --> 00:21:41.480
environment that they form in. The mass of

557
00:21:41.480 --> 00:21:43.080
the disk is important, the mass of the star,

558
00:21:43.080 --> 00:21:44.800
but also the cluster environment they form

559
00:21:44.800 --> 00:21:47.160
in. There's a lot of things going on that

560
00:21:47.160 --> 00:21:49.360
mean if you have two identical stars with two

561
00:21:49.360 --> 00:21:51.160
identical disks, you'll still get different

562
00:21:51.160 --> 00:21:53.440
planetary systems at the end. So we're

563
00:21:53.440 --> 00:21:55.480
learning more about planet formation. And

564
00:21:55.480 --> 00:21:58.160
it's the outliers and the oddities that

565
00:21:58.160 --> 00:21:59.640
really drive that science forward.

566
00:22:00.370 --> 00:22:03.330
Which brings us to TOI 6894. What we

567
00:22:03.330 --> 00:22:05.770
found typically is that, uh, giant planets

568
00:22:05.770 --> 00:22:08.330
are common in the cosmos. We find them easier

569
00:22:08.330 --> 00:22:09.690
than everything else because they're more

570
00:22:09.690 --> 00:22:12.570
obvious. So our discovery techniques are

571
00:22:12.570 --> 00:22:14.410
biased towards finding planets the size of

572
00:22:14.410 --> 00:22:16.650
Jupiter and Saturn and against finding

573
00:22:16.650 --> 00:22:18.490
planets the size of the Earth. That's why we

574
00:22:18.490 --> 00:22:20.530
find a lot more of them. And, um, what the

575
00:22:20.530 --> 00:22:22.890
results have shown is that, uh, giant

576
00:22:22.890 --> 00:22:24.650
planets, massive planets like Jupiter and

577
00:22:24.650 --> 00:22:27.360
Saturn, are, um, more common the more massive

578
00:22:27.360 --> 00:22:30.240
the star is. They're also more common the

579
00:22:30.240 --> 00:22:32.160
higher the metallicity of the star is. So the

580
00:22:32.160 --> 00:22:33.840
higher the amount of solid material would

581
00:22:33.840 --> 00:22:36.440
have been around that star. And typically

582
00:22:36.840 --> 00:22:39.240
we don't find giant planets like Jupiter

583
00:22:39.560 --> 00:22:42.399
and Saturn around the lowest mass stars.

584
00:22:42.399 --> 00:22:44.000
And the argument has always been that low

585
00:22:44.000 --> 00:22:46.560
mass stars form from low mass disks where

586
00:22:46.560 --> 00:22:48.840
there's just not simply enough for planets to

587
00:22:48.840 --> 00:22:51.640
form there. Then you get

588
00:22:51.640 --> 00:22:54.500
TOI 6894B. So the

589
00:22:54.500 --> 00:22:57.340
star TOI 6894 is a little red dwarf.

590
00:22:57.340 --> 00:22:59.460
It's only about 20% the mass of the sun,

591
00:22:59.700 --> 00:23:02.700
about 238 light years away. The

592
00:23:02.700 --> 00:23:05.300
planet going round it is a little bit bigger

593
00:23:05.300 --> 00:23:07.660
than Saturn, but about half the mass of our

594
00:23:07.660 --> 00:23:09.700
giant planet. So it's another one of these

595
00:23:09.779 --> 00:23:11.460
superpuff planets that we've talked about

596
00:23:11.460 --> 00:23:13.980
before. It's heavily irradiated, has been

597
00:23:13.980 --> 00:23:15.620
inflated, and that probably suggests that

598
00:23:15.620 --> 00:23:18.420
it's migrated in in the recent past. Now

599
00:23:18.420 --> 00:23:20.900
people who've looked at data from Kepler

600
00:23:21.290 --> 00:23:23.810
and TESS more recently, which looked at so

601
00:23:23.810 --> 00:23:25.650
many stars, have been able to do a kind of

602
00:23:25.650 --> 00:23:28.090
statistical study. And what they've found is,

603
00:23:28.110 --> 00:23:30.890
uh, for red dwarfs like TOI,

604
00:23:31.130 --> 00:23:33.370
um, 6894, only about

605
00:23:33.370 --> 00:23:36.250
1.5% of all red dwarfs harbor any giant

606
00:23:36.250 --> 00:23:38.290
planets. And TOI

607
00:23:38.290 --> 00:23:41.130
6894 is the least massive star to be found

608
00:23:41.130 --> 00:23:44.010
with an orbiting giant planet around it. So

609
00:23:44.010 --> 00:23:46.010
that's why it's really, really interesting.

610
00:23:46.010 --> 00:23:48.810
Now there's a number of different processes

611
00:23:48.810 --> 00:23:51.090
that go on in planet formation and, um, star

612
00:23:51.090 --> 00:23:53.170
formation. And we've talked before about the

613
00:23:53.170 --> 00:23:56.130
Blurred lines between planets and

614
00:23:56.130 --> 00:23:58.850
brown dwarfs and stars. And back in the day,

615
00:23:58.850 --> 00:24:00.490
we thought we had a very clear rational

616
00:24:00.490 --> 00:24:01.930
explanation that they're formed in different

617
00:24:01.930 --> 00:24:04.690
ways. But now we see brown

618
00:24:04.690 --> 00:24:06.570
dwarfs being discovered free floating that

619
00:24:06.570 --> 00:24:09.330
are lower mass than the canonical traditional

620
00:24:09.330 --> 00:24:11.650
13 Jupiter mass limit. Anything smaller than

621
00:24:11.650 --> 00:24:13.210
13 Jupiter mass used to be thought of as a

622
00:24:13.210 --> 00:24:15.290
planet. Similarly, we're finding things that

623
00:24:15.290 --> 00:24:16.730
they're calling planets that are more than 13

624
00:24:16.730 --> 00:24:18.290
Jupiter masses. So the lines are getting

625
00:24:18.290 --> 00:24:18.930
blurred.

