Light Pollution Dilemmas, Cosmic Parasol Proposals & Salvaging Space Junk

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Jonti Horner: Hi there.

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Andrew Dunkley: Thanks for joining us on Space Nuts Q and A

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edition. This is where the audience sets the

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agenda, and we answer the questions to the

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best of our ability, which is not much

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ability at all, but we'll do it anyway. Uh,

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coming up, questions about light pollution.

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A, uh, space parasol to protect

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Earth. Interesting. Uh, also salvage

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rights in space and radio waves.

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That's all coming up on space nuts.

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15 seconds. Guidance is internal.

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10, 9, ignition

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sequence. Star nuts. 5, 4,

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3, 2. 1, 2, 3, 4, 5, 5, 4,

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3, 2, 1.

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Jonti Horner: Space nuts.

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Andrew Dunkley: Astronauts report it feels good. And

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he's back again. Professor Jonti Horner,

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professor of Astrophysics at the University

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of Southern Queensland. Jonti. Hi there.

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Jonti Horner: Good afternoon. How are you going?

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Andrew Dunkley: I am well. Want to get

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straight into it?

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Jonti Horner: Yeah, let's dive on in.

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Andrew Dunkley: Okay. Question time. And our, uh, first

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question comes from Mark.

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He says, hello. I have a question about light

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pollution. I live in Connecticut, and the

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light pollution is not as bad as New York

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City, but it is enough. I'm planning a trip

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to Montana this summer just to see the night

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sky. My question is, if I was standing

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in my yard and there was a sudden EMP

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burst and all the electric lights went out,

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how long would it take for me to be able to

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see the night sky in Connecticut as clear and

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as. As beautiful as Point Nemo? I understand

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light speed is fast, but how fast

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would it be to clear the view? I've

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just, uh, recently discovered your podcast. I

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learned something new with each uh, one.

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Uh, please keep up the outstanding work. I

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look forward to every new episode.

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Sincerely, Mark Bookbinder. Thank you,

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Mark. That's a lovely comment. Uh, we don't

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get many nice comments. Everyone's usually

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sticking the knife in. No, I'm not kidding.

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Most people, uh, are terrific. Um,

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although we get the occasional jibe, but that

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goes with the territory. Um,

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yeah, look, I. I had a think about this one,

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and I. I would suggest.

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I don't want to steal your thunder, Jonti,

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because I know you've done your homework, but

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I would suggest that it would be fairly

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instantaneous because the amount of light

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coming down would be the same.

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It's just that it's disturbed by the light

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we're sending up. So when that light we are

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creating suddenly disappeared, surely

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the effect would be an instant

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view of what's really happening up there.

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Jonti Horner: Effectively, I think that's pretty much it.

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Um, uh, now, there's a few

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things that fall into that, and that's a

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really good kind of executive summary type

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level. So the reason that Light pollution is

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a problem for you. Seeing the night sky and

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all its wonder is you're basically increasing

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the brightness of the whole sky by an

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artificial amount which washes out the

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fine detail of the darker, the fainter stuff.

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So the brighter your light pollution levels

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are, uh, the brighter the sky is and so the

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fewer faint objects you can see and the more

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you brighten that, the less you'll see. If

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you turn all the lights off at once, the sky

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will almost instantaneously become as dark

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as it could possibly be. And then what's

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working against you is the adaptation of your

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eye. So we have this thing called dark

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adaptation and m, it's how our eye

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adjusts and responds to low light levels to

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allow us to function in those levels

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effectively. And you get the bulk of

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your dark adaption within about the first

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five minutes. But your eyes continue

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adapting and getting better and better at

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seeing in the dark over about

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45 minute period. So you have to be out under

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the night sky and avoid looking at any

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sources of bright light for about 45

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minutes before you're as adapted as you can

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be and you can get the best possible view you

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can get. Now what would happen is if you

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were out and about in your sadly light

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polluted skies in Connecticut, um,

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you are um, not very well dark adapted

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because the sky is very bright. So your clock

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would have to start ticking from the point

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the lights went out. So I would hope that the

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lights stared out for at least an hour for

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you to give you the best possible view. But

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even then you might not get the best view of

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the night sky you could anywhere on Earth,

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because you then run into the issues of the

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Earth's atmosphere. Um, now I

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regularly go out to the wonderful Lady

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Elliott island on the Barrier Reef where

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there's effectively no light pollution at all

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and the sky is dark enough that for example,

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I can see the Triangulum galaxy, which is

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fainter than Andromeda. I can see pretty much

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every time I go out there there's a darker

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light and um, I lead guessing

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some stargazing there and m tell them how

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awesome the sky is. But I make the point that

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if they were to go to the centre of

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Australia, to somewhere like Uluru or out

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into the Nullarborg Desert, they'd actually

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see a better sky there than we see at Lady

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Elliot. Because at Lady Elliot you have a

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limitation that you're surrounded by very

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humid, very turbulent air because of the

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energy from the ocean stirring the air up.

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And so different locations on the Earth offer

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different clarity of the night sky.

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So what I'd suggest is from Connecticut,

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I've got the light pollution map up here,

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which, um, is light pollutionmap.info for

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people who want to look and weep at how bad

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the skies are from their location and plan

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their dark sky holidays. That's a really nice

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little website. You're relatively coastal

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and so therefore your air is going to be

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quite humid and turbulent. And I would

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suggest if you turned, turned all the lights

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on the earth off, that you would have an

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experience probably comparable to what we get

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in coastal Australia. Whereas if you went

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deep into the inland and you got a really

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dark sky and be better if you then went

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to higher ground, like perhaps in Arizona,

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which I understand is a quite high altitude

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desert. If you're at higher altitude

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there is less air, so therefore there is

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less muck and you get a better sky. But

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that's balanced by the fact that if you're at

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high enough altitude, you're not getting as

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much oxygen and you don't see as effectively.

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So I've had stories from colleagues of mine

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who've been up to the great observatories,

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um, in the Andes, in Chile and also up

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in Hawaii who've gone out on a night and

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they've initially been quite disappointed

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that they didn't see a sky quite as

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expensive, as spectacular as they thought

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they would do. And people on Hawaii actually

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will often have a little bowl of oxygen and

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have an inhale to increase their blood oxygen

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levels, to increase the response of their

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eyes to counter the thinner atmosphere and

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then they get a really spectacular view.

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Andrew Dunkley: Wow.

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Jonti Horner: So, like most questions, there's a very

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simple answer which is as soon as the light

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goes out, you'll get a really good view, but

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that view will get better as your eyes adjust

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to the darkness. But how good of you you get

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is not just dependent on the light pollution,

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you'll start to bring in other effects. And

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my hope would be that the EMP burst and the

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end of all street lighting would happen at

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new moon rather than full moon. Because if

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you've got a full moon in the sky, all those

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effects of humidity and dust are exacerbated.

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And even with all the lights turned off, the

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night sky at full moon is a bit

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disappointing. You know, if I could do one

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astronomical thing as a kind of great

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celestial dictator, I get rid of the moon.

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It's just a pen in the backside. It's always

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in the way when I want to take photos and

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stops me seeing the more interesting things.

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It's like um, or lock it into a kind of one

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to one orbit with the Earth's orbit around

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the sun. So we only ever see it as a very

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thin crescent. So it can be beautiful in the

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early evening, then bugger off so I can see

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the prettier things.

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Andrew Dunkley: I can tell you why that's a problem. It's

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because everybody likes mooning in photos.

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Jonti Horner: Oh, totally.

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Andrew Dunkley: Uh, dear. Uh, um,

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um, I just thought about the

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physical effect of the light being

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turned off. But yeah, I didn't consider the

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atmosphere or the location or,

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um, or your eyes adjusting. I just had

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a look at that light pollution map website

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and I've honed in on Duo where I am

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now. If I just look at the nearest

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towns, yeah, I'd have to go just a bit over

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20km out of town to get to a

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dark sky area which is not too bad. But if,

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if you're in Sydney, forget it.

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You're gonna have to drive a few hours.

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Jonti Horner: But do yourself a favor and zoom out and then

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look at the eastern half of the US or look at

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eastern Asia and you'll see why we are so.

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Let's go. Yeah. That's why

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astro tourism's such a growing thing for us

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here in Australia. Because even in the big

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cities, you know, I moved to Sydney in 2010

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and lived very briefly in a

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hotel right in the center of Sydney, the most

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light polluted part. But I could still see

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the Milky Way from the roof of the hotel

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because our skies are so good. There's a

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couple of factors there. One is that, uh,

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Sydney itself puts out a lot of light, but

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there's not much else around. So if you're

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looking away from Sydney over towards the

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ocean, you're looking towards darker skies.

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So that helps. But the other thing is, and

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this ties into why we get sunburnt so easily

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in Australia, the air is just clearer.

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So I moved to Australia and everybody said,

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you're going to get burnt by the sun and it's

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awful. And my first thought was that's the

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ozone hole. Because I thought Australia was

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further south because I'm used to our

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corrupted maps that show the southern

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hemisphere wrong. And so Australia looks like

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it's near Antarctica and Australia is

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actually near the equator. It's. Yeah, it is.

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So it's not the ozone hole at all. But I told

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some people it's actually due to the fact

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that the air in Australia has a much lower

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amount of particulates in than any other

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continent to do with what's on the interior

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of the continent to do with the fact there's

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less pollution. So that means there's less to

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scatter the solar uv, which is why we get

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higher UV indices and therefore more sunburn.

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Um, so it's a quirk of geography rather than

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just lots of clear skies, which mean we get

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UV indices up to 13 or 14 on a hot

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summer's day and basically you fry to a crisp

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very, very quickly.

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What that means for astronomy though is that,

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uh, for a given place with a given, given

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amount of lighting, we actually get a better

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sky than we would do in other places because

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there's less to scatter that light. So that

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same amount of lighting has a slightly lower

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impact. Um, one of the story that ties into

258
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this that I always remember one of the big

259
00:10:04.600 --> 00:10:06.640
hurricanes probably 20 or 30 years ago

260
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knocked out the power across great swathes

261
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of, I think it was Florida. And many people

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saw the Milky Way for the very first time in

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their lives. And there was panic. People were

264
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actually calling up, uh, their local police.

265
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Oh, I remember this because they thought that

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the aliens were coming because the sky looked

267
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so weird and unusual because there were all

268
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these bright points of light in it and this

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weird milky glow going across the sky and ah,

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00:10:28.220 --> 00:10:31.220
we laugh. But it tells you just how decoupled

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people are from something that's been so

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00:10:33.380 --> 00:10:35.700
wonderfully culturally significant for all of

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our history. It's so important to the

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00:10:37.700 --> 00:10:38.940
traditional owners of the land here in

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00:10:38.940 --> 00:10:41.180
Australia, but also all around the world who

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00:10:41.180 --> 00:10:42.980
have this deep and intimate connection to the

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night sky. And an event like that

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really drills home the damage we've done and

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how we've removed this. And I'm always

280
00:10:51.100 --> 00:10:53.700
amazed at the reluctance of people in kind of

281
00:10:53.700 --> 00:10:55.780
groups on social media to accept that light

282
00:10:55.780 --> 00:10:58.090
pollution is a problem because can lay odds

283
00:10:58.090 --> 00:10:59.930
at the same problem who say, don't be grumpy,

284
00:10:59.930 --> 00:11:02.370
we need our lights at night to see would be

285
00:11:02.370 --> 00:11:05.130
really, really unpleasantly happy if we have

286
00:11:05.130 --> 00:11:07.410
the same level of noise pollution. If they

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00:11:07.410 --> 00:11:09.970
had their neighbors kicking out AC DC at 1am

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00:11:09.970 --> 00:11:12.250
in the morning, they'd be kicking off to the

289
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council. And it seems that we view light

290
00:11:14.490 --> 00:11:17.090
pollution a lot less seriously than we view

291
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sound pollution or other forms of pollution.

