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In this episode of Space Nuts, hosts Andrew Dunkley and Professor Fred Watson delve into a captivating Q&A session, tackling a range of intriguing questions from listeners. From the possibility of moons having atmospheres to the mysteries surrounding hot Jupiters and the fascinating realm of black holes, this episode promises to ignite your curiosity about the cosmos.
Key topics include:
- Chris from Exmouth wonders if moons can have atmospheres and if they can share these with their parent planets, leading to a discussion on Titan and Pluto's unique characteristics.
- An anonymous listener poses a thought-provoking question about 'secret astronomy' and the potential for military satellite technology to advance our understanding of the universe.
- Fenton from Minnesota asks about the likelihood of rocky planets existing in solar systems with hot Jupiters, prompting a discussion on planetary migration and the diversity of solar systems.
- Ed raises a classic black hole question regarding the merger of black holes and the concept of mass escaping, leading to an exploration of gravitational waves and their implications.
Join Andrew and Fred Watson as they navigate these fascinating topics, providing insights and sparking further exploration into the wonders of space.
00:00 01:18 04:13 05:37 11:35 16:34 20:35 27:11 31:31
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00:00:00 --> 00:00:02 Andrew Dunkley: Hello again and thank you for joining us on
00:00:02 --> 00:00:04 yet another episode of Space Nuts. I don't
00:00:04 --> 00:00:07 know what we're up to.
00:00:07 --> 00:00:10 Blimey. And we only started yesterday.
00:00:10 --> 00:00:13 Uh, coming up in this Q and A episode, we
00:00:13 --> 00:00:15 will be answering questions about, uh, moons
00:00:15 --> 00:00:18 with atmospheres, secret
00:00:18 --> 00:00:20 astronomy. This is a fascinating question.
00:00:21 --> 00:00:24 Uh, we've also got, uh, a question about hot
00:00:24 --> 00:00:26 Jupiters. We've talked about them before. And
00:00:26 --> 00:00:29 a very rare, never before
00:00:29 --> 00:00:32 asked black hole question that's
00:00:32 --> 00:00:34 coming up in this Q and A edition of space
00:00:34 --> 00:00:36 nuts. 15 seconds.
00:00:36 --> 00:00:39 Professor Fred Watson: Guidance is internal. 10,
00:00:39 --> 00:00:42 9, ignition sequence start. Uh,
00:00:42 --> 00:00:45 space nuts. 5, 4, 3, 2. 1, 2,
00:00:45 --> 00:00:47 3, 4, 5, 5, 4, 3, 2, 1.
00:00:48 --> 00:00:49 Andrew Dunkley: Space nuts.
00:00:49 --> 00:00:51 Professor Fred Watson: Astronauts report it feels good.
00:00:52 --> 00:00:54 Andrew Dunkley: Joining us again to resolve all of that is
00:00:54 --> 00:00:57 Professor Fred Watson Watson, astronomer at
00:00:57 --> 00:00:58 large. Hi, Fred Watson.
00:00:58 --> 00:01:00 Professor Fred Watson: Hello, Andrew. How are you? Good to see you
00:01:00 --> 00:01:00 again.
00:01:00 --> 00:01:03 Andrew Dunkley: I'm as well as I was the last time you saw
00:01:03 --> 00:01:04 me.
00:01:05 --> 00:01:07 Professor Fred Watson: Yes. All those years ago. That's right, yeah.
00:01:08 --> 00:01:10 Andrew Dunkley: Minutes or seconds, whichever comes first.
00:01:12 --> 00:01:14 Uh, we've got some good questions today and,
00:01:14 --> 00:01:16 uh, I thought we might just get straight into
00:01:16 --> 00:01:18 it if you're, uh, ready to.
00:01:18 --> 00:01:20 Oh, no, I've got an announcement.
00:01:20 --> 00:01:23 Professor Fred Watson: Oh, yes, Better do that then.
00:01:23 --> 00:01:25 Andrew Dunkley: It's a bit of shameless self promotion. I've
00:01:25 --> 00:01:27 finally released my science fiction trilogy.
00:01:30 --> 00:01:33 Yes, it's out there. Um, I'm just putting the
00:01:33 --> 00:01:35 final touches on a few bits and bobs. But the
00:01:35 --> 00:01:37 ebook is out. Uh, the paperback
00:01:38 --> 00:01:41 should be out by the time you hear this.
00:01:42 --> 00:01:44 Um, unless you're watching us live on
00:01:44 --> 00:01:44 YouTube.
00:01:44 --> 00:01:44 Professor Fred Watson: Hello.
00:01:45 --> 00:01:47 Andrew Dunkley: It's called the Human Epoch.
00:01:48 --> 00:01:51 M which I did look up to see if there are
00:01:51 --> 00:01:53 any other science fiction books with that
00:01:53 --> 00:01:56 name, and there are not. So the human
00:01:56 --> 00:01:58 epoch, parts 1, 2 and 3. I released them all
00:01:58 --> 00:01:58 at once.
00:01:58 --> 00:01:59 Andrew Dunkley: Oops.
00:01:59 --> 00:02:01 Andrew Dunkley: I, uh, nearly released the microphone. Yeah,
00:02:01 --> 00:02:03 all at once. I thought, I'm gonna write the
00:02:03 --> 00:02:06 whole thing and release it as a batch rather
00:02:06 --> 00:02:07 than write one book and then
00:02:08 --> 00:02:11 release it and then make people wait a year.
00:02:11 --> 00:02:13 Now the whole bang lot's out there already
00:02:14 --> 00:02:15 on its way.
00:02:15 --> 00:02:16 Professor Fred Watson: Seasons one, two and three.
00:02:16 --> 00:02:19 Andrew Dunkley: Yes, exactly. I hope people enjoy it. Can't
00:02:19 --> 00:02:22 wait to get the feedback. Good, bad or
00:02:22 --> 00:02:24 indifferent. So the Human Epoch.
00:02:24 --> 00:02:25 Professor Fred Watson: Look for it.
00:02:25 --> 00:02:27 Andrew Dunkley: Uh, and you should be able to order it from
00:02:27 --> 00:02:29 bookshops. I don't know. I don't know how it
00:02:29 --> 00:02:32 works. Um, but you know, looking
00:02:32 --> 00:02:35 at the cost of printing and the
00:02:35 --> 00:02:38 sharing of spoils, um, if you
00:02:38 --> 00:02:40 sell a book for 20 bucks these days, you
00:02:40 --> 00:02:42 might get two or three dollars out of that.
00:02:42 --> 00:02:44 It's a Tough industry.
00:02:44 --> 00:02:46 Professor Fred Watson: Very. Yeah.
00:02:46 --> 00:02:47 Andrew Dunkley: I mean, you've really got to sell
00:02:49 --> 00:02:51 m tens of thousands of books to even scratch
00:02:51 --> 00:02:54 the surface. Which I have not done.
00:02:55 --> 00:02:56 Professor Fred Watson: Yeah, neither have I.
00:02:56 --> 00:02:59 Andrew Dunkley: No, no. But anyway, I
00:02:59 --> 00:03:01 thought I'd give it a mention. I've mentioned
00:03:01 --> 00:03:03 that I was writing it times. I thought I
00:03:03 --> 00:03:06 might as well people. It's out there. So
00:03:06 --> 00:03:07 there. That's, um, done.
