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Show Notes
Supermassive Black Holes, Voyager 1, and Gravitational Waves In this engaging Q&A episode of Space Nuts , hosts Andrew Dunkley and Professor Fred Watson tackle a variety of intriguing audience questions that span the cosmos. From the formation of supermassive black holes to the journey of Voyager 1 and the nature of gravitational waves, this episode is filled with cosmic curiosities and scientific insights.
Episode Highlights:
- Formation of Supermassive Black Holes: Martin from Merseyside sparks a fascinating discussion about the mechanisms behind the formation of supermassive black holes. Andrew and Fred Watson explore the gravitational instability theory and the contrasting processes that could lead to the creation of these colossal entities in the early universe.
- Voyager 1's Journey: Andy, our favourite train driver, raises an interesting question about whether the particles in space could slow down Voyager 1 as it travels at 38,000 miles per hour. The hosts clarify the nature of space and the spacecraft's trajectory, highlighting the vast emptiness of interstellar space and the spacecraft's remarkable speed.
- Gravitational Waves Explained: Ben from Kent asks a thought-provoking question about the nature of gravitational waves produced by colliding black holes. Andrew and Fred Watson delve into whether these waves are spherical or flat, providing clarity on how they propagate through the fabric of spacetime.
- Thought Experiments on Earth's Rotation: Judd from Brisbane brings up the current speed of Earth's rotation and its effects on gravity. The hosts discuss the fascinating implications of Earth's spin on weight, including the differences between the equator and the poles, and what would happen if Earth suddenly stopped rotating.
For more Space Nuts, including our continuously updating newsfeed and to listen to all our episodes, visit our website. (https://www.spacenutspodcast.com/) Follow us on social media at SpaceNutsPod on Facebook, Instagram, and more. We love engaging with our community, so be sure to drop us a message or comment on your favourite platform.
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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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Episode link: https://play.headliner.app/episode/32965185?utm_source=youtube
00:00:00 --> 00:00:01 Hello again. Thanks for joining us on
00:00:01 --> 00:00:04 Space Nuts, where we talk astronomy and
00:00:04 --> 00:00:07 space and science all at the same time.
00:00:07 --> 00:00:09 Uh, this is a Q&A episode. My name is
00:00:09 --> 00:00:11 Andrew Dunley, your host. Great to have
00:00:11 --> 00:00:13 your company. Coming up, audience
00:00:13 --> 00:00:15 questions. We're going to answer a
00:00:15 --> 00:00:17 question from Martin about super massive
00:00:17 --> 00:00:20 black holes. Uh, Ben has also got a
00:00:20 --> 00:00:21 question about black holes and
00:00:21 --> 00:00:24 gravitational waves. Andy, our favorite
00:00:24 --> 00:00:28 train driver is on about Voyager 1. And
00:00:28 --> 00:00:31 Jud has some thought experiments for us.
00:00:31 --> 00:00:33 We'll check it all out on this episode
00:00:33 --> 00:00:35 of Space Nuts.
00:00:35 --> 00:00:39 >> 15 seconds. Guidance is internal. 10 9
00:00:40 --> 00:00:41 Ignition sequence start.
00:00:41 --> 00:00:42 >> Space nuts.
00:00:42 --> 00:00:45 >> 5 4 3 2
00:00:45 --> 00:00:47 >> 1 2 3 4 5 5 4 3 2 1
00:00:47 --> 00:00:48 >> Space Nuts.
00:00:48 --> 00:00:52 >> Astronauts report. It feels good.
00:00:52 --> 00:00:56 And back to unravel, unpack, and solve
00:00:56 --> 00:00:58 all of that is Professor Fred Watson,
00:00:58 --> 00:01:01 astronomer at large. Hello, Fred.
00:01:01 --> 00:01:03 >> Hello, Andrew. Very good to see you.
00:01:03 --> 00:01:04 >> Good to see you, too. I've still got
00:01:04 --> 00:01:07 McCroy voice. Um, in fact, I've been so
00:01:07 --> 00:01:09 unwell, I'm still wearing the same
00:01:09 --> 00:01:11 clothes as I was last week.
00:01:11 --> 00:01:13 >> Well, there you go.
00:01:13 --> 00:01:15 >> Funnily enough, so am I.
00:01:15 --> 00:01:19 >> Yeah. Well, what a coincidence.
00:01:19 --> 00:01:22 >> Uh, shall we get down to business?
00:01:22 --> 00:01:22 Why not?
00:01:22 --> 00:01:24 >> All right. Something else to do. So,
00:01:24 --> 00:01:24 yeah.
00:01:24 --> 00:01:26 >> Now, we've got some text and audio
00:01:26 --> 00:01:29 questions. We'll go text first today.
00:01:29 --> 00:01:32 Uh, and forgive my rather um unreliable
00:01:32 --> 00:01:34 voice as I work my way through this. Hi,
00:01:34 --> 00:01:36 Fred and Andrew. It's Martin here from
00:01:36 --> 00:01:40 Hezwall on the Whirl in Murzy side. I
00:01:40 --> 00:01:42 posted a question before and Fred
00:01:42 --> 00:01:45 mentioned that he knew Barnston, which
00:01:45 --> 00:01:47 is just a pleasant walk over the fields
00:01:48 --> 00:01:50 from here. I have a question about your
00:01:50 --> 00:01:52 favorite topic, black hole. I thought it
00:01:52 --> 00:01:55 was going to be golf. Black holes. Uh
00:01:55 --> 00:01:57 I'm interested specifically in the
00:01:57 --> 00:01:59 process of their formation and more
00:01:59 --> 00:02:01 particularly in super massive black
00:02:01 --> 00:02:04 holes. The mechanism for the creation of
00:02:04 --> 00:02:06 stellar mass black holes seems to be
00:02:06 --> 00:02:08 well understood. But I find it hard to
00:02:08 --> 00:02:11 believe that this can be the same way
00:02:12 --> 00:02:13 that super massive black holes in the
00:02:13 --> 00:02:15 early universe were formed. I've read
00:02:15 --> 00:02:18 that the gravitational instability
00:02:18 --> 00:02:20 theory posits that black holes can be
00:02:20 --> 00:02:23 formed directly when a massive cloud of
00:02:23 --> 00:02:25 matter collapses under its own gravity.
00:02:25 --> 00:02:28 Why is it not possible that there can be
00:02:28 --> 00:02:30 two processes at work depending on the
00:02:30 --> 00:02:33 size? For me, part of the evidence in
00:02:33 --> 00:02:36 supporting uh in support of invoking
00:02:36 --> 00:02:38 gravitational instability is the lack of
00:02:38 --> 00:02:40 evidence for the existence of
00:02:40 --> 00:02:43 intermediate mass black holes. What are
00:02:43 --> 00:02:45 the arguments against this theory? As it
00:02:45 --> 00:02:48 does seem to be that widely, it doesn't
00:02:48 --> 00:02:50 seem to be that widely accepted. If
00:02:50 --> 00:02:52 black holes are created in two
00:02:52 --> 00:02:54 completely different ways, what effect
00:02:54 --> 00:02:57 would this have on their properties? For
00:02:57 --> 00:02:59 instance, charge, spin, etc. I really
00:02:59 --> 00:03:01 enjoy listening to the show. It helps me
00:03:01 --> 00:03:03 keep up to date with the world of
00:03:03 --> 00:03:05 science, space, and stuff. That's our
00:03:05 --> 00:03:08 slogan. Ha. Well done. Well done,
00:03:08 --> 00:03:11 Martin. That's our slogan. Um, yeah.