292
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And that's changing a bit. But

293
00:11:22.370 --> 00:11:24.250
there's also an energy source side of it, I

294
00:11:24.250 --> 00:11:25.850
mean this is a bit that always makes my head

295
00:11:25.850 --> 00:11:27.770
hurt is if you're throwing 30% of your light

296
00:11:27.770 --> 00:11:30.570
up into the sky, you're wasting 30% of your

297
00:11:30.570 --> 00:11:32.290
electricity and you're therefore just burning

298
00:11:32.290 --> 00:11:35.090
money. And yeah, I'm sure the energy

299
00:11:35.090 --> 00:11:36.610
companies love that because they get bigger

300
00:11:36.610 --> 00:11:39.490
profits. But doesn't seem a very efficient

301
00:11:39.490 --> 00:11:40.410
way to do things.

302
00:11:40.570 --> 00:11:42.850
Andrew Dunkley: No. And when you look at the map, uh, Eastern

303
00:11:42.850 --> 00:11:44.690
United States, basically all the United

304
00:11:44.690 --> 00:11:46.570
States, but particularly the eastern half.

305
00:11:46.650 --> 00:11:49.290
Western Europe, uh, East Asia,

306
00:11:49.600 --> 00:11:52.380
um, and even the east, uh, eastern

307
00:11:52.380 --> 00:11:54.900
half of South America pretty well just

308
00:11:55.460 --> 00:11:58.260
light pollution. Central. Yeah. But you look

309
00:11:58.260 --> 00:12:00.440
at Australia and um,

310
00:12:00.900 --> 00:12:03.340
parts of North Africa, uh,

311
00:12:03.340 --> 00:12:05.539
Greenland, although it's an ice cap so it

312
00:12:05.539 --> 00:12:07.620
makes it a bit difficult. But uh, even the

313
00:12:07.680 --> 00:12:10.540
um, uh, big areas around Russia

314
00:12:10.540 --> 00:12:13.460
and Siberia, uh, complete darkness.

315
00:12:13.620 --> 00:12:16.510
Which is, you know, very good

316
00:12:16.510 --> 00:12:18.910
place to, to go if you. Well probably not

317
00:12:18.910 --> 00:12:21.230
Russia at the moment but um, good places to

318
00:12:21.230 --> 00:12:23.910
go to look at the sky and in terms of air

319
00:12:23.910 --> 00:12:26.390
quality. Um, they did a test a few years ago

320
00:12:26.390 --> 00:12:28.830
and found that the most pure air in the world

321
00:12:28.830 --> 00:12:31.590
crosses Tasmania and southern

322
00:12:31.590 --> 00:12:31.870
Australia.

323
00:12:33.070 --> 00:12:34.990
Jonti Horner: Which sounds about right. But it is why there

324
00:12:34.990 --> 00:12:37.870
is a growing interest in astro tourism

325
00:12:37.870 --> 00:12:39.830
in Australia. I've spoken to a few people

326
00:12:39.830 --> 00:12:42.480
about this in the last 12 months where local

327
00:12:42.480 --> 00:12:43.800
councils and

328
00:12:45.320 --> 00:12:47.480
different commercial groups are looking at

329
00:12:47.480 --> 00:12:49.960
adding astronomy activities to their

330
00:12:49.960 --> 00:12:52.320
offerings because they're aware that for

331
00:12:52.320 --> 00:12:55.120
people coming in from a lot of our places,

332
00:12:55.120 --> 00:12:57.280
um, that source tourists to Australia. These

333
00:12:57.280 --> 00:12:58.800
are people who've never seen the Milky Way,

334
00:12:58.800 --> 00:13:01.240
who've never seen the night sky properly. And

335
00:13:01.240 --> 00:13:03.800
to them it's this kind of romantic ideal that

336
00:13:03.960 --> 00:13:06.240
they could have a night lying under the stars

337
00:13:06.240 --> 00:13:09.240
and see the Milky Way above them. And that's

338
00:13:09.240 --> 00:13:10.640
just the reality here. You know, I step

339
00:13:10.640 --> 00:13:12.440
outside in my backyard and I see the Milky

340
00:13:12.440 --> 00:13:15.280
Way and that makes it a really big

341
00:13:15.280 --> 00:13:17.040
tourist drawer. And people are cottoning onto

342
00:13:17.040 --> 00:13:19.320
that. And that will then be extra ammunition

343
00:13:19.320 --> 00:13:21.160
for us improving lighting laws in Australia.

344
00:13:21.640 --> 00:13:23.160
Because there's an interest beyond just

345
00:13:23.160 --> 00:13:25.640
astronomers. There's a commercial interest to

346
00:13:25.640 --> 00:13:27.280
drive that. So I think it's a real positive

347
00:13:27.280 --> 00:13:29.360
thing. And um, yeah, we'll see more of it.

348
00:13:29.360 --> 00:13:32.360
But in the meantime, roll on the EMP purse.

349
00:13:33.160 --> 00:13:35.360
Andrew Dunkley: Yes, indeed. Uh, thanks for the question

350
00:13:35.360 --> 00:13:37.760
mark. See what you've done. Good, uh, to hear

351
00:13:37.760 --> 00:13:38.040
from.

352
00:13:40.900 --> 00:13:42.140
Jonti Horner: Roger. Your lab is right here.

353
00:13:42.140 --> 00:13:44.740
Andrew Dunkley: Also Space Nuts. This is Space Nuts with

354
00:13:44.740 --> 00:13:46.220
Andrew Dunkley and Jonti Horner.

355
00:13:46.220 --> 00:13:48.500
Our next question comes from

356
00:13:48.900 --> 00:13:50.340
Doug. It's an audio question.

357
00:13:50.420 --> 00:13:52.780
Speaker C: Hi Space Nuts, it's Doug and Hazel the

358
00:13:52.780 --> 00:13:55.420
Wonderdoodle calling again. Thank you for

359
00:13:55.420 --> 00:13:57.860
your responses to my previous questions.

360
00:13:58.180 --> 00:14:00.020
My question this time is about

361
00:14:00.740 --> 00:14:03.740
uh, blocking sunlight. Given that

362
00:14:03.740 --> 00:14:06.740
we as humanity have no ability to

363
00:14:06.740 --> 00:14:08.900
control our carbon emissions, it seems.

364
00:14:09.400 --> 00:14:12.290
Um, the next question is to me,

365
00:14:12.560 --> 00:14:14.450
uh, is geoengineering possible?

366
00:14:15.330 --> 00:14:18.250
Now, given that, uh, seed

367
00:14:18.250 --> 00:14:20.730
in the higher atmosphere with reflective

368
00:14:20.730 --> 00:14:23.410
particles would probably not go over too well

369
00:14:23.410 --> 00:14:25.970
with the, uh, chemtrails people.

370
00:14:26.530 --> 00:14:29.370
I'm going to suggest that, uh, putting

371
00:14:29.370 --> 00:14:32.130
some sort of sun blocker out at Lagrange

372
00:14:32.610 --> 00:14:35.290
point one, uh, would be

373
00:14:35.290 --> 00:14:38.290
a solution that would probably need to be

374
00:14:38.290 --> 00:14:40.650
investigated. Um, ChatGPT

375
00:14:40.810 --> 00:14:43.450
suggested that a 3 million square

376
00:14:43.450 --> 00:14:46.370
meter parasol, for lack of a better word,

377
00:14:46.370 --> 00:14:49.170
would block 1% of the sun's light

378
00:14:49.170 --> 00:14:51.490
hitting the Earth. Don't, um, know what the

379
00:14:51.490 --> 00:14:53.850
magic number is. Don't know if we should even

380
00:14:53.850 --> 00:14:56.410
do this. But the question I have is

381
00:14:56.970 --> 00:14:59.890
does anybody know about anybody working on

382
00:14:59.890 --> 00:15:02.340
this particular program right now

383
00:15:02.900 --> 00:15:05.380
as uh, a contingency? Thanks very much.

384
00:15:06.100 --> 00:15:06.900
Have a good day.

385
00:15:07.220 --> 00:15:09.140
Andrew Dunkley: You too, Doug. Thank you. And hello to Hazel

386
00:15:09.140 --> 00:15:12.140
the Wonder Doodle. Uh, this has come

387
00:15:12.140 --> 00:15:14.620
up before and I do think somebody has been

388
00:15:14.620 --> 00:15:17.380
looking into the possibility of putting a

389
00:15:17.380 --> 00:15:19.900
parasol in space to try and uh,

390
00:15:19.900 --> 00:15:22.740
shade Earth. Um, I

391
00:15:22.900 --> 00:15:24.580
just don't know how well it would work.

392
00:15:25.700 --> 00:15:28.090
Jonti Horner: It's a challenge. I mean it, it, the reason

393
00:15:28.090 --> 00:15:29.890
I'm chuckling a little bit in the background

394
00:15:29.890 --> 00:15:31.690
here is not actually about this idea, which I

395
00:15:31.690 --> 00:15:33.930
think is a good one. It's hazel the wind area

396
00:15:33.930 --> 00:15:34.530
as well, isn't it?

397
00:15:34.530 --> 00:15:35.450
Andrew Dunkley: That's what's making you chuckle.

398
00:15:35.450 --> 00:15:37.010
Jonti Horner: It's not even Hazel the Wonder Doodle. It

399
00:15:37.010 --> 00:15:39.250
just amuses me that on the one hand we're

400
00:15:39.250 --> 00:15:41.170
talking here about building parasols to

401
00:15:41.170 --> 00:15:43.729
shield the sun from the daytime sky, while at

402
00:15:43.729 --> 00:15:45.450
the same time a few weeks ago we talked about

403
00:15:45.450 --> 00:15:47.290
a group of idiots with a startup in

404
00:15:47.290 --> 00:15:49.010
California to reflect the sun to shine it on

405
00:15:49.010 --> 00:15:51.930
the night times. And I've got visions of

406
00:15:51.930 --> 00:15:53.370
the fact that you get these wonderful geo

407
00:15:53.370 --> 00:15:56.170
engineers deliberately shielding blocking

408
00:15:56.170 --> 00:15:58.010
sunlight from the daylight sky only to have

409
00:15:58.010 --> 00:15:59.810
their work undone by a group of equally

410
00:15:59.810 --> 00:16:02.370
stupid people shining, um, lights on the

411
00:16:02.370 --> 00:16:04.130
nighttime sky to just basically make the

412
00:16:04.130 --> 00:16:06.410
nights hotter and offset all of the good

413
00:16:06.410 --> 00:16:08.850
work. Um, but that's more me chuckling at the

414
00:16:08.850 --> 00:16:10.810
idiocy of reflector orbital than it is about

415
00:16:10.810 --> 00:16:12.010
this question. Because this is actually a

416
00:16:12.010 --> 00:16:14.290
really good question, Doug. It is

417
00:16:14.690 --> 00:16:17.650
abundantly clear, um, that.

418
00:16:17.810 --> 00:16:19.410
Okay, don't mind me. I just got a weird pop

419
00:16:19.410 --> 00:16:21.890
up saying I'm going to expire

420
00:16:22.260 --> 00:16:24.220
after 150 minutes of inactivity, which is

421
00:16:24.220 --> 00:16:25.980
never good. But I don't think that's to do

422
00:16:25.980 --> 00:16:27.780
with space nuts. So I've just moved my mouse

423
00:16:27.780 --> 00:16:30.460
and all is good. So I am not going wake spire

424
00:16:30.460 --> 00:16:32.260
live on air. This is good. Yeah.