00:03:07 --> 00:03:10 Professor Fred Watson: So you're not emulating Douglas Adams with a
00:03:10 --> 00:03:12 trilogy in four parts?
00:03:13 --> 00:03:15 Andrew Dunkley: No, but, you know, I
00:03:15 --> 00:03:18 might. Yeah, I might continue the
00:03:18 --> 00:03:21 storey because I became very. Isn't.
00:03:21 --> 00:03:21 Andrew Dunkley: Uh.
00:03:21 --> 00:03:23 Andrew Dunkley: I don't know if this happens to other
00:03:23 --> 00:03:24 authors. I'm sure it does.
00:03:24 --> 00:03:24 Professor Fred Watson: Oh, there you are.
00:03:24 --> 00:03:26 Andrew Dunkley: It happens to Earth.
00:03:26 --> 00:03:27 Professor Fred Watson: Yes, it does. He's a bit late.
00:03:27 --> 00:03:28 Andrew Dunkley: We could have used him in the last episode.
00:03:28 --> 00:03:31 Professor Fred Watson: We could. That's right. With the dogs.
00:03:31 --> 00:03:34 Andrew Dunkley: Um, you get a bit attached to some of
00:03:34 --> 00:03:35 the characters you create.
00:03:35 --> 00:03:38 Professor Fred Watson: Yes. I believe that happens when you write
00:03:38 --> 00:03:38 fiction.
00:03:38 --> 00:03:41 Andrew Dunkley: Um, the main character in this trilogy,
00:03:42 --> 00:03:45 um, I've come to adore. I really. I love his
00:03:45 --> 00:03:47 attitude. That's all I say.
00:03:48 --> 00:03:49 Professor Fred Watson: Okay. All right.
00:03:49 --> 00:03:52 Andrew Dunkley: Okay. He's
00:03:53 --> 00:03:54 a different kind of character.
00:03:55 --> 00:03:57 Professor Fred Watson: Is he based on anybody real?
00:03:57 --> 00:04:00 Andrew Dunkley: No, I made him up. Um, and I made him
00:04:00 --> 00:04:03 Canadian. Uh, I don't know why. I just did.
00:04:03 --> 00:04:05 Professor Fred Watson: I just thought Canadian.
00:04:05 --> 00:04:07 Andrew Dunkley: Canadians never get much of a mention in
00:04:07 --> 00:04:08 science fiction novels. So I thought, I'll
00:04:08 --> 00:04:10 make my hero a Canadian.
00:04:10 --> 00:04:12 Professor Fred Watson: Good on you. Yeah.
00:04:13 --> 00:04:13 Andrew Dunkley: All right.
00:04:14 --> 00:04:16 Professor Fred Watson: Before we do that, I better just go and see
00:04:16 --> 00:04:18 what's, um. Because I'm home alone at the
00:04:18 --> 00:04:21 moment. Jordy, I won't be a sec.
00:04:21 --> 00:04:22 All right?
00:04:22 --> 00:04:25 Andrew Dunkley: Okay. This doesn't happen very often. He
00:04:25 --> 00:04:27 could have done that while I was spruiking
00:04:27 --> 00:04:29 the book, you know, because, um, that would
00:04:29 --> 00:04:32 have been a nice filler. But now he's
00:04:32 --> 00:04:35 just left me swinging in the breeze.
00:04:35 --> 00:04:38 Which, um, happens occasionally.
00:04:39 --> 00:04:41 This used to happen on radio. I remember
00:04:41 --> 00:04:43 once, uh, years ago, um, we were
00:04:43 --> 00:04:45 expecting some guests, so I played an
00:04:45 --> 00:04:47 appropriate song. I think they were circus
00:04:47 --> 00:04:50 performers. And I played
00:04:50 --> 00:04:53 circus by Britney Spears in the hope that
00:04:53 --> 00:04:54 they would actually arrive while the song was
00:04:54 --> 00:04:57 on. And, uh, I got lucky. They
00:04:57 --> 00:04:59 walked in the door just as it was finishing.
00:04:59 --> 00:05:01 So I got the interview on air in time. It's
00:05:02 --> 00:05:05 sometimes a bit scary like that. Anyway,
00:05:05 --> 00:05:06 welcome, uh, back, Fred Watson. Is Jordie
00:05:06 --> 00:05:07 okay?
00:05:07 --> 00:05:10 Professor Fred Watson: Yes. I don't know what was causing
00:05:10 --> 00:05:11 the howling. Uh, ruckus.
00:05:12 --> 00:05:13 Andrew Dunkley: A butterfly, probably.
00:05:13 --> 00:05:15 Professor Fred Watson: Could have been. Honestly, it's that level
00:05:15 --> 00:05:18 that sets him off. You know, a leaf
00:05:18 --> 00:05:21 moves two, uh, hundred metres away across
00:05:21 --> 00:05:23 the forest and off he goes. That's right.
00:05:23 --> 00:05:25 Andrew Dunkley: He could probably use a GPS collar.
00:05:26 --> 00:05:29 Professor Fred Watson: There were times when he could use a muzzle,
00:05:29 --> 00:05:30 I think to speak.
00:05:32 --> 00:05:34 Andrew Dunkley: Um, now let's get into some questions. I
00:05:34 --> 00:05:35 think that's why we're here.
00:05:35 --> 00:05:37 Professor Fred Watson: Oh, I suppose it is, yes. Yes.
00:05:37 --> 00:05:40 Andrew Dunkley: Um, so first question comes from Chris
00:05:40 --> 00:05:42 in Exmouth in the uk. Just
00:05:42 --> 00:05:45 wondering, could a moon ever have
00:05:45 --> 00:05:48 an atmosphere and is it possible for a moon
00:05:48 --> 00:05:51 to be close enough to a planet to share
00:05:51 --> 00:05:54 an atmosphere? Really enjoy the show. Thank,
00:05:54 --> 00:05:56 uh, you Chris for sending that in. Um,
00:05:57 --> 00:06:00 look, we already know in our solar system
00:06:00 --> 00:06:02 there are moons with atmospheres and I do
00:06:02 --> 00:06:05 believe they do share their stuff with their
00:06:05 --> 00:06:06 home planets, some of them.
00:06:06 --> 00:06:09 Professor Fred Watson: Uh, correct. That's right. Although
00:06:09 --> 00:06:12 it's sort of um, probably not quite
00:06:12 --> 00:06:15 what Chris has, his mind. So yes. Uh, I mean
00:06:15 --> 00:06:18 the classic example is Saturn's moon Titan,
00:06:18 --> 00:06:20 that has a very thick atmosphere,
00:06:21 --> 00:06:23 um, atmospheric pressure I think one and a
00:06:23 --> 00:06:25 half times that of the Earth. It's a dense
00:06:25 --> 00:06:27 atmosphere and um, also
00:06:27 --> 00:06:30 opaque because it's rich in um,
00:06:31 --> 00:06:34 ah, hydrocarbons. The same
00:06:34 --> 00:06:37 stuff that makes smog in a city. Uh, is why
00:06:37 --> 00:06:39 we can't see through Titan's atmosphere. So
00:06:39 --> 00:06:41 yes, a moon can have an atmosphere, um,
00:06:42 --> 00:06:45 but you can't have a situation where
00:06:45 --> 00:06:48 uh, you had a planet and a
00:06:48 --> 00:06:51 moon which were sort of embedded in a much
00:06:51 --> 00:06:53 larger dense atmosphere. Uh,
00:06:54 --> 00:06:56 and that's because the, you basically
00:06:57 --> 00:06:59 slow down the moon as it orbits the planet,
00:07:00 --> 00:07:02 uh, and it doesn't last very long. Uh, in
00:07:02 --> 00:07:04 fact that's what brings satellites down uh,
00:07:04 --> 00:07:07 from orbit. Low Earth orbit above the Earth.