00:03:11 --> 00:03:13 Look, that's a really good question and
00:03:13 --> 00:03:15 we only talked in the last episode about
00:03:15 --> 00:03:18 the the the different theories about uh
00:03:18 --> 00:03:21 how black holes are formed and the
00:03:21 --> 00:03:23 possible discovery of primordial black
00:03:23 --> 00:03:24 holes. So uh if you haven't heard that
00:03:24 --> 00:03:26 episode, wind back because it's worth
00:03:26 --> 00:03:28 listening to that story. But uh yeah, he
00:03:28 --> 00:03:31 brings up an interesting point. Uh how
00:03:31 --> 00:03:33 can it be the same process for a super
00:03:33 --> 00:03:37 massive black hole versus a um you know
00:03:37 --> 00:03:40 another one, a smaller one?
00:03:40 --> 00:03:45 >> Yeah. So I I mean Martin's um hit on one
00:03:45 --> 00:03:48 of the key questions at the moment in in
00:03:48 --> 00:03:50 astrophysics and cosmology. So he's
00:03:50 --> 00:03:51 right up to date there.
00:03:51 --> 00:03:54 >> Yeah, he sure is. Um because um this
00:03:54 --> 00:03:58 idea of uh the super massive black holes
00:03:58 --> 00:04:01 in the early universe forming directly
00:04:01 --> 00:04:03 as a as a direct result of a cloud of
00:04:03 --> 00:04:06 gas collapsing without having to go
00:04:06 --> 00:04:09 through the mechanisms or of of a
00:04:09 --> 00:04:11 forming a star and then the stars
00:04:11 --> 00:04:14 basically exploding uh to form a a black
00:04:14 --> 00:04:16 hole. That's quite new.
00:04:16 --> 00:04:19 uh and that might be why as Martin says
00:04:19 --> 00:04:22 it's not yet sort of considered to be
00:04:22 --> 00:04:25 mainstream but it is it is very much an
00:04:25 --> 00:04:28 upand cominging idea and theory that
00:04:28 --> 00:04:31 answers the criticism that the
00:04:31 --> 00:04:35 conventional theory has uh and that is
00:04:35 --> 00:04:37 conventionally uh scientists have
00:04:37 --> 00:04:41 assumed that super massive black holes
00:04:41 --> 00:04:46 are created over long periods of time by
00:04:46 --> 00:04:51 the accretion of material. So um we know
00:04:51 --> 00:04:53 how a stellar mass black hole is formed
00:04:53 --> 00:04:55 exactly as Martin mentioned we
00:04:55 --> 00:04:58 understand that's massive star explodes
00:04:58 --> 00:05:02 at the end of its life when the fuel
00:05:02 --> 00:05:04 balance runs out. uh the outer layers
00:05:04 --> 00:05:07 are shed off and a supernova remnant and
00:05:07 --> 00:05:10 the center basically the central core
00:05:10 --> 00:05:12 collapses to be the black hole which is
00:05:12 --> 00:05:14 a point with zero dimensions a point
00:05:14 --> 00:05:19 where uh density is infinite. Uh so that
00:05:19 --> 00:05:20 the conventional method says you start
00:05:20 --> 00:05:24 off with lots of those in a galaxy and
00:05:24 --> 00:05:29 they eventually uh accrete to form a
00:05:29 --> 00:05:32 bigger object uh mixing with stuff
00:05:32 --> 00:05:34 that's sucked in on the accretion disc
00:05:34 --> 00:05:36 as well. That might include a few odd
00:05:36 --> 00:05:38 black holes dropping in. Yeah.
00:05:38 --> 00:05:40 >> To form eventually a super massive black
00:05:40 --> 00:05:43 hole. But the problem has been how do
00:05:43 --> 00:05:46 you manage to do that in less than a
00:05:46 --> 00:05:49 couple of hundred million years which is
00:05:49 --> 00:05:51 you know where the earliest super
00:05:51 --> 00:05:54 massive black holes are after the big
00:05:54 --> 00:05:56 bang we know about those because we can
00:05:56 --> 00:05:59 we measure them by looking using the
00:05:59 --> 00:06:02 James web space telescope it's measured
00:06:02 --> 00:06:05 I think several objects within maybe 250
00:06:05 --> 00:06:08 million uh years after the big bang in
00:06:08 --> 00:06:10 other words we're looking back almost
00:06:10 --> 00:06:13 13.8 billion years, 13.6 or something
00:06:13 --> 00:06:17 like that. Um, uh, how did they form so
00:06:17 --> 00:06:19 quickly if that's the mechanism? And
00:06:19 --> 00:06:21 that's why this alternative mechanism of
00:06:21 --> 00:06:23 of direct collapse from a an
00:06:23 --> 00:06:24 interstellar
00:06:24 --> 00:06:26 >> from from a not interstellar because
00:06:26 --> 00:06:28 there were no stars then, but from a
00:06:28 --> 00:06:30 primordial gas cloud might have
00:06:30 --> 00:06:35 occurred. And in as I understand it,
00:06:35 --> 00:06:39 the idea of primordial
00:06:39 --> 00:06:41 uh black holes postulated, this is what
00:06:41 --> 00:06:43 we talked about last week uh or the last
00:06:43 --> 00:06:48 episode postulated by Steven Hawking uh
00:06:48 --> 00:06:51 envisaged that there would be a very
00:06:51 --> 00:06:54 very wide range of masses of black holes
00:06:54 --> 00:06:56 ranging from things less than the mass
00:06:56 --> 00:06:58 of the sun. um as we reported in the
00:06:58 --> 00:07:00 last episode, we think we found one of
00:07:00 --> 00:07:01 those now. Yeah.
00:07:01 --> 00:07:05 >> Uh to super massive black holes. I think
00:07:05 --> 00:07:08 that is all within the purview of
00:07:08 --> 00:07:10 Hawking's theory of primordial black
00:07:10 --> 00:07:14 holes. And so the question, you know,
00:07:14 --> 00:07:17 maybe the fact that we're finding these
00:07:17 --> 00:07:19 super massive black holes
00:07:19 --> 00:07:23 too early in the universe um might to to
00:07:23 --> 00:07:24 have been formed by stuff coming
00:07:24 --> 00:07:26 together. uh might be a support for the
00:07:26 --> 00:07:28 Hawings theory that maybe some of these
00:07:28 --> 00:07:30 were actually formed immediately after
00:07:30 --> 00:07:31 the big bang.