425
00:16:32.420 --> 00:16:35.100
So there is fundamentally an issue that the

426
00:16:35.100 --> 00:16:37.540
planet is warming and the planet is warming

427
00:16:37.620 --> 00:16:40.100
because of human activities. And that is

428
00:16:41.060 --> 00:16:43.340
not open, uh, for dispute really anymore. I

429
00:16:43.340 --> 00:16:44.940
know that there are a variety of opinions

430
00:16:44.940 --> 00:16:46.300
available on this, but for me as an

431
00:16:46.300 --> 00:16:48.710
astronomer, the evidence is utterly

432
00:16:48.710 --> 00:16:51.110
overwhelming. And the only thing that can

433
00:16:51.110 --> 00:16:53.270
explain the changes that we're seeing, not

434
00:16:53.270 --> 00:16:55.270
the size of the changes, but the speed of the

435
00:16:55.270 --> 00:16:57.550
changes, is human activity. No

436
00:16:57.870 --> 00:17:00.710
physical process, other than perhaps a

437
00:17:00.710 --> 00:17:03.150
rock hitting the Earth and killing everybody,

438
00:17:03.450 --> 00:17:05.270
um, like the dinosaur level extinction, there

439
00:17:05.270 --> 00:17:07.870
is nothing else that could cause this rate of

440
00:17:07.870 --> 00:17:10.470
change. So it's very, very clear that human

441
00:17:10.470 --> 00:17:13.110
activity is the cause of this and, um, that

442
00:17:13.110 --> 00:17:14.950
there is some inertia in trying to persuade

443
00:17:14.950 --> 00:17:16.590
humans to stop doing the things that cause

444
00:17:16.590 --> 00:17:18.900
the problems and understand that. So there's

445
00:17:18.900 --> 00:17:21.500
a growing list of suggestions of ways that we

446
00:17:21.500 --> 00:17:23.700
could mitigate for climate change out there.

447
00:17:24.020 --> 00:17:26.980
One, as Doug said, is sprinkling reflective

448
00:17:26.980 --> 00:17:28.700
particles into the upper atmosphere to

449
00:17:28.700 --> 00:17:31.280
effectively increase the Earth's albedo, uh,

450
00:17:31.280 --> 00:17:33.380
which would mean more energy was reflected to

451
00:17:33.380 --> 00:17:35.260
space and less makes it down to the surface

452
00:17:35.260 --> 00:17:37.660
of the Earth to kind of heat the pressure

453
00:17:37.660 --> 00:17:40.460
cooker. And that could

454
00:17:40.460 --> 00:17:42.460
possibly work. It'll be interesting to see

455
00:17:42.460 --> 00:17:44.900
what role SpaceX plays in that in the years

456
00:17:44.900 --> 00:17:47.680
to come, because with all of the satellites

457
00:17:47.680 --> 00:17:50.190
they're launching, there's a growing, um,

458
00:17:50.190 --> 00:17:51.800
number of things returning to Earth and

459
00:17:51.800 --> 00:17:53.880
burning up in the upper atmosphere that are

460
00:17:53.880 --> 00:17:56.040
depositing metals like aluminum into the

461
00:17:56.040 --> 00:17:58.160
upper atmosphere. And nobody's really sure

462
00:17:58.160 --> 00:18:00.320
what's going to happen there. So that might

463
00:18:00.320 --> 00:18:02.760
actually inadvertently do exactly what Doug

464
00:18:02.760 --> 00:18:05.600
mentioned and increase the Earth's albedo

465
00:18:05.760 --> 00:18:08.040
and offset some climate change, or it might

466
00:18:08.040 --> 00:18:09.600
make it worse. People are still trying to

467
00:18:09.600 --> 00:18:11.590
figure out what's going to happen there. And

468
00:18:11.590 --> 00:18:13.910
that ties into the idea that space is still a

469
00:18:13.910 --> 00:18:16.190
little bit of the wild, Wild west, in that

470
00:18:16.190 --> 00:18:19.070
things are happening faster than legislation

471
00:18:19.070 --> 00:18:21.310
can adapt. You know, we've got tons of

472
00:18:21.310 --> 00:18:23.270
aluminium being added to the atmosphere and

473
00:18:23.270 --> 00:18:25.230
we don't know what it's going to do, but that

474
00:18:25.230 --> 00:18:27.990
might have part of this effect. But an

475
00:18:27.990 --> 00:18:30.710
obvious way that you could cool the Earth is

476
00:18:30.710 --> 00:18:33.190
by blocking some sunlight. Fundamentally,

477
00:18:33.190 --> 00:18:35.030
that makes sense. If you block 1% of the

478
00:18:35.030 --> 00:18:37.350
sun's light, you block 1% of the energy

479
00:18:37.350 --> 00:18:39.470
coming into the Earth, which will be about

480
00:18:39.470 --> 00:18:41.710
13.6 watts. The solar constant's about

481
00:18:41.710 --> 00:18:44.260
1360 watts per square meter. Block, uh,

482
00:18:44.510 --> 00:18:47.430
1% of that, that will be 13.6 watts,

483
00:18:47.430 --> 00:18:49.310
and that will be more than enough to offset

484
00:18:49.390 --> 00:18:52.390
climate change and probably more so. But

485
00:18:52.390 --> 00:18:54.589
let's say we wanted to block 1% of the light

486
00:18:54.589 --> 00:18:56.710
from the sun. That means you would need a

487
00:18:56.710 --> 00:18:59.670
parasol that is equal to 1% of the

488
00:18:59.670 --> 00:19:01.070
cross section of the Earth, Uh, if that

489
00:19:01.310 --> 00:19:03.590
parasol blocked all of the light from the sun

490
00:19:03.590 --> 00:19:05.870
that was hitting it. So that means

491
00:19:06.190 --> 00:19:08.790
1% of the Earth's surface would be dark. The

492
00:19:08.790 --> 00:19:11.550
sun wouldn't be falling on it. Or you diffuse

493
00:19:11.550 --> 00:19:14.110
that, and, um, you have 1% less light coming

494
00:19:14.110 --> 00:19:16.750
down. So if you do the maths of that. The

495
00:19:16.750 --> 00:19:19.390
Earth has a radius

496
00:19:19.550 --> 00:19:22.070
of about 6,378

497
00:19:22.070 --> 00:19:24.670
kilometers. That varies because the Earth's a

498
00:19:24.670 --> 00:19:26.910
bit ablate. So the radius from pole to pole

499
00:19:27.150 --> 00:19:29.590
is different to the radius across the

500
00:19:29.590 --> 00:19:31.750
equator. But we can use that as a mean

501
00:19:31.750 --> 00:19:34.710
radius. That means that the Earth, uh, has a

502
00:19:34.710 --> 00:19:37.710
surface area of about 10, 1.9,

503
00:19:37.710 --> 00:19:39.630
I think it was, times 10 to the 14

504
00:19:40.510 --> 00:19:43.150
meters squared. So to

505
00:19:43.150 --> 00:19:46.070
block 1% of the light, you'd need a

506
00:19:46.070 --> 00:19:49.030
parasol. That is 1% of that. So that would be

507
00:19:49.030 --> 00:19:51.910
about 1, um, point 28 times 10 to

508
00:19:51.910 --> 00:19:54.910
the 12 meters squared. Which means

509
00:19:54.910 --> 00:19:57.310
that you will need a parasol. I'm sorry,

510
00:19:57.310 --> 00:19:58.590
kilometers squared. I've done this

511
00:19:58.590 --> 00:20:01.110
calculation in kilometers, um, which would.

512
00:20:01.430 --> 00:20:03.510
No, that is in meters, sorry. Which would

513
00:20:03.510 --> 00:20:06.030
mean you'd need a parasol if you made it

514
00:20:06.030 --> 00:20:08.150
Square. That is

515
00:20:08.230 --> 00:20:10.990
1130 kilometers on a

516
00:20:10.990 --> 00:20:11.270
side

517
00:20:13.750 --> 00:20:16.710
that I think is technologically beyond us at

518
00:20:16.710 --> 00:20:19.190
the minute. Um, added to which,

519
00:20:19.590 --> 00:20:21.550
you know that the politicians would want us

520
00:20:21.550 --> 00:20:23.310
to mine that material on Earth and launch it

521
00:20:23.310 --> 00:20:25.340
because that would be more profitable. So the

522
00:20:25.340 --> 00:20:26.940
process of mining and launching all that

523
00:20:26.940 --> 00:20:29.700
material to build 1,000 kilometers on each

524
00:20:29.700 --> 00:20:32.340
side. Parasol Will probably put far more

525
00:20:32.420 --> 00:20:34.180
greenhouse gases into the atmosphere and

526
00:20:34.180 --> 00:20:36.540
exacerbate the problem. The other challenge

527
00:20:36.540 --> 00:20:38.300
you'd have with the parasol issue, though, is

528
00:20:38.300 --> 00:20:40.580
that the L1 point, which would be the obvious

529
00:20:40.580 --> 00:20:43.100
place to put it, that's a point between the

530
00:20:43.100 --> 00:20:45.460
Earth and the Sun. Where an object would

531
00:20:45.460 --> 00:20:47.340
rotate at the same orbital period as the

532
00:20:47.340 --> 00:20:49.420
Earth. And, um, be in this kind of semi

533
00:20:49.420 --> 00:20:51.100
stable location. That's where a lot of our

534
00:20:51.100 --> 00:20:53.700
solar observation spacecraft go, like soho,

535
00:20:53.910 --> 00:20:55.590
to give us early warning of space weather.

536
00:20:56.150 --> 00:20:59.110
Now, the L1 point is about 1.5 million

537
00:20:59.110 --> 00:21:01.750
kilometers away. Things at

538
00:21:01.750 --> 00:21:04.150
L1 are not fully stable. So they need rockets

539
00:21:04.150 --> 00:21:05.990
and actuators to keep them on point. Because

540
00:21:05.990 --> 00:21:08.270
if they drift too far away, they'll fall out

541
00:21:08.270 --> 00:21:10.830
of the stable area and go off orbiting the

542
00:21:10.830 --> 00:21:13.350
sun on the rock. So what you need to do is

543
00:21:13.350 --> 00:21:16.310
have an object 1,000 kilometers on each

544
00:21:16.310 --> 00:21:18.790
side. Located one and a half million

545
00:21:18.790 --> 00:21:21.440
kilometers away. That could be positioned

546
00:21:21.440 --> 00:21:23.680
accurately enough that the shadow it casts

547
00:21:23.760 --> 00:21:26.680
hits a target 6,300 km

548
00:21:26.680 --> 00:21:29.120
in radius rather than missing us. So as it

549
00:21:29.120 --> 00:21:31.200
drifts around, we'd have to keep it on point

550
00:21:31.680 --> 00:21:33.720
to an accuracy of just a few hundred

551
00:21:33.720 --> 00:21:36.119
kilometers. And so this is one of those

552
00:21:36.119 --> 00:21:38.000
things where it's a fabulous idea for science

553
00:21:38.000 --> 00:21:40.440
fiction and it is the kind of thing where we

554
00:21:40.440 --> 00:21:42.760
can imagine all of the steps we need to take

555
00:21:42.760 --> 00:21:44.920
to make it work. So it's within the bounds of

556
00:21:44.920 --> 00:21:47.860
our technology in terms of our ability to

557
00:21:47.860 --> 00:21:50.660
make stuff, but it's the scale of it that

558
00:21:50.660 --> 00:21:53.580
makes it impractical. And that's why a

559
00:21:53.580 --> 00:21:56.020
lot of these ideas of parasols

560
00:21:56.420 --> 00:21:59.180
fall down, is that the amount of area

561
00:21:59.180 --> 00:22:01.140
you'd have to cover to block enough light to

562
00:22:01.140 --> 00:22:03.780
make it feasible are so huge that it's just

563
00:22:03.780 --> 00:22:06.460
technologically the building of them and the

564
00:22:06.460 --> 00:22:08.180
keeping them on point will be too much of a

565
00:22:08.180 --> 00:22:10.780
challenge. It be a global endeavor that would

566
00:22:10.780 --> 00:22:13.700
make the efforts for the Apollo missions seem

567
00:22:13.700 --> 00:22:16.140
like tiny little small fry in comparison.

568
00:22:16.540 --> 00:22:18.940
I don't know if anybody's ever done a

569
00:22:18.940 --> 00:22:21.420
calculation of the cost that this would have.