00:07:08 --> 00:07:09 They are slowed down by the Earth's
00:07:09 --> 00:07:12 atmosphere, even though it's very tenuous up
00:07:12 --> 00:07:14 there. And uh, nevertheless it slows them
00:07:14 --> 00:07:16 down and they fall deeper into the atmosphere
00:07:16 --> 00:07:19 and the deceleration continues.
00:07:19 --> 00:07:22 But the example that you've mentioned is the
00:07:22 --> 00:07:24 one that came to mind when I read this
00:07:24 --> 00:07:27 question as well. Uh, which is
00:07:27 --> 00:07:30 the dwarf planet Pluto, uh,
00:07:30 --> 00:07:33 which has a large moon. It's uh,
00:07:34 --> 00:07:35 about half the size of Pluto actually. It's
00:07:35 --> 00:07:38 called Charon, uh, or Charon, not
00:07:38 --> 00:07:40 Charon. Some people call it Charon.
00:07:40 --> 00:07:40 Andrew Dunkley: They do.
00:07:42 --> 00:07:44 Professor Fred Watson: Charon, Shaz for short.
00:07:45 --> 00:07:48 Shaza. Yeah, um,
00:07:48 --> 00:07:51 it's uh, it's a large moon, as
00:07:51 --> 00:07:53 I said, half the size of Pluto.
00:07:54 --> 00:07:56 Uh, and so they are in a sense a
00:07:56 --> 00:07:59 binary dwarf planet system because
00:08:00 --> 00:08:03 they orbit around a point which
00:08:03 --> 00:08:06 is outside the body of Pluto, uh,
00:08:06 --> 00:08:08 which is the kind of definition of a binary
00:08:08 --> 00:08:10 system, something orbiting around a common
00:08:10 --> 00:08:13 centre of gravity. Uh, so you've
00:08:13 --> 00:08:16 got that ah, unusual situation to start
00:08:16 --> 00:08:18 with, but um,
00:08:19 --> 00:08:21 it Appears that because of that
00:08:22 --> 00:08:23 geometry,
00:08:25 --> 00:08:27 the atmosphere of
00:08:27 --> 00:08:30 Pluto, which is very, very thin, but it is
00:08:30 --> 00:08:33 there. I was once helping a project that
00:08:33 --> 00:08:35 measured the atmosphere of Pluto not from
00:08:35 --> 00:08:37 space, but by Pluto passing in front of a
00:08:37 --> 00:08:40 star as observed with the Anglo Australian
00:08:40 --> 00:08:42 telescope. We could see it dimmed gradually,
00:08:42 --> 00:08:44 the light of the star rather than just
00:08:44 --> 00:08:46 switching off as it would have been if
00:08:46 --> 00:08:48 there'd been no atmosphere. So, uh, that
00:08:48 --> 00:08:51 atmosphere is mostly nitroge gas,
00:08:51 --> 00:08:54 uh, or the part that's
00:08:54 --> 00:08:56 escaping. Uh, and
00:08:56 --> 00:08:59 apparently it is basically
00:08:59 --> 00:09:02 captured by Charon. There's
00:09:02 --> 00:09:05 this flow of the nitrogen
00:09:05 --> 00:09:08 from Pluto to its dwarf
00:09:08 --> 00:09:10 planet companion. Um,
00:09:10 --> 00:09:13 there's probably something similar happens
00:09:13 --> 00:09:16 with the Earth and Moon, but very, very much
00:09:17 --> 00:09:20 less intense. Uh, there's probably a
00:09:20 --> 00:09:23 bit of gas transfer, uh, from
00:09:25 --> 00:09:28 the Earth, uh, to the Moon. Given that
00:09:28 --> 00:09:31 the pressure of the Earth's atmosphere
00:09:31 --> 00:09:33 doesn't just stop suddenly, it falls away
00:09:33 --> 00:09:35 very gradually. And in fact there are some of
00:09:35 --> 00:09:37 the molecules of the Earth's atmosphere that
00:09:37 --> 00:09:40 are out at the distance of the Moon. Uh, so
00:09:40 --> 00:09:42 they probably do exchange, you
00:09:42 --> 00:09:45 know, some low levels of gas, but
00:09:45 --> 00:09:48 not very much. And it is, yes, it's
00:09:48 --> 00:09:50 a different situation from perhaps what Chris
00:09:50 --> 00:09:52 had in mind with an atmosphere, with a planet
00:09:52 --> 00:09:54 and its moon both orbiting within it.
00:09:55 --> 00:09:57 Andrew Dunkley: Yeah, I understand what he was saying. Uh,
00:09:57 --> 00:10:00 and as you suggested, um, it
00:10:00 --> 00:10:03 would be an impossible situation. Although
00:10:03 --> 00:10:05 we do see, I think around the gas giants,
00:10:06 --> 00:10:08 some of those planets, particularly the ice
00:10:08 --> 00:10:10 worlds, do shed some of their
00:10:10 --> 00:10:13 material, which is picked up by
00:10:13 --> 00:10:16 um, um, the gas giant, I think.
00:10:17 --> 00:10:18 Is it Enceladus?
00:10:19 --> 00:10:22 Professor Fred Watson: Uh, yeah, that forms, um, that's correct.
00:10:22 --> 00:10:24 So that's solid matter. Actually it's the
00:10:24 --> 00:10:27 ice crystals that come from Enceladus
00:10:27 --> 00:10:30 Ocean. They form, uh, Saturn's E
00:10:30 --> 00:10:33 ring, uh, which is a very, um,
00:10:33 --> 00:10:36 non dense, very, uh, rarefied ring.
00:10:36 --> 00:10:38 One. I think it's the outermost ring of
00:10:38 --> 00:10:40 Saturn. Um, and it's basically,
00:10:41 --> 00:10:43 uh, the orbit of uh, Enceladus is embedded in
00:10:43 --> 00:10:46 that. So, yes, that's a sort of similar sort
00:10:46 --> 00:10:47 of situation. Yeah, that's right.
00:10:47 --> 00:10:50 Andrew Dunkley: It's not sharing atmosphere, but it's sharing
00:10:50 --> 00:10:52 material in a way.
00:10:53 --> 00:10:55 So, uh, the answer to both of your points,
00:10:55 --> 00:10:57 Chris, is definite. Yes, um,
00:10:59 --> 00:11:01 but no, in terms of them both sharing the
00:11:01 --> 00:11:04 same atmosphere. Hold us,
00:11:04 --> 00:11:07 Bolus. As we say so. Yeah, but great
00:11:07 --> 00:11:10 question, uh, Christian Exmouth. Where's
00:11:10 --> 00:11:10 Exmouth, Fred Watson?