626
00:24:19.010 --> 00:24:19.490
Andrew Dunkley: Yeah.

627
00:24:19.490 --> 00:24:22.130
Jonti Horner: And I think we may see a bit of a

628
00:24:22.130 --> 00:24:24.930
paradigm shift in years and decades to come,

629
00:24:25.250 --> 00:24:27.450
where part of what defines whether you're a

630
00:24:27.450 --> 00:24:29.130
planet or a brown dwarf at the top end is

631
00:24:29.130 --> 00:24:31.410
actually how you formed and by extension,

632
00:24:31.650 --> 00:24:34.450
what's buried deep in your core. So a

633
00:24:34.450 --> 00:24:36.770
planet like Jupiter has a massive,

634
00:24:37.490 --> 00:24:40.010
you know, 20, 30 earth mass, solid core at

635
00:24:40.010 --> 00:24:41.570
the middle because it formed from a process

636
00:24:41.570 --> 00:24:44.300
of core accretion. You get solid material

637
00:24:44.300 --> 00:24:46.140
agglomerating, forming bigger and bigger

638
00:24:46.140 --> 00:24:47.900
bits, until you form things kilometers

639
00:24:47.900 --> 00:24:50.220
across, then thousands of kilometers across

640
00:24:50.620 --> 00:24:52.740
objects like the Earth. And the more they

641
00:24:52.740 --> 00:24:54.820
eat, the bigger they get. Eventually you get

642
00:24:54.820 --> 00:24:56.740
to 20 or 30 times the mass of the earth,

643
00:24:56.740 --> 00:24:58.420
well, 10 or 12 times the mass of the Earth to

644
00:24:58.420 --> 00:25:00.540
start the process. When you're at that point,

645
00:25:00.540 --> 00:25:02.060
your gravity is strong enough to start

646
00:25:02.060 --> 00:25:04.460
capturing hydrogen and helium gas from the

647
00:25:04.540 --> 00:25:06.900
nebula that previously would have escaped,

648
00:25:06.900 --> 00:25:08.770
you finally can hold onto, um, it. And, um,

649
00:25:08.780 --> 00:25:10.420
because there's more of hydrogen and helium

650
00:25:10.420 --> 00:25:12.700
than everything else combined by a couple of

651
00:25:12.700 --> 00:25:15.100
orders of magnitude, 98% of everything is

652
00:25:15.100 --> 00:25:17.260
hydrogen or helium. Suddenly you've got this

653
00:25:17.260 --> 00:25:19.820
enormous new untapped food source. You can

654
00:25:19.820 --> 00:25:21.380
quickly devour all there is, and your mass

655
00:25:21.380 --> 00:25:23.380
grows really rapidly until you open a gap in

656
00:25:23.380 --> 00:25:25.180
the disk, and voila, you've got a giant

657
00:25:25.180 --> 00:25:27.140
planet in a gap. And we talked about this a

658
00:25:27.140 --> 00:25:30.140
bit last week. That's core accretion.

659
00:25:30.140 --> 00:25:32.380
That leads to giant planets that are planets

660
00:25:32.380 --> 00:25:34.780
with a solid core and a thick atmosphere. And

661
00:25:34.780 --> 00:25:36.220
that atmosphere can be the bulk of their

662
00:25:36.220 --> 00:25:38.640
mass. You've then got a

663
00:25:38.800 --> 00:25:40.640
method called gravitational instability,

664
00:25:40.720 --> 00:25:42.960
where your disk is sufficiently massive

665
00:25:42.960 --> 00:25:44.640
compared to the star in the middle, that it

666
00:25:44.640 --> 00:25:47.400
can become unstable itself. And you can get

667
00:25:47.400 --> 00:25:49.120
it essentially globbing together to form

668
00:25:49.120 --> 00:25:51.360
massive objects on a very short time scale.

669
00:25:51.600 --> 00:25:53.320
And that's probably, to be honest, the

670
00:25:53.320 --> 00:25:56.240
process by which binary stars form, where you

671
00:25:56.240 --> 00:25:58.560
get a second star forming on a quite wide,

672
00:25:58.560 --> 00:26:00.960
elongated orbit, whatever. And I've always

673
00:26:00.960 --> 00:26:03.880
had a suspicion back from when earlier in my

674
00:26:03.880 --> 00:26:05.600
career I was at the University of Bern, and

675
00:26:05.600 --> 00:26:07.960
this is 20 years ago now, there was this kind

676
00:26:07.960 --> 00:26:09.600
of conflict for giant Planets where people

677
00:26:09.600 --> 00:26:12.040
said one of these two methods will be right

678
00:26:12.040 --> 00:26:13.360
and the other one will be wrong. And you've

679
00:26:13.360 --> 00:26:15.080
got core accretion or, uh, gravitational

680
00:26:15.080 --> 00:26:16.880
instability. And it was a big kind of which

681
00:26:16.880 --> 00:26:18.960
one of them is right. And I've always had the

682
00:26:18.960 --> 00:26:20.760
feeling that in the right conditions both of

683
00:26:20.760 --> 00:26:23.440
them can happen. And this suspicion that

684
00:26:23.680 --> 00:26:26.240
brown dwarfs and stellar companions

685
00:26:26.880 --> 00:26:28.600
probably form through this gravitational

686
00:26:28.600 --> 00:26:31.080
instability process, which leads to more

687
00:26:31.080 --> 00:26:32.880
instability and kind of lowers the likelihood

688
00:26:32.880 --> 00:26:34.920
of planets then forming in the system. And

689
00:26:34.920 --> 00:26:36.480
you'd form an object there, ah, that doesn't

690
00:26:36.480 --> 00:26:38.480
have that massive core in the center. It's

691
00:26:38.480 --> 00:26:41.240
basically the composition will match the

692
00:26:41.240 --> 00:26:43.040
composition of the material in the universe.

