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Q&A: Ultra Hot Jupiters and Rocket Fuel Recycling In this engaging Q&A episode of Space Nuts, hosts Andrew Dunkley and Professor Jonti Horner tackle a variety of intriguing questions from listeners. From the nature of ultra hot Jupiters to the complexities of reusing spent rocket fuel, this episode is packed with insights and cosmic curiosities.
Episode Highlights:
- Ultra Hot Jupiters Explained: David from the Sunshine Coast asks about the origins of the materials that form stars and their planets, leading to a fascinating discussion about the lifecycle of stars and the cosmic recycling of elements.
- Rocket Fuel Reuse: Mark from the UK presents a thought-provoking idea regarding the potential for reusing water ice as rocket fuel, prompting a deep dive into the challenges of capturing exhaust and the physics of propulsion.
- Flat Earth Conspiracies: Paul shares his experiences with flat Earth discussions and questions the feasibility of the Artemis mission, allowing Jonty to clarify orbital mechanics and the importance of relative motion in space travel.
- Astrophysical Insights: The hosts explore the implications of past star generations on our solar system's composition and the future of space travel technologies, including the potential for innovative propulsion methods beyond traditional rockets.
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Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
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- Origins of Stellar Material
- Challenges in Rocket Fuel Reuse
- Addressing Flat Earth Theories
- Future of Space Propulsion Technologies
- Cosmic Recycling of Elements
00:00:00 --> 00:00:02 Andrew Dunkley: Hello again. Thank you for joining us on
00:00:02 --> 00:00:04 another episode of Space Nuts. This is a Q
00:00:04 --> 00:00:06 and A edition where we take audience
00:00:06 --> 00:00:08 questions, we write them on a piece of paper
00:00:08 --> 00:00:11 and then we throw it in the bin. Or we
00:00:11 --> 00:00:14 could answer them. We'll do the latter. Uh,
00:00:14 --> 00:00:17 we got questions about ultra hot
00:00:17 --> 00:00:19 Jupiters. We've also got questions about,
00:00:19 --> 00:00:22 uh, reusing spent rocket fuel. How would
00:00:22 --> 00:00:25 you do that? That is the question. And
00:00:26 --> 00:00:29 wow, how about this one? Uh, some conspiracy
00:00:29 --> 00:00:31 with the Artemis 2 mission
00:00:31 --> 00:00:34 being fake. We'll deal with all of that on
00:00:34 --> 00:00:36 this episode of space nuts.
00:00:36 --> 00:00:39 Generic: 15 seconds. Guidance is internal.
00:00:39 --> 00:00:42 10, 9. Ignition
00:00:42 --> 00:00:43 sequence start.
00:00:43 --> 00:00:44 Jonti Horner: Uh, space nuts.
00:00:44 --> 00:00:47 Generic: 5, 4, 3, 2, 1. 3, 4, 5,
00:00:47 --> 00:00:49 5, 4, 3, 2', 1.
00:00:49 --> 00:00:50 Jonti Horner: Space nuts.
00:00:50 --> 00:00:52 Generic: Astronauts report. It feels good.
00:00:53 --> 00:00:56 Andrew Dunkley: And joining us to try and sort all that out
00:00:56 --> 00:00:58 is Jonty Horner, professor of Astrophysics at
00:00:58 --> 00:01:01 the University of Southern Queensland.
00:01:01 --> 00:01:02 Jonty, hello.
00:01:02 --> 00:01:03 Jonti Horner: Good afternoon. How are you?
00:01:04 --> 00:01:07 Andrew Dunkley: I'm, um, all right. Um, please forgive me if
00:01:07 --> 00:01:09 there's some background noise. There's a
00:01:09 --> 00:01:11 gardener working, uh, just out the front, and
00:01:12 --> 00:01:13 he's, uh, doing a fabulous job. But he's
00:01:13 --> 00:01:15 using that kind of equipment that you would,
00:01:16 --> 00:01:18 um, you know, demolish a building with.
00:01:19 --> 00:01:22 So, uh, it's, um, it's making
00:01:22 --> 00:01:24 quite a noise. But, um, I've got my filter
00:01:24 --> 00:01:26 turned on, so hopefully it'll just keep it
00:01:26 --> 00:01:27 blocked out.
00:01:27 --> 00:01:28 Jonti Horner: Oh, it's amazing just how well these things
00:01:28 --> 00:01:31 work. I use this microphone in front of me
00:01:31 --> 00:01:32 for my teaching. I've had a number of
00:01:32 --> 00:01:35 occasions where the dog has decided that I'm
00:01:35 --> 00:01:36 painting too much attention to my students
00:01:36 --> 00:01:38 and not enough to her. And it's got quite
00:01:38 --> 00:01:40 vocal about that lying just behind me here
00:01:40 --> 00:01:41 next to her fire at the minute, keeping her
00:01:41 --> 00:01:44 really happy. And they say, no, we can't hear
00:01:44 --> 00:01:46 anything. It's amazing how well it can filter
00:01:46 --> 00:01:47 out the background noise.
00:01:47 --> 00:01:50 Andrew Dunkley: Yeah, the technology is amazing today. It's
00:01:50 --> 00:01:53 like the telescope technology that exists now
00:01:53 --> 00:01:56 where you can filter out light pollution.
00:01:56 --> 00:01:59 I don't know how that works, but, uh, it's
00:01:59 --> 00:02:02 quite incredible these days. Works really
00:02:02 --> 00:02:04 well. I want to answer some questions.
00:02:04 --> 00:02:05 Jonti Horner: Of course.
00:02:05 --> 00:02:08 Andrew Dunkley: All right, let's start with David, who's on
00:02:08 --> 00:02:11 the Sunshine coast in Queensland, Australia.
00:02:12 --> 00:02:14 David: G', day, David from the sunny coast again. I,
00:02:14 --> 00:02:17 uh, just had a question regarding the, uh,
00:02:17 --> 00:02:20 ultra hot Jupiter article from the latest,
00:02:20 --> 00:02:22 uh, podcast. Um,
00:02:23 --> 00:02:25 in the conversation, Fred Watson, uh,
00:02:25 --> 00:02:28 mentioned that, uh, the belief is
00:02:28 --> 00:02:31 that stars and their surrounding planets all
00:02:31 --> 00:02:34 form from the same, uh, disc of material.
00:02:34 --> 00:02:37 Um, I just had a question regarding the
00:02:37 --> 00:02:40 material. Um, you know, we tend to
00:02:40 --> 00:02:43 think of stars as Helium or hydrogen or both,
00:02:43 --> 00:02:46 um, and everything else as metals. And we
00:02:46 --> 00:02:49 believe those metals formed within stars,
00:02:49 --> 00:02:50 uh, due to the
00:02:51 --> 00:02:54 fusion burning. Um, where then
00:02:54 --> 00:02:57 does this material come from in the disc to
00:02:57 --> 00:03:00 form a star and its planets? Is that from
00:03:00 --> 00:03:02 material from. Do we believe it's material
00:03:02 --> 00:03:05 from another star or, um, is there some
00:03:05 --> 00:03:08 other process going on? Thanks very much for
00:03:08 --> 00:03:10 the show. Awesome. See you guys.
00:03:10 --> 00:03:12 Andrew Dunkley: See you, David. Thank you very much. Um, that
00:03:12 --> 00:03:14 sounds like it's right up your alley.
00:03:14 --> 00:03:17 Jonti Horner: It is. It's a good film to start off with.
00:03:17 --> 00:03:19 Sah. Uh, you're right. The
00:03:19 --> 00:03:22 material that forms a star and its planets
00:03:23 --> 00:03:25 has been contributed to by many previous
00:03:25 --> 00:03:28 stars. If you imagine after the Big Bang, the
00:03:28 --> 00:03:31 universe was hydrogen and helium and a tiny
00:03:31 --> 00:03:32 little bit of other stuff, but it really was
00:03:32 --> 00:03:35 barely any, which meant that a generation of
00:03:35 --> 00:03:37 stars formed that were pretty much just
00:03:37 --> 00:03:39 hydrogen and helium and very little else.
00:03:39 --> 00:03:41 Those stars in the early universe, there's
00:03:41 --> 00:03:43 some speculation that they may have been,
00:03:43 --> 00:03:46 including mega megastars, much
00:03:46 --> 00:03:48 bigger than something called the Eddington
00:03:48 --> 00:03:51 Limit, which is a maximum size a
00:03:51 --> 00:03:53 stable star can form, um, because of how
00:03:53 --> 00:03:55 dense the universe was at the time, how much
00:03:55 --> 00:03:57 material there was. So speculation of stars
00:03:57 --> 00:04:00 up to several thousand solar mass. Those
00:04:00 --> 00:04:02 stars lived fast, died young, put
00:04:02 --> 00:04:05 material back out into the cosmos. So they,
00:04:05 --> 00:04:07 when they died, they locked some of the stuff
00:04:07 --> 00:04:09 up in the remnants to the left, whether
00:04:09 --> 00:04:11 that's a black hole, a neutron star, a white
00:04:11 --> 00:04:14 dwarf, whatever. But the material that was
00:04:14 --> 00:04:16 flung outwards to form planetary nebulae,
00:04:16 --> 00:04:19 supernova remnants, disperses into the
00:04:19 --> 00:04:21 wider galaxy. So what's happening over
00:04:22 --> 00:04:24 the aeons of time since the Milky Way formed
00:04:25 --> 00:04:28 is that stars are born, live and
00:04:28 --> 00:04:31 die. And when they die, they pollute the
00:04:31 --> 00:04:33 cosmos. Stars of different masses throughout
00:04:33 --> 00:04:35 different things. But what that means is that
00:04:35 --> 00:04:37 you gradually get more and more heavy
00:04:37 --> 00:04:40 elements introduced into the galaxy.