00:11:11 --> 00:11:13 Professor Fred Watson: Uh, down in Devon. It's a lovely part of the
00:11:13 --> 00:11:16 country. Uh, and um, it's
00:11:16 --> 00:11:19 uh, not far from Exeter. The River X
00:11:19 --> 00:11:20 runs through both of them, as you'd expect.
00:11:21 --> 00:11:23 Andrew Dunkley: Uh, and the River X owned by Elon
00:11:23 --> 00:11:24 Musk.
00:11:25 --> 00:11:27 Professor Fred Watson: Probably, yes. It's spelled
00:11:27 --> 00:11:29 slightly differently from Elon Musk's X, but
00:11:29 --> 00:11:31 yes, probably still the same thing.
00:11:33 --> 00:11:34 Andrew Dunkley: Thanks for the question, Chris.
00:11:35 --> 00:11:38 Next question comes from, uh, somebody
00:11:38 --> 00:11:40 who's keeping their name a secret. And it's,
00:11:40 --> 00:11:43 uh, it's about secret astronomy. Oh, hang
00:11:43 --> 00:11:45 on, That's. I've got to change pages. Here we
00:11:45 --> 00:11:46 go. Here we go.
00:11:46 --> 00:11:48 Professor Fred Watson: I have a question about secret
00:11:49 --> 00:11:51 astronomy. We know that gamma
00:11:51 --> 00:11:53 ray bursts were first detected by spy
00:11:53 --> 00:11:56 satellites looking for nuclear testing. We
00:11:56 --> 00:11:58 know that satellites use star tracking and
00:11:58 --> 00:12:00 star catalogues for calculating their
00:12:00 --> 00:12:03 position. And we, uh, know that the Nancy
00:12:03 --> 00:12:06 Grace Roman launching, hopefully in August,
00:12:06 --> 00:12:09 uses, um, is built out of a,
00:12:09 --> 00:12:11 um, spy satellite the National Reconnaissance
00:12:11 --> 00:12:14 Office, the US Uh spy satellite agency,
00:12:14 --> 00:12:16 donated to NASA because they weren't going to
00:12:16 --> 00:12:19 launch it. They donated two and only one is
00:12:19 --> 00:12:21 being used yet. And we know that the Space
00:12:21 --> 00:12:24 Force released, um, a bunch of observational
00:12:24 --> 00:12:26 data around bolides to, um, help with
00:12:26 --> 00:12:29 planetary defence and asteroid detection
00:12:29 --> 00:12:32 and understanding. So by their nature, spy
00:12:32 --> 00:12:35 satellites tend to point at the Earth. Um,
00:12:35 --> 00:12:37 but obviously they push into a lot of
00:12:37 --> 00:12:40 astronomy and astronomy adjacent, um, things.
00:12:41 --> 00:12:43 I just wondered if you could speculate, given
00:12:44 --> 00:12:46 their budgets and um,
00:12:46 --> 00:12:49 constantly improving capabilities, where they
00:12:49 --> 00:12:51 might be ahead of public astronomy or running
00:12:51 --> 00:12:54 into things that, um. Uh,
00:12:54 --> 00:12:56 yeah, it might be pretty interesting in a few
00:12:56 --> 00:12:59 years. Thank you so much.
00:12:59 --> 00:13:01 Andrew Dunkley: Thank you for the question.
00:13:01 --> 00:13:01 Professor Fred Watson: Um,
00:13:03 --> 00:13:05 Andrew Dunkley: yeah, I don't know who that was, but, um.
00:13:05 --> 00:13:07 That's okay. Happens from time to time. But
00:13:07 --> 00:13:09 interesting, uh, question, Fred Watson.
00:13:10 --> 00:13:12 Professor Fred Watson: Really, it's, uh, not just an interesting
00:13:12 --> 00:13:14 question, but a very well posed one as well.
00:13:14 --> 00:13:16 Because everything our anonymous questioner
00:13:16 --> 00:13:19 said is true. Uh, and so we are being
00:13:19 --> 00:13:22 invited to speculate on what, what else
00:13:22 --> 00:13:25 might be up and running. Uh, we didn't know
00:13:25 --> 00:13:27 for a long time that there were two more
00:13:27 --> 00:13:29 Hubble telescopes, uh, because,
00:13:30 --> 00:13:33 you know, the company kept their. Built
00:13:33 --> 00:13:35 it. I think it might have been perkinelmer.
00:13:35 --> 00:13:38 I'm, um, not sure. But they kept their cards
00:13:38 --> 00:13:40 very close to their chest, uh, in terms
00:13:40 --> 00:13:43 of, uh, the existence of the Hubble
00:13:43 --> 00:13:45 telescope. But it turned out subsequently we
00:13:45 --> 00:13:48 found out there were two more built for
00:13:48 --> 00:13:51 surveillance. Um, something else
00:13:51 --> 00:13:54 that did find its way into astronomy
00:13:54 --> 00:13:56 that was originally secret was, um,
00:13:56 --> 00:13:59 President Reagan's Star wars technology,
00:13:59 --> 00:14:02 uh, which, um, required
00:14:02 --> 00:14:05 adaptive optics. And those are optical
00:14:05 --> 00:14:08 surfaces that change in response to, um,
00:14:08 --> 00:14:10 basically things like, um,
00:14:11 --> 00:14:14 uh, scintillation in the atmosphere or
00:14:14 --> 00:14:16 twinkling for a star. So that adaptive
00:14:16 --> 00:14:19 optics technology is now used very commonly
00:14:19 --> 00:14:22 in astronomy. Uh, it's not Used
00:14:22 --> 00:14:25 here in Australia we don't have a
00:14:25 --> 00:14:28 site that is naturally good enough um,
00:14:28 --> 00:14:31 to be able to compensate for um,
00:14:31 --> 00:14:33 this um, atmospheric turbulence. Whereas some
00:14:33 --> 00:14:36 of the better sites in the world like Mauna
00:14:36 --> 00:14:38 Kea in Hawaii and Ceropa
00:14:38 --> 00:14:41 Paranal, uh, in Chile, they do. And
00:14:41 --> 00:14:44 so they use um, adaptive optics
00:14:44 --> 00:14:46 very, very uh, commonly for their work.
00:14:47 --> 00:14:49 Basically allows you to take out the
00:14:49 --> 00:14:51 twinkling of a star which is something that
00:14:51 --> 00:14:53 ruins the images as you see them through
00:14:53 --> 00:14:55 telescopes. Uh and um,
00:14:56 --> 00:14:58 as I said, came from Star wars technology.
00:14:58 --> 00:15:01 Uh, that technology by the way, this is uh.