00:07:31 --> 00:07:33 >> Wow. Wouldn't that be interesting?
00:07:33 --> 00:07:34 >> Um
00:07:34 --> 00:07:35 >> there was something about um something
00:07:35 --> 00:07:37 that um Martin mentioned about
00:07:37 --> 00:07:38 intermediate.
00:07:38 --> 00:07:41 >> Yeah. He said for me part of the
00:07:41 --> 00:07:43 evidence in support of invoking
00:07:43 --> 00:07:45 gravitational instability is the lack of
00:07:45 --> 00:07:46 evidence for the existence of
00:07:46 --> 00:07:49 intermediate mass black holes. Although
00:07:49 --> 00:07:51 they're the ones we were talking about
00:07:51 --> 00:07:54 recently that we now have discovered,
00:07:54 --> 00:07:55 have we not?
00:07:55 --> 00:07:58 >> Yes. Um but they're still and they still
00:07:58 --> 00:08:01 seem to be Yes. much rarer than the
00:08:01 --> 00:08:03 super massive black holes or the stellar
00:08:03 --> 00:08:05 mass black holes which are which exist
00:08:05 --> 00:08:08 in profusion. Uh intermediate mass black
00:08:08 --> 00:08:11 holes have been quite hard to find. Uh
00:08:11 --> 00:08:13 >> maybe they're just beaten up.
00:08:13 --> 00:08:16 >> Yeah, I mean you know what Martin says
00:08:16 --> 00:08:20 is right. um that might point to uh to
00:08:20 --> 00:08:22 the the idea of gravitational
00:08:22 --> 00:08:24 instability, in other words, sort of
00:08:24 --> 00:08:27 primordial type black holes as being the
00:08:27 --> 00:08:30 formation. Uh that might point to that.
00:08:30 --> 00:08:33 Um and so I don't think there's an issue
00:08:34 --> 00:08:37 there. Uh but yes, his final question,
00:08:37 --> 00:08:39 uh if black holes are created in two
00:08:39 --> 00:08:40 completely different ways, what effect
00:08:40 --> 00:08:43 would that have on their properties? For
00:08:43 --> 00:08:46 example, charge, spin, etc.
00:08:46 --> 00:08:48 >> Now, in fact, the only properties of a
00:08:48 --> 00:08:51 black hole that you can observe um are
00:08:51 --> 00:08:54 the charge and the spin as well as the
00:08:54 --> 00:08:57 mass. Um and that um that's because of
00:08:57 --> 00:08:59 something that you and I might have
00:08:59 --> 00:09:00 mentioned before, Andrew, something
00:09:00 --> 00:09:03 called the no hair theorem, uh which I'm
00:09:03 --> 00:09:06 very fond of, uh as you can guess. And
00:09:06 --> 00:09:08 the no hair theorem basically says that
00:09:08 --> 00:09:10 there's
00:09:10 --> 00:09:14 you know there's virtually nothing um of
00:09:14 --> 00:09:16 the black holes characteristics that you
00:09:16 --> 00:09:18 can see from the outside. It's like
00:09:18 --> 00:09:20 suggesting a baldness of the of the
00:09:20 --> 00:09:22 black hole the event horizon. It doesn't
00:09:22 --> 00:09:25 give much away. Charge and spin are I
00:09:25 --> 00:09:28 think I think only the only two apart
00:09:28 --> 00:09:30 from mass. Now I don't know the answer
00:09:30 --> 00:09:32 to that. Would there be any difference
00:09:32 --> 00:09:34 in those properties uh for two different
00:09:34 --> 00:09:36 methods of black hole formation? And
00:09:36 --> 00:09:39 it's a really good question. Uh and um
00:09:39 --> 00:09:40 it's something that I probably should
00:09:40 --> 00:09:42 have a look at and see if I can find
00:09:42 --> 00:09:42 out.
00:09:42 --> 00:09:44 >> Yeah, I I thought I'd look up no hair
00:09:44 --> 00:09:47 theorem to see what happened. And um I I
00:09:47 --> 00:09:50 didn't get um an ad for a for a hair
00:09:50 --> 00:09:52 pill. It actually took me it actually
00:09:52 --> 00:09:53 took me to the
00:09:53 --> 00:09:55 >> to the to the no hair theorem
00:09:55 --> 00:09:56 >> to the no hair theorem about black
00:09:56 --> 00:09:59 holes. Yeah. So there you go.
00:09:59 --> 00:10:02 The internet actually worked.
00:10:02 --> 00:10:02 >> Yes,
00:10:02 --> 00:10:04 >> nice change. Nice change. And a nice
00:10:04 --> 00:10:07 question. Uh Martin, thanks for sending
00:10:07 --> 00:10:08 that to us. Hopefully that helped you
00:10:08 --> 00:10:11 sort a few things out, but uh yeah, it's
00:10:11 --> 00:10:13 there's still a lot of theory around
00:10:13 --> 00:10:15 black holes yet to be proven, but we're
00:10:15 --> 00:10:17 chipping away at it. We are chipping
00:10:17 --> 00:10:19 away at it. Not me personally. I leave
00:10:19 --> 00:10:21 that to other people who are more
00:10:21 --> 00:10:24 astute. Uh thanks for sending it in. Our
00:10:24 --> 00:10:26 next question comes from our favorite
00:10:26 --> 00:10:29 train driver. His name is Andy.
00:10:30 --> 00:10:31 >> Train driver here. Uh just a question
00:10:31 --> 00:10:35 for you on Voyager One. Um I know that
00:10:35 --> 00:10:36 he's currently traveling about 38
00:10:36 --> 00:10:40 mph and it's very low on fuel and the
00:10:40 --> 00:10:42 fuel is used for the thrusters to point
00:10:42 --> 00:10:45 it antennas back to Earth. Um and I know
00:10:45 --> 00:10:47 that space is not empty. There's
00:10:47 --> 00:10:50 particles and space dust. So, because
00:10:50 --> 00:10:52 he's got such a long journey before he
00:10:52 --> 00:10:54 reaches anything significant, would the
00:10:54 --> 00:10:57 particles in space
00:10:57 --> 00:11:00 slow it enough to bring it to a halt?
00:11:00 --> 00:11:02 Cuz as far as I'm aware, it's got about
00:11:02 --> 00:11:04 40 years before it reaches something
00:11:04 --> 00:11:07 significant. So, is that a long enough
00:11:07 --> 00:11:10 time, would you say, to maybe not bring
00:11:10 --> 00:11:12 it to a halt, but to to slow it
00:11:12 --> 00:11:14 significantly that it really does
00:11:14 --> 00:11:17 increase that time scale?
00:11:17 --> 00:11:19 Uh, sorry if that doesn't make much
00:11:19 --> 00:11:21 sense. Uh, thanks for your podcast,
00:11:21 --> 00:11:23 guys. Really enjoy it. Speak to you
00:11:23 --> 00:11:24 soon. Bye.