570
00:22:22.050 --> 00:22:23.420
Um, but I suspect there are other

571
00:22:23.420 --> 00:22:26.100
geoengineering ideas that will be more

572
00:22:26.100 --> 00:22:28.160
financially feasible. Uh,

573
00:22:29.340 --> 00:22:31.260
I'm always an optimist. I mean, I am very

574
00:22:31.260 --> 00:22:32.940
worried, like everybody is, about climate

575
00:22:32.940 --> 00:22:35.140
change. I have been since I was a kid. I've

576
00:22:35.140 --> 00:22:38.140
lived in places where it is writ large on

577
00:22:38.140 --> 00:22:39.820
the landscape. I always talk about when I

578
00:22:39.820 --> 00:22:41.180
lived in Switzerland, and they've got

579
00:22:41.180 --> 00:22:43.550
photographs from mid summer, uh, in all these

580
00:22:43.550 --> 00:22:45.870
little Alpine villages of the glacier just

581
00:22:45.870 --> 00:22:47.830
behind the village. Evening, midsummer. And

582
00:22:47.830 --> 00:22:49.430
then you step outside and you can't see the

583
00:22:49.430 --> 00:22:51.230
glacier because it's retreated so far up the

584
00:22:51.230 --> 00:22:53.950
mountains it's no longer in view. So I've

585
00:22:53.950 --> 00:22:56.550
lived in places where it's obvious. But I'm

586
00:22:56.550 --> 00:22:58.670
always of the idea that eventually human

587
00:22:58.670 --> 00:23:01.560
ingenuity and commercial, um,

588
00:23:01.560 --> 00:23:03.630
interests will get to the point where it is

589
00:23:04.110 --> 00:23:06.030
something we'll solve. And I think we're

590
00:23:06.030 --> 00:23:07.950
seeing that a bit now with electric cars.

591
00:23:07.950 --> 00:23:10.330
We've had the technology to have electric

592
00:23:10.330 --> 00:23:12.490
vehicles for more than 100 years. I remember

593
00:23:12.570 --> 00:23:14.730
getting milk delivered by the milkman as a

594
00:23:14.730 --> 00:23:16.210
kid. And, uh, they were going around in

595
00:23:16.210 --> 00:23:18.130
electric milk carts, you know, so we have

596
00:23:18.130 --> 00:23:21.090
that technology even then. But for a long

597
00:23:21.090 --> 00:23:22.970
time nobody's had electric cars, nobody's

598
00:23:22.970 --> 00:23:25.250
considered it solvable. But eventually the

599
00:23:25.250 --> 00:23:26.650
costs have dropped enough that they're a

600
00:23:26.650 --> 00:23:28.370
viable alternative and now people are taking

601
00:23:28.370 --> 00:23:30.410
them up. So you're seeing a drop in the

602
00:23:30.410 --> 00:23:32.890
number of petrol vehicles. And I'd like to

603
00:23:32.890 --> 00:23:35.130
think that because a lot of the things that

604
00:23:35.130 --> 00:23:37.010
we do to cause climate change are

605
00:23:37.010 --> 00:23:39.440
fundamentally inefficient, as our technology

606
00:23:39.600 --> 00:23:42.120
improves, we'll move to much more

607
00:23:42.120 --> 00:23:44.320
efficient processes that generate less of the

608
00:23:44.320 --> 00:23:46.600
things that cause climate change. And, uh, we

609
00:23:46.600 --> 00:23:48.360
will find a solution. But the problem is the

610
00:23:48.360 --> 00:23:50.920
lag time is such that the longer we wait, the

611
00:23:50.920 --> 00:23:52.760
worse it's going to get before it gets better

612
00:23:52.760 --> 00:23:54.880
again. And there are some suggestions that,

613
00:23:54.880 --> 00:23:57.120
for example, the horrendous hurricane that

614
00:23:57.360 --> 00:24:00.320
hit Jamaica last week was significantly

615
00:24:00.320 --> 00:24:02.000
worse because of the effect of climate change

616
00:24:02.000 --> 00:24:03.920
on the temperatures of the water. There's now

617
00:24:03.920 --> 00:24:06.160
actually a whole branch of mathematical

618
00:24:06.160 --> 00:24:08.730
science that delves into

619
00:24:09.690 --> 00:24:12.530
calculating not a yes, no did climate change

620
00:24:12.530 --> 00:24:15.450
cause this event, but rather a statistical

621
00:24:15.450 --> 00:24:18.130
analysis of how much worse was this

622
00:24:18.130 --> 00:24:20.930
event as a result of the effects of climate

623
00:24:20.930 --> 00:24:22.970
change. And I think the numbers for that

624
00:24:22.970 --> 00:24:25.930
hurricane last week were quite startling

625
00:24:25.930 --> 00:24:28.570
that it was made noticeably worse because of

626
00:24:28.570 --> 00:24:30.130
the increased heating of the ocean and all

627
00:24:30.130 --> 00:24:32.170
the rest of it. Yeah, it is a real problem

628
00:24:32.170 --> 00:24:34.140
with. We want to get solutions, but I think

629
00:24:34.140 --> 00:24:35.940
the parasol is a bit too hard.

630
00:24:36.020 --> 00:24:38.420
Andrew Dunkley: Yeah, I did read the science behind why that

631
00:24:38.420 --> 00:24:40.860
storm was so severe and it was quite an

632
00:24:40.860 --> 00:24:42.660
interesting read. And I won't go into it now

633
00:24:42.660 --> 00:24:44.260
because I probably get half of it wrong.

634
00:24:44.260 --> 00:24:47.220
But, um, you might also be interested,

635
00:24:47.220 --> 00:24:49.620
Doug, to know that there have been some

636
00:24:49.860 --> 00:24:52.340
researchers looking into this. Not just

637
00:24:53.140 --> 00:24:56.100
maybe a single object in space to,

638
00:24:56.500 --> 00:24:59.260
to block the sun. But University, uh, of

639
00:24:59.260 --> 00:25:01.700
Arizona was looking at a, uh, cloud of small

640
00:25:02.080 --> 00:25:04.560
spacecraft. Uh, there was another research,

641
00:25:05.310 --> 00:25:08.150
uh, effort at mit, uh,

642
00:25:08.150 --> 00:25:10.930
looking at inflatable space bubbles. Uh,

643
00:25:10.930 --> 00:25:13.600
another idea out of the University of Hawaii,

644
00:25:13.810 --> 00:25:16.520
um, tethering shades to an asteroid. The

645
00:25:16.520 --> 00:25:18.320
asteroid being used as a counterweight if

646
00:25:18.320 --> 00:25:19.680
they could capture one. That's another

647
00:25:20.240 --> 00:25:22.480
impossible dream at the moment. Solar sails

648
00:25:22.480 --> 00:25:24.800
and lightweight films and, and even one,

649
00:25:25.590 --> 00:25:27.760
uh, proposed only a couple of years ago was,

650
00:25:27.850 --> 00:25:30.780
um, to start ejecting lunar

651
00:25:30.780 --> 00:25:33.220
dust into space to create

652
00:25:33.940 --> 00:25:36.710
a dust cloud to block the sun. M.

653
00:25:36.710 --> 00:25:39.660
My worry is if we do decide

654
00:25:39.660 --> 00:25:41.740
that that's the solution and we do it and

655
00:25:41.740 --> 00:25:44.180
then we solve the problem of global warming,

656
00:25:45.060 --> 00:25:47.140
won't we then put ourselves in a position

657
00:25:47.220 --> 00:25:50.180
where we could cause, uh, a global

658
00:25:50.180 --> 00:25:50.740
winter?

659
00:25:51.810 --> 00:25:51.970
Jonti Horner: Um.

660
00:25:54.910 --> 00:25:56.990
Andrew Dunkley: Even if we reach a point where we've got the

661
00:25:56.990 --> 00:25:59.710
technology to solve the problem, as

662
00:25:59.710 --> 00:26:01.470
Doug said, should we do it?

663
00:26:01.950 --> 00:26:04.270
Jonti Horner: And we also come to

664
00:26:04.910 --> 00:26:06.670
really interesting questions because

665
00:26:07.150 --> 00:26:10.050
underlying the climate change we've got, um,

666
00:26:10.050 --> 00:26:12.230
there's also the fact that the Earth's, uh,

667
00:26:12.230 --> 00:26:14.110
climate changes naturally on much longer

668
00:26:14.110 --> 00:26:15.430
timescales. We get the glacial and

669
00:26:15.430 --> 00:26:18.310
interglacial periods. So if we ever do get to

670
00:26:18.310 --> 00:26:20.350
the point where we've got climate control,

671
00:26:20.510 --> 00:26:23.510
so. So in other words, we can set the Earth's

672
00:26:23.510 --> 00:26:25.630
climate to be. At a certain point we can fix

673
00:26:25.630 --> 00:26:27.750
a problem. And if we can fix a problem, we

674
00:26:27.750 --> 00:26:29.430
can then say where we want the climate to

675
00:26:29.430 --> 00:26:31.630
sit. What do we choose? Do we allow

676
00:26:32.190 --> 00:26:34.310
that very slow pace of climate change to

677
00:26:34.310 --> 00:26:36.749
happen? Do we figure out the conditions that

678
00:26:36.749 --> 00:26:39.710
are optimal and set it there? There's

679
00:26:39.710 --> 00:26:41.270
a lot of really interesting stuff that would

680
00:26:41.270 --> 00:26:42.910
feed into science fiction rather than science

681
00:26:42.910 --> 00:26:44.590
fact that come from the fact that if you've

682
00:26:44.590 --> 00:26:45.830
got to the point where you can solve the

683
00:26:45.830 --> 00:26:47.890
problem, you've got to the point where you

684
00:26:47.890 --> 00:26:50.130
can geoengineer the Earth's climate to suit.

685
00:26:50.850 --> 00:26:52.850
So where do you therefore set the sweet spot?

686
00:26:52.850 --> 00:26:55.570
Do you set it at uh, the year 2000 mean, the

687
00:26:55.570 --> 00:26:58.330
1900 mean? Do you make it a little bit

688
00:26:58.330 --> 00:26:59.770
cooler than that? Do you make it a little bit

689
00:26:59.770 --> 00:27:01.690
warmer than that? It's a really interesting

690
00:27:01.690 --> 00:27:04.130
one. Which for an incredibly complex and

691
00:27:04.130 --> 00:27:06.810
chaotic system, um, would lead to a lot of

692
00:27:06.810 --> 00:27:09.010
implications about weather disasters and all

693
00:27:09.010 --> 00:27:11.210
the rest of it. Yeah, there's a lot of

694
00:27:11.210 --> 00:27:12.530
interesting stuff there. I think it's going

695
00:27:12.530 --> 00:27:14.050
to be interesting times for the next hundred

696
00:27:14.050 --> 00:27:16.690
or two hundred years as humanity tries to

697
00:27:16.690 --> 00:27:17.930
solve the problems it's made.

698
00:27:18.730 --> 00:27:21.010
Andrew Dunkley: Indeed. Yes. Thank you Doug, Great to hear

699
00:27:21.010 --> 00:27:23.050
from you. Keep them coming. There's some

700
00:27:23.050 --> 00:27:25.490
terrific ideas out there that uh, people want

701
00:27:25.490 --> 00:27:28.490
to learn more about. And this is

702
00:27:28.490 --> 00:27:31.489
Space Nuts with Andrew Dunkley and Jonti

703
00:27:31.489 --> 00:27:32.090
Horner.

704
00:27:36.490 --> 00:27:37.530
Space Nuts.

705
00:27:37.690 --> 00:27:40.170
Our next question, uh, comes from another

706
00:27:40.250 --> 00:27:42.650
YouTuber. Uh, and

707
00:27:42.870 --> 00:27:45.650
uh, the question is who has the salvage

708
00:27:45.650 --> 00:27:48.650
rights on all the scrap satellites and is

709
00:27:48.650 --> 00:27:51.490
there a plan or a uh, map of all the

710
00:27:51.490 --> 00:27:54.130
defunct scrap in orbit? Possibly in the

711
00:27:54.130 --> 00:27:56.490
future there would be good business in

712
00:27:56.490 --> 00:27:58.610
recovering all the precious metals, et

713
00:27:58.610 --> 00:28:00.610
cetera. It's a good question. I know they

714
00:28:00.610 --> 00:28:02.810
were experimenting with different ways of

715
00:28:02.890 --> 00:28:05.860
bringing down defunct satellites, uh,

716
00:28:06.330 --> 00:28:08.610
and all they were doing was like testing

717
00:28:08.610 --> 00:28:11.500
harpoons and things like that or whatever to

718
00:28:11.500 --> 00:28:14.300
make them re enter and burn up. But this is,

719
00:28:14.380 --> 00:28:17.020
this is um, a whole new ball game. Salvage.