00:15:01 --> 00:15:04 Not really along the lines of the question
00:15:04 --> 00:15:06 but uh. It's leapfrogged as well from
00:15:06 --> 00:15:09 astronomy into um,
00:15:09 --> 00:15:12 ophthalmology. So uh, people are now using
00:15:12 --> 00:15:15 adaptive optics to compensate for
00:15:15 --> 00:15:17 the turbulence inside your eye
00:15:18 --> 00:15:21 when they're doing sort of retinoscopy and
00:15:21 --> 00:15:23 things like that. Uh, so that adaptive optics
00:15:23 --> 00:15:26 technology is now uh, gone from
00:15:27 --> 00:15:29 defence through astronomy and is
00:15:29 --> 00:15:32 now um, being developed for uh,
00:15:33 --> 00:15:35 health reasons, which is very, very good.
00:15:35 --> 00:15:37 Andrew Dunkley: Don't know if it's quite the same thing but
00:15:37 --> 00:15:40 my optometrist was telling me they've
00:15:40 --> 00:15:42 invented a new um, kind of
00:15:42 --> 00:15:45 um, lens that replaces human
00:15:45 --> 00:15:47 lens that can now
00:15:49 --> 00:15:51 do the same thing as a human lens. Like okay,
00:15:52 --> 00:15:54 when you have a cataract operation they
00:15:54 --> 00:15:56 replace the human lens. That's all fogged up
00:15:56 --> 00:15:59 with generally a plastic lens of some
00:15:59 --> 00:16:02 kind. But it was a fixed lens. It could only
00:16:02 --> 00:16:05 do one thing. They've now advanced the
00:16:05 --> 00:16:07 technology to the point where they can put a
00:16:07 --> 00:16:10 lens in that will be able to
00:16:10 --> 00:16:13 be controlled by your brain and give you
00:16:13 --> 00:16:15 various focal lengths.
00:16:15 --> 00:16:15 Professor Fred Watson: Yeah.
00:16:15 --> 00:16:17 Andrew Dunkley: Which I think is amazing.
00:16:17 --> 00:16:19 Professor Fred Watson: It's what you. What your eye naturally does.
00:16:19 --> 00:16:21 It's called accommodation you that the eye
00:16:21 --> 00:16:23 accommodates to different distances by
00:16:23 --> 00:16:25 changing the shape of the lens. Yeah, yeah.
00:16:25 --> 00:16:28 So um, that's pretty. Yes. Quite remarkable
00:16:28 --> 00:16:31 and um. Would be a real breakthrough for
00:16:31 --> 00:16:34 um. You know, for vision, uh, for poor
00:16:34 --> 00:16:34 vision.
00:16:34 --> 00:16:36 Anyway, we've strayed off the topic here. We
00:16:36 --> 00:16:38 have a bit and uh.
00:16:38 --> 00:16:40 Andrew Dunkley: I do, I'm sure never happens usually.
00:16:43 --> 00:16:45 Professor Fred Watson: I'm sure that um. Uh. Our uh.
00:16:45 --> 00:16:47 Listener is on the money suggesting that
00:16:47 --> 00:16:50 there are technologies that are being used
00:16:51 --> 00:16:52 in secrets, um.
00:16:53 --> 00:16:53 Professor Fred Watson: Ah.
00:16:53 --> 00:16:56 Professor Fred Watson: Or restricted environments.
00:16:56 --> 00:16:59 Uh, that would be of great
00:16:59 --> 00:17:02 value for astronomy. I uh.
00:17:02 --> 00:17:05 Guess the kind of thing that comes to mind is
00:17:05 --> 00:17:08 quantum detectors and. And things of that
00:17:08 --> 00:17:11 sort. Um, there is no. I don't think there's
00:17:11 --> 00:17:14 any equivalent uh, for example in the
00:17:14 --> 00:17:16 field of gravitational wave astronomy. I
00:17:16 --> 00:17:18 don't think there's anything that the
00:17:18 --> 00:17:19 military are doing that could feed into that.
00:17:19 --> 00:17:21 Although quantum optics are being used in
00:17:21 --> 00:17:24 that now. So, um, I
00:17:24 --> 00:17:26 suspect it's in, you know, in relation to the
00:17:26 --> 00:17:29 tools that are developed for, uh,
00:17:30 --> 00:17:32 our observations. Um,
00:17:32 --> 00:17:35 we owe infrared detectors,
00:17:35 --> 00:17:37 the things that see redder than red light or
00:17:37 --> 00:17:40 heat radiation. We owe them to the military.
00:17:40 --> 00:17:43 That's a spin off from military work. Um,
00:17:43 --> 00:17:46 I do remember, uh, one of the first
00:17:46 --> 00:17:48 infrared instruments on the Anglo Australian
00:17:48 --> 00:17:51 telescope. When it was being delivered.
00:17:51 --> 00:17:53 Uh, I think,
00:17:54 --> 00:17:56 um, the detector came under armed guard
00:17:56 --> 00:17:58 almost. It wasn't quite like that. But there
00:17:58 --> 00:18:01 was a lot of hoops to jump through when this
00:18:01 --> 00:18:03 detector was delivered. Because it had to be
00:18:03 --> 00:18:06 certain not to stray into the hands
00:18:06 --> 00:18:09 of certain foreign nations who the
00:18:09 --> 00:18:12 Americans who developed this detector didn't
00:18:12 --> 00:18:15 want, uh, them to get hold of.
00:18:15 --> 00:18:17 So those technologies do eventually
00:18:19 --> 00:18:21 kind of sprinkle down to astronomy where the
00:18:21 --> 00:18:24 poor relations in that regard, uh, although
00:18:24 --> 00:18:25 we do push the limits perhaps more than
00:18:25 --> 00:18:28 anybody else, uh, in technology.
00:18:29 --> 00:18:31 So, um, yes,
00:18:31 --> 00:18:34 I, I don't have any
00:18:35 --> 00:18:38 definite, um, speculations, uh,
00:18:38 --> 00:18:40 except to say that nothing would
00:18:40 --> 00:18:42 surprise me in that regard
00:18:43 --> 00:18:44 when it comes.
00:18:45 --> 00:18:47 Andrew Dunkley: I'm not a conspiracy theorist, but I do
00:18:47 --> 00:18:50 believe there's a heck of a lot going on up
00:18:50 --> 00:18:53 there that we do not and probably will
00:18:53 --> 00:18:56 not know about. Um, and
00:18:56 --> 00:18:59 I truly believe that the technology
00:18:59 --> 00:19:02 available today in space and on
00:19:02 --> 00:19:05 the planet, um, in those
00:19:05 --> 00:19:08 dark corners of government buildings
00:19:08 --> 00:19:10 is far, far more advanced than we
00:19:11 --> 00:19:14 could possibly imagine. I think given what
00:19:14 --> 00:19:16 we've got access to in a domestic sense in
00:19:16 --> 00:19:18 the public arena today,
00:19:19 --> 00:19:22 uh, what's been developed already behind
00:19:22 --> 00:19:25 closed doors that we're unaware of. And
00:19:25 --> 00:19:27 it's probably up. They're circling the planet
00:19:27 --> 00:19:28 as we speak.
00:19:29 --> 00:19:31 Professor Fred Watson: Yeah, I think it works both ways though,
00:19:31 --> 00:19:34 because I think, um, we're now
00:19:34 --> 00:19:37 seeing, uh, the military adopting
00:19:37 --> 00:19:39 what would have been thought of as commercial
00:19:39 --> 00:19:41 products before. Uh,
00:19:42 --> 00:19:45 and that's happened certainly in Ukraine.