693
00:26:44.000 --> 00:26:46.080
This is a really interesting one because this

694
00:26:46.080 --> 00:26:48.920
planet is so much so massive compared to

695
00:26:48.920 --> 00:26:51.920
its star. This is kind of equivalent to the

696
00:26:51.920 --> 00:26:54.280
sun having a 5 or 10 Jupiter mass planet,

697
00:26:54.280 --> 00:26:56.440
probably something like that, because m more

698
00:26:56.440 --> 00:26:57.840
massive star would have more mass and you

699
00:26:57.840 --> 00:26:59.720
wouldn't just five times the mass of the star

700
00:26:59.720 --> 00:27:01.240
is five times the mass of the planet. It will

701
00:27:01.240 --> 00:27:03.400
go a bit more than that. So it's a real

702
00:27:03.400 --> 00:27:06.240
surprise and there's a lot of investigation

703
00:27:06.240 --> 00:27:07.800
to be done to try and figure out what the

704
00:27:07.800 --> 00:27:10.560
formation process of this object is. The fact

705
00:27:10.560 --> 00:27:13.280
it's a super puff, it's puffed up, it's

706
00:27:13.280 --> 00:27:14.800
bigger than Saturn, but less massive than

707
00:27:14.800 --> 00:27:17.800
Saturn, suggests that, um, either

708
00:27:17.800 --> 00:27:19.280
it's very close into the star and it's

709
00:27:19.280 --> 00:27:22.240
getting hugely irradiated. If that's the

710
00:27:22.240 --> 00:27:23.760
case and it's been losing mass, it was

711
00:27:23.760 --> 00:27:26.730
probably more massive in the past. Um, which

712
00:27:26.730 --> 00:27:28.650
adds further weight to maybe this was a

713
00:27:28.650 --> 00:27:30.090
bigger thing in the past and maybe it could

714
00:27:30.090 --> 00:27:32.210
have been a very low mass brown dwarf rather

715
00:27:32.210 --> 00:27:34.530
than a very high mass planet. Or maybe it's

716
00:27:34.530 --> 00:27:37.130
telling us that you can get M dwarfs, red

717
00:27:37.130 --> 00:27:39.490
dwarfs, which have a disk massive enough to

718
00:27:39.490 --> 00:27:41.770
form giant planets on occasion in the right

719
00:27:41.770 --> 00:27:44.370
setup, and we just need to learn more.

720
00:27:45.020 --> 00:27:47.730
Um, but it seems very unlikely

721
00:27:48.370 --> 00:27:51.290
that if the properties of the disk

722
00:27:51.290 --> 00:27:53.250
around this star, uh, were similar to the

723
00:27:53.250 --> 00:27:55.650
bulk of disk we found, there should not have

724
00:27:55.650 --> 00:27:58.210
been enough solid material to get the core

725
00:27:58.210 --> 00:28:00.330
accretion process to go quickly enough for

726
00:28:00.330 --> 00:28:02.250
you to get a giant planet, never mind one

727
00:28:02.250 --> 00:28:04.530
close enough in like this one, to then become

728
00:28:04.530 --> 00:28:07.090
a bit of a superpuff. So there's a lot to

729
00:28:07.090 --> 00:28:08.970
learn. It's very close to its star. It's only

730
00:28:09.370 --> 00:28:12.210
3.9 million kilometers out from the

731
00:28:12.210 --> 00:28:14.810
star. So it's much more

732
00:28:14.810 --> 00:28:17.370
comparable to the Jovian moons. If you

733
00:28:17.370 --> 00:28:19.250
imagine the star being where Jupiter is, this

734
00:28:19.250 --> 00:28:20.970
is comparable to some of the moons of Jupiter

735
00:28:20.970 --> 00:28:23.130
and distance. And that's another of the

736
00:28:23.130 --> 00:28:24.730
reasons it's just really hard to imagine how

737
00:28:24.730 --> 00:28:26.230
it could been have form so close in.

738
00:28:27.510 --> 00:28:29.470
There's a lot to dig into in this. They're

739
00:28:29.470 --> 00:28:30.830
looking at the chemistry of the atmosphere

740
00:28:30.830 --> 00:28:32.510
because this planet's close enough in to be

741
00:28:32.510 --> 00:28:34.310
hot enough that we can actually get light

742
00:28:34.310 --> 00:28:36.150
from it and we can look at its atmosphere

743
00:28:36.390 --> 00:28:38.310
seems to be kind of methane dominated, I

744
00:28:38.310 --> 00:28:40.730
think, which is really, really odd. Um,

745
00:28:40.730 --> 00:28:42.790
there's all sorts of weird stuff going on.

746
00:28:43.450 --> 00:28:46.230
Um, but because red dwarf

747
00:28:46.230 --> 00:28:47.950
stars are so common, even though giant

748
00:28:47.950 --> 00:28:50.630
planets like this are rare per red dwarf,

749
00:28:50.630 --> 00:28:52.070
there's probably a hell of a lot of them out

750
00:28:52.070 --> 00:28:53.840
there. You know, red dwarfs are the most

751
00:28:53.840 --> 00:28:56.440
common star in the galaxy by far. You know,

752
00:28:56.440 --> 00:28:58.760
some estimates are, you know, up to three

753
00:28:58.760 --> 00:29:01.200
quarters of all gas in our size in our galaxy

754
00:29:01.200 --> 00:29:02.960
will count as red dwarfs. Which means he

755
00:29:02.960 --> 00:29:05.664
could have 100, 200,

756
00:29:05.776 --> 00:29:08.720
300 billion of them out there. So even if

757
00:29:08.720 --> 00:29:11.440
only 1% of those stars have a giant planet

758
00:29:11.440 --> 00:29:13.800
like this, you know, 1% of,

759
00:29:14.200 --> 00:29:16.880
you know, 100 billion stars is still a

760
00:29:16.880 --> 00:29:17.800
billion stars.