00:11:24 --> 00:11:26 >> Thank you, Andy. Hope all is well on
00:11:26 --> 00:11:29 your daily commute, although you're the
00:11:29 --> 00:11:31 driver, so you just drag everyone else
00:11:31 --> 00:11:35 around. But what a great job. Um, right.
00:11:35 --> 00:11:38 Okay. Voyager 1, 38 mph. Uh, is
00:11:38 --> 00:11:40 there enough material to ultimately stop
00:11:40 --> 00:11:42 it? Cuz it's going to run into a few
00:11:42 --> 00:11:44 things here and there, possibly. But I
00:11:44 --> 00:11:46 would question the spread of the dust
00:11:46 --> 00:11:48 when you get out into those uh
00:11:48 --> 00:11:51 interstellar places. The amount of
00:11:51 --> 00:11:53 material thins out significantly,
00:11:54 --> 00:11:55 doesn't it?
00:11:55 --> 00:11:58 >> Yeah, very much so. Um there is still
00:11:58 --> 00:12:01 you know there are still atoms there um
00:12:01 --> 00:12:04 or nuclei probably subatomic particles
00:12:04 --> 00:12:10 um but it's not uh it's not enough to
00:12:10 --> 00:12:14 significantly slow the spacecraft.
00:12:14 --> 00:12:16 >> Uh
00:12:16 --> 00:12:18 it's you know you you basically to all
00:12:18 --> 00:12:20 intents and purposes it's moving through
00:12:20 --> 00:12:24 a vacuum. Um it's I was thinking
00:12:24 --> 00:12:26 kilometers/s.
00:12:26 --> 00:12:30 Current speed is uh 16
00:12:30 --> 00:12:33 kilometers/s relative to the sun.
00:12:33 --> 00:12:36 >> 61 kilometers an hour. 17 km a
00:12:36 --> 00:12:39 secondish. Uh 38 mph. Yep. It's
00:12:40 --> 00:12:41 going. It's fast.
00:12:41 --> 00:12:43 >> It is. Uh the the speed I like is in
00:12:44 --> 00:12:47 units of astronomical units per year. Uh
00:12:47 --> 00:12:51 and that is 3 3.6
00:12:51 --> 00:12:55 nearly 3. So, uh, three times a year
00:12:55 --> 00:12:58 it covers the distance from the Earth to
00:12:58 --> 00:13:00 the Sun here. So,
00:13:00 --> 00:13:03 >> yeah, that's 150 million kilometers.
00:13:03 --> 00:13:04 >> Sure is. That's that's amazing, isn't
00:13:04 --> 00:13:08 it? And it's still going strong.
00:13:08 --> 00:13:10 >> Yeah. So, and andy's right. I think the
00:13:10 --> 00:13:13 fuel's low, but the fuel is uh just for
00:13:13 --> 00:13:16 the thrusters. It's just to keep the
00:13:16 --> 00:13:19 antenna pointed towards Earth.
00:13:19 --> 00:13:22 >> So, yeah. and and he said it might come
00:13:22 --> 00:13:25 across something in about 40 40
00:13:25 --> 00:13:27 years. I I thought when we talked about
00:13:27 --> 00:13:30 this last that it it could just keep
00:13:30 --> 00:13:33 going. It might not run into anything.
00:13:33 --> 00:13:35 Yeah. Simply because it's not aimed at
00:13:35 --> 00:13:37 anything and space is very empty. Uh
00:13:37 --> 00:13:39 even though there's a you know 400
00:13:39 --> 00:13:41 billion stars in the Milky Way or
00:13:41 --> 00:13:43 whatever, the Milky Way is very very big
00:13:43 --> 00:13:49 indeed. Uh and um it's look it's uh its
00:13:49 --> 00:13:52 distance is I think I think the odds are
00:13:52 --> 00:13:54 that it will keep going forever. It
00:13:54 --> 00:13:55 might be captured by the gravity of
00:13:55 --> 00:13:59 another star. I think the um the notion
00:13:59 --> 00:14:02 of a collision is vanishingly small.
00:14:02 --> 00:14:05 >> Um I've just um
00:14:05 --> 00:14:07 statistics just come into my head that I
00:14:07 --> 00:14:10 used to use a lot uh to to give people
00:14:10 --> 00:14:13 the idea of just how big the galaxy is.
00:14:13 --> 00:14:15 uh and I'm sure you and I have discussed
00:14:15 --> 00:14:18 it too. If you imagine a diagram of our
00:14:18 --> 00:14:22 galaxy uh that was the size of the earth
00:14:22 --> 00:14:25 so 12 and a half thousand kilometers in
00:14:25 --> 00:14:28 diameter that's your map of the galaxy
00:14:28 --> 00:14:32 uh the size of the earth. The separation
00:14:32 --> 00:14:35 from the sun to the earth on that scale
00:14:35 --> 00:14:40 is 2 mm. That tells you that the galaxy
00:14:40 --> 00:14:42 is very very large compared with the
00:14:42 --> 00:14:45 size of the solar system.
00:14:46 --> 00:14:48 That's just mind-boggling stuff really
00:14:48 --> 00:14:50 easily.
00:14:50 --> 00:14:52 >> And the other thing I suppose like we
00:14:52 --> 00:14:55 talk about the or cloud which is this
00:14:55 --> 00:14:58 thing around our um is it around our
00:14:58 --> 00:14:59 solar system or around a galaxy? I can't
00:15:00 --> 00:15:00 remember.
00:15:00 --> 00:15:01 >> No, it's around the solar system.
00:15:01 --> 00:15:03 >> Solar system. Yeah.
00:15:03 --> 00:15:05 >> Yeah. Um, they reckon it's going to take
00:15:05 --> 00:15:07 300 years for Voyager One to reach that.
00:15:07 --> 00:15:11 >> That That's right. Um, that's right.
00:15:11 --> 00:15:12 >> That and
00:15:12 --> 00:15:13 >> still a long way off,
00:15:13 --> 00:15:14 >> which means it still hasn't really left
00:15:14 --> 00:15:17 our solar system in real terms.
00:15:17 --> 00:15:19 >> I'm not even sure that it will be 300
00:15:19 --> 00:15:22 years because the cloud is about a light
00:15:22 --> 00:15:24 year away.
00:15:24 --> 00:15:27 >> Well, actually, it says here um the
00:15:27 --> 00:15:29 inner edge in 300 years, but it will
00:15:29 --> 00:15:31 take 30 years to pass through it.
00:15:31 --> 00:15:33 >> That's more like it. Yeah. Yeah. It's
00:15:33 --> 00:15:33 more like
00:15:34 --> 00:15:35 >> So, I should have finished reading the
00:15:35 --> 00:15:39 sentence, shouldn't I?
00:15:39 --> 00:15:40 >> There was there was an unpredictable
00:15:40 --> 00:15:42 full stop in there, though. So,
00:15:42 --> 00:15:43 >> yeah.
