# Cosmic Connections: Mapping Magnetic Fields, Dark Matter Mysteries & SpaceX's IPO Success

An episode of [Space Nuts: Astronomy Insights & Cosmic Discoveries](https://invisiblenetwork.ai/podcast/1080090608), 18 Jun 2026, 34 min.

Audio: https://dts.podtrac.com/redirect.mp3/pscrb.fm/rss/p/op3.dev/e/api.spreaker.com/download/episode/72574138/cosmic_connections_mapping_magnetic_fields_dark_matter_mysteries_spacex_s_ipo_success.mp3

Join us as we delve into the latest space science stories, from the universe's most comprehensive magnetic map to the mysteries of black holes and dark matter. Our casual chat is packed with insights into ongoing research and space exploration plans, including Elon Musk's ventures into space and beyond. In this episode: The CSIRO's groundbreaking map of the universe's magnetic fields, five times more extensive than previous efforts, revealing complex galactic structures and the role of magnetic fields in galaxy evolution \[00:00–10:00\] How polarization and Faraday rotation are used to infer magnetic fields across the cosmos, and what the map tells us about the Milky Way's center \[10:00–12:40\] The innovative method of reverberation mapping in studying black holes and the potential connection to dark matter congregations around these cosmic giants \[16:37–22:39\] The speculative but exciting prospects for interstellar travel, including the limitations posed by physics, time dilation effects near relativistic speeds, and the Breakthrough Starshot initiative \[50:57–55:36\] Elon Musk's recent public offer of SpaceX ventures, merchandise, and the symbolism of mission patches and rockets, illustrating his flair and boldness in space entrepreneurship \[24:00–34:10\] The impact of lunar and planetary dynamics on Earth's tides, weather, and ocean currents, with reflections on moonless Earth scenarios \[60:00–62:48\] Nostalgic references to 70s science fiction, notably Space 1999, and its imaginative visions of moon-based colonies and space wandering \[58:56–59:53\] For enthusiasts eager to explore further, check out resources like: CSIRO's Magnetic Map of the Universe Breakthrough Starshot Initiative SpaceX Official Website Physical Review D - Space Science Publications Connect with our guest, Professor Fred Watson: LinkedIn | Twitter Looking for the perfect space-themed gear? Visit our Shop for stickers, caps, T-shirts, and mission patches that celebrate our cosmic curiosity. Join the conversation: Share your questions or comments at spacenutspodcast.com, and help us explore the universe together. Thanks for listening—until next time, keep looking up! Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support.

## Transcript

[0:00] Andrew Dunkley: Hello again. Thanks for joining us on another
[0:02] episode of Space Nuts. My name is Andrew
[0:04] Dunkley. It's great to have your company. I
[0:06] hope you're well. Uh, coming up in this
[0:08] episode, some exciting storeys. And
[0:11] one of them is a new
[0:13] CSIRO map
[0:16] developed in Australia of
[0:19] magnetic fields. Now, it's been quite a while
[0:21] since they updated this and they've got a new
[0:23] one out. And, uh, it's quite extraordinary,
[0:26] uh, the way it was done and what it shows and
[0:28] what it can be used for. Uh, we've also got
[0:31] a new report about the relationship
[0:34] or otherwise between, uh, black holes
[0:36] and dark matter. Now this is interesting
[0:39] because it's only been a theory
[0:41] until now. Now, this isn't absolute
[0:44] proof, but it's a step closer to
[0:47] proving there is something going on between
[0:49] the two of them and they just don't want
[0:51] anyone to know. And the world's first
[0:53] trillionaire goes public. We'll talk
[0:56] about all of that on this episode of space
[0:59] nuts.
[1:00] Professor Fred Watson: 15 seconds. Guidance is internal.
[1:02] 10, 9. Ignition
[1:05] sequence start.
[1:06] Professor Fred Watson: Space nuts.
[1:07] Professor Fred Watson: 5, 4, 3, 2. 1, 2, 3, 4,
[1:10] 5, 5, 4, 3, 2, 1.
[1:12] Andrew Dunkley: Space nuts.