761
00:29:17.800 --> 00:29:18.360
Jonti Horner: Yes.

762
00:29:18.360 --> 00:29:20.560
Jonti Horner: Now maybe this planet is both rare and common

763
00:29:20.560 --> 00:29:21.230
at the same time.

764
00:29:21.700 --> 00:29:24.180
Andrew Dunkley: Yeah, that sounds like a very good

765
00:29:24.500 --> 00:29:27.420
theory actually. Um, Casey, thanks

766
00:29:27.420 --> 00:29:29.380
for the question. If you'd like to read up on

767
00:29:29.380 --> 00:29:32.180
it, uh, you can go to uh, Psy News,

768
00:29:32.340 --> 00:29:34.100
the website, because they've got a great

769
00:29:34.100 --> 00:29:35.940
article on it, uh, but they've also published

770
00:29:35.940 --> 00:29:38.700
a recent paper, uh, in the

771
00:29:38.700 --> 00:29:40.820
journal Nature Astronomy.

772
00:29:43.540 --> 00:29:45.780
Jonti Horner: 3, 2, 1.

773
00:29:46.340 --> 00:29:46.740
Space.

774
00:29:48.110 --> 00:29:49.150
Andrew Dunkley: Our uh, final question.

775
00:29:50.590 --> 00:29:52.990
Jonti. Uh, I don't know how to introduce

776
00:29:52.990 --> 00:29:55.150
this, so I'm just going to let it speak for

777
00:29:55.150 --> 00:29:55.630
itself.

778
00:29:55.790 --> 00:29:57.110
Jonti Horner: Hello, space nuts.

779
00:29:57.110 --> 00:29:59.830
Andrew Dunkley: This is Philip McCrackpipe, future Nobel

780
00:29:59.830 --> 00:30:02.390
Prize winner, here again. This time I've got

781
00:30:02.390 --> 00:30:03.590
my bony lassie.

782
00:30:03.590 --> 00:30:06.430
Jonti Horner: The famous English soprano. I need a fix here

783
00:30:06.430 --> 00:30:06.990
with me.

784
00:30:07.710 --> 00:30:10.670
Jonti Horner: That's a neater fix. F I C K S.

785
00:30:10.670 --> 00:30:13.150
Thank you. Not if F I X.

786
00:30:13.470 --> 00:30:16.040
So many people get that wrong. I have this

787
00:30:16.040 --> 00:30:19.000
question about Gale Crater on Mars and what

788
00:30:19.000 --> 00:30:21.880
kind of life it might have supported. Being

789
00:30:21.880 --> 00:30:24.880
a famous soprano, I'd like uh, to sing it

790
00:30:24.880 --> 00:30:27.480
to you. Pardon my voice today

791
00:30:27.640 --> 00:30:30.440
I have a slight touch of the anthrax.

792
00:30:32.520 --> 00:30:35.400
How many lovely life old might have grown

793
00:30:35.400 --> 00:30:37.960
in an ancient Martian crater?

794
00:30:38.680 --> 00:30:41.520
Could they have thrived or only just survived

795
00:30:41.520 --> 00:30:43.240
in an ancient Martian?

796
00:30:45.060 --> 00:30:47.220
Were they all just single soul? Did they fly

797
00:30:47.220 --> 00:30:49.940
like Tinkerbell and laugh and sing and play

798
00:30:50.180 --> 00:30:52.020
a microscopic trees?

799
00:30:53.940 --> 00:30:56.940
How, um, many lovely life forms made grown in

800
00:30:56.940 --> 00:30:59.060
an ancient Martian crater?

801
00:30:59.290 --> 00:30:59.640
Jonti Horner: Ah.

802
00:30:59.940 --> 00:31:02.180
Jonti Horner: Did they breathe the atmosphere where the

803
00:31:02.180 --> 00:31:04.980
predators, the fear elucidate your views,

804
00:31:04.980 --> 00:31:08.840
ecosystem.

805
00:31:10.030 --> 00:31:12.670
Thank lovely space nuts for listening to this

806
00:31:12.670 --> 00:31:15.070
tripe about an ancient Martian

807
00:31:15.230 --> 00:31:16.510
creator.

808
00:31:22.830 --> 00:31:25.790
Andrew Dunkley: Uh, um, I hope you get over the antlex real

809
00:31:25.790 --> 00:31:28.670
soon. Thanks, Anita. Um, I

810
00:31:28.670 --> 00:31:29.750
think I need a very.

811
00:31:29.750 --> 00:31:31.910
Jonti Horner: Different kind of musical ensemble. If I

812
00:31:31.910 --> 00:31:32.590
remember rightly.

813
00:31:32.590 --> 00:31:34.110
Andrew Dunkley: Yes, I think I need a fix.

814
00:31:34.490 --> 00:31:34.540
Jonti Horner: Uh.

815
00:31:36.510 --> 00:31:39.350
Andrew Dunkley: Bottom line, was there, or

816
00:31:39.350 --> 00:31:42.150
could there still be life in Gale Crater and

817
00:31:42.150 --> 00:31:42.990
what would it be like?