00:15:43 --> 00:15:44 >> But, um,
00:15:44 --> 00:15:44 >> yeah,
00:15:44 --> 00:15:46 >> incredible.
00:15:46 --> 00:15:48 >> Sorry, I meant to say, um, last time
00:15:48 --> 00:15:50 Andy came on, I meant to tell him that
00:15:50 --> 00:15:53 I'm a train driver, too. Uh, but it's
00:15:53 --> 00:15:56 ends scale. Uh, which he'll know. He'll
00:15:56 --> 00:15:58 know what that is. Not some people might
00:15:58 --> 00:16:00 not know. Actually, probably quite a lot
00:16:00 --> 00:16:02 of our listeners do. But I drive my
00:16:02 --> 00:16:04 trains in Nscale. I love it.
00:16:04 --> 00:16:07 >> I should send Andy, if if he sends me
00:16:07 --> 00:16:09 his email address, um some video of our
00:16:09 --> 00:16:11 brand new regional trains in New South
00:16:11 --> 00:16:12 Wales that are being
00:16:12 --> 00:16:13 >> I'd like to see that.
00:16:13 --> 00:16:15 >> Yeah. They're being fitted out in um in
00:16:15 --> 00:16:18 do where I live and they've been doing
00:16:18 --> 00:16:19 test runs on them. I've actually heard
00:16:20 --> 00:16:21 it
00:16:21 --> 00:16:23 >> uh in the we small hours passing by
00:16:23 --> 00:16:24 because it it's got a completely
00:16:24 --> 00:16:26 different sound. And I've actually
00:16:26 --> 00:16:27 reached a point now where I recognize
00:16:27 --> 00:16:31 the different trains by sound.
00:16:31 --> 00:16:35 How pathetic is that? But um
00:16:35 --> 00:16:38 >> much much quieter than the current train
00:16:38 --> 00:16:41 which is the XPT uh which is well past
00:16:41 --> 00:16:43 its use by date but never let the New
00:16:44 --> 00:16:46 South Wales government, you know, build
00:16:46 --> 00:16:48 a train because they will they will say,
00:16:48 --> 00:16:50 "Okay, it's got a 20-y year life, so
00:16:50 --> 00:16:52 we'll replace it in 50." Cuz that's
00:16:52 --> 00:16:57 what's happening. Um but uh these are
00:16:57 --> 00:16:58 very slick. These are Spanish trains
00:16:58 --> 00:17:01 that are being fitted out in do and um
00:17:01 --> 00:17:04 really really lovely piece of kit as
00:17:04 --> 00:17:07 Fred would say. So um Andy sent me your
00:17:07 --> 00:17:09 email address and I will send you a
00:17:09 --> 00:17:12 video of of our um our new trains that
00:17:12 --> 00:17:13 it's weird watching them run around with
00:17:13 --> 00:17:17 nobody in them. It's just no passengers,
00:17:17 --> 00:17:19 nothing. Just all the lights are on.
00:17:19 --> 00:17:22 Nobody's home. Nobody's home.
00:17:22 --> 00:17:24 >> Yeah. If you're on the metro in Sydney,
00:17:24 --> 00:17:25 there's not even a driver on board
00:17:25 --> 00:17:27 either. Yeah, I know. I've been on the
00:17:28 --> 00:17:29 metro a couple of times. It's a slick
00:17:29 --> 00:17:30 system.
00:17:30 --> 00:17:31 >> Oh, it's brilliant.
00:17:31 --> 00:17:33 >> One of my boys lives in a suburb where
00:17:33 --> 00:17:35 they're just about to complete a metro
00:17:35 --> 00:17:37 line. So, he's really happy about that
00:17:37 --> 00:17:39 cuz it'll get him to work, you know,
00:17:39 --> 00:17:40 three times as fast.
00:17:40 --> 00:17:43 >> So, he's really he's thrilled cuz he got
00:17:43 --> 00:17:45 rid of his car. He doesn't use a car in
00:17:45 --> 00:17:48 Sydney. Doesn't see the need. Got to
00:17:48 --> 00:17:50 have one out here though in the country.
00:17:50 --> 00:17:51 Uh, thanks Andy. Lovely to hear from
00:17:52 --> 00:17:53 you. This is Space Nuts with Andrew
00:17:53 --> 00:17:58 Dunley and Professor Fred Watson.
00:17:58 --> 00:18:01 Let's take a short break from Space Nuts
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00:19:31 --> 00:19:32 >> Roger, you're here also.
00:19:32 --> 00:19:34 >> Space nuts.
00:19:34 --> 00:19:39 >> Oh boy. Um, okay. Next question. Uh, I
00:19:39 --> 00:19:40 don't even know where we're up to. Where
00:19:40 --> 00:19:42 are we up to? We've spoken to Andy. All
00:19:42 --> 00:19:44 right. Um, question three. Hi, Space
00:19:44 --> 00:19:45 Nuts. Ben Harding here from Kent,
00:19:46 --> 00:19:47 England. Uh, having listened to your
00:19:48 --> 00:19:51 show for several years now, uh, I know
00:19:51 --> 00:19:52 everything there is to know about black
00:19:52 --> 00:19:54 holes. Indeed, I'm ready to start
00:19:54 --> 00:19:57 building my own any day now. But wait,
00:19:57 --> 00:19:59 if I build two and they crash together,
00:20:00 --> 00:20:02 they will create gravitational waves and
00:20:02 --> 00:20:04 I need to account for the ensuing
00:20:04 --> 00:20:06 distortion of the fabric of spaceime or
00:20:06 --> 00:20:09 my cats will be upset.
00:20:09 --> 00:20:13 So are gravitational waves spherical or
00:20:13 --> 00:20:15 flat? I'm thinking they must be
00:20:15 --> 00:20:18 spherical. But then again, if they are
00:20:18 --> 00:20:20 created by two objects spiraling in
00:20:20 --> 00:20:23 together, the waves may be flat uh by
00:20:23 --> 00:20:26 some sort of uh conservation of angular
00:20:26 --> 00:20:29 momentum rule. Uh I hope you can help me
00:20:29 --> 00:20:32 with my cats. Um they get a bit scratchy
00:20:32 --> 00:20:34 when they're upset.
00:20:34 --> 00:20:37 Thanks for the awesome show, Ben. H
00:20:37 --> 00:20:39 Thank you, Ben. Um I'm just imagining
00:20:39 --> 00:20:43 your cats. Uh freaking out over
00:20:43 --> 00:20:44 gravitational waves. There's a comic
00:20:44 --> 00:20:48 strip in that I reckon somewhere. My my
00:20:48 --> 00:20:50 brother would do a a comic on that. I
00:20:50 --> 00:20:54 reckon he's very artistic as my brother.
00:20:54 --> 00:20:56 >> Okay. All right. So, gravitational waves
00:20:56 --> 00:21:00 from the um cataclysmic collision of uh
00:21:00 --> 00:21:03 two black holes spherical.