00:04:41 --> 00:04:44 And, um, that goes to basically contributing
00:04:44 --> 00:04:46 to the composition of the gas and dust that
00:04:46 --> 00:04:48 floats around in our galaxy. If you go out,
00:04:48 --> 00:04:50 particularly this time of year in the
00:04:50 --> 00:04:52 Southern Hemisphere. But if you go out on any
00:04:52 --> 00:04:54 night of the year where you can see the Milky
00:04:54 --> 00:04:56 Way, you'll see that in the band of the Milky
00:04:56 --> 00:04:58 Way, there are dark patches as well as
00:04:58 --> 00:05:00 glowing bits. The dark patches are not
00:05:00 --> 00:05:02 places where there is a lack of stars, but
00:05:02 --> 00:05:04 rather they're places where you've got huge
00:05:04 --> 00:05:07 clouds of gas and dust that are opaque, that
00:05:07 --> 00:05:09 are blocking the light from stars that are
00:05:09 --> 00:05:11 more distant from reaching us. So they look
00:05:11 --> 00:05:14 dark in the same way that a cloud blocking
00:05:14 --> 00:05:16 the sun will look dark in the daytime. It's
00:05:16 --> 00:05:19 blocking light from beyond. These clouds
00:05:19 --> 00:05:21 can be vast and they're made of gas and dust
00:05:21 --> 00:05:24 and ice, mainly hydrogen and
00:05:24 --> 00:05:26 helium, but lots of other stuff. And that
00:05:26 --> 00:05:29 other stuff will vary from one cloud to the
00:05:29 --> 00:05:32 next to some degree, based on what it has
00:05:32 --> 00:05:34 been polluted with. You'll have to some
00:05:34 --> 00:05:36 degree a stirring, a pollution of the galaxy
00:05:36 --> 00:05:37 that gives you a background increase in the
00:05:37 --> 00:05:40 amount of metals. But you'll also get local
00:05:40 --> 00:05:42 variation. We see all of this
00:05:42 --> 00:05:44 incidentally in the Earth and the solar
00:05:44 --> 00:05:47 system. There are suggestions that the solar
00:05:47 --> 00:05:49 system, when it was young, when it was
00:05:49 --> 00:05:51 forming, was polluted by a nearby supernova
00:05:51 --> 00:05:53 that injected a lot of very short lived
00:05:53 --> 00:05:56 radioactive aluminium isotopes that
00:05:56 --> 00:05:58 accelerated the degree of melting you got in
00:05:58 --> 00:06:01 the rocky objects. There's a signature there
00:06:01 --> 00:06:04 of a radioisotope that is so short
00:06:04 --> 00:06:05 lived, there shouldn't really have been any
00:06:05 --> 00:06:07 of it around, unless a supernova exploded
00:06:07 --> 00:06:10 nearby to pollute our disc, giving us a
00:06:10 --> 00:06:12 slightly unusual composition. There is also
00:06:12 --> 00:06:15 an argument that the Earth is richer
00:06:15 --> 00:06:17 in gold than it should be, because
00:06:18 --> 00:06:20 sometime between 10 and 100 million years
00:06:20 --> 00:06:22 before the formation of the Earth, 10
00:06:22 --> 00:06:25 light years from where we formed, two neutron
00:06:25 --> 00:06:27 stars collided, polluting the universe with
00:06:27 --> 00:06:30 gold. And some of that gold made its way into
00:06:30 --> 00:06:32 the disc that formed the solar system, got
00:06:32 --> 00:06:33 incorporated into the Earth. And that's why
00:06:33 --> 00:06:35 we are a particularly good place for
00:06:35 --> 00:06:38 Goldfinger to, uh, have his little layer.
00:06:38 --> 00:06:39 We've got more gold than normal.
00:06:40 --> 00:06:40 Andrew Dunkley: Yeah.
00:06:40 --> 00:06:42 Jonti Horner: What this all means is that those giant
00:06:42 --> 00:06:45 clouds of gas and dust in space can be truly
00:06:45 --> 00:06:47 vast. When they get nudged and start to
00:06:47 --> 00:06:49 collapse, they'll fragment in their interiors
00:06:50 --> 00:06:52 to form a cluster of stars, a number of
00:06:52 --> 00:06:54 stars, which form from the little denser
00:06:54 --> 00:06:56 bits. It's like driving through a fog bank.
00:06:56 --> 00:06:58 Fog banks are never one uniform density.
00:06:58 --> 00:06:59 There's denser patches and less dense
00:06:59 --> 00:07:02 patches. A denser patch in one of these
00:07:02 --> 00:07:04 clouds will collapse under its own gravity.
00:07:04 --> 00:07:07 And so you'll get lots of stars forming. As
00:07:07 --> 00:07:09 that material collapses in, it collapses down
00:07:09 --> 00:07:11 to form a disc around that young protostar
00:07:11 --> 00:07:13 that's forming. And the star and the
00:07:13 --> 00:07:16 disc are made of the same material. They're
00:07:16 --> 00:07:18 forming from the same material. All that
00:07:18 --> 00:07:20 material that was in the cloud from which
00:07:20 --> 00:07:22 they're formed, which has been polluted over
00:07:22 --> 00:07:24 many generations of stars, cooking the
00:07:24 --> 00:07:27 books to give the composition that is uniform
00:07:27 --> 00:07:30 across that star system. What happens then is
00:07:30 --> 00:07:32 that the star forms from everything, so it
00:07:32 --> 00:07:35 ends up very rich in hydrogen and helium.
00:07:35 --> 00:07:37 Because even after all that pollution and all
00:07:37 --> 00:07:40 that evolution, hydrogen and helium still
00:07:40 --> 00:07:43 make up something like between 98 and 99% of
00:07:43 --> 00:07:45 all atoms in the universe. So the star is
00:07:45 --> 00:07:47 going to be primarily hydrogen and helium
00:07:47 --> 00:07:50 with a thin veneer of everything else. In
00:07:50 --> 00:07:52 other words, the abundance of material in the
00:07:52 --> 00:07:54 star is going to be very nearly
00:07:54 --> 00:07:57 identical to the disc. Star will end
00:07:57 --> 00:08:00 up being very, very, very slightly enriched
00:08:00 --> 00:08:03 in the heavier elements, because from
00:08:03 --> 00:08:04 the disc, particularly when the disc is
00:08:04 --> 00:08:07 cleared, there will be some infall of rocky
00:08:07 --> 00:08:09 and icy objects like the Kreutz sun, grazing
00:08:09 --> 00:08:11 comets, we see that fall into the star and
00:08:11 --> 00:08:13 pollute it further. But that' very, very
00:08:13 --> 00:08:16 small effect compared to the overall mass of
00:08:16 --> 00:08:18 the star. The planets form in the
00:08:18 --> 00:08:20 disc in the main
00:08:21 --> 00:08:23 form through a process we call core
00:08:23 --> 00:08:24 accretion. There are some suggestions that
00:08:24 --> 00:08:26 some of the most massive stars can form
00:08:26 --> 00:08:29 through a process of instability. And those
00:08:29 --> 00:08:32 planets and binary stars would form with a
00:08:32 --> 00:08:34 more stellar composition, I.e. lots of
00:08:34 --> 00:08:36 hydrogen, helium. But most planets
00:08:37 --> 00:08:39 will form by initially growing a core of
00:08:39 --> 00:08:42 solid material, because when you have a low,
00:08:42 --> 00:08:44 uh, mass, you can't capture gas,
00:08:44 --> 00:08:47 and so therefore your composition will be
00:08:47 --> 00:08:49 dominated by the solid material, not the
00:08:49 --> 00:08:51 gases. So that's why the Earth doesn't have
00:08:51 --> 00:08:54 free hydrogen and helium. We simply don't
00:08:54 --> 00:08:56 have enough mass to capture those gases and
00:08:56 --> 00:08:59 hold onto them. So even though 99% of all
00:08:59 --> 00:09:01 atoms in the protoplanetary disc were
00:09:01 --> 00:09:02 hydrogen and helium, we didn't get any of
00:09:02 --> 00:09:05 them, other than the old tiny little atom
00:09:05 --> 00:09:07 that was captured in a cage of other
00:09:07 --> 00:09:10 compounds called clathrate,
00:09:10 --> 00:09:12 that was captured in a mineral effectively.
00:09:13 --> 00:09:15 So we barely got any of those materials
00:09:15 --> 00:09:17 because we couldn't hold onto them. We formed
00:09:17 --> 00:09:19 out of the solid stuff. The further you are
00:09:19 --> 00:09:21 from the star, the colder it is, so the more
00:09:21 --> 00:09:23 different things can be solid rather than
00:09:23 --> 00:09:24 gas, which is where we get the idea of the
00:09:24 --> 00:09:27 ice line. If you're far enough from the star,
00:09:27 --> 00:09:30 water can be solid, can be ice, and then
00:09:30 --> 00:09:32 suddenly you've got a lot more solid material
00:09:32 --> 00:09:34 because water's about the most common
00:09:34 --> 00:09:36 compound there is, almost it's the most
00:09:36 --> 00:09:38 common atom, hydrogen, and the third most
00:09:38 --> 00:09:39 common atom, oxygen. And you put them
00:09:39 --> 00:09:42 together and you've got water. So beyond the
00:09:42 --> 00:09:43 ice line, you've got a lot more solid, and
00:09:43 --> 00:09:46 you can form planets much quicker, which is
00:09:46 --> 00:09:48 why we think Jupiter and Saturn got so big so
00:09:48 --> 00:09:50 quickly. They had a lot to feed on. And
00:09:50 --> 00:09:52 eventually they got massive enough that their
00:09:52 --> 00:09:54 gravity was strong enough to hold onto the
00:09:54 --> 00:09:56 hydrogen and helium around them and devour
00:09:56 --> 00:09:58 it. So they are
00:09:59 --> 00:10:01 in composition much more similar to the sun
00:10:01 --> 00:10:03 than the, uh, Earth. Is because they have all
00:10:03 --> 00:10:05 that hydrogen and helium, but they are still
00:10:05 --> 00:10:08 richer in solid material than the sun
00:10:08 --> 00:10:11 because at their core, there was all the
00:10:11 --> 00:10:13 solid material needed to build up before they
00:10:13 --> 00:10:16 could gather the hydrogen and helium. So they
00:10:16 --> 00:10:18 started with more solids. Effectively.