818
00:31:43.950 --> 00:31:46.190
Jonti Horner: Lots of places to go with this. I mean, two

819
00:31:46.190 --> 00:31:48.030
immediate diversions just spring to mind

820
00:31:48.030 --> 00:31:49.230
listening to that. It's lovely to get a

821
00:31:49.230 --> 00:31:51.870
musical entry from such a storied soprano,

822
00:31:51.870 --> 00:31:54.590
but reminds me, probably my favorite group,

823
00:31:55.950 --> 00:31:57.670
Finnish symphonic metal group called

824
00:31:57.670 --> 00:32:00.350
Nightwish. And this is relevant, I promise.

825
00:32:00.690 --> 00:32:03.470
Um, symphonic metal is this weird fusion of

826
00:32:03.470 --> 00:32:05.750
metal and opera, so you could describe it as

827
00:32:05.750 --> 00:32:08.570
operatic met. And the lead singer is a very

828
00:32:08.570 --> 00:32:11.530
storied classical soprano called Flo

829
00:32:11.530 --> 00:32:13.690
Jansen, who's just ridiculously awesome in

830
00:32:13.690 --> 00:32:16.250
many, many ways. Um, reason it's relevant is

831
00:32:16.250 --> 00:32:17.890
we were talking earlier on about Eugene

832
00:32:17.890 --> 00:32:20.170
Shoemaker, um, in the previous episode about

833
00:32:20.170 --> 00:32:22.730
Asher's going to the moon, things like this.

834
00:32:23.140 --> 00:32:26.010
Um, Nightwish, on their most recent

835
00:32:26.330 --> 00:32:29.250
no album before last had a track called

836
00:32:29.250 --> 00:32:31.810
Shoemaker, which was a eulogy, a tribute to

837
00:32:31.810 --> 00:32:34.410
Eugene Shoemaker, which has a lot of rocky

838
00:32:34.410 --> 00:32:36.090
stuff at the start, but from about 3 minutes

839
00:32:36.090 --> 00:32:38.170
50 onwards has a very, very operatic,

840
00:32:39.290 --> 00:32:41.930
classical, um, Latin funeral mass,

841
00:32:42.400 --> 00:32:44.290
um, which is utterly astonishing. So I do

842
00:32:44.290 --> 00:32:46.330
recommend people. I don't know if we can play

843
00:32:46.330 --> 00:32:47.810
it on the podcast. I don't know if we can

844
00:32:47.810 --> 00:32:49.369
play out because I don't know how rights

845
00:32:49.369 --> 00:32:50.090
issues work.

846
00:32:50.840 --> 00:32:53.450
Andrew Dunkley: Um, but, yeah, there are rights issues

847
00:32:53.450 --> 00:32:56.450
which precludes us, I'm afraid. I did

848
00:32:56.450 --> 00:32:58.130
listen to what you sent me. You sent me a

849
00:32:58.130 --> 00:33:00.580
link, uh, on YouTube Music, so we could

850
00:33:00.820 --> 00:33:02.780
probably send people there.

851
00:33:02.780 --> 00:33:04.700
Jonti Horner: But, yeah, it's a bit of a musical tour de

852
00:33:04.700 --> 00:33:06.740
force because it's got bits from William

853
00:33:06.740 --> 00:33:09.460
Shakespeare in there, which is the epitaph on

854
00:33:09.460 --> 00:33:11.460
Schumacher's tomb. That's why you've got the

855
00:33:11.860 --> 00:33:13.660
bit of Shakespeare's book and what in that.

856
00:33:13.660 --> 00:33:15.860
It's unusual, but it's incredibly touching

857
00:33:16.099 --> 00:33:18.420
anyway, so. Love a bit of musical science.

858
00:33:18.420 --> 00:33:20.100
The other thing that occurs without casting

859
00:33:20.100 --> 00:33:23.100
any aspersions on Anita there is the ability

860
00:33:23.100 --> 00:33:25.580
to sing while saying in character, which is

861
00:33:25.580 --> 00:33:28.550
good. And it reminds me of another thing I

862
00:33:28.550 --> 00:33:30.310
listened to, and I've listened to multiple

863
00:33:30.310 --> 00:33:32.390
times now, the phenomenon that is Dungeon

864
00:33:32.390 --> 00:33:35.350
Crawler Carl. Um, and at the end of the

865
00:33:35.750 --> 00:33:38.350
first audiobook, I was a bit put

866
00:33:38.350 --> 00:33:40.590
aback because there wasn't a cast list. And I

867
00:33:40.590 --> 00:33:43.030
thought, hang on, this is a bit Dodged.

868
00:33:43.830 --> 00:33:45.390
There's multiple people involved with this

869
00:33:45.390 --> 00:33:46.790
who are not getting credit. There's just this

870
00:33:46.790 --> 00:33:48.470
one guy getting credit for doing all the

871
00:33:48.470 --> 00:33:49.910
voice work and all the rest of it. And it

872
00:33:49.910 --> 00:33:52.230
really is just one guy. And it's

873
00:33:52.230 --> 00:33:54.430
remarkable how certain

874
00:33:54.830 --> 00:33:57.430
performers can voice multiple different

875
00:33:57.430 --> 00:33:59.870
characters to a degree of distinction that

876
00:34:00.560 --> 00:34:02.750
um, you assume that there's multiple people

877
00:34:02.750 --> 00:34:04.670
involved in the voicing. So, you know,

878
00:34:04.670 --> 00:34:07.110
incredible ability to sing well in character

879
00:34:07.110 --> 00:34:09.350
and stuff like that. So huge uh, credit on

880
00:34:09.350 --> 00:34:12.350
that in terms of the question and

881
00:34:12.350 --> 00:34:13.110
questions.