00:21:03 --> 00:21:08 Um, so I think what uh Ben is
00:21:08 --> 00:21:11 referring to um in his description is
00:21:11 --> 00:21:14 whether they whether they're they're
00:21:14 --> 00:21:16 radiated gravitational waves are
00:21:16 --> 00:21:18 radiated in all directions. Yeah.
00:21:18 --> 00:21:21 >> What we would call isotropic or just in
00:21:22 --> 00:21:24 a plane in the plane of the collision.
00:21:24 --> 00:21:27 >> And um to the best of my understanding
00:21:27 --> 00:21:29 the answer is that they're isotropic.
00:21:29 --> 00:21:30 They go off in all directions.
00:21:30 --> 00:21:34 >> Right? So space shutters uh just because
00:21:34 --> 00:21:37 of the the gravitational interaction.
00:21:37 --> 00:21:40 It's not got any pref I don't think I do
00:21:40 --> 00:21:42 not believe it's got any preferred
00:21:42 --> 00:21:45 direction because of the you know the
00:21:45 --> 00:21:46 direction of the collision. I think it's
00:21:46 --> 00:21:50 um it is the same in all directions. Um
00:21:50 --> 00:21:52 there's another way of interpreting
00:21:52 --> 00:21:56 Ben's question though and that is uh how
00:21:56 --> 00:21:59 the oscillations of gravitational waves
00:21:59 --> 00:22:02 take place. Um, and they're not they're
00:22:02 --> 00:22:05 not the same as sound waves where which
00:22:05 --> 00:22:07 are compression waves where things push
00:22:07 --> 00:22:09 backwards and forwards. And they're not
00:22:09 --> 00:22:12 the same as light waves which are
00:22:12 --> 00:22:14 transverse waves where the electric
00:22:14 --> 00:22:17 field and magnetic field vary in a in a
00:22:17 --> 00:22:19 transverse manner. In other words,
00:22:19 --> 00:22:21 opposite to the direction of propagation
00:22:21 --> 00:22:23 or right angles to the direction of
00:22:23 --> 00:22:25 propagation. There's something called
00:22:25 --> 00:22:27 quadruple waves which is a sort of
00:22:28 --> 00:22:30 combination of not quite a combination
00:22:30 --> 00:22:33 of the two but certainly um a slightly
00:22:33 --> 00:22:36 unusual form of of transverse wave
00:22:36 --> 00:22:38 quadrupole waves is what they are. Um
00:22:38 --> 00:22:40 but I don't think that's what he means.
00:22:40 --> 00:22:42 I think what Ben means is what I
00:22:42 --> 00:22:44 answered in the first place that uh yes
00:22:44 --> 00:22:46 they're isotropic rather than limited to
00:22:46 --> 00:22:48 a particular plane. So, they go out in
00:22:48 --> 00:22:50 all directions, unlike the gravitational
00:22:50 --> 00:22:53 wave that um I detected on a plane.
00:22:53 --> 00:22:55 >> Uh I don't know what that guy was
00:22:55 --> 00:22:57 eating, but um yeah, I hope I don't have
00:22:57 --> 00:23:00 to experience that again.
00:23:00 --> 00:23:02 >> Yeah, I know about those things as well.
00:23:02 --> 00:23:04 >> Pretty awful stuff. Really?
00:23:04 --> 00:23:05 >> Yep, they are.
00:23:05 --> 00:23:08 >> I'm impressed that Ben says he knows
00:23:08 --> 00:23:09 everything there is to know about black
00:23:09 --> 00:23:11 holes. Does that mean we've been doing
00:23:11 --> 00:23:14 our job?
00:23:14 --> 00:23:16 It means he he knows more than us, which
00:23:16 --> 00:23:18 is pretty easy to do. Really
00:23:18 --> 00:23:19 >> possible, too. Yeah.
00:23:19 --> 00:23:20 >> Yes.
00:23:20 --> 00:23:21 >> But but we're learning more and more
00:23:21 --> 00:23:22 about them. Um
00:23:22 --> 00:23:24 >> we are. That's cuz we listen to our
00:23:24 --> 00:23:24 listeners.
00:23:24 --> 00:23:28 >> That's that's exactly right. But uh
00:23:28 --> 00:23:30 yeah, they've been the topic of I I
00:23:30 --> 00:23:32 think since we started a decade ago,
00:23:32 --> 00:23:35 Fred, I um you reminded me earlier, uh
00:23:35 --> 00:23:37 it's been 10 years we've been doing this
00:23:37 --> 00:23:39 podcast. That's that's extraordinary. We
00:23:39 --> 00:23:41 should have had a party, but I think we
00:23:41 --> 00:23:43 just can't stay up that late anymore.
00:23:43 --> 00:23:47 But um it it's um it's probably been the
00:23:47 --> 00:23:50 hottest topic on Space Nuts since day
00:23:50 --> 00:23:52 one is black holes.
00:23:52 --> 00:23:54 >> Uh closely followed by dark matter, dark
00:23:54 --> 00:23:57 energy and um I yeah, I don't know where
00:23:57 --> 00:23:59 you go from there, but uh it's been of
00:23:59 --> 00:23:59 >> life in space.
00:23:59 --> 00:24:02 >> Yes, life. Yes, you are right. That's
00:24:02 --> 00:24:04 those are the top four topics. So, I
00:24:04 --> 00:24:06 expect next week our four questions will
00:24:06 --> 00:24:09 be on black holes, dark matter, dark
00:24:09 --> 00:24:11 energy, and life elsewhere.
00:24:11 --> 00:24:13 >> Yeah, there's there's a good chance they
00:24:13 --> 00:24:14 will.
00:24:14 --> 00:24:16 >> That will be the standard.
00:24:16 --> 00:24:18 >> Yep. Very good. Thank you, Ben. Uh,
00:24:18 --> 00:24:20 lovely to hear from you. Hope all is
00:24:20 --> 00:24:24 well in Kent. Our final question comes
00:24:24 --> 00:24:26 from Jud.
00:24:26 --> 00:24:29 >> Good day, Fred and Andrew. It's Jud from
00:24:29 --> 00:24:31 Brisbane. Been a big fan of the show for
00:24:31 --> 00:24:34 a long time. My wife and I were
00:24:34 --> 00:24:38 listening to a recent episode uh where
00:24:38 --> 00:24:40 one of the stories was about the uh spun
00:24:40 --> 00:24:43 out asteroid that's spinning at a
00:24:43 --> 00:24:46 incredibly fast rate. And you know we
00:24:46 --> 00:24:50 found Andrew's um thought experiments um
00:24:50 --> 00:24:53 about how that would affect Earth if we
00:24:53 --> 00:24:57 were spinning at a similar rate. Um and
00:24:57 --> 00:25:00 yeah got my head spinning and uh came up
00:25:00 --> 00:25:02 with lots of other thought experiments.