00:10:19 --> 00:10:21 The Earth doesn't really have the hydrogen
00:10:21 --> 00:10:23 and helium. So all of the objects in our
00:10:23 --> 00:10:25 solar system will have the same composition
00:10:25 --> 00:10:28 as the sun in terms of the balance between
00:10:28 --> 00:10:30 carbon and nitrogen and iron and all these
00:10:30 --> 00:10:33 elements, except for where they weren't able
00:10:33 --> 00:10:36 to capture those elements because they
00:10:36 --> 00:10:38 weren't massive enough. So the Earth doesn't
00:10:38 --> 00:10:39 have the same composition as the sun in terms
00:10:39 --> 00:10:42 of hydrogen and helium, but it does in terms
00:10:42 --> 00:10:45 of iron, nickel, all those things,
00:10:45 --> 00:10:47 the balance between iron and nickel and
00:10:47 --> 00:10:48 carbon and all the rest of it are all in the
00:10:48 --> 00:10:51 same ratios as the sun, um, to an
00:10:51 --> 00:10:54 incredibly high precision. And that's because
00:10:54 --> 00:10:56 we all formed from the same material that
00:10:56 --> 00:10:58 quite rightly was mentioned in the question
00:10:58 --> 00:11:00 was delivered by past generation of stars
00:11:00 --> 00:11:02 that had lived and died. And that's where the
00:11:02 --> 00:11:03 whole concept that we are stardust comes
00:11:03 --> 00:11:05 from. It's the idea that all the atoms that
00:11:05 --> 00:11:07 we need to make us, us, other than the
00:11:07 --> 00:11:10 hydrogen atoms, were cooked in the furnaces
00:11:10 --> 00:11:12 of stars long de. All the carbon, the
00:11:12 --> 00:11:15 nitrogen, the oxygen, the phosphorus, all
00:11:15 --> 00:11:16 those wonderful things, calcium, that
00:11:16 --> 00:11:18 contributes to our bones are all stardust
00:11:18 --> 00:11:20 from stars that died long before the solar
00:11:20 --> 00:11:21 system formed.
00:11:23 --> 00:11:25 Andrew Dunkley: There you are, David. Um, a very
00:11:26 --> 00:11:28 good, uh, answer. That pretty m. Well, nails
00:11:28 --> 00:11:30 it. I like the bit about there being more
00:11:30 --> 00:11:33 gold on Earth than there probably would be in
00:11:33 --> 00:11:33 other places.
00:11:33 --> 00:11:35 So that's. That was a lucky break for us.
00:11:35 --> 00:11:38 Jonti Horner: Absolutely. So useful for a
00:11:38 --> 00:11:40 lot of the technology we use. Not just for
00:11:40 --> 00:11:42 those who are sparkly, bangly things, but,
00:11:42 --> 00:11:45 you know, there's a lot of those rarer type
00:11:45 --> 00:11:48 things that are so vital to our technological
00:11:48 --> 00:11:50 growth that are all linked to our ancient
00:11:50 --> 00:11:51 heritage.
00:11:52 --> 00:11:54 Andrew Dunkley: Yeah, yeah. Um, well,
00:11:54 --> 00:11:56 there's gold, there's lithium.
00:11:57 --> 00:11:59 There's just so many of them. But we've got a
00:11:59 --> 00:12:00 lithium mine just down the road from us,
00:12:00 --> 00:12:01 actually.
00:12:01 --> 00:12:03 Jonti Horner: And that lithium, probably all primordial,
00:12:03 --> 00:12:05 the lithium in the universe, is almost
00:12:05 --> 00:12:07 certainly, almost all leftovers from the Big
00:12:07 --> 00:12:08 Bang.
00:12:09 --> 00:12:12 Andrew Dunkley: Wow, that's interesting. There you go,
00:12:12 --> 00:12:14 David, thanks for the question. Lovely to
00:12:14 --> 00:12:15 hear from you. Hope all is well on the
00:12:15 --> 00:12:18 Sunshine Coast. This is Space Nuts with
00:12:18 --> 00:12:21 Andrew Dunkley and Jonty Horner, A
00:12:21 --> 00:12:22 Q and A Edition.
00:12:25 --> 00:12:26 Generic: Roger, your lab is right here.
00:12:26 --> 00:12:28 David: Also Space Nuts.
00:12:28 --> 00:12:31 Andrew Dunkley: And we're with Professor Jonty Horner today
00:12:31 --> 00:12:34 with Fred Watson away. Uh, let's Go to our,
00:12:34 --> 00:12:37 uh, next question. Jonty, this one comes from
00:12:37 --> 00:12:37 Mark.
00:12:38 --> 00:12:40 Mark: Hi, it's Mark from Sunny Siddlesham in the
00:12:40 --> 00:12:42 uk. I've eventually plugged up the courage to
00:12:42 --> 00:12:45 send in an audio question, so here goes. You
00:12:45 --> 00:12:48 quite often mention water ice and the
00:12:48 --> 00:12:50 possibility of turning this into rocket fuel.
00:12:50 --> 00:12:52 So my what do you think? Sort of question is,
00:12:53 --> 00:12:55 when you use hydrogen and oxygen as a rocket
00:12:55 --> 00:12:57 fuel, it must turn back into water ice in
00:12:57 --> 00:13:00 space. So do you think it would be possible
00:13:00 --> 00:13:02 to collect it and reuse it through the rocket
00:13:02 --> 00:13:05 engine, again massively reducing the amount
00:13:05 --> 00:13:07 of fuel you would need to carry for an
00:13:07 --> 00:13:09 extended journey, say, to Mars? I've sort of
00:13:09 --> 00:13:12 drawn up an idea, but what do you think? Once
00:13:12 --> 00:13:15 again, keep up the great work, Mark from the
00:13:15 --> 00:13:15 uk.
00:13:16 --> 00:13:18 Andrew Dunkley: Thank you, Mark. It's an interesting idea.
00:13:18 --> 00:13:21 My, uh, first thought when I
00:13:21 --> 00:13:24 first heard the question was, um,
00:13:24 --> 00:13:27 how would you collect it? That
00:13:27 --> 00:13:28 might be the first challenge.
00:13:29 --> 00:13:30 Jonti Horner: That would be a bit of a challenge. I mean,
00:13:30 --> 00:13:32 the thing is, your exhaust is being pushed
00:13:32 --> 00:13:34 out of the bucket, the rocket, at very high
00:13:34 --> 00:13:36 speed in a very dispersed form. Now the
00:13:36 --> 00:13:38 rocket's going forward because you're
00:13:38 --> 00:13:40 throwing the things out the back. You've got
00:13:40 --> 00:13:43 the momentum, um, being transferred and it's
00:13:43 --> 00:13:46 equivalent, I guess, to you. The way I'd
00:13:46 --> 00:13:48 visualise this is imagining, again, sitting
00:13:48 --> 00:13:50 on an ice rink on a wheelie chair. So you've
00:13:50 --> 00:13:53 got no friction whatsoever, really slippy and
00:13:53 --> 00:13:55 you're holding, Normally, I'd just say one
00:13:55 --> 00:13:56 medicine ball, but instead imagine that
00:13:56 --> 00:13:59 you're holding a big bag of short puts. You
00:13:59 --> 00:14:01 throw a short put away from you and you'll
00:14:01 --> 00:14:03 recall in the other direction. You throw
00:14:03 --> 00:14:04 another short put and you'll speed up and
00:14:04 --> 00:14:06 you'll move in the opposite direction to the
00:14:06 --> 00:14:08 direction your short puts are going. So
00:14:08 --> 00:14:10 that's how you'll work. And that's
00:14:10 --> 00:14:11 essentially what you're doing with the
00:14:11 --> 00:14:13 rocket. You're pushing material out of the
00:14:13 --> 00:14:15 back and you're moving the opposite way,
00:14:15 --> 00:14:17 because overall, the momentum is conserved
00:14:17 --> 00:14:19 between the stuff going one way and you going
00:14:19 --> 00:14:21 the other. The problem with the
00:14:21 --> 00:14:24 rocket itself capturing its own exhaust,
00:14:24 --> 00:14:27 pumping it back in and reusing it, is
00:14:27 --> 00:14:29 then you're taking that momentum and bringing
00:14:29 --> 00:14:30 it back to you, which means you're getting
00:14:30 --> 00:14:31 pulled back towards it and you'll end up
00:14:31 --> 00:14:34 having gone nowhere to some degree.
00:14:34 --> 00:14:36 So imagine now that situation with the short
00:14:36 --> 00:14:39 puts on the I shrink, but
00:14:39 --> 00:14:42 instead you've got a really efficient bungee
00:14:42 --> 00:14:43 cord, so that when you throw them away, they
00:14:43 --> 00:14:45 bounce back and you catch them again. What'll
00:14:45 --> 00:14:47 Happen is as they're moving away from you,
00:14:47 --> 00:14:49 you'll wheel away from them. And then as they
00:14:49 --> 00:14:50 get pulled back towards you, you get pulled
00:14:50 --> 00:14:51 back towards them and you end up where you
00:14:51 --> 00:14:54 started from. Here will know a little bit of
00:14:54 --> 00:14:56 change due to friction and loss of energy and
00:14:56 --> 00:14:59 stuff like that. So the problem I'd have
00:14:59 --> 00:15:01 with this suggestion is not actually the idea
00:15:01 --> 00:15:03 of capturing and reusing the fuel.
00:15:04 --> 00:15:06 Um, I think that will be hard because the
00:15:06 --> 00:15:08 fuel will get so dispersed, so water will be
00:15:08 --> 00:15:09 scattered out there. It's just easier to go
00:15:09 --> 00:15:12 get a big lump of ice from somewhere than try
00:15:12 --> 00:15:14 and pick up individual water molecules or
00:15:14 --> 00:15:16 small grains of ice disperse over a large
00:15:16 --> 00:15:19 area. But the idea of being able to capture
00:15:19 --> 00:15:21 it from the same rocket and reuse it would
00:15:21 --> 00:15:23 get you into this problem of having to pull
00:15:23 --> 00:15:25 back material that you've pushed away, which
00:15:25 --> 00:15:27 means you'd be pulling yourself back to where
00:15:27 --> 00:15:29 you started from. So you can't get away, I
00:15:29 --> 00:15:32 think, from that momentum issue there.
00:15:32 --> 00:15:34 So I think it's two different things. I think
00:15:34 --> 00:15:37 if you had the ability to, instead of using
00:15:37 --> 00:15:39 hydrogen and oxygen as a fuel and burning
00:15:39 --> 00:15:42 them to be water, you can instead have a
00:15:42 --> 00:15:44 rocket fired powered by firing
00:15:44 --> 00:15:47 pellets of water out of the back. You could
00:15:47 --> 00:15:49 fire them at a target that captures them, um,
00:15:50 --> 00:15:52 collect them and reuse those pellets for
00:15:52 --> 00:15:53 something else. But that target will get
00:15:53 --> 00:15:56 pushed around by the arriving water pellets.