00:19:45 --> 00:19:48 There's been an adaptation of
00:19:48 --> 00:19:51 all sorts of commercial products for
00:19:51 --> 00:19:54 military purposes. Um, so
00:19:54 --> 00:19:55 what I guess I'm saying is that the
00:19:55 --> 00:19:58 technology that we use every day is not
00:19:58 --> 00:20:01 as far removed from what the military use
00:20:01 --> 00:20:04 as it would have been 20 or 30 years ago.
00:20:05 --> 00:20:08 Uh, I think that's probably fair to say, but
00:20:08 --> 00:20:09 that's me going out on a limb. And who can
00:20:09 --> 00:20:10 prove me wrong?
00:20:11 --> 00:20:14 Andrew Dunkley: Well, that's a good point too. Yeah, it's a,
00:20:14 --> 00:20:16 uh, really interesting question. Thank you
00:20:16 --> 00:20:18 for sending it in. This is Space Nuts Andrew
00:20:18 --> 00:20:20 Dunkley here with Professor Fred Watson
00:20:20 --> 00:20:20 Watson.
00:20:22 --> 00:20:25 Professor Fred Watson: I believe that this nation should commit
00:20:25 --> 00:20:27 itself to achieving the goal
00:20:27 --> 00:20:30 before this decade is out of landing A man
00:20:30 --> 00:20:33 on the moon and returning him safely
00:20:33 --> 00:20:34 Andrew Dunkley: to the Earth face nuts.
00:20:35 --> 00:20:38 Another audio question from Fred.
00:20:39 --> 00:20:41 Andrew Dunkley: Hi, this is Fred calling you from St. Paul,
00:20:41 --> 00:20:44 Minnesota in the US I have a question for
00:20:44 --> 00:20:47 you regarding the solar systems that contain
00:20:48 --> 00:20:50 uh, so called hot Jupiter planets, those
00:20:50 --> 00:20:53 which are very close, ah, around their
00:20:53 --> 00:20:55 suns. Is it reasonable at all to
00:20:55 --> 00:20:58 expect that they will have
00:20:58 --> 00:21:00 smaller planets, rocky planets,
00:21:01 --> 00:21:04 or are there good reasons that
00:21:04 --> 00:21:06 come to mind where that should not be the
00:21:06 --> 00:21:08 case? Um, I'd uh, appreciate hearing
00:21:09 --> 00:21:12 your theories on this, uh, what the variables
00:21:12 --> 00:21:14 would be in this and I of course enjoy
00:21:15 --> 00:21:17 listening to your show. Thank you very much.
00:21:18 --> 00:21:19 Goodbye.
00:21:19 --> 00:21:22 Andrew Dunkley: Thank you Fred. Uh, Fred's one of our semi
00:21:22 --> 00:21:24 regular sender inners and um,
00:21:24 --> 00:21:27 he's always got a very interesting question
00:21:27 --> 00:21:30 in mind. Um, so uh, yeah, I'm
00:21:30 --> 00:21:32 guessing that what he is asking is if you've
00:21:32 --> 00:21:35 got a solar system with hot Jupiters, uh,
00:21:35 --> 00:21:38 that are orbiting their parent star in
00:21:38 --> 00:21:41 close proximity, could those systems
00:21:41 --> 00:21:43 have rocky planets further out? Now, uh, the
00:21:43 --> 00:21:45 downside of exoplanet detection is rocky
00:21:45 --> 00:21:47 planets are very hard to find at a distance.
00:21:47 --> 00:21:50 You generally find the gas giants
00:21:50 --> 00:21:53 fast or first. Um,
00:21:53 --> 00:21:55 we do know there are a lot of hot Jupiters
00:21:55 --> 00:21:57 out there because we've talked about them.
00:21:58 --> 00:22:00 Um, but uh, yeah,
00:22:01 --> 00:22:04 uh, what's the likelihood that that's a
00:22:04 --> 00:22:06 common thing? Um, not that there's
00:22:06 --> 00:22:09 anything absolutely common about anything you
00:22:09 --> 00:22:12 find when you start looking around at other
00:22:12 --> 00:22:13 solar systems?
00:22:13 --> 00:22:16 Professor Fred Watson: Yeah, that's exactly right. Our solar
00:22:16 --> 00:22:18 system is very neat and tidy compared with
00:22:18 --> 00:22:20 most of the other ones that we've detected.
00:22:20 --> 00:22:23 But you're absolutely right Andrew. Um, the
00:22:23 --> 00:22:25 rocky planets are the, the tricky ones to
00:22:25 --> 00:22:28 observe. And so it might well be that
00:22:28 --> 00:22:31 what we're seeing is effectively a selection
00:22:31 --> 00:22:33 effect. We're selecting the easiest ones,
00:22:34 --> 00:22:37 uh, to discover. Uh, and that's why we see a
00:22:37 --> 00:22:40 lot of hot Jupiters without any evidence
00:22:40 --> 00:22:42 of rocky planets in the same solar systems,
00:22:43 --> 00:22:46 I think, and I haven't looked at this for
00:22:46 --> 00:22:49 some time but um, one of the ideas
00:22:49 --> 00:22:52 for why we've got this
00:22:52 --> 00:22:55 situation with hot Jupiters is basically
00:22:56 --> 00:22:59 a planetary migration. This is where planets
00:22:59 --> 00:23:01 change their positions in the solar system.
00:23:02 --> 00:23:04 Uh, and that might have happened to some
00:23:04 --> 00:23:07 extent in our solar system, but not
00:23:07 --> 00:23:10 in um, a really sort
00:23:10 --> 00:23:13 of existential way. Not in a way that will
00:23:13 --> 00:23:15 totally alter the shape of the solar system
00:23:16 --> 00:23:17 because we've got four rocky planets which
00:23:17 --> 00:23:20 are the innermost ones and they exist within
00:23:20 --> 00:23:23 a zone where um,
00:23:23 --> 00:23:26 water exists as a
00:23:26 --> 00:23:29 gas, whereas beyond the orbit of Mars,
00:23:29 --> 00:23:31 and we sometimes call that the frost line or
00:23:31 --> 00:23:34 the ice line water exists
00:23:34 --> 00:23:37 uh, as ice and that ice is what
00:23:37 --> 00:23:40 has allowed the gas giants to grow
00:23:40 --> 00:23:43 to the size that they have because the ice
00:23:43 --> 00:23:46 basically collects and uh, the
00:23:46 --> 00:23:48 planets absorb it. So you've got ah,
00:23:50 --> 00:23:52 not just a massive rock being formed but ice
00:23:52 --> 00:23:55 as well. And then you end up with a gas
00:23:55 --> 00:23:58 giant planet. Uh so the four gas giants
00:23:58 --> 00:24:00 we think are ah, like that because they're
00:24:00 --> 00:24:03 outside the frost line. Now if you've got
00:24:03 --> 00:24:05 planetary migration taking place then
00:24:06 --> 00:24:08 some of those planets could wander in to the
00:24:08 --> 00:24:10 inner solar system. Uh and
00:24:11 --> 00:24:14 it may essentially leave your solar
00:24:14 --> 00:24:16 system looking like some of the ones that we
00:24:16 --> 00:24:19 see with a hot Jupiter orbiting very close
00:24:19 --> 00:24:22 to Paris star. But also
00:24:22 --> 00:24:24 perhaps with some rocky planets lingering
00:24:25 --> 00:24:27 uh, moaning around or moping around
00:24:28 --> 00:24:31 uh, where they've been uh, projected
00:24:31 --> 00:24:33 to by the rearrangement of the planets
00:24:33 --> 00:24:35 because some of them could be ejected by
00:24:35 --> 00:24:38 planetary migration. If you've got your gas
00:24:38 --> 00:24:40 giant wanders too near your little rocky
00:24:40 --> 00:24:42 planet, it's going to boot it out the solar
00:24:42 --> 00:24:45 system altogether. Uh but um, I
00:24:45 --> 00:24:47 suspect that there will be solar systems uh,
00:24:48 --> 00:24:50 ah that will turn out to have both hot
00:24:50 --> 00:24:53 Jupiters and rocky planets. And as our
00:24:54 --> 00:24:56 um, technology improves and allows us to
00:24:56 --> 00:24:59 detect these things uh, at lower masses, I
00:24:59 --> 00:25:01 think we'll be finding them as well. So um,
00:25:01 --> 00:25:03 watch this space phantom. That's the bottom
00:25:03 --> 00:25:03 line there.