[1:13] Professor Fred Watson: Astronauts report it feels good.
[1:16] Andrew Dunkley: And he's with us again for another dose of
[1:19] whatever it is he takes before he talks to
[1:21] me.
[1:21] It's Professor Fred Watson Watson, Astronomer
[1:23] at, uh, large. Hello, Fred Watson.
[1:25] Professor Fred Watson: It's good cup of tea that I take
[1:27] normally.
[1:29] Andrew Dunkley: Uh, I've been drinking a bit more
[1:32] tea of late. Um, only because, um,
[1:36] by the afternoon I'm not really into coffee.
[1:38] But today I did have coffee, so.
[1:41] Do love my coffee.
[1:43] Professor Fred Watson: I do too, but I make my own.
[1:45] Andrew Dunkley: I got the whole barista thing going.
[1:48] I'm even doing latte art, Fred Watson.
[1:50] Professor Fred Watson: Oh, really?
[1:51] Andrew Dunkley: Yeah. I don't know if you'll see this. I took
[1:53] this photo, um,
[1:56] today of my latte art. Can you see that?
[1:59] Professor Fred Watson: That is brilliant.
[2:00] Professor Fred Watson: Yeah.
[2:01] Andrew Dunkley: Whoa.
[2:01] Professor Fred Watson: That's real pro stuff. Self taught
[2:03] barista.
[2:05] Professor Fred Watson: Yes.
[2:06] Andrew Dunkley: I don't know what it is. It's like some kind
[2:08] of flower, like a lotus flower.
[2:09] Professor Fred Watson: Well, it reminds me of ears of corn.
[2:12] Andrew Dunkley: Oh, yeah, it does, doesn't it? Yeah, yeah,
[2:14] yeah, that's what it was. Or just ducks
[2:16] sitting on top of each other or something.
[2:17] Professor Fred Watson: Could be your. Could be your corny latte.
[2:20] Andrew Dunkley: Yes, it could be. Anyway, I've been working
[2:23] on that.
[2:23] Professor Fred Watson: That's very good. Yeah.
[2:25] Andrew Dunkley: I was going to do a whole series and put them
[2:27] on Instagram of my progression through being
[2:30] really crap at it and to reaching a
[2:32] point where it's, you know, something to look
[2:35] at, but I didn't bother and now I wish I had
[2:37] because I've had some epic fails.
[2:40] But um, that one came out quite well today.
[2:43] Professor Fred Watson: That's very nice. Well done.
[2:44] Andrew Dunkley: M. Right, let's uh, let's get on with this
[2:47] because, uh, we've got a lot to talk about as
[2:49] always.
[2:50] And our first storey comes from Australia,
[2:53] mate. And it is the uh,
[2:56] remapping of uh, the magnetic
[2:58] fields of a, uh, large swathe of
[3:01] um, uh, the universe. Or is it a large
[3:04] swathe of uh, whatever piece of the backyard
[3:07] sky someone can see out of. Not sure how much
[3:09] of it they
[3:10] Professor Fred Watson: got a good chunk of it
[3:13] actually. I, uh, thought so because, um.
[3:16] So these observations were made
[3:19] at uh, uh, a site in
[3:22] Western Australia known as Inyariman il Ghare
[3:24] Bundara, which is Wajari for
[3:27] sharing sky and stars. The Wodgery people are
[3:29] the traditional owners there. And it's also
[3:32] called the CSIRO Murchison Radio Astronomy
[3:34] Observatory, but we tend to refer to it as
[3:36] Inyarimana il Ghari Bundara because it's a
[3:39] very nice name. Uh,
[3:42] so what's there? There is, um, first of
[3:45] all, um, it's the site for the
[3:47] Low Frequency, uh, arm, um, of the
[3:50] Square Kilometre Array. Uh, Square Kilometre
[3:53] Array Observatory exists in three places.