00:15:56 --> 00:15:57 So you'd want to be clever with that and
00:15:57 --> 00:15:59 you'd need to continually change its orbit
00:15:59 --> 00:16:02 and stuff. So in theory, potentially, you
00:16:02 --> 00:16:04 could gather the fuel for use on another
00:16:04 --> 00:16:06 rocket without it being the rocket you're
00:16:06 --> 00:16:09 flying that gathers that fuel. But in
00:16:09 --> 00:16:11 reality, you're dispersing over such a large
00:16:11 --> 00:16:14 area that unfortunately, it wouldn't be that
00:16:14 --> 00:16:15 practical anyway. Especially when we've got
00:16:15 --> 00:16:17 just huge lumps of ice floating around
00:16:17 --> 00:16:19 anyway. I mean, you and I have both been
00:16:19 --> 00:16:21 photographing a beautiful lump of ice flying
00:16:21 --> 00:16:23 through the solar system. There we go in the
00:16:23 --> 00:16:26 background. That's enough fuel for
00:16:26 --> 00:16:28 missions forevermore. If we were to go and
00:16:28 --> 00:16:30 mine there, and that's a lot more efficient
00:16:30 --> 00:16:33 to mine one big comet or
00:16:33 --> 00:16:36 asteroid for water ice or mine the moon for
00:16:36 --> 00:16:38 water ice, then try and catch it when it's
00:16:38 --> 00:16:40 dispersed, I think. So it's a really good
00:16:40 --> 00:16:43 idea. It's really good thinking. But it's
00:16:43 --> 00:16:44 something that wouldn't work. I think that's
00:16:44 --> 00:16:45 the way I'd view it.
00:16:47 --> 00:16:49 Andrew Dunkley: It'd be very complicated. And as you said,
00:16:49 --> 00:16:51 um, trying to capture it in the ship, you're
00:16:51 --> 00:16:53 actually propelling would be
00:16:53 --> 00:16:56 counterproductive. Using another
00:16:56 --> 00:16:59 spaceship to capture the ice after it's been
00:16:59 --> 00:17:02 expelled, uh, would be difficult because it
00:17:02 --> 00:17:04 would spread out too far. But then you're
00:17:04 --> 00:17:06 using the same technology
00:17:07 --> 00:17:09 to chase the ice that's been spent already
00:17:10 --> 00:17:13 and spending more to get the ice back. So it,
00:17:13 --> 00:17:15 yeah, It's a catch 22. It's just going to
00:17:15 --> 00:17:18 keep going around and around. So um,
00:17:19 --> 00:17:21 it makes it a little bit difficult. Uh, Mark,
00:17:21 --> 00:17:24 but, uh, thanks for your question, that
00:17:24 --> 00:17:26 was a fun one actually. But, uh, yeah,
00:17:26 --> 00:17:29 um, yeah, I like the way people
00:17:29 --> 00:17:32 think. But I, uh, suppose just to expand on
00:17:32 --> 00:17:35 it a bit, um, there's going to come a
00:17:35 --> 00:17:37 time where using those kinds of fuels
00:17:37 --> 00:17:39 probably won't be necessary. They're
00:17:39 --> 00:17:41 developing all sorts of different kinds of
00:17:41 --> 00:17:44 engine technology, uh, everything
00:17:44 --> 00:17:46 from solar sails to scramjets, and
00:17:48 --> 00:17:50 they don't use that kind of fuel.
00:17:50 --> 00:17:52 Jonti Horner: There's all sorts of things you could do. I
00:17:52 --> 00:17:54 mean again, going back to the Bobiverse,
00:17:54 --> 00:17:55 which I mentioned before, the Van Neumann
00:17:55 --> 00:17:58 probes going through, they used kind of um,
00:17:58 --> 00:18:01 ram scoots essentially initially in the book
00:18:01 --> 00:18:03 set. They then move on to other kind of
00:18:03 --> 00:18:05 speculative sci fi things. But initially the
00:18:05 --> 00:18:08 idea of having a fusion drive where you scoop
00:18:08 --> 00:18:10 up hydrogen atoms and turn them into helium
00:18:10 --> 00:18:12 and push them out the back where in front of
00:18:12 --> 00:18:14 you you deploy a big thing that gathers the
00:18:14 --> 00:18:16 hydrogen you're moving through. This is also
00:18:16 --> 00:18:18 what they did in Tau Zero by Poole Anderson
00:18:18 --> 00:18:20 is you know, you're moving really quickly,
00:18:20 --> 00:18:22 you gather hydrogen from in front of you and
00:18:22 --> 00:18:24 compress it like a ramjet effectively.
00:18:25 --> 00:18:26 There's all these kind of things, but they
00:18:26 --> 00:18:29 will all, unless we get to truly sci fi
00:18:29 --> 00:18:32 type things like warp driver albatier drives
00:18:32 --> 00:18:34 or whatever, which require physics to be
00:18:34 --> 00:18:36 somewhat different than how we can only
00:18:36 --> 00:18:39 understand it. You still have
00:18:39 --> 00:18:42 either a source of propellant which you
00:18:42 --> 00:18:44 then get rid of out the back one way or the
00:18:44 --> 00:18:47 other, or with solar sails you're using
00:18:47 --> 00:18:50 the stellar wind and that pushes you away.
00:18:51 --> 00:18:54 Um, people who are sailors can probably tell
00:18:54 --> 00:18:55 you a lot more about the complexity of how
00:18:55 --> 00:18:57 you can tack into the wind and move across
00:18:57 --> 00:18:59 the wind. But the wind, the solar wind is
00:18:59 --> 00:19:02 incredibly tenuous compared to the wind in
00:19:02 --> 00:19:03 the Earth's atmosphere. So you need a very,
00:19:03 --> 00:19:06 very big sail. And I think that will be
00:19:06 --> 00:19:08 somewhat limiting. If you were wanting to do,
00:19:09 --> 00:19:11 I guess, Star wars style dogfight manoeuvres,
00:19:11 --> 00:19:13 you wouldn't do that with a solar sail. So
00:19:13 --> 00:19:15 people will pick the right technology for the
00:19:15 --> 00:19:17 kind of mission that they want. And that was
00:19:17 --> 00:19:19 where the dawn mission which went to Ceres
00:19:20 --> 00:19:22 and um, Juno in the asteroid belt was really
00:19:22 --> 00:19:24 interesting because it used an ion drive
00:19:25 --> 00:19:27 where it was using I think ionised xenon. And
00:19:27 --> 00:19:30 um, that kind of drive achieves a much,
00:19:30 --> 00:19:33 much lower thrust but can operate for much
00:19:33 --> 00:19:35 much longer time. So it's very energy
00:19:35 --> 00:19:38 efficient um, but it wouldn't be any good for
00:19:38 --> 00:19:39 getting off the surface of the Earth. But
00:19:39 --> 00:19:41 it's very, very good for cruising around the
00:19:41 --> 00:19:43 solar system when you're not in a rush. And
00:19:43 --> 00:19:45 so what will happen is I think different
00:19:45 --> 00:19:48 people will have different types of drives
00:19:48 --> 00:19:50 for different types of scenario
00:19:51 --> 00:19:53 and choose the one that works best.
00:19:53 --> 00:19:56 Andrew Dunkley: Yeah but to get off the planet at the moment
00:19:56 --> 00:19:59 you need rockets. There's no real
00:19:59 --> 00:20:01 other technology that will get you out there.
00:20:01 --> 00:20:04 I know they've been trying um, sort
00:20:04 --> 00:20:07 of catapult technology uh, which
00:20:08 --> 00:20:11 um, could deploy satellites in the
00:20:11 --> 00:20:13 future. I um, think
00:20:13 --> 00:20:15 you'd need to be in the right place on the
00:20:15 --> 00:20:18 planet to take advantage of the um, rotation
00:20:18 --> 00:20:20 of the Earth so that you don't have to like
00:20:20 --> 00:20:22 you couldn't do it too far away from the
00:20:22 --> 00:20:25 equator, that kind of thing. But um,
00:20:25 --> 00:20:27 at the moment uh, yeah the um, standard
00:20:27 --> 00:20:30 old rocket engine is uh, the best option at
00:20:30 --> 00:20:31 the moment.
00:20:31 --> 00:20:33 Jonti Horner: Um, part of where the refuelling station idea
00:20:33 --> 00:20:36 around uh, the moon comes from which is if
00:20:36 --> 00:20:38 you have to take your fuel with you, you're
00:20:38 --> 00:20:39 carrying a lot of extra weight so you've got
00:20:39 --> 00:20:41 to burn extra fuel to carry that fuel which
00:20:41 --> 00:20:43 means you're carrying extra weight so you've
00:20:43 --> 00:20:44 got to take even more fuel to burn um, to
00:20:44 --> 00:20:46 carry the weight of the fuel you're carrying
00:20:46 --> 00:20:48 to carry the extra fuel. And so uh, it
00:20:48 --> 00:20:50 becomes very inefficient very quickly. So if
00:20:50 --> 00:20:52 instead you can small launches from Earth and
00:20:52 --> 00:20:54 then refuel once you're beyond the Earth,
00:20:54 --> 00:20:57 that's a lot more effective. And the other
00:20:57 --> 00:20:58 thing that people have suggested long term
00:20:58 --> 00:21:01 um, as a solution to get things off the Earth
00:21:01 --> 00:21:03 more cheaply are things like space elevators
00:21:04 --> 00:21:06 which are ah, probably still far science
00:21:06 --> 00:21:08 fiction. I don't, don't think we have the
00:21:08 --> 00:21:10 material science to do that nor the political
00:21:10 --> 00:21:12 will. I mean putting that in perspective,
00:21:12 --> 00:21:14 just saw the announcement this week that the
00:21:14 --> 00:21:17 vast inland rail project that was happening
00:21:17 --> 00:21:20 in Australia is no longer happening because
00:21:20 --> 00:21:22 it got too expensive and it's taken too long.