882
00:34:13.110 --> 00:34:15.630
It's all about life on Mars. Now we know that

883
00:34:15.870 --> 00:34:18.790
Mars in its youth was both

884
00:34:18.790 --> 00:34:21.510
warm and wet. It was an ocean planet that's

885
00:34:21.510 --> 00:34:23.280
fairly well established. Uh, and the

886
00:34:23.280 --> 00:34:25.520
transition from warm, wet Mars to cool, dry

887
00:34:25.520 --> 00:34:27.320
Mars would have been very slow and gradual.

888
00:34:27.320 --> 00:34:30.080
So any life that did get going will have had

889
00:34:30.080 --> 00:34:32.640
time to adapt and move potentially. That's a

890
00:34:32.640 --> 00:34:34.680
big part of the focus of the search for life

891
00:34:34.680 --> 00:34:37.360
on Mars. Both looking for evidence of past

892
00:34:37.360 --> 00:34:39.560
life and um, that's part of what the rovers

893
00:34:39.560 --> 00:34:41.840
are doing, driving around in gray in Gale and

894
00:34:41.840 --> 00:34:44.480
Jezero Crater, or Jezero Crater I think it's

895
00:34:44.480 --> 00:34:46.440
pronounced. It's also why we're interested,

896
00:34:46.440 --> 00:34:48.160
for example in the lakes of permanent liquid

897
00:34:48.160 --> 00:34:51.030
water at Mars south pole. But we

898
00:34:51.030 --> 00:34:52.950
don't know for a fact that there was life on

899
00:34:52.950 --> 00:34:55.390
Mars. It still was there, wasn't there? We're

900
00:34:55.390 --> 00:34:58.150
trying to find out. The idea though is that

901
00:34:58.150 --> 00:35:01.030
when Mars was young it was warm and wet, it

902
00:35:01.030 --> 00:35:03.310
had oceans. There may have been icy, slushy

903
00:35:03.310 --> 00:35:05.310
oceans, more like what you get in the Arctic

904
00:35:05.469 --> 00:35:07.270
than what you get near the equator. We don't

905
00:35:07.270 --> 00:35:09.990
fully know on that yet. But there was a

906
00:35:09.990 --> 00:35:12.550
vast expanse of liquid water on Mars surface

907
00:35:12.550 --> 00:35:14.670
for an incredibly long protracted period.

908
00:35:15.480 --> 00:35:17.680
All the conditions that on Earth would lead

909
00:35:17.680 --> 00:35:20.680
to life establishing and thriving. So

910
00:35:20.680 --> 00:35:22.600
there's a very real possibility that Gale

911
00:35:22.600 --> 00:35:25.600
Krata, this ancient Martian creator, was

912
00:35:25.600 --> 00:35:28.440
teeming with life in the past. It is,

913
00:35:28.760 --> 00:35:31.640
I think. So the challenge here is that

914
00:35:31.640 --> 00:35:33.320
we've only got one example of life in the

915
00:35:33.320 --> 00:35:35.040
universe to go off, which is life on the

916
00:35:35.040 --> 00:35:37.640
Earth. So we tend to form all our

917
00:35:37.640 --> 00:35:39.920
assumptions about the pathway that life will

918
00:35:39.920 --> 00:35:41.920
follow and how it will develop based on that

919
00:35:41.920 --> 00:35:44.560
example. Now just with the last question, we

920
00:35:44.560 --> 00:35:47.200
were talking about our ideas on the formation

921
00:35:47.200 --> 00:35:49.040
of planets when we only had one planetary

922
00:35:49.040 --> 00:35:51.440
system to go on and how wrong they were when

923
00:35:51.440 --> 00:35:53.480
we found the second planetary system around a

924
00:35:53.480 --> 00:35:56.080
sun like star. So the caveat to everything

925
00:35:56.080 --> 00:35:58.439
I'm about to say is that currently we know of

926
00:35:58.439 --> 00:36:00.360
one place with life and one planet with life.

927
00:36:00.760 --> 00:36:03.120
So I'm basing it off assumptions based on how

928
00:36:03.120 --> 00:36:06.040
things developed on Earth. And on Earth, we

929
00:36:06.040 --> 00:36:08.960
had simple life from about three and a

930
00:36:08.960 --> 00:36:11.160
half thousand million years ago. The evidence

931
00:36:11.300 --> 00:36:13.570
of, so the oldest fossils on Earth that are

932
00:36:13.570 --> 00:36:16.090
widely accepted, it's about 3.5 billion years

933
00:36:16.090 --> 00:36:18.690
ago, found in the Pilbara region in Western

934
00:36:18.690 --> 00:36:20.370
Australia. There are some fossils that are

935
00:36:20.370 --> 00:36:21.770
arguably older, but they're still

936
00:36:21.770 --> 00:36:24.770
controversial. For

937
00:36:24.770 --> 00:36:27.290
the first 3 billion years of life on Earth,

938
00:36:27.290 --> 00:36:29.130
all you had was single celled life. You had

939
00:36:29.130 --> 00:36:31.810
an incredible diversity and variety of simple

940
00:36:31.810 --> 00:36:34.090
life, but that's all you had. So only about

941
00:36:34.090 --> 00:36:36.210
500 million years ago, give or take, that,

942
00:36:36.210 --> 00:36:39.070
you start to get complex life. So the

943
00:36:39.070 --> 00:36:41.270
argument following that would be if

944
00:36:41.670 --> 00:36:44.430
Mars had life and, um, if that

945
00:36:44.430 --> 00:36:46.870
life followed a similar pathway to the Earth,

946
00:36:47.270 --> 00:36:49.030
then you would expect that that ancient life

947
00:36:49.030 --> 00:36:51.070
would all have been simple life. Now, the

948
00:36:51.070 --> 00:36:52.670
other thing that argues for that is if you

949
00:36:52.670 --> 00:36:54.270
look around on the Earth today, we've got

950
00:36:54.270 --> 00:36:56.910
life in abundance all over the place. But the

951
00:36:56.910 --> 00:36:58.910
more complex the life is, the more limited

952
00:36:58.910 --> 00:37:00.950
the variety of environments that it can exist

953
00:37:00.950 --> 00:37:02.790
in, if that makes sense.