[3:56] Uh, one is western, earlier where the Low
[3:58] Frequency antennas are. The uh, other is
[4:00] in South Africa where the mid Frequency
[4:03] antennas are. And the other is near
[4:05] Manchester where the headquarters are. Um,
[4:08] that's Chodrell bank is where the
[4:10] headquarters of SKAO are. Uh, uh, and
[4:13] they've just got a new Director General, uh,
[4:15] by the way, um, Jessica Dempsey I think is
[4:18] her name. Somebody I've kind of run
[4:21] into before over the years. Uh, is um,
[4:24] uh, the new Director General of the SKAO
[4:27] Observatory. Sorry, SKA Observatory. Anyway,
[4:30] yeah, also on the site in Western Australia
[4:33] is ascap, which is the
[4:35] Australian SKA
[4:38] Pathfinder. A s K a p.
[4:41] Coincidence.
[4:43] Andrew Dunkley: Uh, an ASCAP is also something you can wear
[4:45] if you don't have any pants.
[4:50] Professor Fred Watson: There's no answer to that, Andrew.
[4:52] Andrew Dunkley: Uh, no,
[4:55] no, that one. Can't we just let that one.
[4:56] Professor Fred Watson: No, I might leave that one alone. Yeah.
[4:59] Anyway, notwithstanding that.
[5:02] See, you don't get this on other podcasts, do
[5:04] you? It's why we're number one in Iceland.
[5:07] Andrew Dunkley: That's right, we are. Thank you.
[5:10] Iceland.
[5:11] Professor Fred Watson: Absolutely. Go for it. Um,
[5:14] I forgot. Yes. ASCAP,
[5:17] not the garment, but the um,
[5:20] Radio Telescope Array, 3612 metre
[5:23] dishes which were built um, over
[5:25] the. I guess 15 years ago was when they
[5:28] started. It's been operational for probably
[5:30] more than 10 years now and done some fabulous
[5:33] work. Uh, but the latest piece of high
[5:36] profile research that's come from ASCAP is
[5:39] exactly as you've said, the largest
[5:41] magnetic map of the universe ever produced,
[5:44] five times larger than all previous efforts
[5:46] combined. And it marks the beginning of a new
[5:49] generation of research into the field of
[5:51] intergalactic magnetism. And I'm reading
[5:53] there from the CSIRO news release,
[5:56] um, probably spot the hype but it's well
[5:58] deserved type as well and a, uh, well
[6:01] deserved kudos to the team leader Alec
[6:03] Thompson of csiro. Um,
[6:06] what they've done is used
[6:08] the telescope uh, in a, I
[6:11] suppose in an innovative way.
[6:14] Uh, how do you measure magnetic fields? Well
[6:16] you know normally to measure a magnetic field
[6:18] we stick uh, a magnetometer in the way.
[6:21] That's how magnetic fields are measured in
[6:23] the solar system by various spacecraft
[6:25] because they carry magnetometers which
[6:27] measure the local magnetic field of where you
[6:29] are. Um, and that gives us
[6:32] some insights into not just the sun's
[6:35] magnetic field, not the Earth's magnetic
[6:36] field and the sun's magnetic field, but also
[6:39] uh, courtesy of Voyager, the two Voyager
[6:41] spacecraft. The galaxy's magnetic field
[6:44] because we can sense the direction of that
[6:46] with the magnetometers uh, carried by those
[6:49] spacecraft which are now beyond the sun's
[6:51] magnetic influence. But
[6:54] uh, it's quite a long jump
[6:57] from the environs of the
[7:00] solar system to the universe as a whole,
[7:03] uh, which is what these scientists have done.
[7:06] And the basic technique
[7:09] is uh, it's all about
[7:12] um, polarisation and
[7:15] we've talked about polarisation before, we
[7:18] all know what it does when we
[7:21] wear our uh, polarising sunglasses and you're
[7:23] driving your car into the sunlight and
[7:26] there's a huge reflection coming off the
[7:29] road, especially if it's wet. Uh, and your
[7:31] polarising sunglasses magically take away
[7:35] that's happening because uh, the light waves
[7:38] uh, have um,
[7:41] if you think of them as just being wiggles in
[7:43] space, which they are, ah, electromagnetic
[7:45] wiggles, they have a preferred direction.