00:25:02 --> 00:25:06 Um uh first my question is uh what is
00:25:06 --> 00:25:09 the current speed of the earth's
00:25:09 --> 00:25:13 rotation? Um
00:25:13 --> 00:25:18 and yeah does that speed affect the pole
00:25:18 --> 00:25:23 of gravity that we feel on earth? Um
00:25:23 --> 00:25:27 like for instance if uh if I weigh 100
00:25:27 --> 00:25:31 kg at spinning at this rate of speed uh
00:25:31 --> 00:25:34 if the earth stops spinning tomorrow
00:25:34 --> 00:25:39 would I weigh significantly more? Just
00:25:39 --> 00:25:41 wondering about that. And another
00:25:41 --> 00:25:46 question, um, would I weigh less at the
00:25:46 --> 00:25:49 equator than I would standing at the
00:25:49 --> 00:25:52 north or south pole because the equator
00:25:52 --> 00:25:55 is spinning much more rapidly than the
00:25:55 --> 00:25:59 Earth is at the poles. So, just uh some
00:25:59 --> 00:26:02 thoughts to make your head spin and
00:26:02 --> 00:26:05 maybe give me some answers. Thank you.
00:26:05 --> 00:26:07 >> Thank you, Jud. Thanks to you and your
00:26:07 --> 00:26:09 wife for being fans of the show for so
00:26:09 --> 00:26:11 long. Much appreciated and uh we can
00:26:11 --> 00:26:13 make this quick. Yes. And we're finished
00:26:13 --> 00:26:16 for the No. Um there's a lot more to it
00:26:16 --> 00:26:19 than that, but uh I think he he he
00:26:19 --> 00:26:20 pretty well nailed a few of the thoughts
00:26:20 --> 00:26:23 that he's had in terms of what the
00:26:23 --> 00:26:25 answers are. Uh what is the current
00:26:25 --> 00:26:26 speed of Earth's rotation? If you listen
00:26:26 --> 00:26:28 to the Monty Python song from the life
00:26:28 --> 00:26:31 of Brian, or was it one of the others?
00:26:31 --> 00:26:33 Um,
00:26:33 --> 00:26:35 yeah, they they were wrong, weren't
00:26:35 --> 00:26:37 they, with their assessment of the speed
00:26:37 --> 00:26:42 of the rotation of the planet. Um,
00:26:42 --> 00:26:45 I can't remember I I do remember from I
00:26:45 --> 00:26:46 don't know know what the speed is, but
00:26:46 --> 00:26:48 I'll get to that in a second. I can't
00:26:48 --> 00:26:49 remember what the song says, but I do
00:26:50 --> 00:26:52 remember listening to that song a long
00:26:52 --> 00:26:54 time ago and thinking, "Yeah, pretty
00:26:54 --> 00:26:56 well most of the astronomical statistics
00:26:56 --> 00:26:58 in it are correct." uh or they were when
00:26:58 --> 00:27:02 it was written back in the day. Um but
00:27:02 --> 00:27:05 uh Jud is right. Um the speed of
00:27:05 --> 00:27:08 rotation at the earth on the equator,
00:27:08 --> 00:27:10 which is where your linear speed is
00:27:10 --> 00:27:15 maximum, is uh 1 kilometers an hour.
00:27:15 --> 00:27:19 So that's significant. It's about uh
00:27:19 --> 00:27:22 half a kilometer/s roughly. Uh, and
00:27:22 --> 00:27:25 that's why you tend to build space
00:27:25 --> 00:27:27 launch sites at the equator because
00:27:27 --> 00:27:31 you've got that additional.5
00:27:31 --> 00:27:32 kilometers/s.
00:27:32 --> 00:27:34 That's quite significant when you're
00:27:34 --> 00:27:36 trying to get up to 8 kilometers/s to
00:27:36 --> 00:27:39 get into into orbit. So, you're kind of
00:27:39 --> 00:27:41 a 16th of the way there already just by
00:27:41 --> 00:27:43 putting your launch site on the equator
00:27:43 --> 00:27:45 and of course launching towards the east
00:27:45 --> 00:27:46 which is the direction that we're
00:27:46 --> 00:27:50 rotating in. Um, at middle latitudes it
00:27:50 --> 00:27:53 reduces. At our latitude here in uh, New
00:27:53 --> 00:27:56 South Wales, it's about 1 kilometers
00:27:56 --> 00:28:00 per hour. Um, uh, at Jud's latitude in
00:28:00 --> 00:28:02 Brisbane, it's a little bit less. Not
00:28:02 --> 00:28:05 that much less, though. Uh, but there's
00:28:05 --> 00:28:07 So, what's the effect on your weight?
00:28:07 --> 00:28:09 That's the interesting thing. Yeah.
00:28:10 --> 00:28:14 >> And, um, there are two two parts to
00:28:14 --> 00:28:16 this. Um,
00:28:16 --> 00:28:19 one is kind of what we've just alluded
00:28:19 --> 00:28:23 to, the fact that you are rotating uh
00:28:23 --> 00:28:26 1 kilometers uh an hour, roughly
00:28:26 --> 00:28:29 1 miles an hour. Um, it basically
00:28:29 --> 00:28:31 there's a centrifugal force that means
00:28:31 --> 00:28:34 that you are slightly lighter. Uh, your
00:28:34 --> 00:28:36 mass doesn't change of course, but your
00:28:36 --> 00:28:38 weight does because of that centrifugal
00:28:38 --> 00:28:42 force. But there there is another effect
00:28:42 --> 00:28:45 that acts with that too. And that's
00:28:45 --> 00:28:48 because the Earth isn't spherical. It's
00:28:48 --> 00:28:50 slightly bulging. And in the center,
00:28:50 --> 00:28:53 it's what we call an abl spheroid.
00:28:53 --> 00:28:58 >> And at the equator, you're about 20
00:28:58 --> 00:29:00 kilometers
00:29:00 --> 00:29:02 further away from the Earth's center of
00:29:02 --> 00:29:06 gravity than you are at the poles. And
00:29:06 --> 00:29:10 so that too reduces the gravitational
00:29:10 --> 00:29:13 pull that you feel. Um so those two
00:29:13 --> 00:29:15 things together the equatorial bulge of
00:29:15 --> 00:29:18 the earth and the centrifugal force of
00:29:18 --> 00:29:21 the earth's rotation come they basically
00:29:21 --> 00:29:24 combine to give you a figure that's a
00:29:24 --> 00:29:28 bit less than 1% of your weight changes
00:29:28 --> 00:29:30 if you're at the equator compared with
00:29:30 --> 00:29:30 the poles.
00:29:30 --> 00:29:32 >> That that'd be a lot for some people
00:29:32 --> 00:29:33 maybe.
00:29:33 --> 00:29:35 >> Yes. Yeah. that I mean it means that if
00:29:35 --> 00:29:38 you do weigh 100 kg then at the equator
00:29:38 --> 00:29:40 then you're only going to be 99 at the
00:29:40 --> 00:29:40 pole.
00:29:40 --> 00:29:41 >> Yeah.