00:25:04 --> 00:25:06 Andrew Dunkley: Theo was a wandering planet.
00:25:06 --> 00:25:08 Professor Fred Watson: Yes, that's right. Theo wandered into the
00:25:08 --> 00:25:11 Earth back in the uh, literally
00:25:11 --> 00:25:14 late 4 B.C. yeah,
00:25:15 --> 00:25:17 4 million BCS. I beg your pardon. Four
00:25:17 --> 00:25:18 billion. Yeah.
00:25:19 --> 00:25:22 Andrew Dunkley: I think um, the train of thought these days
00:25:22 --> 00:25:25 is that uh, in terms of solar systems,
00:25:25 --> 00:25:28 um, just about every star has at least got
00:25:28 --> 00:25:31 one planet. Um, that's based
00:25:31 --> 00:25:33 on an average assumption. But um,
00:25:34 --> 00:25:36 it also stands to reason that uh,
00:25:37 --> 00:25:40 solar systems are as many and as varied as
00:25:40 --> 00:25:43 there are stars in the sky. Ours
00:25:43 --> 00:25:45 which has the four rocky planets, then the
00:25:45 --> 00:25:47 gas giants as you move out and then the dwarf
00:25:47 --> 00:25:50 planets beyond that um, ours
00:25:50 --> 00:25:53 seems to be quite different
00:25:53 --> 00:25:54 from most.
00:25:54 --> 00:25:56 Professor Fred Watson: It does, that's what I meant. It's very neat
00:25:56 --> 00:25:59 and tidy compared with uh, what we see
00:25:59 --> 00:26:02 elsewhere. Um, certainly
00:26:02 --> 00:26:05 if you were on uh, the planet of
00:26:05 --> 00:26:08 a star 100 light years away, our rocky
00:26:08 --> 00:26:10 planets would be very difficult to detect.
00:26:10 --> 00:26:12 And you just think, you'd probably think all
00:26:12 --> 00:26:15 it had was Jupiter, uh because you'd be
00:26:15 --> 00:26:17 able to detect Jupiter relatively easily. If
00:26:17 --> 00:26:19 it passed in front of the sun it would, would
00:26:19 --> 00:26:22 produce a 1% drop in the um, light
00:26:22 --> 00:26:25 of the sun. And that's easy to
00:26:25 --> 00:26:28 measure. So yes. So um,
00:26:28 --> 00:26:30 uh is the future
00:26:31 --> 00:26:33 of our solar system, one that does involve
00:26:33 --> 00:26:36 planetary migration. Um, it doesn't seem
00:26:36 --> 00:26:38 to be. The planets seem to be in very, very
00:26:38 --> 00:26:40 stable orbits. And maybe that's just
00:26:40 --> 00:26:42 something to do with the geometry of the
00:26:42 --> 00:26:44 solar system itself. But maybe it's something
00:26:44 --> 00:26:47 to do also with why intelligent
00:26:47 --> 00:26:49 life has evolved on one of those planets.
00:26:49 --> 00:26:51 Because we've had this idea long term
00:26:51 --> 00:26:53 stability over many millions of years,
00:26:54 --> 00:26:54 which
00:26:54 --> 00:26:56 Andrew Dunkley: is why it's going to be near impossible to
00:26:56 --> 00:26:59 find another intelligent, communicative
00:26:59 --> 00:27:02 civilization. Because, um, the circumstances
00:27:02 --> 00:27:03 are unique.
00:27:03 --> 00:27:05 Professor Fred Watson: Could be, probably, yeah, could be almost
00:27:05 --> 00:27:06 unique. Yes.
00:27:06 --> 00:27:07 Andrew Dunkley: Thank you, Fred.
00:27:10 --> 00:27:11 Professor Fred Watson: Roger, you're allowed to clear here.
00:27:11 --> 00:27:14 Andrew Dunkley: Also space nuts. Our final question
00:27:14 --> 00:27:17 comes from Ed. Now this is not dissimilar to
00:27:17 --> 00:27:19 a question we had recently, but it's not
00:27:19 --> 00:27:21 quite the same either. Uh, we believe
00:27:22 --> 00:27:25 that nothing can escape from a black hole.
00:27:25 --> 00:27:27 And yet when two black holes merge, the mass
00:27:27 --> 00:27:30 of the surviving black hole is significantly
00:27:30 --> 00:27:31 less than the combined mass of the two
00:27:31 --> 00:27:34 merging black holes. It would appear this
00:27:34 --> 00:27:36 missing mass, which I understand is converted
00:27:36 --> 00:27:39 to gravitational waves, has to come from the
00:27:39 --> 00:27:42 black holes, hence energy. Matter does
00:27:42 --> 00:27:44 escape from black holes. Is this
00:27:44 --> 00:27:47 wrong? Ed asks. Hello, Ed, thanks for the
00:27:47 --> 00:27:50 question. Uh, black hole questions,
00:27:50 --> 00:27:52 Fred Watson. It's not. A week goes by we
00:27:52 --> 00:27:54 don't get a black hole.
00:27:54 --> 00:27:56 Professor Fred Watson: A great one, though. It's a good question
00:27:56 --> 00:27:59 that Ed's raised. Um, so it's.
00:27:59 --> 00:28:02 Yes, the uh, gravitational radiation
00:28:03 --> 00:28:03 is
00:28:06 --> 00:28:07 quite different from
00:28:09 --> 00:28:11 uh, the electromagnetic radiation that's
00:28:12 --> 00:28:14 coming from a black hole which does get
00:28:14 --> 00:28:16 trapped. It can't pass the event horizon.
00:28:16 --> 00:28:18 That's what the event horizon is all about.