[7:48] Um, normal light has a mix of all these
[7:51] directions but uh, it turns out that
[7:54] you can separate out them by using
[7:56] well a polarising filter which is what we've
[7:59] got in our sunglasses that only lets through
[8:01] the vibrations that are vertical. That's the
[8:04] vertical direction of the light that's coming
[8:06] to you because the horizontal ones which are
[8:10] very um, much reflected uh,
[8:14] in the reflection from the wet road, they are
[8:17] cancelled out and so you don't see them. Uh,
[8:21] so we're kind of familiar with that idea of
[8:24] the direction of vibration of
[8:26] Light waves. Well, the same holds good
[8:29] in, um, in radio waves. And
[8:32] so ASCAP and many other radio
[8:34] telescopes can actually sense the
[8:37] polarisation of the radio
[8:39] signals that they're receiving from deep
[8:41] space. Uh, and so that's all
[8:44] well and good, you can sense the
[8:46] polarisation, but you can also
[8:48] detect if that polarisation's
[8:51] been twisted. And that's what happens
[8:54] when the light passes through a magnetic
[8:56] field. Um, it actually rotates,
[8:59] called Faraday rotation. It's the plane of
[9:02] the radio waves twists. And
[9:05] you can detect that with an array like
[9:08] ascap. And that is what has allowed
[9:11] people to measure the magnetic field of the
[9:13] universe. Because what you do
[9:16] is you look at, uh, the light from
[9:19] a distant galaxy and you look at the way
[9:22] its polarisation changes, uh, as that
[9:25] light comes towards us by using this
[9:28] technique. And so what you're saying is
[9:31] that you've got a kind of, um,
[9:34] a beacon lamp in the distance and
[9:37] what you can sense is what's happening to the
[9:39] light coming from that as it passes through
[9:41] magnetic fields on its way. And so
[9:44] that's the basis of the map, as
[9:47] far as I can tell from, because I'm not a
[9:50] radio astronomer, which is pain, the obvious,
[9:52] probably from the way I'm talking about it.
[9:54] Um, I think you probably
[9:57] don't know how far away that magnetic field
[10:00] is. And so, um, what you can
[10:02] infer is, uh,
[10:06] for example, how rapidly it changes, uh,
[10:08] depending on the position
[10:11] in the sky. Um,
[10:15] when you look at this map, and I urge our
[10:17] listeners to have a look at it, it's pretty
[10:19] easy to find and largest magnetic map of the
[10:21] universe yet. Um, you'll see lots of colours.
[10:24] Um, the colours, I think, are colour coded in
[10:27] that. I, um, think if I remember rightly,
[10:29] red is with the North Pole
[10:32] pointing towards us of the magnetism, and
[10:35] blue is it pointing the other way. Um,
[10:38] and so that, uh, lets you sense the
[10:41] magnetism along that line of sight. And so
[10:44] the biggest detail is actually in the
[10:46] galactic centre, which is full of churning
[10:49] magnetic fields. I guess you are having a
[10:51] look at it now.
[10:52] Andrew Dunkley: I'm looking at it right this minute. And
[10:54] yeah, you're right that they're explaining
[10:56] that just like, um, you've got blue shift and
[10:58] redshift with light waves, the magnetic
[11:01] fields have the same kind of qualities in
[11:04] terms of north, south, um, on the
[11:07] magnetic plane. And yes, the centre of the
[11:09] Milky Way galaxy is probably the most
[11:11] volatile part of this entire picture. Um,
[11:14] which is not surprising. We live there.
[11:17] Professor Fred Watson: That's right.
[11:17] Andrew Dunkley: We know all about volatility.
[11:19] Professor Fred Watson: Yeah. It's home from home.