954
00:37:02.790 --> 00:37:03.210
Andrew Dunkley: Yeah.

955
00:37:03.840 --> 00:37:06.600
Jonti Horner: So obviously simple life can exist in a

956
00:37:06.600 --> 00:37:09.360
wider variety of conditions and, um, will

957
00:37:09.360 --> 00:37:12.280
exist earlier than complex life. And

958
00:37:12.280 --> 00:37:15.120
so the argument then would be with all those

959
00:37:15.120 --> 00:37:16.680
assumptions, and I know I'm doing a lot of

960
00:37:16.680 --> 00:37:18.600
COVID your own ass here, but with the

961
00:37:18.600 --> 00:37:20.200
assumption that everything followed the way

962
00:37:20.200 --> 00:37:22.480
that things went on Earth, my expectation

963
00:37:22.480 --> 00:37:24.360
would have been that Gale Crater could well

964
00:37:24.360 --> 00:37:26.600
have been teeming with life, but it would

965
00:37:26.600 --> 00:37:27.880
have been simple life. It would have been

966
00:37:27.880 --> 00:37:29.680
single celled life. Now, single celled life

967
00:37:29.680 --> 00:37:32.030
still lives, a very vibrant and

968
00:37:32.030 --> 00:37:34.830
diverse set of lives. So there will be things

969
00:37:34.830 --> 00:37:36.510
interfering with each other and eating each

970
00:37:36.510 --> 00:37:38.310
other and all that kind of happy stuff going

971
00:37:38.310 --> 00:37:41.190
on. But it's likely that there

972
00:37:41.190 --> 00:37:44.150
weren't giant sharks or octo sharks

973
00:37:44.150 --> 00:37:46.509
or whatever you know, swimming around in the

974
00:37:46.509 --> 00:37:49.390
ocean in Gale Crater. And I suspect that if

975
00:37:49.390 --> 00:37:51.950
there had have been, we'd already possibly be

976
00:37:51.950 --> 00:37:53.590
finding evidence in the form of fossils. I

977
00:37:53.590 --> 00:37:56.270
may be wrong on that, but I suspect that the

978
00:37:56.270 --> 00:37:58.510
fact we haven't yet got definitive proof of

979
00:37:58.510 --> 00:38:01.000
ancient life on Mars suggests that the life

980
00:38:01.000 --> 00:38:03.040
that was there, if it was there, uh, was

981
00:38:03.040 --> 00:38:05.360
simple life and single celled life rather

982
00:38:05.360 --> 00:38:08.080
than complex stuff. But I stand to be

983
00:38:08.080 --> 00:38:09.760
corrected on that. I look forward to the

984
00:38:09.760 --> 00:38:12.360
confirmation of the discovery of ancient

985
00:38:12.360 --> 00:38:14.120
fossils on Mars, if we ever get there.

986
00:38:14.280 --> 00:38:15.720
Confirmation of life elsewhere will be

987
00:38:15.720 --> 00:38:18.440
awesome. So it might be worth getting Anita

988
00:38:18.440 --> 00:38:21.080
back on the show, uh, in a decade or so

989
00:38:21.320 --> 00:38:23.200
to sing the sequel is now that we know there

990
00:38:23.200 --> 00:38:25.880
Was life there? What was it like? Yeah, yeah.

991
00:38:25.890 --> 00:38:28.700
Andrew Dunkley: Um, but I think we will

992
00:38:28.700 --> 00:38:31.700
find something somewhere. Probably Mars,

993
00:38:31.700 --> 00:38:33.860
but maybe on some of the ice moons

994
00:38:34.580 --> 00:38:37.420
further out. But there's got to be

995
00:38:37.420 --> 00:38:39.900
something. Uh, I think it'll be microbial, as

996
00:38:39.900 --> 00:38:42.740
you said. But it's just,

997
00:38:43.300 --> 00:38:45.780
you look how life just grabs on

998
00:38:46.260 --> 00:38:49.140
on Earth given

999
00:38:49.140 --> 00:38:51.620
minimal opportunity. And

1000
00:38:51.940 --> 00:38:53.990
I think that that same

1001
00:38:55.030 --> 00:38:57.590
thing exists in the universe

1002
00:38:57.590 --> 00:39:00.510
elsewhere. Um, life, if there is

1003
00:39:00.510 --> 00:39:03.350
just a small opportunity, it will grow

1004
00:39:03.830 --> 00:39:06.730
and I think that's what we will find. But,

1005
00:39:06.730 --> 00:39:09.510
uh, whether or not we find another

1006
00:39:10.870 --> 00:39:12.070
so called intelligent

1007
00:39:13.590 --> 00:39:16.510
place in the universe or an intelligent

1008
00:39:16.510 --> 00:39:19.190
species, that's a bigger call

1009
00:39:19.350 --> 00:39:21.870
and a completely different ball game indeed.

1010
00:39:21.970 --> 00:39:23.950
Uh, thank you for the question, Anita. And if

1011
00:39:23.950 --> 00:39:25.470
you would like to listen to the music that

1012
00:39:25.950 --> 00:39:27.750
Jonti, uh, was referring to, you can go to

1013
00:39:27.750 --> 00:39:30.190
YouTube Music, do a search for Nightwish,

1014
00:39:30.190 --> 00:39:32.350
Shoemaker, uh, the official lyric video.