720
00:28:17.550 --> 00:28:19.940
Uh, I don't, I haven't heard of it.

721
00:28:19.940 --> 00:28:22.780
Jonti Horner: Have you? It's yet

722
00:28:22.780 --> 00:28:25.580
another area where legislation is not keeping

723
00:28:25.580 --> 00:28:28.540
up with use. So there's a

724
00:28:28.540 --> 00:28:30.940
lot of challenges with this. Space is vastly

725
00:28:30.940 --> 00:28:32.740
big and um, the things we put up there are

726
00:28:32.740 --> 00:28:34.540
very small compared to the size of the space

727
00:28:34.540 --> 00:28:37.270
that's up there. There are a lot of efforts

728
00:28:37.270 --> 00:28:39.750
going on to map and to keep track of all of

729
00:28:39.750 --> 00:28:42.590
the bits of debris, both large scale like

730
00:28:42.590 --> 00:28:44.830
satellites and former rocket bodies, down to

731
00:28:44.830 --> 00:28:46.350
the very small fragments you've got out

732
00:28:46.350 --> 00:28:48.870
there. And that's the whole Area of space,

733
00:28:48.870 --> 00:28:50.670
situational awareness. There's telescopes

734
00:28:50.670 --> 00:28:52.750
around the world tracking debris, keeping it

735
00:28:52.750 --> 00:28:55.750
in databases. And the thing there is

736
00:28:55.750 --> 00:28:57.430
that you can't just assume that once you've

737
00:28:57.430 --> 00:28:58.790
seen it, you know what it's orbit is and

738
00:28:58.790 --> 00:29:00.790
you'll know where it is forevermore, because

739
00:29:00.790 --> 00:29:02.550
it's a complex environment where the Earth's

740
00:29:02.550 --> 00:29:04.230
atmosphere is breathing in and out, getting

741
00:29:04.230 --> 00:29:06.190
bigger and smaller, and the solar wind is

742
00:29:06.190 --> 00:29:08.460
varying. And all these things that happen,

743
00:29:08.460 --> 00:29:11.420
even down to the subtleties of the varying

744
00:29:11.420 --> 00:29:13.500
densities of different parts of the Earth's

745
00:29:13.500 --> 00:29:15.460
surface, causing slight changes in the

746
00:29:15.460 --> 00:29:17.740
Earth's gravity at, uh, the kind of level you

747
00:29:17.740 --> 00:29:19.820
want to track these things, all of that means

748
00:29:19.820 --> 00:29:21.100
that you need to keep tracking them. You

749
00:29:21.100 --> 00:29:22.660
can't just find them once and say it's there

750
00:29:22.660 --> 00:29:25.060
and that's it. So there's a whole burgeoning

751
00:29:25.060 --> 00:29:26.980
kind of research industry built around

752
00:29:27.460 --> 00:29:29.660
tracking this debris, using laser range

753
00:29:29.660 --> 00:29:31.580
finding to get as accurate a position as

754
00:29:31.580 --> 00:29:34.030
possible. And part of the reason for that is

755
00:29:34.030 --> 00:29:36.590
so that things like expensive satellites and

756
00:29:36.590 --> 00:29:38.750
the space station can dodge when there's a

757
00:29:38.750 --> 00:29:40.910
chance of an impact. That's always helpful.

758
00:29:41.430 --> 00:29:43.550
Um, it is also just so that we were aware of

759
00:29:43.550 --> 00:29:44.990
what's up there, and it's a problem that's

760
00:29:44.990 --> 00:29:46.550
only going to get worse. Now, I did a little

761
00:29:46.550 --> 00:29:49.510
bit of searching around because I had never

762
00:29:49.510 --> 00:29:52.390
thought of the salvage of

763
00:29:52.390 --> 00:29:55.230
satellites and stuff like that as being a

764
00:29:55.230 --> 00:29:58.150
thing. Now, in maritime

765
00:29:58.150 --> 00:30:00.430
law, there's this concept of the right to

766
00:30:00.430 --> 00:30:02.350
salvage, which is when something is becoming

767
00:30:02.350 --> 00:30:05.170
dangerous or when it's out, which allows

768
00:30:05.170 --> 00:30:07.930
people to claim salvage rights. There is no

769
00:30:07.930 --> 00:30:09.970
such thing in space. I found a few articles

770
00:30:09.970 --> 00:30:12.250
that all confirm that. And I quote from an

771
00:30:12.250 --> 00:30:15.050
article in the spacereview.com, there is no

772
00:30:15.050 --> 00:30:17.250
right of salvage analogous to the right found

773
00:30:17.250 --> 00:30:19.570
in maritime law. Which means that even though

774
00:30:19.570 --> 00:30:21.490
a satellite or some other space object may

775
00:30:21.490 --> 00:30:24.050
not be functioning, that does not imply that

776
00:30:24.050 --> 00:30:26.250
it has been abandoned by the nation that

777
00:30:26.250 --> 00:30:29.010
launched it. And there's a pretty lengthy

778
00:30:29.010 --> 00:30:31.090
spiel following that which basically says, if

779
00:30:31.090 --> 00:30:32.930
you don't have concept for the nation that

780
00:30:32.930 --> 00:30:35.490
launched and operated that thing, you're not

781
00:30:35.490 --> 00:30:37.250
allowed to dispose of it or interfere with

782
00:30:37.250 --> 00:30:37.530
it.

783
00:30:38.730 --> 00:30:41.610
Andrew Dunkley: In fact, uh, I might just add a caveat to

784
00:30:41.610 --> 00:30:43.770
that. Uh, if you launch something into space,

785
00:30:43.770 --> 00:30:45.050
it is your responsibility.

786
00:30:45.290 --> 00:30:48.250
Jonti Horner: Yes, absolutely. Which follows on to the

787
00:30:48.250 --> 00:30:50.970
next point. That's the issue about salvaging

788
00:30:50.970 --> 00:30:53.170
it while it is still in space. And, um, I

789
00:30:53.170 --> 00:30:55.930
could imagine that with sufficiently future

790
00:30:56.090 --> 00:30:58.410
technology and a more crowded environment

791
00:30:58.490 --> 00:31:00.210
around space, there could be a commercial

792
00:31:00.210 --> 00:31:02.490
opportunity for somebody to develop Yeah, a

793
00:31:02.490 --> 00:31:05.090
cleanup crew, which companies

794
00:31:05.250 --> 00:31:08.090
who own a satellite can pay to

795
00:31:08.090 --> 00:31:09.930
recover their satellite and dispose of it

796
00:31:09.930 --> 00:31:12.730
safely or to give harvesting rights or

797
00:31:12.730 --> 00:31:14.730
whatever, where that's dealt with. I could

798
00:31:14.730 --> 00:31:16.530
see that as a commercial thing down the line.

799
00:31:16.770 --> 00:31:18.890
But it also has an impact on what happens

800
00:31:18.890 --> 00:31:21.890
when satellites fall back to Earth. Should

801
00:31:21.890 --> 00:31:23.370
they make it through the Earth's atmosphere

802
00:31:23.370 --> 00:31:25.050
intact and make it to the surface of the

803
00:31:25.050 --> 00:31:27.530
Earth, as we saw with Skylab In Australia in

804
00:31:27.530 --> 00:31:30.410
1973, for example, um, and more

805
00:31:30.410 --> 00:31:33.330
recently with fragments of SpaceX debris

806
00:31:33.330 --> 00:31:36.090
littering the planet, you might think that if

807
00:31:36.090 --> 00:31:38.450
it falls in your backyard, it's yours, but it

808
00:31:38.450 --> 00:31:41.170
isn't. The ownership remains with the people

809
00:31:41.170 --> 00:31:44.010
or the country that launched it. And so

810
00:31:44.250 --> 00:31:47.130
back when Skylab, um, landed in Western

811
00:31:47.130 --> 00:31:49.730
Australia, the area in Western Australia

812
00:31:49.730 --> 00:31:52.130
where it landed cheekily sent NASA a

813
00:31:52.130 --> 00:31:55.130
littering notice for a fine, which got paid,

814
00:31:55.510 --> 00:31:57.630
um, which was quite good fun a few years ago

815
00:31:57.630 --> 00:32:00.350
when large pieces of SpaceX rocket landed in

816
00:32:00.350 --> 00:32:01.750
the Snowy Mountains in Australia.

817
00:32:02.150 --> 00:32:02.590
Andrew Dunkley: Yes.

818
00:32:02.590 --> 00:32:04.430
Jonti Horner: People were advised not to pick the bits up

819
00:32:04.430 --> 00:32:06.350
and collect them to let the Australian Space

820
00:32:06.350 --> 00:32:09.190
Agency know, because technically,

821
00:32:09.190 --> 00:32:11.950
the space agency has a whole plan. And this

822
00:32:11.950 --> 00:32:13.910
is laid out on the space agency website under

823
00:32:13.910 --> 00:32:15.430
space.govau

824
00:32:16.150 --> 00:32:18.150
discovery of space

825
00:32:18.550 --> 00:32:21.540
debris in Australia. So

826
00:32:21.540 --> 00:32:24.180
space.govau discovery of space

827
00:32:24.180 --> 00:32:26.780
debris in Australia details

828
00:32:26.940 --> 00:32:29.620
the regulatory side of things and what the

829
00:32:29.620 --> 00:32:32.300
space agency does, and says the Australian

830
00:32:32.300 --> 00:32:33.860
government has plans in place for events

831
00:32:33.860 --> 00:32:35.420
where space debris impacts Australia.

832
00:32:36.060 --> 00:32:37.700
Description of what it is and what the role

833
00:32:37.700 --> 00:32:39.500
is, and it lays out the steps that if you

834
00:32:39.500 --> 00:32:41.540
find space debris in your backyard, you

835
00:32:41.540 --> 00:32:44.540
should follow. Step one is do not touch it.