[11:21] Uh, and just going back to, um, what
[11:24] you said a few minutes ago, um, there is a
[11:27] hole in the, uh, map. And
[11:30] that's because ascap, there's certainly
[11:33] regions of the northern sky that ASCAP can't
[11:35] see because they're permanently below the
[11:37] horizon. They're relatively small, actually,
[11:38] because ASCAP can look a long way down
[11:41] towards the horizon, much further than we
[11:42] can. In optical astronomy. In optical
[11:45] astronomy, the atmosphere just gets too thick
[11:47] when you're looking very low down until you
[11:49] get all the distortions and everything from
[11:51] the atmosphere. That doesn't happen, uh, with
[11:53] low frequency radio waves. Um,
[11:56] the gap that's missing because of the
[11:58] Northern Hemisphere, uh, because it's not
[12:00] visible to the telescope, that's actually
[12:02] relatively small compared with if it was an
[12:04] optical astronomy picture that you were
[12:06] looking at. But yes, this map has
[12:09] the line of the Milky Way across its equator,
[12:11] across the middle. Um, lots of magnetic
[12:14] turbulence in there, some really intriguing
[12:17] features, things that look like magnetic
[12:19] fingers just sort of pointing around. It's
[12:22] a remarkable map which, um, yeah, I encourage
[12:24] people to have a look at.
[12:26] Andrew Dunkley: Now, just by way of, um, taking this a step
[12:29] further. Uh, what can they now,
[12:31] or what can anybody now do with a map like
[12:34] this? Because it's been made publicly
[12:36] available, hasn't it?
[12:37] Professor Fred Watson: Yes, so that's exactly right. Those data, uh,
[12:40] are now publicly available. By the way, I
[12:43] do like the name of it, which is
[12:45] Spice.
[12:46] Andrew Dunkley: Spice Racks.
[12:47] Professor Fred Watson: Yeah. Uh, so Racks is
[12:50] the Rapid ASCAP Continuum Survey.
[12:53] And I've forgotten what Spice is, but it's
[12:56] something equally, equally delightful.
[12:59] Uh, but the Spice Racks Survey, I think is,
[13:01] uh, is. It's got its own, uh,
[13:04] own. Own charm about it.
[13:06] Andrew Dunkley: I was going to say something tongue in
[13:09] cheek about a girl group named Something to
[13:11] do with spice.
[13:12] Professor Fred Watson: Oh, yes, I know that.
[13:14] Andrew Dunkley: Then I thought, no, you can't really
[13:16] associate that with racks. You could get
[13:17] yourself smashed.
[13:20] Professor Fred Watson: I would leave that well alone. I will.
[13:22] Andrew Dunkley: I won't mention it.
[13:23] Professor Fred Watson: Yeah, so, um,
[13:25] it's. Yes, so it's so. And, and yes,
[13:28] as data are already publicly
[13:31] available, uh, research groups are already
[13:35] actually digging through this to see
[13:37] what it tells us about the, you know, the
[13:40] magnetism of galaxies, for a start.
[13:42] Professor Fred Watson: Uh,
[13:44] Professor Fred Watson: and just the way the environment of a galaxy
[13:48] is dominated by a particular magnetic field.
[13:50] It's only recently that we've understood
[13:53] that cosmic magnetic fields. That,
[13:56] uh, is magnetic fields in space play a huge
[13:58] role in so many areas of astrophysics,
[14:01] but certainly in the way galaxies evolve
[14:04] over the millennia. Millennia.
[14:07] I suppose they are uh, the way they evolve,
[14:10] uh, is, um, very much
[14:13] dominated by the local magnetic fields. And
[14:16] one of the big puzzles in cosmology, the
[14:19] science of the universe as a whole, is where
[14:22] did these magnetic fields come from in the
[14:23] first place? And it's actually
[14:26] one of the things on the list of target
[14:29] science. The Square Kilometre Array
[14:32] itself was designed to address what's the
[14:35] origin of the cosmic magnetic field, uh,
[14:38] because we really don't know how they came to
[14:41] exist. And more than that, we don't
[14:44] know how magnetic fields have changed as, you
[14:46] know, as the universe itself has evolved. All
[14:49] this lets you do that because, of course, as
[14:51] you look further out into space, you're
[14:52] looking further back in time. So there's a
[14:55] time dimension of this as well.
[14:57] Andrew Dunkley: Yeah, there's a lot of magnetism out there.
[14:59] And as you say, they don't know where it came
[15:01] from. Uh, we probably would have solved it
[15:04] except dark matter and dark energy came along
[15:06] and we went, oh, well, this is more exciting.