00:29:41 --> 00:29:43 >> No, I've got it the other way around. If
00:29:43 --> 00:29:45 you're 100 kg at the pole, you're only
00:29:45 --> 00:29:47 going to be 99 at the equator.
00:29:47 --> 00:29:49 >> I knew what you meant.
00:29:49 --> 00:29:50 >> Yeah.
00:29:50 --> 00:29:54 >> Um yeah, it's fascinating really. And um
00:29:54 --> 00:29:58 yeah, that was one of his questions. Um
00:29:58 --> 00:30:00 weight at the equator versus the poles.
00:30:00 --> 00:30:04 Uh what would happen if Earth stops
00:30:04 --> 00:30:07 spinning? Like I think we'd all be
00:30:07 --> 00:30:08 doomed for starters. That would be the
00:30:08 --> 00:30:10 end.
00:30:10 --> 00:30:11 >> But um
00:30:11 --> 00:30:13 >> we'd all be projected eastwards at uh
00:30:13 --> 00:30:15 1 kilometers an hour if you're on
00:30:15 --> 00:30:16 the equator.
00:30:16 --> 00:30:19 >> Yeah. Yeah. That'd be that'd be pretty
00:30:19 --> 00:30:20 messy. Um
00:30:20 --> 00:30:23 >> but it Yeah. But if the Earth stopped
00:30:23 --> 00:30:25 spinning, you'd only have that uh
00:30:25 --> 00:30:28 equatorial bulge component that's
00:30:28 --> 00:30:29 reducing your weight. the fact that
00:30:29 --> 00:30:31 you're a little bit further away from
00:30:31 --> 00:30:32 the center and that's almost negligible
00:30:32 --> 00:30:33 on its own.
00:30:33 --> 00:30:37 >> Yeah, fair enough. That was easy. And I
00:30:37 --> 00:30:39 found that Monty Python song. It was
00:30:39 --> 00:30:40 from the meaning of life, not from the
00:30:40 --> 00:30:42 life of Brian.
00:30:42 --> 00:30:42 >> That's right.
00:30:42 --> 00:30:45 >> And it's called the Galaxy song. And the
00:30:45 --> 00:30:47 first verse first verse says, just
00:30:47 --> 00:30:48 remember that you're standing on a
00:30:48 --> 00:30:51 planet that's evolving and revolving at
00:30:51 --> 00:30:54 900 miles an hour.
00:30:54 --> 00:30:57 >> Um, which is Yeah. All right. So, it's
00:30:57 --> 00:31:00 it's uh A bit slow.
00:31:00 --> 00:31:02 >> 100 miles an hour slow. Yeah,
00:31:02 --> 00:31:05 >> but it rhymes.
00:31:05 --> 00:31:07 >> That's it. A thousand would have rhymed.
00:31:07 --> 00:31:08 >> It would have worked.
00:31:08 --> 00:31:08 >> Yeah.
00:31:09 --> 00:31:11 >> Oh, well, maybe they needed two words
00:31:11 --> 00:31:13 rather than No, it would have still been
00:31:13 --> 00:31:13 two words.
00:31:13 --> 00:31:16 >> Or or or Andrew, maybe the Earth has
00:31:16 --> 00:31:18 speeded up since they recorded the song.
00:31:18 --> 00:31:20 >> That's poss. It's slowing down though,
00:31:20 --> 00:31:21 isn't it?
00:31:21 --> 00:31:22 >> Yes.
00:31:22 --> 00:31:24 Yeah.
00:31:24 --> 00:31:26 >> Well, eventually their song will be
00:31:26 --> 00:31:27 right.
00:31:27 --> 00:31:30 Yes, it will.
00:31:30 --> 00:31:31 >> That's right.
00:31:31 --> 00:31:32 >> Oh gosh.
00:31:32 --> 00:31:34 >> All right. Um, thank you so much, Jud.
00:31:34 --> 00:31:36 Lovely to hear from you. Hope all is
00:31:36 --> 00:31:38 well in Brisbane. Uh, sorry about your
00:31:38 --> 00:31:42 football team. Not. Um, and I think that
00:31:42 --> 00:31:44 brings us to the end. Uh, if you have
00:31:44 --> 00:31:47 questions for us, uh, we would love to
00:31:47 --> 00:31:49 hear from you. Uh, you can go to our
00:31:49 --> 00:31:51 website, spacenuts.io, io and click on
00:31:51 --> 00:31:55 the AMA uh link at the top of the page
00:31:55 --> 00:31:57 uh where you can ask me anything or ask
00:31:57 --> 00:31:59 me and I'll give it to Fred to figure it
00:31:59 --> 00:32:02 out. Uh so uh send us text and audio
00:32:02 --> 00:32:03 questions. Don't forget to tell us who
00:32:03 --> 00:32:05 you are and where you're from. And a
00:32:05 --> 00:32:08 little request if you will uh when you
00:32:08 --> 00:32:10 uh next listen or are listening to us
00:32:10 --> 00:32:12 right now, please leave a review on
00:32:12 --> 00:32:15 whatever podcast platform you uh use
00:32:15 --> 00:32:18 because uh reviews are very handy. Um,
00:32:18 --> 00:32:21 it sort of moves us up some laddery
00:32:22 --> 00:32:25 thing, ranking thing, which is very good
00:32:25 --> 00:32:28 for us apparently. I don't understand
00:32:28 --> 00:32:31 how this works. It's it's all to do with
00:32:31 --> 00:32:34 gravity. Uh, and thank you, Fred, uh,
00:32:34 --> 00:32:36 once again for helping us out today. I
00:32:36 --> 00:32:40 think you did all the work, actually.
00:32:40 --> 00:32:42 >> Nice to help, Andrew. Always good to
00:32:42 --> 00:32:43 talk. And we'll catch up again.
00:32:43 --> 00:32:45 >> We will, Professor Fred Watson,
00:32:45 --> 00:32:48 astronomer at large. And thanks to Hugh
00:32:48 --> 00:32:51 in the studio, although he couldn't be
00:32:51 --> 00:32:56 with us today, he um had a thought and
00:32:56 --> 00:32:59 um it was experimental and he's going to
00:32:59 --> 00:33:00 go and investigate that right now and
00:33:00 --> 00:33:02 see if it's real.
00:33:02 --> 00:33:04 I don't know what that means. Uh and
00:33:04 --> 00:33:05 from me, Andrew Dunley, thanks for your
00:33:05 --> 00:33:07 company. We'll see you on the next
00:33:07 --> 00:33:09 episode of Space Nuts. Bye-bye.
00:33:09 --> 00:33:11 >> Space Nuts. You've been listening to the
00:33:11 --> 00:33:14 Space Nuts podcast
00:33:14 --> 00:33:17 >> available at Apple Podcasts, Spotify,
00:33:17 --> 00:33:20 iHeart Radio, or your favorite podcast
00:33:20 --> 00:33:22 player. You can also stream on demand at
00:33:22 --> 00:33:25 bytes.com. This has been another quality
00:33:25 --> 00:33:30 podcast production from byes.com.