00:28:18 --> 00:28:21 Because gravitation is a property
00:28:22 --> 00:28:25 not of the black hole, but of
00:28:25 --> 00:28:28 the universe itself. Ah. It's
00:28:28 --> 00:28:30 the underlying sort of fabric of space that
00:28:30 --> 00:28:33 is what carries gravity. Um,
00:28:33 --> 00:28:36 and so if you've got these colliding
00:28:36 --> 00:28:39 black holes, they shake the space
00:28:39 --> 00:28:42 itself rather than emit
00:28:43 --> 00:28:45 something. So that's the
00:28:45 --> 00:28:48 difference. The gravitational waves. Uh,
00:28:48 --> 00:28:51 yes, indeed. They're caused by, uh, the,
00:28:51 --> 00:28:54 by a loss of mass from the black holes. But
00:28:54 --> 00:28:56 they're not a property of the black holes. If
00:28:56 --> 00:28:59 I can put it that way. Yes, it's an
00:28:59 --> 00:29:02 effect rather than something being emitted.
00:29:02 --> 00:29:05 So, um, um, Ed's quite right that
00:29:05 --> 00:29:07 nothing can escape a black hole, but
00:29:07 --> 00:29:10 gravitational waves apparently do. But
00:29:10 --> 00:29:13 they're not. Basically what you're seeing is,
00:29:13 --> 00:29:15 uh, something to do with the universe, not
00:29:15 --> 00:29:16 the black hole.
00:29:17 --> 00:29:20 Andrew Dunkley: Okay, yeah, I get it. It's the old pebble in
00:29:20 --> 00:29:21 the pond trick.
00:29:21 --> 00:29:23 Professor Fred Watson: Yeah, that's right. Yes it is, yeah.
00:29:24 --> 00:29:27 The ripples in the pond, uh, don't come
00:29:27 --> 00:29:30 from the pebble. They come from the fact that
00:29:30 --> 00:29:32 the pebble has disturbed the underlying
00:29:33 --> 00:29:35 fabric. Uh, of the water, in fact. Put it
00:29:35 --> 00:29:37 that way. Yeah, it's a really good analogy.
00:29:39 --> 00:29:41 Andrew Dunkley: I come up with all sorts.
00:29:41 --> 00:29:43 Professor Fred Watson: You do, but that's a cracking good one,
00:29:43 --> 00:29:44 Andrew. Well done. I like that.
00:29:45 --> 00:29:46 Andrew Dunkley: I think you told it to me once before.
00:29:48 --> 00:29:49 Maybe.
00:29:49 --> 00:29:49 Professor Fred Watson: Maybe.
00:29:49 --> 00:29:52 Andrew Dunkley: Um, so that's the simplicity of it, really.
00:29:52 --> 00:29:53 There's not much more to tell.
00:29:53 --> 00:29:55 Professor Fred Watson: No, no, that's right. It's not. You know, it
00:29:55 --> 00:29:58 doesn't defy the logic of nothing being able
00:29:58 --> 00:30:01 to escape a black hole. Uh, it's, um,
00:30:01 --> 00:30:04 because you, um. Yes, Ed's right. Nothing
00:30:04 --> 00:30:06 can. Nothing solid or,
00:30:07 --> 00:30:09 um, electromagnetic or particles
00:30:09 --> 00:30:12 can't either. Uh, but the
00:30:12 --> 00:30:15 gravitational field is different. It's
00:30:15 --> 00:30:17 something to do with the underlying universe.
00:30:18 --> 00:30:20 Andrew Dunkley: Indeed it is. Uh, thanks, Ed. Great question.
00:30:21 --> 00:30:24 And, um, yeah, answered
00:30:24 --> 00:30:26 very simply in the end. Which
00:30:27 --> 00:30:28 doesn't happen often, does it, really?
00:30:29 --> 00:30:30 Professor Fred Watson: No, usually they're not answered at all.
00:30:32 --> 00:30:33 Andrew Dunkley: Or just adequately.
00:30:33 --> 00:30:36 Professor Fred Watson: Yes, adequately. That's right.
00:30:36 --> 00:30:38 Andrew Dunkley: Thanks, Ed. Uh, thanks to everyone who's sent
00:30:38 --> 00:30:39 in questions. And if you would like to send a
00:30:39 --> 00:30:41 question to us, please do go to our website,
00:30:41 --> 00:30:44 spacenutspodcast.com or spacenuts
00:30:44 --> 00:30:47 IO and there's a little button, uh, up the
00:30:47 --> 00:30:49 top top. Uh, or a tab or a link or whatever.
00:30:49 --> 00:30:52 It's a link. Uh, AMA stands for Ask me
00:30:52 --> 00:30:54 Anything. And you can send your questions in
00:30:54 --> 00:30:56 through that particular interface,
00:30:57 --> 00:31:00 text or audio. Don't forget to tell us who
00:31:00 --> 00:31:01 you are or where you're from. Although
00:31:01 --> 00:31:03 sometimes people forget. And you're not going
00:31:03 --> 00:31:06 to get into trouble for that. We're not that
00:31:06 --> 00:31:07 kind of people. M
00:31:08 --> 00:31:10 Nobody there. Have a look around. Visit the
00:31:10 --> 00:31:13 shop, become a supporter. And don't forget to
00:31:13 --> 00:31:15 leave, uh, reviews wherever you listen to us.
00:31:15 --> 00:31:18 Maybe the people listening live right now
00:31:18 --> 00:31:20 via YouTube could leave reviews. That'd be
00:31:20 --> 00:31:23 nice. Unless they hated us. Just don't do
00:31:23 --> 00:31:26 anything. No, I'm just kidding. They've stuck
00:31:26 --> 00:31:27 around, so we must be doing something right.
00:31:28 --> 00:31:28 Professor Fred Watson: Yeah.
00:31:28 --> 00:31:30 Andrew Dunkley: And we're all done, Fred Watson. Thank you
00:31:30 --> 00:31:30 very much.
00:31:31 --> 00:31:34 Professor Fred Watson: Thank you, Andrew. Um, we'll talk again soon.
00:31:34 --> 00:31:35 I, uh, look forward to it.
00:31:35 --> 00:31:37 Andrew Dunkley: I hope so. Uh, Professor Fred Watson Watson,
00:31:37 --> 00:31:39 astronomer at large, thanks to Huw in the
00:31:39 --> 00:31:42 studio, um, who couldn't be with
00:31:42 --> 00:31:45 us today because, uh, he's got a black
00:31:45 --> 00:31:48 hole problem. He called a plumber and neither
00:31:48 --> 00:31:50 of them can get out. And from me, Andrew
00:31:50 --> 00:31:52 Dunkley. Thanks for your company. I'll catch
00:31:52 --> 00:31:55 you on the next episode of Space Nuts. Until
00:31:55 --> 00:31:58 then, bye bye. You've been
00:31:58 --> 00:32:00 listening to the Space Nuts podcast
00:32:01 --> 00:32:04 available at Apple Podcasts, Spotify,
00:32:05 --> 00:32:07 iHeartRadio or your favourite podcast
00:32:07 --> 00:32:09 player. You can also stream on
00:32:09 --> 00:32:11 demand@bytes.com um,
00:32:11 --> 00:32:13 Professor Fred Watson: this has been another quality podcast
00:32:13 --> 00:32:15 production from bytes.um com.