[15:08] But, um, yeah, it's just another one of those
[15:10] mysteries.
[15:12] Professor Fred Watson: It is. And I'm sure,
[15:14] um, all the scientists who've been involved
[15:17] with this have got magnetic personalities.
[15:20] Oh, sorry. I do my best.
[15:23] We aim to please.
[15:24] Andrew Dunkley: Pretty good, that one. All right. If you'd
[15:26] like to read up on it, you can do that
[15:28] through the scene. CSIRO website. It's an
[15:30] Australian website and you can download the
[15:33] map. It's only 6 million megabytes. It's
[15:35] a 6 megabytes. It's not a big file in the
[15:38] modern age. Uh, you can also read the
[15:41] paper in publications of the Astronomical
[15:44] Society of Australia. This is
[15:47] Space Nuts with Professor Fred Watson Watson
[15:49] and Andrew Dunkley.
[15:55] Space Nuts.
[15:56] Professor Fred Watson: All right. Um, now, you
[15:59] did press, didn't you?
[16:01] Andrew Dunkley: I did press record. Yes. Um, yes,
[16:04] the giant gap was a misfire.
[16:06] Professor Fred Watson: Oh, good. That's good.
[16:07] Andrew Dunkley: Okay, we get those.
[16:09] Uh, now our next storey, it's a, uh, new
[16:12] report about the relationship between
[16:14] black holes and dark matter. Now this is,
[16:16] this is something that our audience has quite
[16:19] often thrown up. You know, there's got to be
[16:21] a connection, uh, between black holes and
[16:24] dark matter, et cetera, et cetera. Uh,
[16:27] and now they've released a paper that's
[16:29] suggesting just that.
[16:31] Professor Fred Watson: Yes, this is really interesting stuff. And of
[16:34] course, um, it covers
[16:37] two of the most popular topics that we
[16:40] discuss on, uh, Spacenuts. This is
[16:43] research, uh, from Virginia Tech,
[16:46] uh, in the United States. And
[16:49] it's very neat because it uses a technique
[16:51] that I've always found absolutely
[16:53] fascinating, um, which
[16:56] is it's got A fancy name, uh,
[16:59] called reverberation mapping. Uh,
[17:02] but we usually talk about light echoes.
[17:06] Uh, and the easiest way to
[17:08] envisage it is, uh, the one that
[17:11] I think drew
[17:13] everybody's attention to this phenomenon back
[17:16] in the 1980s, uh, when
[17:19] supernova 1987A,
[17:22] the nearest supernova to us since
[17:24] Kepler's supernova in 1604, I think it was,
[17:28] um, that uh, became very much the object
[17:30] of attention. Uh, it was in the Large
[17:32] magellanic Cloud, to 165,000 light
[17:35] years away from us as the crow flies.
[17:38] And what was discovered as time
[17:41] went on was the. So that the
[17:43] supernova explodes. You've got this brilliant
[17:46] flash of light. It was easily visible to the
[17:48] naked eye. I remember looking at it. Uh,
[17:51] and uh, then as time goes by, the light
[17:54] fades. But what you get,
[17:57] uh, uh, as time goes on is a series of
[18:00] rings around the, apparently around
[18:04] the site of the explosion. And those
[18:07] rings are caused by light being
[18:11] reflected off clouds of dust which
[18:13] are between us and the supernova. And you
[18:16] can do all kinds of really neat calculations,
[18:20] uh, to discover how thick those clouds of
[18:23] dust are, where they are in relation to the
[18:25] supernova. Um, um, one of my
[18:27] colleagues, now sadly no longer with us,
[18:30] David Allen, was a past master,
[18:32] uh, about working on this and writing about
[18:35] it. And uh, those rings are called
[18:37] light echoes because it's the echo of the
[18:39] light of the supernova which has now faded
[18:42] away. But you can still see it because it's
[18:44] bouncing off clouds of dust in space.