00:21:22 --> 00:21:24 And if we can't build a railway between
00:21:24 --> 00:21:26 Melbourne and Brisbane, it's going to be
00:21:26 --> 00:21:29 really hard to build an elevator between low
00:21:29 --> 00:21:31 Earth orbit, well between the Earth's surface
00:21:31 --> 00:21:33 geostationary orbit and the same distance
00:21:33 --> 00:21:36 beyond for the counterweight. Yeah,
00:21:36 --> 00:21:38 So I don't see it happening anytime soon.
00:21:39 --> 00:21:41 Andrew Dunkley: We can't even get a tunnel under the Blue
00:21:41 --> 00:21:43 Mountains between the west and Sydney.
00:21:44 --> 00:21:47 Uh, and that's despite the fact
00:21:47 --> 00:21:49 that that road is currently closed due to
00:21:50 --> 00:21:52 a structural failure in Victoria Pass.
00:21:52 --> 00:21:55 The old convict bridge, that's, uh, 200
00:21:55 --> 00:21:58 years old or something, or 150 years old. And
00:21:58 --> 00:22:01 it's finally given up the ghost. And so
00:22:01 --> 00:22:02 they've closed the road.
00:22:02 --> 00:22:05 It's. You know, people have been screaming
00:22:05 --> 00:22:08 for a tunnel for decades. And,
00:22:08 --> 00:22:11 um, no politicians willing to spend the
00:22:11 --> 00:22:12 money because there aren't enough people.
00:22:13 --> 00:22:14 Bottom line is there aren't enough people
00:22:14 --> 00:22:17 living west of the mountains to make it worth
00:22:17 --> 00:22:17 your vote.
00:22:18 --> 00:22:20 Jonti Horner: Really. What it comes down.
00:22:20 --> 00:22:21 Andrew Dunkley: That's what it comes down to.
00:22:21 --> 00:22:23 Jonti Horner: Reminds me of the old episode of the Simpsons
00:22:23 --> 00:22:24 when I was a kid with the kind of argument
00:22:24 --> 00:22:26 about books for the kids or something.
00:22:26 --> 00:22:28 There's the two people at the front room
00:22:28 --> 00:22:30 basically shouting, but our children, but
00:22:30 --> 00:22:33 taxes. But our children, but taxes. And it's
00:22:33 --> 00:22:35 this whole thing of everybody wants it, but
00:22:35 --> 00:22:36 nobody wants to pay for it.
00:22:36 --> 00:22:39 Andrew Dunkley: Exactly, yes. Uh, a tunnel under the Blue
00:22:39 --> 00:22:41 Mounds would be wonderful, though. Although,
00:22:41 --> 00:22:44 um, some. Some of the arguments against it
00:22:44 --> 00:22:46 are, uh. Well, it'll only save you 15
00:22:46 --> 00:22:48 minutes. I think it'd probably save you more.
00:22:48 --> 00:22:50 Gets pretty log jammed up over that mountain.
00:22:50 --> 00:22:52 Jonti Horner: We have those arguments about the Toowoomba
00:22:52 --> 00:22:54 bypass, and that's been a godsend.
00:22:54 --> 00:22:57 Andrew Dunkley: I mean, yeah, I used it last, uh, year. Yeah,
00:22:57 --> 00:22:58 it's fantastic.
00:22:58 --> 00:22:59 Jonti Horner: It fell apart and bits fell onto it because
00:22:59 --> 00:23:02 they contracted fairly cheaply.
00:23:02 --> 00:23:04 Um, but that has saved about half an hour
00:23:04 --> 00:23:06 from my trip down to Brisbane when I go to
00:23:06 --> 00:23:08 the airport and stuff because I don't have to
00:23:08 --> 00:23:10 go through Toowoomba and all the freight
00:23:10 --> 00:23:12 companies use it even though the tolls are
00:23:12 --> 00:23:15 quite high. Because the tolls being high is a
00:23:15 --> 00:23:16 lot better than the wear and tear on their
00:23:16 --> 00:23:18 vehicles coming up the old road into
00:23:18 --> 00:23:19 Toowoomba and having to stop at all the
00:23:19 --> 00:23:21 traffic lights and stuff. So it works out
00:23:21 --> 00:23:23 deeper for them. It's better for the
00:23:23 --> 00:23:25 Toowoomba council because they're having to
00:23:25 --> 00:23:26 repair less potholes and they have less
00:23:26 --> 00:23:28 accidents. And it's one of those things where
00:23:28 --> 00:23:29 it was a little controversial when it was
00:23:29 --> 00:23:32 being built, but since it's there, it's been
00:23:32 --> 00:23:34 a godsend. And I'd like to think that some of
00:23:34 --> 00:23:36 these big infrastructure projects would be
00:23:36 --> 00:23:38 the same. And I mean, a space elevator would
00:23:38 --> 00:23:40 be wonderful, but, you know, gonna be hard to
00:23:40 --> 00:23:42 persuade people to commit to building it,
00:23:42 --> 00:23:43 even when we get the technology.
00:23:43 --> 00:23:46 Andrew Dunkley: I think, uh, wait till there are
00:23:46 --> 00:23:48 orbiting hotels that'll change everything.
00:23:49 --> 00:23:52 You wait and see. Might be
00:23:52 --> 00:23:54 waiting a while. Um, thanks, Mark. Lovely to
00:23:54 --> 00:23:55 hear from you.
00:23:55 --> 00:23:58 This is Space Nuts with Andrew Dunkley and
00:23:58 --> 00:23:59 Professor Jonty Horner.
00:24:04 --> 00:24:05 Jonti Horner: Space Nuts.
00:24:05 --> 00:24:08 Andrew Dunkley: One more question, uh, Jonty. And this one
00:24:08 --> 00:24:10 comes from Paul.
00:24:10 --> 00:24:12 Joe: G', day, Fred Watson and Andrew. Paul here
00:24:12 --> 00:24:15 from Sunnybridge, Vegas. I have
00:24:15 --> 00:24:17 a question and a dirty secret that
00:24:18 --> 00:24:19 I need to confess.
00:24:21 --> 00:24:24 So I was on this Flat Earth group on
00:24:24 --> 00:24:27 Facebook. Yes, I know, I know. Uh, anyway,
00:24:27 --> 00:24:30 this guy provided some AI information
00:24:30 --> 00:24:33 which was absolutely correct to
00:24:33 --> 00:24:36 contend that there is no way that the Artemis
00:24:36 --> 00:24:38 mission could have ever caught up to the
00:24:38 --> 00:24:40 Earth because the Earth travels a hell of a
00:24:40 --> 00:24:43 lot faster than that little spaceship.
00:24:43 --> 00:24:46 I pointed out that they didn't need to
00:24:47 --> 00:24:49 catch up to the Earth at all. They just
00:24:49 --> 00:24:51 needed to point themselves to where it was
00:24:51 --> 00:24:54 going to be and then splash down,
00:24:54 --> 00:24:57 land safely, and be
00:24:57 --> 00:24:59 applauded by everybody except for the Flat
00:24:59 --> 00:25:02 Earthers like him, uh, who are absolutely
00:25:02 --> 00:25:04 incensed at the moment about
00:25:05 --> 00:25:07 how it's all fake, as per, uh, usual.
00:25:08 --> 00:25:11 Anyway, I told him
00:25:11 --> 00:25:13 that if he really wanted a better answer,
00:25:13 --> 00:25:15 exact answer, he really needed to talk to an
00:25:15 --> 00:25:18 astrophysicist. So my second question
00:25:18 --> 00:25:21 is. Well, my first question is, was I on the
00:25:21 --> 00:25:23 right track? And my second question is,
00:25:24 --> 00:25:26 are there any astrophysicists or any websites
00:25:26 --> 00:25:29 out there that can give us an animation
00:25:30 --> 00:25:32 of the Earth going around
00:25:32 --> 00:25:35 the sun that also has, uh, the
00:25:35 --> 00:25:38 animated version of the Artemis going around
00:25:38 --> 00:25:40 the moon so that we can see the whole thing
00:25:40 --> 00:25:43 in context in terms of the solar system, or
00:25:43 --> 00:25:45 at least our area of the solar system system.
00:25:45 --> 00:25:48 Uh, it's not going to convince him, I'm sure,
00:25:48 --> 00:25:51 but I think it'd be pretty cool to see
00:25:51 --> 00:25:54 something like that. Anyway, thanks very
00:25:54 --> 00:25:56 much, gentlemen, for the show, as always. Um,
00:25:56 --> 00:25:59 look forward to it every week and catch you
00:25:59 --> 00:25:59 later.
00:26:00 --> 00:26:01 Jonti Horner: Have a good one.
00:26:01 --> 00:26:04 Andrew Dunkley: You too, Paul. Thank you. If only we had
00:26:04 --> 00:26:06 an astrophysicist somewhere nearby.
00:26:07 --> 00:26:09 Jonty, any I know
00:26:10 --> 00:26:12 was directing the question to Fred Watson,
00:26:12 --> 00:26:13 but he asked for an
00:26:13 --> 00:26:15 astrophysicist.
00:26:15 --> 00:26:17 Jonti Horner: Yeah. We are legion, for we are many. There's
00:26:17 --> 00:26:19 plenty of us around. It, uh, was always a
00:26:19 --> 00:26:22 thing when I was at uni of what title you use
00:26:22 --> 00:26:23 for what you're studying would depend on how
00:26:23 --> 00:26:25 bothered you were about the conversation.
00:26:25 --> 00:26:27 Because if, you know, if I told someone I was
00:26:27 --> 00:26:30 studying physics, said very quickly, exit
00:26:30 --> 00:26:31 stage left, if I told them I was doing
00:26:31 --> 00:26:33 astronomy, they'd stay and chat. And if I
00:26:33 --> 00:26:34 told them I was doing astrophysics, they'd
00:26:34 --> 00:26:37 just look a little bit scared. Um, but I was
00:26:37 --> 00:26:38 doing all three.
00:26:39 --> 00:26:41 This is an interesting one. I mean,
00:26:42 --> 00:26:45 people like the flat Earthers are difficult.
00:26:45 --> 00:26:45 David: Ah.