836
00:32:44.700 --> 00:32:46.660
And I cannot stress this enough, do not touch

837
00:32:46.660 --> 00:32:48.970
it. Space objects are built from materials

838
00:32:48.970 --> 00:32:51.330
that can be hazardous. This is exacerbated by

839
00:32:51.330 --> 00:32:52.450
coming back through the atmosphere and

840
00:32:52.450 --> 00:32:55.050
getting damaged. So it says space debris

841
00:32:55.050 --> 00:32:56.530
should only be handled by appropriately

842
00:32:56.530 --> 00:32:59.370
trained and equipped professionals. That was

843
00:32:59.370 --> 00:33:01.330
particularly relevant with the fragments of

844
00:33:01.330 --> 00:33:03.330
the SpaceX rocket that fell near the Turks

845
00:33:03.330 --> 00:33:05.410
and Caicos Islands earlier this year, because

846
00:33:05.410 --> 00:33:07.450
there was a whole brouhaha about the cleanup

847
00:33:07.450 --> 00:33:10.090
and SpaceX was not following its requirements

848
00:33:10.090 --> 00:33:12.650
and not doing much, and people were upset and

849
00:33:12.650 --> 00:33:14.170
some people had been going and collecting

850
00:33:14.170 --> 00:33:15.730
bits of debris and there was a risk they'd

851
00:33:15.730 --> 00:33:18.130
fall ill and stuff like this. So, step one,

852
00:33:18.130 --> 00:33:20.970
don't touch it. Step two, contact your local

853
00:33:20.970 --> 00:33:23.530
authorities. So, um, if the situation is

854
00:33:23.530 --> 00:33:25.410
urgent, contact triple zero. So I guess

855
00:33:25.410 --> 00:33:27.450
that's if a piece of a SpaceX satellite hits

856
00:33:27.450 --> 00:33:30.250
your Tesla, don't contact the museum, call

857
00:33:30.250 --> 00:33:32.930
the police. Fair enough. Otherwise, call the

858
00:33:32.930 --> 00:33:34.930
police assistant line. So you get some advice

859
00:33:35.010 --> 00:33:37.930
and Then you notify the space agency. And

860
00:33:37.930 --> 00:33:40.610
what the space agency then has to do is

861
00:33:40.610 --> 00:33:43.550
figure out whose bit of debris it is, get in

862
00:33:43.550 --> 00:33:45.430
touch with them, um, and liaise with them

863
00:33:45.670 --> 00:33:47.550
because there is a requirement for us to

864
00:33:47.550 --> 00:33:50.070
return the material to them. It is their

865
00:33:50.070 --> 00:33:52.550
property. And um, so from

866
00:33:52.550 --> 00:33:55.110
salvaging here on Earth you don't have those

867
00:33:55.110 --> 00:33:57.350
salvage laws because even if it's a burnt up

868
00:33:57.350 --> 00:33:59.630
fragment of rocket, it's still property of

869
00:33:59.630 --> 00:34:01.630
SpaceX or it's still property of the Chinese

870
00:34:01.630 --> 00:34:04.230
government. And so we don't have that kind of

871
00:34:04.230 --> 00:34:06.230
salvage set up at the minute. There's a

872
00:34:06.230 --> 00:34:08.110
description of what happens once debris is

873
00:34:08.110 --> 00:34:10.030
identified as space debris. And it says if an

874
00:34:10.030 --> 00:34:12.230
item is confirmed as space debris, the

875
00:34:12.230 --> 00:34:14.190
Australian government has international

876
00:34:14.350 --> 00:34:16.830
obligations to notify the launching authority

877
00:34:16.990 --> 00:34:19.670
of the discovery and upon request may be

878
00:34:19.670 --> 00:34:22.430
required to return the debris. So you

879
00:34:22.430 --> 00:34:24.590
can't salvage it. Now this

880
00:34:25.470 --> 00:34:28.109
may become something where the laws evolve in

881
00:34:28.109 --> 00:34:30.700
the years to come. As I say all the time our

882
00:34:30.700 --> 00:34:32.670
uh, user space is still in this Wild west

883
00:34:32.670 --> 00:34:35.470
phase where our ability to do stuff is

884
00:34:35.470 --> 00:34:37.750
growing much more rapidly than our ability to

885
00:34:37.750 --> 00:34:39.959
legislate for it. Um, and there's a lot of

886
00:34:39.959 --> 00:34:41.799
commercial interest in not advancing the

887
00:34:41.799 --> 00:34:44.599
legislation because if you advance the

888
00:34:44.599 --> 00:34:46.239
legislation you put more costs on the

889
00:34:46.239 --> 00:34:47.959
commercial entities. So they have a vested

890
00:34:47.959 --> 00:34:50.799
interest in not having legislation about

891
00:34:50.799 --> 00:34:52.919
launches, not legislating for the number you

892
00:34:52.919 --> 00:34:54.799
can make or the environmental requirements.

893
00:34:55.359 --> 00:34:57.679
And countries are leery of doing it because

894
00:34:57.679 --> 00:34:59.559
you can launch the space from all over the

895
00:34:59.559 --> 00:35:01.919
globe. So if you say to uh, SpaceX,

896
00:35:02.479 --> 00:35:04.879
you need to meet all these punishing

897
00:35:04.879 --> 00:35:06.719
environmental conditions before you launch

898
00:35:06.719 --> 00:35:07.959
and you've got to do all this with your

899
00:35:07.959 --> 00:35:10.050
satellites, SpaceX can easily say, well

900
00:35:10.050 --> 00:35:11.650
that's fine, we'll take our investment and

901
00:35:11.650 --> 00:35:14.010
move it to another country. So there's a lot

902
00:35:14.010 --> 00:35:16.730
of challenges there. But I could imagine in

903
00:35:16.730 --> 00:35:18.690
decades to come, as commercial space becomes

904
00:35:18.690 --> 00:35:20.690
more established and our use of space becomes

905
00:35:20.690 --> 00:35:23.090
much more varied and much more numerous,

906
00:35:23.490 --> 00:35:25.610
a astronomers will complain because you get

907
00:35:25.610 --> 00:35:27.930
more and more spoiling of the night sky, but

908
00:35:27.930 --> 00:35:29.330
you'll also get the opportunity for

909
00:35:29.330 --> 00:35:30.730
businesses, just like this question

910
00:35:30.730 --> 00:35:33.290
describes, to develop why there may be the

911
00:35:33.290 --> 00:35:35.800
commercial value for people to recover

912
00:35:35.800 --> 00:35:38.440
defunct satellites in orbit, capture them,

913
00:35:38.600 --> 00:35:40.720
maybe even lift them up to a higher orbit to

914
00:35:40.720 --> 00:35:43.200
a factory that can process the materials and

915
00:35:43.200 --> 00:35:44.880
let people then build new satellites in

916
00:35:44.880 --> 00:35:47.840
orbit. That way you lower the risk of them

917
00:35:47.840 --> 00:35:49.640
burning up in Earth's atmosphere, you get rid

918
00:35:49.640 --> 00:35:51.560
of the possibility of them altering the

919
00:35:51.560 --> 00:35:53.360
atmosphere to make climate change worse or

920
00:35:53.360 --> 00:35:55.520
better, as we discussed before. And um,

921
00:35:55.520 --> 00:35:57.280
you'll lower the cost of launching new ones

922
00:35:57.280 --> 00:35:59.040
if you could reprocess and salvage and

923
00:35:59.040 --> 00:36:01.590
rebuild. Yeah, it's probably not commercially

924
00:36:01.590 --> 00:36:03.590
feasible yet, which is why nobody's doing it

925
00:36:03.590 --> 00:36:06.590
yet. But it may well become so and so. This

926
00:36:06.590 --> 00:36:08.350
is something that I'd expect to evolve in the

927
00:36:08.350 --> 00:36:11.070
next say 50 years as all this stuff becomes

928
00:36:11.070 --> 00:36:11.830
more entrenched.

929
00:36:13.270 --> 00:36:15.630
Andrew Dunkley: It's interesting uh, in regard to the

930
00:36:15.630 --> 00:36:17.710
ownership side of things. Uh, it's like when

931
00:36:17.710 --> 00:36:19.870
you put your garbage bin out with all your

932
00:36:19.870 --> 00:36:22.710
stuff in it, it's still your stuff. And even

933
00:36:22.710 --> 00:36:25.430
as far as it being dumped in

934
00:36:25.430 --> 00:36:27.650
landfill, if you've thrown out your son's

935
00:36:27.650 --> 00:36:30.490
favorite toy and he wants it back, it's still

936
00:36:30.490 --> 00:36:33.410
his toy. So it's

937
00:36:33.410 --> 00:36:36.050
the same kind of thing, um, in a down to

938
00:36:36.050 --> 00:36:38.490
earth kind of way. And to our YouTube Music

939
00:36:38.490 --> 00:36:41.290
listener, um, just one final

940
00:36:41.290 --> 00:36:41.690
point.

941
00:36:41.770 --> 00:36:42.250
Jonti Horner: Yes.

942
00:36:42.410 --> 00:36:45.410
Andrew Dunkley: There are companies researching salvage in

943
00:36:45.410 --> 00:36:45.690
space.

944
00:36:46.330 --> 00:36:46.370
Jonti Horner: Newman.

945
00:36:46.370 --> 00:36:48.850
Andrew Dunkley: Ah space. Another one called AstroDailyPod

946
00:36:48.850 --> 00:36:51.290
Scale and of course the major parties, NASA

947
00:36:51.290 --> 00:36:54.050
and ESA and several others are

948
00:36:54.050 --> 00:36:56.850
looking into this. Uh but right now it's,

949
00:36:56.850 --> 00:36:59.570
it's not a very easy thing to do. But thanks

950
00:36:59.570 --> 00:37:01.210
for the question. Thanks for the question.

951
00:37:01.290 --> 00:37:01.850
Really good.

952
00:37:04.330 --> 00:37:06.730
Okay, we checked all four systems and being

953
00:37:06.730 --> 00:37:09.690
with a go space nats, uh, we have one

954
00:37:09.770 --> 00:37:12.730
final question. This one comes from Robert

955
00:37:12.810 --> 00:37:15.370
and Robert uh, is from the Netherlands

956
00:37:15.820 --> 00:37:17.850
uh, and he's got backing music on his

957
00:37:17.850 --> 00:37:18.170
question.

958
00:37:18.540 --> 00:37:21.460
Robert: Hello, this is Robert from Netherlands. I

959
00:37:21.460 --> 00:37:24.460
have a question for you today about radio

960
00:37:24.460 --> 00:37:27.420
waves because as we all know it's a very

961
00:37:27.420 --> 00:37:30.380
efficient low energy way of communicating

962
00:37:31.260 --> 00:37:34.220
data over vast distances. And

963
00:37:34.380 --> 00:37:36.060
I would think that if we are looking for

964
00:37:36.060 --> 00:37:38.980
aliens which I find very tantalizing at

965
00:37:38.980 --> 00:37:41.780
the subject, we should be looking for radio

966
00:37:41.780 --> 00:37:44.750
waves probably like 500

967
00:37:44.750 --> 00:37:47.670
light years of a radius of the earth which

968
00:37:48.150 --> 00:37:50.990
seems to be kind of a low priority. Never

969
00:37:50.990 --> 00:37:53.270
understood why, why there's there's a

970
00:37:53.270 --> 00:37:56.230
beanbags uh, observatory that can

971
00:37:56.550 --> 00:37:58.910
know really pinpoint these but you can't

972
00:37:58.910 --> 00:38:01.430
really cast a white net so to speak. Another

973
00:38:01.430 --> 00:38:04.270
square kilometer ray might be capable of

974
00:38:04.270 --> 00:38:07.070
this being built. Australia of course. I

975
00:38:07.070 --> 00:38:09.270
was hoping you guys would have some insights.

976
00:38:09.760 --> 00:38:12.160
They're going to be interact radio waves.

977
00:38:12.480 --> 00:38:14.500
Thank you so much time.

978
00:38:14.500 --> 00:38:17.440
Andrew Dunkley: Um, thank you Robert. Lovely

979
00:38:17.440 --> 00:38:20.240
music. Yeah, very, very spacey

980
00:38:20.480 --> 00:38:23.160
indeed. Um, I would have thought that

981
00:38:23.160 --> 00:38:26.160
that's prime target number one when

982
00:38:26.160 --> 00:38:28.760
searching for life beyond Earth. Um,

983
00:38:29.360 --> 00:38:31.920
would be to be listening for radio waves

984
00:38:32.080 --> 00:38:34.680
and, and Robert's right, the Square Kilometer

985
00:38:34.680 --> 00:38:37.070
Array will be capable for that. I think it be

986
00:38:37.070 --> 00:38:39.440
able to pick up airport radar uh

987
00:38:39.950 --> 00:38:42.030
as far away as 50 light years.

988
00:38:42.670 --> 00:38:45.310
Jonti Horner: Yes, it's an incredible, incredible tool and

989
00:38:45.470 --> 00:38:47.350
in fact this is what people have been doing.

990
00:38:47.350 --> 00:38:50.030
So this is the whole foundation of a subset

991
00:38:50.030 --> 00:38:52.270
of our science called seti, the Search for

992
00:38:52.270 --> 00:38:54.910
Extraterrestrial Intelligence. Often you

993
00:38:54.910 --> 00:38:56.670
describe this as a search for a needle in a

994
00:38:56.670 --> 00:38:57.950
hair stack, where you don't know what a

995
00:38:57.950 --> 00:38:59.870
needle looks like and you've never seen a

996
00:38:59.870 --> 00:39:02.870
hair stack before. So if you're trying to

997
00:39:02.870 --> 00:39:05.720
find life that is as technologically

998
00:39:05.720 --> 00:39:08.680
advanced as us, or more. So then there

999
00:39:08.680 --> 00:39:10.480
is an argument that listening for signals

1000
00:39:10.480 --> 00:39:12.240
would be a good way to do it. And kind of

1001
00:39:12.240 --> 00:39:14.480
corroborating that is the idea that we are

1002
00:39:14.960 --> 00:39:17.480
broadcasting into the voyage, screaming like

1003
00:39:17.480 --> 00:39:20.240
a toddler in a dark cave with our

1004
00:39:20.240 --> 00:39:22.800
radio broadcasts and, um, our TV broadcasts

1005
00:39:22.800 --> 00:39:25.240
and all this stuff with radio waves. And it's

1006
00:39:25.240 --> 00:39:27.880
often argued that either the Berlin Olympics,

1007
00:39:27.880 --> 00:39:30.770
which I think were 1936, or the coronation of

1008
00:39:30.770 --> 00:39:33.002
Queen Elizabeth the Second in possibly 1952.