[18:48] So, so what this article is
[18:51] about, the Virginia Tech work that we've just
[18:53] mentioned is we know that black
[18:56] holes, supermassive black holes, are
[18:58] surrounded by swirling discs of
[19:01] matter. Uh, they're called the accretion
[19:04] disc. It's the stuff that's basically
[19:06] swirling around the plug hole, um, before it
[19:09] either gets sucked into the black hole or
[19:11] shot out vertically from the poles of the
[19:14] black hole. The rotation poles it in the form
[19:16] of these jets, which we hear a lot about. But
[19:18] the accretion disc itself is bright,
[19:21] um, in X rays and radio radiation.
[19:25] Uh, once in a while, um, a
[19:27] larger dollop of matter enters the
[19:30] accretion disc. And you get this
[19:32] outburst, you get a brilliant outburst
[19:36] of radiation. Um, and
[19:39] that outburst is relatively short lived.
[19:42] It might last for a few weeks or even months,
[19:44] but it's short lived. And so what you can
[19:47] look for is a light echo
[19:50] around it. Because that light radiates
[19:52] outwards from the accretion disc. And if it
[19:55] hits anything outside it,
[19:58] it will reflect back to us. And we'll see it
[20:01] at a later date from when
[20:04] the bright event itself
[20:06] happened. So you see the bright event in the
[20:09] accretion disc and then at, uh, some time
[20:11] later you see an echo of that
[20:14] light which is being reflected off,
[20:17] usually gas and D which is surrounding,
[20:20] uh, the accretion disc. What this storey is
[20:23] all about though, is that, uh, when you do
[20:25] calculations about how
[20:28] much material there
[20:31] is in the accretion disc where the echo
[20:34] is taking place, you get a much
[20:37] higher mass than what you can see. And
[20:39] that's always the, um,
[20:42] that's always the um, uh, kind of
[20:44] telltale signature of dark matter
[20:48] when you can only see a limited, limited
[20:50] amount of stuff. But gravity tells you
[20:53] there's much more, there's more there. And
[20:55] that's exactly the basis of this storey. So
[20:57] it's just a new way of detecting
[21:00] the dark matter, uh, around
[21:03] black holes. But it looks as though black
[21:06] holes, as you'd expect, not only
[21:09] are a magnet for regular matter. I, uh,
[21:12] mean a gravitational magnet. I guess it's not
[21:15] magnetic in the sense that we've just been
[21:16] talking about, uh, but a gravitational,
[21:19] uh, pull from, for normal matter. It's also a
[21:21] gravitational pull for dark matter as
[21:24] well. And it looks as though the dark matter
[21:26] actually congregates around black holes that
[21:29] we've got, um, these buildups of dark
[21:32] matter, ah, in the vicinity of a black
[21:34] hole. Quite remarkable.
[21:37] Andrew Dunkley: Now, the situation is that they
[21:39] haven't absolutely proven it. They've
[21:42] just come up with a way of suggesting that
[21:45] this might be the case. But, um.
[21:47] Yeah, it's not absolute. It's not.
[21:52] Professor Fred Watson: It is in the sense that, um, they've looked
[21:55] at this for 14 different
[21:57] galaxies and all found
[22:00] cases where, uh,
[22:03] what you're looking for is the way the mass
[22:06] changes with distance from the black hole.
[22:08] And that mass is increasing because you're
[22:11] looking at stuff swirling around. But the
[22:14] increase in mass is faster
[22:17] than the visible matter on its own can
[22:19] explain. And that's the a. It's
[22:22] a kind of smoking gun for dark matter,
[22:24] really.
[22:24] Andrew Dunkley: Yeah, I, I've, I've found the paragraph. It
[22:27] says data limitations mean the results are a
[22:30] proof of concept, not a definitive,
[22:32] Definitive detection. Detection. But the
[22:34] study outlines a clear path to confirmation.
[22:36] Professor Fred Watson: That's right, yeah. So that.
[22:37] Andrew Dunkley: We're almost there.
[22:38] Professor Fred Watson: We're almost there. That's. That's exactly
[22:40] right. We're almost there.
[22:41] Andrew Dunkley: That is very exciting news. And, um, that
[22:44] will stop probably 75% of the questions we
[22:47] get on our Q A editions.