00:26:46 --> 00:26:48 Jonti Horner: Because there is no amount of truth, no
00:26:48 --> 00:26:51 amount of evidence that you can put before
00:26:51 --> 00:26:52 people who are convinced that they've been
00:26:52 --> 00:26:55 lied to, um, other than talking to
00:26:55 --> 00:26:57 them gently about it. And it's like
00:26:58 --> 00:26:59 discussions of climate change I've had in the
00:26:59 --> 00:27:02 past with people who argue climate change
00:27:02 --> 00:27:04 isn't real. Arguing and fighting with people
00:27:05 --> 00:27:07 over this doesn't win hearts and minds. It
00:27:07 --> 00:27:09 just gets them more entrenched. But talking
00:27:09 --> 00:27:11 to them about it and talking about why we
00:27:11 --> 00:27:14 think something is the case, this is our
00:27:14 --> 00:27:17 evidence, this is what it is. That can
00:27:17 --> 00:27:18 be a little bit more fruitful, I guess, but
00:27:18 --> 00:27:19 it is really challenging. I mean, especially
00:27:19 --> 00:27:21 given that we had a beautiful eclipse of the
00:27:21 --> 00:27:23 moon just a few months ago, where you can see
00:27:23 --> 00:27:25 that the shadow of the Earth is round.
00:27:27 --> 00:27:30 Andrew Dunkley: And that's the big argument. If the Earth was
00:27:30 --> 00:27:33 flat, the shadow at some stage would be
00:27:33 --> 00:27:35 just a line across the Moon.
00:27:35 --> 00:27:38 Jonti Horner: We'd see the elephants in the turtle. Um,
00:27:38 --> 00:27:40 the other thing is, if the Earth was flat,
00:27:40 --> 00:27:41 the cats would have pushed everything off the
00:27:41 --> 00:27:44 edge by now. Yes, yes,
00:27:44 --> 00:27:47 that's the other one. But, uh, in terms of
00:27:47 --> 00:27:50 Artemis, at the end of the day,
00:27:50 --> 00:27:53 we know it happened because we saw it. You
00:27:53 --> 00:27:56 know, I was over in Europe at the
00:27:56 --> 00:27:58 time, and, um, my colleagues at UNISQ were
00:27:58 --> 00:28:00 happily sharing their own little footage of
00:28:00 --> 00:28:02 the spacecraft that they got from our
00:28:02 --> 00:28:05 telescopes. They have no reason to lie.
00:28:05 --> 00:28:08 They have no vested interest in this. It's
00:28:08 --> 00:28:09 not like they're secretly on the payroll of
00:28:09 --> 00:28:12 NASA, ignoring the fact that if it was faked,
00:28:13 --> 00:28:15 Russia and China will be racing to tell
00:28:15 --> 00:28:17 everybody because that will be the best PR
00:28:17 --> 00:28:20 victory ever. You know, I mean, it's the same
00:28:20 --> 00:28:22 with the Moon landings in, uh, 1969.
00:28:23 --> 00:28:25 Did anybody really, really think that the
00:28:25 --> 00:28:26 Russians would have stayed quiet if there was
00:28:26 --> 00:28:28 a sniff of it being faked?
00:28:28 --> 00:28:31 Andrew Dunkley: In fact, my great grandmother
00:28:32 --> 00:28:34 always thought the Apollo landings were
00:28:34 --> 00:28:37 faked. Uh, she absolutely refused
00:28:37 --> 00:28:40 to believe it. But she grew up in an era
00:28:40 --> 00:28:42 before flight, so
00:28:43 --> 00:28:46 I can understand why she would
00:28:46 --> 00:28:47 think that, but she just thought it was all
00:28:47 --> 00:28:50 just some sort of publicity stunt. But I
00:28:50 --> 00:28:51 don't remember what they might have been
00:28:52 --> 00:28:53 trying to get publicity for,
00:28:53 --> 00:28:54 Jonti Horner: because they beat the Russians. I mean,
00:28:54 --> 00:28:56 that's what it was to them. I'll beat the
00:28:56 --> 00:28:58 Soviets as it was then, have been pulled up
00:28:58 --> 00:28:58 on that a couple of times.
00:28:58 --> 00:29:00 Andrew Dunkley: It was definitely a big PR, um,
00:29:00 --> 00:29:03 Jonti Horner: exercise in that regard. Uh, a former
00:29:03 --> 00:29:05 PhD student who worked with me, Jake Clark,
00:29:05 --> 00:29:08 Dr. Jack Clark, now M, gave a wonderful talk
00:29:08 --> 00:29:10 a couple of times about the
00:29:10 --> 00:29:13 moon landings in 1969 and why they couldn't
00:29:13 --> 00:29:14 have been faked because we couldn't afford
00:29:14 --> 00:29:17 it. Talking about faking it with the
00:29:17 --> 00:29:19 technology we had at the time would have
00:29:19 --> 00:29:20 actually been more expensive than going
00:29:20 --> 00:29:23 there. Um, which is fairly compelling
00:29:23 --> 00:29:25 for me. I mean, there's always a joke that,
00:29:25 --> 00:29:26 you know, yeah, the moon landings were always
00:29:26 --> 00:29:28 going to be faked, but they hired Stanley
00:29:28 --> 00:29:29 Kubrick to direct and he was such a
00:29:29 --> 00:29:31 perfectionist that they demanded that they do
00:29:31 --> 00:29:32 it on site. Um,
00:29:34 --> 00:29:37 um, with Artemis 2, there
00:29:38 --> 00:29:40 is abundant evidence that it really happened.
00:29:41 --> 00:29:43 You could, with a small telescope or
00:29:43 --> 00:29:44 binoculars, go outside and see the
00:29:44 --> 00:29:46 spacecraft. And I mean, you can't fake that.
00:29:46 --> 00:29:48 It's not like we're beaming thoughts into
00:29:48 --> 00:29:49 your head. And if you think we are, you can
00:29:49 --> 00:29:51 wear some tinfoil. That's all good.
00:29:52 --> 00:29:54 Um, in terms of the
00:29:54 --> 00:29:56 argument that the Earth is going too quick
00:29:56 --> 00:29:59 for this thing to catch up, that is
00:30:00 --> 00:30:03 in the kindest interpretation of it, that
00:30:03 --> 00:30:06 is allowing common sense
00:30:06 --> 00:30:08 based on your understanding of how day to day
00:30:08 --> 00:30:10 life works, interfere with
00:30:11 --> 00:30:13 looking at how things would move through
00:30:13 --> 00:30:15 space. I can see why you would get to that.
00:30:15 --> 00:30:18 If you think about a small child running
00:30:18 --> 00:30:20 along with a model of Artemis in the hand and
00:30:20 --> 00:30:22 a Ferrari driving down the motorway, or
00:30:22 --> 00:30:23 insert the make of car driving down the
00:30:23 --> 00:30:26 motorway at 100 kilometres an hour, the child
00:30:26 --> 00:30:27 is not going to catch the thing because
00:30:27 --> 00:30:30 they're not quick enough. And there are, uh,
00:30:30 --> 00:30:32 limits on how fast a child can run and how
00:30:32 --> 00:30:33 fast the car can move to do with air
00:30:33 --> 00:30:36 resistance. It's
00:30:36 --> 00:30:39 however, almost similar to saying, you know,
00:30:39 --> 00:30:41 I can't throw a ball up in the air and catch
00:30:41 --> 00:30:43 it because I'm Moving at over 1000 kilometres
00:30:43 --> 00:30:45 an hour around the Earth. So I'm moving too
00:30:45 --> 00:30:48 fast to catch up with that ball. Doesn't work
00:30:48 --> 00:30:49 like that because me and the ball are both
00:30:49 --> 00:30:52 moving at 1000 kilometres per hour. And so
00:30:52 --> 00:30:54 it's a relative speed between us that
00:30:54 --> 00:30:57 matters. So the Earth is going around the sun
00:30:57 --> 00:30:59 at about 30 kilometres a second. That's
00:30:59 --> 00:31:02 demonstrably true. Artemis moving
00:31:02 --> 00:31:05 in orbit around the Earth is moving around
00:31:05 --> 00:31:07 the sun at 30 kilometres a second with the
00:31:07 --> 00:31:09 Earth. It's falling with the Earth. Uh, so
00:31:09 --> 00:31:11 it's a relative speed that matters.
00:31:12 --> 00:31:12 Andrew Dunkley: Yeah.
00:31:12 --> 00:31:14 Jonti Horner: Now, if I went above the Earth, onto the
00:31:14 --> 00:31:17 space station, but instead of orbiting the,
00:31:17 --> 00:31:19 uh, Earth and falling with things, I was able
00:31:19 --> 00:31:22 to use rockets to stand still. Or I had
00:31:22 --> 00:31:24 an imaginary hovering platform of doom that
00:31:24 --> 00:31:26 wasn't moving. I'm, um, out of the
00:31:26 --> 00:31:28 atmosphere. If I threw a ball up in the air,
00:31:29 --> 00:31:30 it would move away from the Earth and the
00:31:30 --> 00:31:31 Earth's gravity would slow it down and pull
00:31:31 --> 00:31:33 it back, and it'd fall back down to me just
00:31:33 --> 00:31:35 the same as how it does on the ground.
00:31:36 --> 00:31:39 Now, if I was in orbit around the Earth and
00:31:39 --> 00:31:40 I was stood on the International Space
00:31:40 --> 00:31:42 Station and I tossed the ball upward, it
00:31:42 --> 00:31:44 would actually start moving on a different
00:31:44 --> 00:31:45 orbit around the Earth. So while it would
00:31:45 --> 00:31:47 move up, away from me and it would move down,
00:31:47 --> 00:31:49 it'd be going around the Earth on an orbit
00:31:49 --> 00:31:51 that takes slightly longer to go around the
00:31:51 --> 00:31:52 Earth than I do. So it also fall behind,
00:31:53 --> 00:31:54 behind. And that would look like wind
00:31:54 --> 00:31:57 resistance. But it's actually just a quirk of
00:31:57 --> 00:31:59 orbital mechanics in that I've put it onto a
00:31:59 --> 00:32:02 different orbit, um, because we are both
00:32:02 --> 00:32:05 falling at the time I let go of it. So if we
00:32:05 --> 00:32:07 imagine our flat Earther jumped off a cliff,
00:32:07 --> 00:32:09 and I'm not encouraging them to please do not
00:32:09 --> 00:32:11 do this, but imagine one jumps off a cliff
00:32:11 --> 00:32:14 while holding one of the shot puts from the
00:32:14 --> 00:32:16 previous answer without it being on a bungee
00:32:16 --> 00:32:18 cord. And they let go of the shot put, but
00:32:18 --> 00:32:20 the shot put will fall with them at the same
00:32:20 --> 00:32:23 speed. It won't move away from them and come
00:32:23 --> 00:32:26 back. It will accelerate downwards in exactly
00:32:26 --> 00:32:28 the same way that they do. And, uh, they'll
00:32:28 --> 00:32:30 only diverge once air resistance takes
00:32:30 --> 00:32:33 effect, depending on which of them feels more
00:32:33 --> 00:32:33 air resistance.