1009
00:39:33.178 --> 00:39:35.770
1953, yeah, were the first broadcasts that

1010
00:39:35.770 --> 00:39:37.450
were powerful enough that would be easily

1011
00:39:37.450 --> 00:39:40.370
detected from elsewhere. So if you were

1012
00:39:40.450 --> 00:39:42.490
magically able to take the Square Kilometer

1013
00:39:42.490 --> 00:39:45.210
Array and place it as a star, ah, within

1014
00:39:45.210 --> 00:39:48.130
about 80 light years of the Earth, you'd be

1015
00:39:48.130 --> 00:39:49.650
able to listen in and watch the development

1016
00:39:49.730 --> 00:39:52.090
of our technological society as our

1017
00:39:52.090 --> 00:39:54.770
broadcasts get more numerous and more varied.

1018
00:39:54.850 --> 00:39:56.850
You'd probably be able to broadcast back and

1019
00:39:57.260 --> 00:39:58.860
say, please stop broadcasting, neighbours,

1020
00:39:58.860 --> 00:40:01.300
we're sick of it. We want to know more about

1021
00:40:01.300 --> 00:40:04.060
Scott and Charlene or whatever, um, people

1022
00:40:04.060 --> 00:40:05.940
will be able to listen in. And so this gives

1023
00:40:05.940 --> 00:40:07.780
everybody the idea that just like this

1024
00:40:07.780 --> 00:40:09.980
question, we could do the same thing and we

1025
00:40:09.980 --> 00:40:12.300
could try and tune in onto the broadcasts of

1026
00:40:12.380 --> 00:40:15.380
other societies. And that's

1027
00:40:15.380 --> 00:40:18.060
fundamentally the foundation of seti. Back

1028
00:40:18.060 --> 00:40:20.700
when I was an undergraduate, back when I was

1029
00:40:20.700 --> 00:40:22.780
at high school, in the early days of personal

1030
00:40:22.780 --> 00:40:24.740
computing, there was a program called SETI at

1031
00:40:24.740 --> 00:40:27.710
home, which was a way of distributing through

1032
00:40:27.710 --> 00:40:30.670
cloud computing, packets of data obtained by

1033
00:40:30.670 --> 00:40:32.670
radio telescopes to search for signals of

1034
00:40:32.670 --> 00:40:35.190
radio broadcasts. And nothing was found.

1035
00:40:35.590 --> 00:40:38.270
There are global usage of radio telescopes

1036
00:40:38.270 --> 00:40:39.510
around the world to try and do this still.

1037
00:40:39.510 --> 00:40:41.950
The most famous of them these days is the

1038
00:40:41.950 --> 00:40:44.350
Breakthrough Listen Initiative, which was

1039
00:40:44.350 --> 00:40:46.990
funded to the tune of $100 million starting

1040
00:40:46.990 --> 00:40:49.270
back in 2015. So it's 10 years old now.

1041
00:40:49.990 --> 00:40:52.320
That did a wonderful thing for Australia

1042
00:40:52.400 --> 00:40:53.880
because the government at the time in

1043
00:40:53.880 --> 00:40:56.720
Australia was our, um, less

1044
00:40:56.720 --> 00:40:58.760
science friendly party, let's put it that

1045
00:40:58.760 --> 00:41:00.640
way. And, uh, they were looking to save money

1046
00:41:00.640 --> 00:41:03.400
by killing science, as often happens, and

1047
00:41:03.400 --> 00:41:05.640
that's having knock on effects nowadays. But

1048
00:41:05.640 --> 00:41:07.760
one of the things they wanted to do was close

1049
00:41:07.840 --> 00:41:10.800
the dish, the Parks Radio Observatory,

1050
00:41:11.200 --> 00:41:14.120
which is the Biggest, most iconic observatory

1051
00:41:14.120 --> 00:41:16.000
building I think in Australia, famous for

1052
00:41:16.410 --> 00:41:18.210
awesome movie the Dish with Sam Neill many

1053
00:41:18.210 --> 00:41:18.610
years ago.

1054
00:41:18.610 --> 00:41:20.050
Andrew Dunkley: And it's just down the road from.

1055
00:41:20.050 --> 00:41:22.090
Jonti Horner: Where I live, just down the road. And there

1056
00:41:22.090 --> 00:41:23.930
was a lot of upset that this wonderful

1057
00:41:23.930 --> 00:41:25.690
facility was going to be mothballed and

1058
00:41:25.690 --> 00:41:27.850
closed down to cut budgets,

1059
00:41:28.140 --> 00:41:30.850
um, because, you know, they wanted to put

1060
00:41:30.850 --> 00:41:32.529
more money into fossil fuel extraction to

1061
00:41:32.529 --> 00:41:35.130
satisfy their donors or whatever. I, um, have

1062
00:41:35.130 --> 00:41:38.010
views anyway, many do.

1063
00:41:38.490 --> 00:41:41.450
Parks was saved by an injection of a very

1064
00:41:41.450 --> 00:41:43.170
large sum of money from the Breakthrough

1065
00:41:43.170 --> 00:41:45.830
Listen initiative, which has kept the

1066
00:41:45.830 --> 00:41:47.630
telescope operating for another decade.

1067
00:41:47.630 --> 00:41:49.430
There's a lot of awesome new science has come

1068
00:41:49.430 --> 00:41:51.790
out of it as a result, but it is bought a

1069
00:41:51.790 --> 00:41:53.230
certain fraction of the time of that

1070
00:41:53.230 --> 00:41:55.790
telescope, which I think is about 40% to

1071
00:41:55.790 --> 00:41:57.830
specifically point that telescope around the

1072
00:41:57.830 --> 00:42:00.790
star to listen to radio broadcasts, to

1073
00:42:00.790 --> 00:42:03.550
look for radio broadcasts from nearby stars.

1074
00:42:04.190 --> 00:42:06.670
And there's been a number of papers come out

1075
00:42:06.670 --> 00:42:09.550
on this over the years that detail

1076
00:42:09.550 --> 00:42:11.350
the incredible work people have done. And to

1077
00:42:11.350 --> 00:42:12.830
illustrate the challenge of these things,

1078
00:42:12.830 --> 00:42:14.470
there's been a few occasions where people

1079
00:42:14.470 --> 00:42:16.830
think there's been a potential signal only

1080
00:42:16.830 --> 00:42:18.830
for it to be turned out to be something else.

1081
00:42:19.150 --> 00:42:21.590
One example was that they thought they'd

1082
00:42:21.590 --> 00:42:22.830
found a potential signal. And when they

1083
00:42:22.830 --> 00:42:24.470
investigated more, it happened at the same

1084
00:42:24.470 --> 00:42:26.870
time every evening and investigated more. And

1085
00:42:26.870 --> 00:42:28.390
it was that the astronomers were walking

1086
00:42:28.390 --> 00:42:29.750
across one of the building and putting their

1087
00:42:29.750 --> 00:42:32.349
food in the microwave. Yes, the building was

1088
00:42:32.349 --> 00:42:34.590
shielded. They were picking up the radiation

1089
00:42:34.590 --> 00:42:36.590
from the microwaves, you know, so it's really

1090
00:42:36.590 --> 00:42:39.230
hard to do today. We have found

1091
00:42:39.230 --> 00:42:41.550
nothing. No. And ah, there are some arguments

1092
00:42:41.550 --> 00:42:43.760
that, uh, it's very unlikely we will do.

1093
00:42:43.760 --> 00:42:45.520
That's a needle in a hair sack thing.

1094
00:42:46.320 --> 00:42:49.040
Firstly, we need to figure out where

1095
00:42:49.120 --> 00:42:51.600
in the radio spectrum to look. And um, the

1096
00:42:51.600 --> 00:42:54.200
radio wave frequency spectrum spans an

1097
00:42:54.200 --> 00:42:56.800
enormous range. A lot of efforts have been

1098
00:42:56.800 --> 00:42:59.280
focused around the hydrogen 21 centimeter

1099
00:42:59.280 --> 00:43:01.760
line viewing. That has been an obvious place

1100
00:43:01.760 --> 00:43:03.680
for people who are deliberately broadcasting

1101
00:43:03.680 --> 00:43:05.280
to broadcast, because everyone will know

1102
00:43:05.280 --> 00:43:07.840
about that. But in terms of accidental

1103
00:43:07.840 --> 00:43:09.320
broadcasts like what we're doing on the

1104
00:43:09.320 --> 00:43:11.570
Earth, there's no guarantee that another

1105
00:43:11.570 --> 00:43:13.970
species would pick the same frequencies that

1106
00:43:13.970 --> 00:43:16.690
we've chosen for the broadcast. So we might

1107
00:43:16.690 --> 00:43:18.610
be listening to the wrong tune, we might just

1108
00:43:18.610 --> 00:43:21.330
be listening at the wrong frequency. The

1109
00:43:21.330 --> 00:43:22.770
other thing though is that, uh, the kind of

1110
00:43:22.770 --> 00:43:24.090
broadcasting we've been doing for the last

1111
00:43:24.090 --> 00:43:25.610
hundred years is incredibly energy

1112
00:43:25.849 --> 00:43:28.610
inefficient because we broadcast in

1113
00:43:28.610 --> 00:43:30.970
all directions at ah, once.

1114
00:43:31.450 --> 00:43:34.050
To have a very small number of directions

1115
00:43:34.050 --> 00:43:35.930
pick up that signal, you know, all your TV

1116
00:43:35.930 --> 00:43:38.270
aerials Or whatever. It is much more

1117
00:43:38.270 --> 00:43:40.470
efficient to do point to point communications

1118
00:43:40.470 --> 00:43:43.070
or to send things through optical cables.

1119
00:43:43.390 --> 00:43:45.150
So there is some argument that as your

1120
00:43:45.150 --> 00:43:47.750
technology gets better, the amount of waste

1121
00:43:47.750 --> 00:43:49.950
noise you broadcast to space will fall off.

1122
00:43:49.950 --> 00:43:51.790
Yes. And so there's an argument that in the

1123
00:43:51.790 --> 00:43:53.630
next 30 or 40 years the Earth will become

1124
00:43:53.630 --> 00:43:56.270
radio silent again. So then there'll be this

1125
00:43:56.270 --> 00:43:57.950
little bubble around the earth getting bigger

1126
00:43:57.950 --> 00:43:59.710
and bigger where if you're in that bubble,

1127
00:43:59.950 --> 00:44:01.990
you hear our radio broadcast, but then

1128
00:44:01.990 --> 00:44:03.430
there's a smaller bubble in the middle where

1129
00:44:03.430 --> 00:44:04.510
we go silent again.

1130
00:44:04.830 --> 00:44:05.110
Andrew Dunkley: Yeah.