1015
00:39:33.010 --> 00:39:35.710
Um, they've got 1.82 million

1016
00:39:35.950 --> 00:39:38.510
subscribers. Yeah, it's extraordinary.

1017
00:39:38.830 --> 00:39:41.070
Jonti Horner: It's a style of music that isn't really

1018
00:39:41.550 --> 00:39:43.470
widely known in Australia. So when I've gone

1019
00:39:43.470 --> 00:39:44.870
to see them on the odd occasion, they've come

1020
00:39:44.870 --> 00:39:46.510
over here. We've been down at the Tivoli in

1021
00:39:46.510 --> 00:39:48.190
Brisbane, which is kind of a thousand people.

1022
00:39:49.070 --> 00:39:50.910
When they go anywhere else in the world,

1023
00:39:50.910 --> 00:39:52.670
they're doing packed stadiums with a hundred

1024
00:39:52.670 --> 00:39:55.470
thousand plus. So it's a different genre.

1025
00:39:55.630 --> 00:39:58.350
Um, they, along with a group called Epica and

1026
00:39:58.670 --> 00:40:00.550
a male group called Camelot, are probably the

1027
00:40:00.550 --> 00:40:02.390
three leading light groups in that genre of

1028
00:40:02.390 --> 00:40:05.030
symphonic metal, which is the interface of

1029
00:40:05.030 --> 00:40:07.470
opera and rock effectively. Um,

1030
00:40:07.710 --> 00:40:10.350
but they've had a number of scientifically

1031
00:40:10.350 --> 00:40:12.110
themed songs over the years. In fact, there's

1032
00:40:12.110 --> 00:40:14.710
one that I have as recommended reading stroke

1033
00:40:14.710 --> 00:40:16.470
listening for my undergrad students. That's

1034
00:40:16.470 --> 00:40:19.410
kind of of a 20 odd minute long story of the

1035
00:40:19.410 --> 00:40:21.090
evolution of the planetary system and life on

1036
00:40:21.090 --> 00:40:23.010
Earth and all the rest of it. So they've done

1037
00:40:23.010 --> 00:40:23.770
interesting things.

1038
00:40:24.010 --> 00:40:25.050
Andrew Dunkley: I'm sure they have.

1039
00:40:25.050 --> 00:40:26.890
Jonti Horner: All right. Shoemakers are good. Listen.

1040
00:40:27.050 --> 00:40:29.770
Andrew Dunkley: Excellent. All right, uh, thanks to everyone

1041
00:40:29.770 --> 00:40:32.130
who contributed. If you would like to send a

1042
00:40:32.130 --> 00:40:34.970
question into, um, the Space

1043
00:40:35.130 --> 00:40:36.810
Nuts website, just go to

1044
00:40:36.810 --> 00:40:39.530
spacenutspodcast.com or spacenuts

1045
00:40:39.690 --> 00:40:42.490
IO and click on the AMA

1046
00:40:42.490 --> 00:40:44.880
button at the top and send us your, uh, text

1047
00:40:44.880 --> 00:40:47.000
or audio question. Don't forget to tell us,

1048
00:40:47.000 --> 00:40:48.560
tell us who you are and where you're from,

1049
00:40:49.060 --> 00:40:51.120
uh, and leave your email address so we can

1050
00:40:51.120 --> 00:40:52.800
spam the hell out of you. No, I'm only

1051
00:40:52.800 --> 00:40:55.080
kidding. Although I think that is part of the

1052
00:40:55.080 --> 00:40:58.010
deal. M. We'll see. But, um,

1053
00:40:58.010 --> 00:41:00.800
yes. And, uh, uh, Guess what? Huw in the

1054
00:41:00.800 --> 00:41:03.360
studio just turned up. Hi, Huw. Bye,

1055
00:41:03.360 --> 00:41:06.320
Huw. And thanks to you,

1056
00:41:06.320 --> 00:41:08.240
Jonti. We'll catch you on the next episode.

1057
00:41:08.400 --> 00:41:09.900
Jonti Horner: It's a pleasure. Looking forward to it.

1058
00:41:10.700 --> 00:41:12.680
Andrew Dunkley: Uh, Johnny Horner, professor of astrophysics,

1059
00:41:12.680 --> 00:41:15.330
uh, at the University of Southern Queensland.

1060
00:41:15.490 --> 00:41:17.970
And we thank him. We thank everybody and

1061
00:41:18.130 --> 00:41:20.730
thank you. Uh, uh, and from me, Andrew

1062
00:41:20.730 --> 00:41:23.090
Dunkley, thank you for your company. We'll

1063
00:41:23.090 --> 00:41:24.970
catch you on the very next episode of Space

1064
00:41:24.970 --> 00:41:25.570
Nuts.

1065
00:41:25.809 --> 00:41:26.450
Jonti Horner: Bye. Bye.

1066
00:41:27.490 --> 00:41:29.690
You'll be listening to the Space Nuts

1067
00:41:29.690 --> 00:41:32.690
podcast, available at

1068
00:41:32.690 --> 00:41:34.690
Apple Podcasts, Spotify,

1069
00:41:34.850 --> 00:41:37.650
iHeartRadio, or your favorite podcast

1070
00:41:37.650 --> 00:41:39.130
player. You can also stream

1071
00:41:39.130 --> 00:41:41.050
ondemand@bytes.com.

1072
00:41:41.370 --> 00:41:43.370
Andrew Dunkley: This has been another quality podcast

1073
00:41:43.370 --> 00:41:45.050
production from bytes.

1074
00:41:45.130 --> 00:41:45.220
Jonti Horner: Com.

1075
00:41:45.220 --> 00:41:45.390
Jonti Horner: Um.