00:32:35 --> 00:32:37 Andrew Dunkley: It's the Galileo experiment, isn't it?
00:32:37 --> 00:32:39 Jonti Horner: So if you're on the space station, you throw
00:32:39 --> 00:32:40 a tennis ball up in the air. Ah, you're both
00:32:40 --> 00:32:42 actually falling, but you've changed the
00:32:42 --> 00:32:43 speed the tennis ball's falling, so it'll
00:32:43 --> 00:32:45 move away from you and not appear to come
00:32:45 --> 00:32:47 back because you're both still falling.
00:32:48 --> 00:32:50 The reason all this is relevant to Artemis is
00:32:50 --> 00:32:53 Artemis boosted off towards the Moon at, uh,
00:32:53 --> 00:32:55 a speed that was not greater than the escape
00:32:55 --> 00:32:57 velocity from the Earth. It was a speed that
00:32:57 --> 00:33:00 was high enough to get to the Moon. And, uh,
00:33:00 --> 00:33:01 the moon steered it around and flung it back
00:33:01 --> 00:33:04 towards the Earth. But then it fell towards
00:33:04 --> 00:33:06 the Earth under Earth's gravity, moving
00:33:06 --> 00:33:09 with insufficient sideward speed that as
00:33:09 --> 00:33:11 it fell towards the Earth, it would miss us.
00:33:12 --> 00:33:13 It instead was going to hit us. And they
00:33:13 --> 00:33:15 controlled it with rockets and stuff so that
00:33:15 --> 00:33:16 it entered in a controlled rather than
00:33:16 --> 00:33:19 uncontrolled fashion. What matters is
00:33:19 --> 00:33:21 not the speed the Earth's moving around the
00:33:21 --> 00:33:23 sun, or the speed the sun's moving around our
00:33:23 --> 00:33:25 galaxy, or the speed that the galaxy is
00:33:25 --> 00:33:27 moving through space. All that matters is the
00:33:27 --> 00:33:29 difference in speed between the Earth and the
00:33:29 --> 00:33:32 object, because they're moving together. This
00:33:32 --> 00:33:34 thing's speed was at no time greater than the
00:33:34 --> 00:33:36 escape velocity of the Earth, so it could
00:33:36 --> 00:33:38 never fall away from the Earth and never come
00:33:38 --> 00:33:40 back. It was always going to go up and then
00:33:40 --> 00:33:43 come down again. Unless they use rockets to
00:33:43 --> 00:33:44 boost it into an orbit around the moon to
00:33:44 --> 00:33:46 shed some of that energy, which they didn't.
00:33:46 --> 00:33:48 They instead slingshot it around the moon to
00:33:48 --> 00:33:51 come back. All of that is perfectly
00:33:51 --> 00:33:53 rational and straightforward given our
00:33:53 --> 00:33:55 understanding of physics. But it doesn't
00:33:55 --> 00:33:58 necessarily fit your common sense, because
00:33:58 --> 00:34:00 you think about throwing a ball out of the
00:34:00 --> 00:34:02 window of your car while your car's doing 100
00:34:02 --> 00:34:03 kilometres an hour and the ball will fall
00:34:03 --> 00:34:06 behind you and never catch you up. And so
00:34:06 --> 00:34:09 a lot of the arguments that
00:34:09 --> 00:34:11 flat Earth, uh, believers or other people in
00:34:11 --> 00:34:14 that kind of situation are making good faith
00:34:14 --> 00:34:16 are, uh, built on a faulty groundwork
00:34:17 --> 00:34:20 where the common sense of how they understand
00:34:20 --> 00:34:22 the world to work is not applicable to the
00:34:22 --> 00:34:25 situation they're applying it in. Um,
00:34:25 --> 00:34:27 and that's true of things like, you know, the
00:34:27 --> 00:34:30 oceans are flat. If you put a spirit level on
00:34:30 --> 00:34:32 them, they're flat. Well, it's actually that
00:34:32 --> 00:34:33 they're curved, but they're curved at such
00:34:33 --> 00:34:35 small level that locally they look flat.
00:34:36 --> 00:34:37 It's a subtle difference, but it's one that's
00:34:37 --> 00:34:39 easy to miss because it's hard to get your
00:34:39 --> 00:34:40 head around those distances.
00:34:41 --> 00:34:43 In terms of the animations. I just did a
00:34:43 --> 00:34:45 quick Google search for Artemis animation of
00:34:45 --> 00:34:48 orbit, and there's some beautiful. The first
00:34:48 --> 00:34:51 hit is a NASA flight with an annotated and
00:34:51 --> 00:34:53 animated path. There's a few YouTube videos,
00:34:53 --> 00:34:56 there is a Reddit link with an interactive 3D
00:34:56 --> 00:34:59 animation. There's a lot of
00:34:59 --> 00:35:01 little YouTube short videos that pop up
00:35:02 --> 00:35:04 which are not to scale, because if you make
00:35:04 --> 00:35:06 things to scale, the sun and the Earth and
00:35:06 --> 00:35:08 the Moon are points that are one pixel
00:35:08 --> 00:35:11 across. And, um, the spaceship is a point
00:35:11 --> 00:35:12 that is a pixel across as well, because
00:35:12 --> 00:35:15 nothing can be smaller than a pixel. Um,
00:35:15 --> 00:35:17 there is a fabulous thing, incidentally, and,
00:35:17 --> 00:35:18 um, I'm gonna see if I can find it, see if
00:35:18 --> 00:35:19 it's still there.
00:35:21 --> 00:35:23 There's this great thing called if the Moon
00:35:23 --> 00:35:26 were Only One Pixel. Um,
00:35:26 --> 00:35:29 it is. I'm gonna see if the website still
00:35:29 --> 00:35:30 works, because this is one of the great
00:35:30 --> 00:35:32 things on the Internet. Here we go. I'm gonna
00:35:32 --> 00:35:35 Drop it into the chat window. This, um,
00:35:35 --> 00:35:37 was an effort somebody made many, many, long,
00:35:37 --> 00:35:39 long years ago. I'll put this into the public
00:35:39 --> 00:35:41 chat, which never gets used. There we go. To
00:35:41 --> 00:35:44 visualise the scale of the solar system,
00:35:44 --> 00:35:47 if you made the moon one pixel across,
00:35:47 --> 00:35:49 so the Earth will then be two or three pixels
00:35:49 --> 00:35:52 across, you can, when you get bored of
00:35:52 --> 00:35:54 scrolling, you can click Play. But if you
00:35:54 --> 00:35:55 open that up and then you scroll to the right
00:35:55 --> 00:35:58 to explore, you move along
00:35:58 --> 00:36:00 and then you've got the scale. One pixel is
00:36:00 --> 00:36:03 3 kilometres, so the sun is a fairly big
00:36:03 --> 00:36:06 blob. And you scroll to the right from the
00:36:06 --> 00:36:08 sun and you've got a distance at the bottom.
00:36:08 --> 00:36:10 Scroll to the right a long way. We've gone 10
00:36:10 --> 00:36:12 million kilometres. This is this fabulous
00:36:12 --> 00:36:14 visualisation to let you see how big
00:36:15 --> 00:36:15 things are.
00:36:16 --> 00:36:17 Andrew Dunkley: Oh, isn't that clever?
00:36:17 --> 00:36:20 Jonti Horner: How fast light travels. You can click, um.
00:36:20 --> 00:36:23 That's slow. It's fabulous. Now what
00:36:23 --> 00:36:26 you can do is you can skip through.
00:36:26 --> 00:36:29 I need to find where there was a way to skip
00:36:29 --> 00:36:31 to the Earth. Yes, at the top. Skip to the
00:36:31 --> 00:36:33 Earth, goes whiz, whiz, whiz, whiz, whiz.
00:36:33 --> 00:36:34 Really quick, goes past Venus, comes to the
00:36:34 --> 00:36:37 Earth and the Moon. If the moon is one pixel,
00:36:37 --> 00:36:39 the earth is only two or three and you get
00:36:39 --> 00:36:42 the scale of them 8.3 light minutes out from
00:36:42 --> 00:36:44 the sun. And think how far you've got to
00:36:44 --> 00:36:47 scroll to get there. Think with that moon
00:36:47 --> 00:36:49 being a single pixel, how far it is from the
00:36:49 --> 00:36:52 Earth. This is why none of those animations
00:36:52 --> 00:36:55 have things to scale, because you wouldn't
00:36:55 --> 00:36:56 see the spacecraft, you wouldn't see the
00:36:56 --> 00:36:57 Earth and the moon, they wouldn't look
00:36:57 --> 00:37:00 pretty. So the caution there is that, uh, the
00:37:00 --> 00:37:02 animations that you see, even the beautiful
00:37:02 --> 00:37:05 NASA ones that show the flight path, are,
00:37:05 --> 00:37:07 ah, not to scale. And, um, that can be
00:37:07 --> 00:37:09 misleading. That can also
00:37:10 --> 00:37:12 add to some of the arguments that this is
00:37:12 --> 00:37:14 fake, because people say, well, the Earth and
00:37:14 --> 00:37:15 the Moon are much smaller than that and
00:37:15 --> 00:37:16 they're much further apart. Uh, that looks
00:37:16 --> 00:37:19 wrong. Um, so it's worth being explicit
00:37:19 --> 00:37:22 that these are, these visualisations are, um,
00:37:22 --> 00:37:25 definitively not to scale. Um, the one,
00:37:25 --> 00:37:26 incidentally, that was linked on the Reddit
00:37:26 --> 00:37:29 page looks like the dots for Earth and Moon
00:37:29 --> 00:37:30 actually are more to scale. So I'll just drop
00:37:30 --> 00:37:33 that one in as well. Not sure how this works,
00:37:33 --> 00:37:34 I've not really played with it. But you can
00:37:34 --> 00:37:36 drag the orbits around, you can move them
00:37:36 --> 00:37:38 back and forward in time, you can see the in
00:37:38 --> 00:37:41 and out of plane stuff and you can move the
00:37:41 --> 00:37:43 visualisation around even with the background
00:37:43 --> 00:37:45 stars, which is quite nice. Um, so that's
00:37:45 --> 00:37:47 worth a play as well. And that looks a bit
00:37:47 --> 00:37:49 more to scale. And there's lots of things you
00:37:49 --> 00:37:52 can play with, but fundamentally we
00:37:52 --> 00:37:55 could see it. The hardest part for me, about
00:37:55 --> 00:37:57 the small number of people who have argued
00:37:57 --> 00:37:59 that the Artemis mission didn't happen,
00:38:00 --> 00:38:02 is that it's something that anybody on the
00:38:02 --> 00:38:03 planet could see, so long as they owned a
00:38:03 --> 00:38:06 binoculars or a telescope. You could have
00:38:06 --> 00:38:07 pointed somewhere and you could see the
00:38:07 --> 00:38:10 capsule moving there if you really wanted. At
00:38:10 --> 00:38:12 any time when the moon was above the horizon,
00:38:12 --> 00:38:13 you could track it round.