1131
00:44:05.110 --> 00:44:06.830
Jonti Horner: And it may be that every technological

1132
00:44:06.830 --> 00:44:08.870
species is only loud when it's in its

1133
00:44:08.870 --> 00:44:11.390
infancy, when it is that toddler screaming

1134
00:44:11.390 --> 00:44:12.710
that they don't want to leave the beach like

1135
00:44:12.710 --> 00:44:15.470
the kid I saw yesterday. And eventually

1136
00:44:15.790 --> 00:44:18.710
a uh, society learns to self regulate and

1137
00:44:18.710 --> 00:44:21.390
has more efficient ways of broadcasting. So

1138
00:44:21.390 --> 00:44:24.070
it is a fabulous question. If you want to

1139
00:44:24.070 --> 00:44:26.030
learn more about it. I do recommend looking

1140
00:44:26.030 --> 00:44:28.310
up and googling and reading around SETI as a

1141
00:44:28.310 --> 00:44:30.550
project SETI at home and the Breakthrough

1142
00:44:30.550 --> 00:44:33.480
Listen initiative. You can also look up

1143
00:44:33.720 --> 00:44:36.680
an associated thing which is mete. Mete,

1144
00:44:36.840 --> 00:44:39.840
which is, I think METE is the acronym which

1145
00:44:39.840 --> 00:44:42.560
is a search for the artifacts of advanced

1146
00:44:42.560 --> 00:44:45.520
civilizations. Oh, and I know colleague

1147
00:44:45.520 --> 00:44:47.720
of mine in the US who's part of our planet

1148
00:44:47.720 --> 00:44:50.440
search team has put out a few papers looking

1149
00:44:50.600 --> 00:44:53.480
at things that appear in science fiction like

1150
00:44:53.480 --> 00:44:56.160
Dyson spheres and ringworlds and

1151
00:44:56.160 --> 00:44:58.160
what effect they would have on the light from

1152
00:44:58.160 --> 00:45:00.420
their stars. So what the observational

1153
00:45:00.420 --> 00:45:03.260
signatures would be not with any

1154
00:45:03.260 --> 00:45:05.380
expectation that we'll ever find them, but

1155
00:45:05.380 --> 00:45:06.980
because if we don't model what they would be

1156
00:45:06.980 --> 00:45:09.100
like, if we ever see something that displays

1157
00:45:09.100 --> 00:45:10.740
that odd behavior, we wouldn't know what it

1158
00:45:10.740 --> 00:45:13.500
was. So it's again this very low

1159
00:45:13.500 --> 00:45:15.220
likelihood of finding something, but very

1160
00:45:15.220 --> 00:45:18.100
high reward if you ever do. I

1161
00:45:18.100 --> 00:45:20.100
guess that people are actually actively

1162
00:45:20.100 --> 00:45:22.780
thinking about what could we feasibly do

1163
00:45:23.100 --> 00:45:25.460
as a technological civilization in the future

1164
00:45:25.460 --> 00:45:27.990
with improving technology. How would that

1165
00:45:27.990 --> 00:45:30.550
affect our environment around the sun? How

1166
00:45:30.550 --> 00:45:32.590
would that affect the way that our planetary

1167
00:45:32.590 --> 00:45:34.950
system pairs from around other stars? And uh,

1168
00:45:35.030 --> 00:45:36.670
what would that look like if we saw a

1169
00:45:36.670 --> 00:45:39.470
different civilization doing it? So that we

1170
00:45:39.470 --> 00:45:41.230
have the predictions there so that when we

1171
00:45:41.230 --> 00:45:43.710
get vast amounts of data from these all sky

1172
00:45:43.710 --> 00:45:46.190
surveys, whether they be in the radio or

1173
00:45:46.190 --> 00:45:48.510
whether they be in the optical, we can

1174
00:45:48.510 --> 00:45:50.350
identify the oddities and figure out what

1175
00:45:50.350 --> 00:45:52.070
they are. And similarly with a square

1176
00:45:52.070 --> 00:45:54.360
kilometer array that will be pointing all

1177
00:45:54.360 --> 00:45:57.280
over the sky, doing lots of astronomy, but

1178
00:45:57.280 --> 00:45:59.760
the data from that will be analyzed by teams

1179
00:45:59.760 --> 00:46:01.920
who are interested in could there be an alien

1180
00:46:01.920 --> 00:46:04.280
signal buried in this. So you will get

1181
00:46:04.280 --> 00:46:06.640
serendipitous imaging there because wherever

1182
00:46:06.640 --> 00:46:08.960
it's looking, you get the data and you can

1183
00:46:08.960 --> 00:46:10.760
survey that to see what there is. So it is

1184
00:46:10.760 --> 00:46:13.040
something people are actively doing. You're

1185
00:46:13.040 --> 00:46:14.520
onto something good there. And I can

1186
00:46:14.520 --> 00:46:15.760
recommend, like I said, reading about

1187
00:46:15.760 --> 00:46:18.520
breakthrough lists and reading about SETI to

1188
00:46:18.520 --> 00:46:20.000
learn more about it, if that is what you're

1189
00:46:20.000 --> 00:46:20.750
interested in it.

1190
00:46:20.750 --> 00:46:23.230
Andrew Dunkley: Yeah, uh, it'd be uh, interesting to

1191
00:46:23.230 --> 00:46:26.070
discover another race somewhere

1192
00:46:26.070 --> 00:46:28.470
out there that's uh, built a megastructure,

1193
00:46:28.550 --> 00:46:31.510
um, like, oh, I don't know, a space parasol

1194
00:46:32.150 --> 00:46:35.150
array of some kind. Imagine that same

1195
00:46:35.150 --> 00:46:37.670
problem. Someone else has solved it. Yeah,

1196
00:46:37.690 --> 00:46:38.830
uh, we are going to be.

1197
00:46:38.830 --> 00:46:40.870
Jonti Horner: Doing a little, little baby test of that

1198
00:46:40.950 --> 00:46:42.870
potentially in the next 10 or 20 years if

1199
00:46:42.870 --> 00:46:45.710
NASA ever gets its funding back. There is the

1200
00:46:45.710 --> 00:46:48.390
Habitable Worlds Observatory that is

1201
00:46:48.870 --> 00:46:51.110
looking at planets around other stars. And

1202
00:46:51.110 --> 00:46:53.310
um, what they're proposing to do to allow

1203
00:46:53.310 --> 00:46:55.350
them to gather light from planets the size of

1204
00:46:55.350 --> 00:46:57.390
the Earth, uh, around stars like the sun, is

1205
00:46:57.390 --> 00:46:59.350
reflectively fly a very giant,

1206
00:46:59.830 --> 00:47:01.830
beautifully designed, very intricate,

1207
00:47:01.830 --> 00:47:04.110
fractally edged, um, space

1208
00:47:04.110 --> 00:47:06.828
parasol that would go out about 100,000

1209
00:47:06.952 --> 00:47:09.870
km from the telescope and fly in formation,

1210
00:47:09.870 --> 00:47:11.950
line up to block the light from stars so that

1211
00:47:11.950 --> 00:47:13.500
we can see the planets going around them.

1212
00:47:13.970 --> 00:47:16.010
Now that size of parasol would be way too

1213
00:47:16.010 --> 00:47:18.370
small to impact climate change, but it's a

1214
00:47:18.370 --> 00:47:20.130
really good tech demonstrator. It shows that

1215
00:47:20.130 --> 00:47:22.330
we can do that and we can get the station

1216
00:47:22.330 --> 00:47:24.810
keeping just much too small. And again, if

1217
00:47:24.810 --> 00:47:26.370
people are interested in that looking up, the

1218
00:47:26.370 --> 00:47:29.250
Habitable Worlds Observatory would be a

1219
00:47:29.250 --> 00:47:30.690
good place to look. And there's some lovely

1220
00:47:30.690 --> 00:47:32.650
videos of the animation of this thing being

1221
00:47:32.650 --> 00:47:34.730
launched and unfolding and moving out in

1222
00:47:34.730 --> 00:47:37.250
space. And they've even done tests in labs

1223
00:47:37.490 --> 00:47:40.170
for mini versions of it on long corridors to

1224
00:47:40.170 --> 00:47:41.370
prove the concept works.

1225
00:47:42.240 --> 00:47:45.080
Andrew Dunkley: All very cool, very cool indeed. And uh, a

1226
00:47:45.080 --> 00:47:46.920
cool question too, Robert. Thanks for sending

1227
00:47:46.920 --> 00:47:48.480
it in. And if you would like to send us

1228
00:47:48.480 --> 00:47:50.320
questions, don't Forget our website

1229
00:47:50.400 --> 00:47:52.160
spacenutspodcast.com

1230
00:47:52.640 --> 00:47:55.280
spacenuts IO and

1231
00:47:55.620 --> 00:47:57.920
uh, click on the AMA link and you can send us

1232
00:47:58.000 --> 00:48:00.920
text, uh, and audio questions, uh, through

1233
00:48:00.920 --> 00:48:03.240
that system. And uh, we'd be happy to get

1234
00:48:03.240 --> 00:48:04.960
them and we'll do our very best to answer

1235
00:48:04.960 --> 00:48:06.800
them. Sometimes we get the same questions,

1236
00:48:07.540 --> 00:48:10.190
um, which is not unusual if people sort of

1237
00:48:10.190 --> 00:48:12.710
hone in on a topic. Uh, so we will,

1238
00:48:12.960 --> 00:48:14.990
um, if we don't answer your question, it's

1239
00:48:14.990 --> 00:48:17.600
possibly because we've already done it, uh,

1240
00:48:17.600 --> 00:48:19.710
but we do redo questions from time to time

1241
00:48:19.710 --> 00:48:21.830
because they keep coming up, um, particularly

1242
00:48:21.830 --> 00:48:24.030
black hole questions. We quite often get a

1243
00:48:24.030 --> 00:48:26.350
repeat. Might be a couple of years later, but

1244
00:48:26.350 --> 00:48:28.070
we get a repeat of a question we've already

1245
00:48:28.310 --> 00:48:30.870
covered. So we'll, we'll sometimes redo them.

1246
00:48:31.190 --> 00:48:32.790
But, uh, good to hear from you, Robert.

1247
00:48:32.790 --> 00:48:34.910
Thanks to everyone who contributed and thanks

1248
00:48:34.910 --> 00:48:37.230
to you, Jonti, for having a crack at the

1249
00:48:37.230 --> 00:48:37.750
answers.

1250
00:48:38.560 --> 00:48:39.960
Jonti Horner: That's all good. It's what I'm here for. And

1251
00:48:39.960 --> 00:48:42.040
it's fun to face new and interesting

1252
00:48:42.040 --> 00:48:42.520
questions.

1253
00:48:42.520 --> 00:48:45.280
Andrew Dunkley: It is indeed. Uh, we'll see you on the next

1254
00:48:45.280 --> 00:48:47.640
episode. Jonti, uh, Horner, professor of

1255
00:48:47.640 --> 00:48:49.720
Astrophysics at the University of Southern

1256
00:48:49.720 --> 00:48:51.680
Queensland. And thanks to Huw in the studio.

1257
00:48:52.960 --> 00:48:55.360
Not, um, sure you're aware that Huw used to

1258
00:48:55.360 --> 00:48:57.920
work in radio. That's how we actually met. In

1259
00:48:57.920 --> 00:49:00.630
fact, he was working at a radio station, uh,

1260
00:49:00.630 --> 00:49:03.120
in Newcastle in New South Wales when I was a

1261
00:49:03.120 --> 00:49:04.840
kid and I did job experience there. And

1262
00:49:04.840 --> 00:49:06.960
that's how I met Huw originally, when I was

1263
00:49:06.960 --> 00:49:09.130
about 13 years old or something.

1264
00:49:09.450 --> 00:49:12.330
Anyway, he's an old radio man these days

1265
00:49:12.330 --> 00:49:15.130
and, uh, when it comes to radio waves,

1266
00:49:15.450 --> 00:49:17.650
he feels that that means he should stand out

1267
00:49:17.650 --> 00:49:20.010
the front waving at traffic. That's why he's

1268
00:49:20.010 --> 00:49:22.570
not with us today. And he may never come

1269
00:49:22.570 --> 00:49:24.690
back. And from me, Andrew Dunkley, thanks for

1270
00:49:24.690 --> 00:49:27.130
your company. I'll see you on the next

1271
00:49:27.130 --> 00:49:29.130
episode of Space Nuts. Bye. Bye.

1272
00:49:30.330 --> 00:49:32.530
Jonti Horner: You'll be listening to the Space Nuts.

1273
00:49:32.530 --> 00:49:33.130
Robert: Podcast.

1274
00:49:34.900 --> 00:49:37.540
Jonti Horner: Available at Apple Podcasts, Spotify,

1275
00:49:37.700 --> 00:49:40.460
iHeartRadio or your favorite podcast

1276
00:49:40.460 --> 00:49:42.780
player. You can also stream on demand at

1277
00:49:42.780 --> 00:49:43.860
bytes. Com.

1278
00:49:44.180 --> 00:49:46.260
Andrew Dunkley: This has been another quality podcast

1279
00:49:46.260 --> 00:49:47.940
production from Bytes.

1280
00:49:47.940 --> 00:49:48.070
Jonti Horner: Com.

1281
00:49:48.070 --> 00:49:48.230
Speaker C: Um.