00:38:15 --> 00:38:17 Andrew Dunkley: And if you've got good enough gear, you can
00:38:17 --> 00:38:19 actually look at the moon and see
00:38:20 --> 00:38:23 the landing positions of some
00:38:23 --> 00:38:25 of the Apollos. If you've got the gear.
00:38:25 --> 00:38:26 Jonti Horner: If you've got the gear, I mean, that's kind
00:38:26 --> 00:38:28 of spice athlete level. But what you can do
00:38:28 --> 00:38:31 if you've got slightly less of the gear is
00:38:31 --> 00:38:33 bounce laser pulses
00:38:34 --> 00:38:36 off the retroreflectors that the astronauts
00:38:36 --> 00:38:38 left at those sites and measure the distance
00:38:38 --> 00:38:41 to the moon and measure its recession to an
00:38:41 --> 00:38:43 incredible precision. And we can only do that
00:38:43 --> 00:38:44 because people went to the moon.
00:38:46 --> 00:38:48 Andrew Dunkley: Yeah, absolutely.
00:38:50 --> 00:38:53 I remember the day that Neil
00:38:53 --> 00:38:55 Armstrong stepped on the moon. I was, um,
00:38:55 --> 00:38:56 sent home from school.
00:38:59 --> 00:39:01 It's one of the strongest memories of my
00:39:01 --> 00:39:03 childhood. I was seven years old and, uh,
00:39:03 --> 00:39:06 I'll never forget it. It was, um, quite
00:39:06 --> 00:39:08 an extraordinary thing in human history.
00:39:09 --> 00:39:09 Inspirational.
00:39:09 --> 00:39:12 Jonti Horner: I mean, I, I'm not old enough to have ever
00:39:12 --> 00:39:14 seen anybody walk on the moon. I'm hoping
00:39:14 --> 00:39:16 that'll change. But the generation of
00:39:16 --> 00:39:19 astronomers who are 15,
00:39:19 --> 00:39:21 20 years older than me, who were old enough
00:39:21 --> 00:39:23 to see the moon landings and take them in,
00:39:24 --> 00:39:25 so many people were inspired to become
00:39:25 --> 00:39:28 scientists and engineers by that. We got a
00:39:28 --> 00:39:31 whole generation of people across
00:39:31 --> 00:39:34 the sciences, across the engineering subjects
00:39:34 --> 00:39:37 that changed the world, who were all inspired
00:39:37 --> 00:39:39 by seeing people walk on the moon.
00:39:40 --> 00:39:42 And, um, it's kind of exciting to me, even
00:39:42 --> 00:39:43 ignoring the signs, even ignoring the
00:39:43 --> 00:39:45 technology, that we're going to get that
00:39:45 --> 00:39:46 experience again in the coming years. If we
00:39:46 --> 00:39:48 go back there, there'll be a whole new
00:39:48 --> 00:39:50 generation who will change the world. All
00:39:50 --> 00:39:52 inspired by those people touching down and
00:39:52 --> 00:39:53 seeing it happen.
00:39:54 --> 00:39:57 Andrew Dunkley: Yes, yes. I was very lucky to meet one
00:39:57 --> 00:40:00 of them. Uh, Buzz Aldrin, um, some years ago,
00:40:00 --> 00:40:03 came here because they built a Reutt
00:40:03 --> 00:40:05 Flyer at a place called Narrowmine, just up
00:40:05 --> 00:40:08 the road from here, 40 kilomet, and they took
00:40:08 --> 00:40:10 it out for a fly and he came for the
00:40:10 --> 00:40:13 occasion and, uh, gave A wonderful
00:40:13 --> 00:40:16 speech and a, uh, handful of us in the media
00:40:16 --> 00:40:18 got to interview him afterwards in a, in a
00:40:18 --> 00:40:21 hangar at the same time as a helicopter
00:40:21 --> 00:40:22 decided to take off.
00:40:23 --> 00:40:24 Jonti Horner: That sounds about right.
00:40:24 --> 00:40:26 Andrew Dunkley: He famously, you know what? You just, you
00:40:26 --> 00:40:27 just go with it.
00:40:27 --> 00:40:30 Jonti Horner: Oh, he very famously gave very short shrift
00:40:30 --> 00:40:31 to people who told him that he'd not been to
00:40:31 --> 00:40:32 the moon.
00:40:32 --> 00:40:35 Andrew Dunkley: Oh, I know. Uh, Ah, yeah, I did
00:40:35 --> 00:40:38 actually raise that question, but gee, it was
00:40:38 --> 00:40:39 such an interesting answer.
00:40:41 --> 00:40:42 Yeah, fabulous.
00:40:42 --> 00:40:44 Um, Paul, great question, really
00:40:44 --> 00:40:46 enjoyed that one and I,
00:40:48 --> 00:40:51 I can understand your frustration, but, um,
00:40:51 --> 00:40:53 maybe just avoid those Facebook pages,
00:40:54 --> 00:40:56 um, because you can't, you just can't save
00:40:56 --> 00:40:58 them, my friend. Uh, but good to hear from
00:40:58 --> 00:41:00 you. Uh, if you've got questions for us,
00:41:00 --> 00:41:02 please send them in. Uh, you can do that via
00:41:02 --> 00:41:04 our website, space nutspodcast.com or
00:41:04 --> 00:41:07 spacenut. You can also
00:41:08 --> 00:41:09 visit us on social media. We've got the
00:41:09 --> 00:41:11 official Space Nuts Facebook page and the
00:41:11 --> 00:41:14 official. What's, uh, the
00:41:14 --> 00:41:17 Instagram page. Uh, we've also got the
00:41:17 --> 00:41:19 user group on Facebook, um, the
00:41:19 --> 00:41:22 podcast group, uh, uh, which is
00:41:22 --> 00:41:25 all. It's a lot of fun. It's where people who
00:41:25 --> 00:41:28 listen get together, swap photos of stuff
00:41:28 --> 00:41:30 they've taken in space and ask, uh,
00:41:31 --> 00:41:34 questions. And, uh, it is a really good
00:41:34 --> 00:41:37 group. So the Space Nuts podcast group on
00:41:37 --> 00:41:39 Facebook book very much worth, uh, joining
00:41:39 --> 00:41:42 that one as well and hope you'll join us
00:41:42 --> 00:41:44 again real soon. And thank you to Johnny
00:41:44 --> 00:41:46 Horner for filling in for Fred Watson for the
00:41:46 --> 00:41:49 last month or so. It's been fantastic and
00:41:49 --> 00:41:51 hopefully we can get that photography, uh,
00:41:51 --> 00:41:53 special off the ground and get you back and
00:41:53 --> 00:41:56 have a chat about astrophotography. Jonty,
00:41:56 --> 00:41:57 that would be a real good one.
00:41:57 --> 00:41:58 Jonti Horner: Fingers crossed. That would be awesome.
00:41:59 --> 00:42:01 Andrew Dunkley: Yeah. All right, catch you soon. Thank you so
00:42:01 --> 00:42:01 much.
00:42:01 --> 00:42:03 Jonti Horner: M m. Take care. Thank you very much.
00:42:04 --> 00:42:05 Andrew Dunkley: Professor Johnty Horner, professor of
00:42:05 --> 00:42:07 Astrophysics at the University of Southern
00:42:07 --> 00:42:09 Queensland, filling, uh, in for Fred Watson.
00:42:09 --> 00:42:12 Fred Watson should be back, uh, next week
00:42:12 --> 00:42:15 or later this week. I can't get my head
00:42:15 --> 00:42:18 around when it'll be. It's a time slip thing.
00:42:18 --> 00:42:20 Uh, but, uh, yeah, thanks to Jonty for
00:42:20 --> 00:42:22 filling in and thanks to Huw in the studio,
00:42:22 --> 00:42:25 who couldn't be with us today because he's
00:42:25 --> 00:42:28 fake. Boom, boom. And from me, Andrew
00:42:28 --> 00:42:30 Dunkley. Thanks for your company. We'll see
00:42:30 --> 00:42:31 you on the next episode of Space Nuts.
00:42:32 --> 00:42:32 Jonti Horner: Bye.
00:42:32 --> 00:42:32 Andrew Dunkley: Bye.
00:42:34 --> 00:42:36 Jonti Horner: You've been listening to the Space Nuts
00:42:36 --> 00:42:39 podcast, available at
00:42:39 --> 00:42:41 Apple Podcasts, Spotify,
00:42:41 --> 00:42:44 iHeartRadio or your favourite podcast
00:42:44 --> 00:42:45 player. You can also stream on
00:42:45 --> 00:42:47 demand@bytes.um com
00:42:47 --> 00:42:50 Andrew Dunkley: this has been another quality podcast
00:42:50 --> 00:42:51 production from bytes.com
00:42:51 --> 00:42:53 um.