[22:50] Professor Fred Watson: Well, it, it might, but I Bet it produces
[22:53] another 150 about what it is that we're
[22:56] finding and how do we know why? Isn't it mond
[22:58] and things like that? Yeah.
[23:00] Andrew Dunkley: Yes. Oh gosh, it will just. It'll never end.
[23:03] It will never end. I hope it never ends.
[23:05] Professor Fred Watson: I think it's great.
[23:07] Andrew Dunkley: But if you want to read about it,
[23:08] it's@fizz.org uh, they publish the paper
[23:11] in the Physical Review D. Does that mean
[23:14] there's an A, B and C that comes with.
[23:16] Professor Fred Watson: Yes it does.
[23:17] Andrew Dunkley: I assume so.
[23:18] Professor Fred Watson: But um, that's a high profile journal though.
[23:20] Physical Review. It's uh, definitely uh,
[23:24] uh, you know it's, it's uh, ranks with Nature
[23:26] and Science and these very high profile
[23:28] journals. So it's not work that is
[23:31] in any way secondary. It's not like Space
[23:34] Nuts where it's adequate. This is top
[23:38] ranked stuff.
[23:39] Andrew Dunkley: Indeed it is. Uh, yes. So read about it
[23:42] at Physical review or@phys.org this is
[23:45] space Nuts. Andrew Dunkley here with
[23:46] Professor Fred Watson Watson.
[23:51] Professor Fred Watson: Okay, we checked all four systems.
[23:54] Professor Fred Watson: Space Nets.
[23:56] Andrew Dunkley: Our final storey. Fred Watson takes us
[23:58] into the realm of um,
[24:01] publicly offering your company up on the
[24:04] stock exchange.
[24:05] Professor Fred Watson: I wonder why we're going to talk about that.
[24:07] Andrew Dunkley: I wonder why uh, the world's first
[24:09] trillionaire has just done that in um, a
[24:12] very interesting way. And to coincide with
[24:14] the launch, um, he's selling stuff
[24:17] like we do on the Space Nuts shop. All
[24:20] sorts of little bits and bobs if you want a
[24:23] piece of the action.
[24:24] Professor Fred Watson: Yes, the IPO merch.
[24:26] Andrew Dunkley: It really is a remarkable storey though. Uh,
[24:29] elon Musk and SpaceX. Because uh,
[24:32] as this article briefly um, mentions,
[24:35] he didn't think the company would survive. He
[24:37] didn't expect it to actually be a success.
[24:40] He gave it a very low chance of lasting
[24:43] and look at him now.
[24:46] Professor Fred Watson: Quite so. The world's world first
[24:48] trillionaire. Ah yeah, it's um,
[24:52] I mean I don't honestly I know virtually
[24:54] nothing about the world of high finance.
[24:57] Andrew Dunkley: Um, well you know more than me then.
[25:00] Professor Fred Watson: When I see numbers like millions and
[25:02] billions, I always expect there to be light
[25:04] years after them rather than dollars.
[25:07] But yeah, it's uh, the, the public,
[25:10] the IPO initial public offering, um, has
[25:13] valued this company at uh, something
[25:15] absolutely huge. Compared with all the other
[25:18] tech companies that are being floated or are
[25:20] likely to be floated into public ownership.
[25:23] It's enormous. Um, is it
[25:26] 170 billion? Am I thinking of the right
[25:28] number there or is that light years? That
[25:30] could be light years, I don't know.
[25:33] Anyway, um, the bottom line so, yes, that
[25:35] was, um, uh, over the weekend that
[25:39] m offering IPO
[25:42] happened, uh, and it was very successful.
[25:45] Um, I heard people on Friday saying, oh, no,
[25:48] it'll probably just fail because nobody will
[25:50] actually believe what Elon Musk's saying.
[25:53] Well, they might not have believed what he
[25:55] was saying, but they put their money where
[25:56] their mouths were. And um, yeah, so it's done
[25:59] very, very well. Um, I think the number
[26:02] I'm thinking of is $160.95,
[26:05] which is the share price.
[26:07] Andrew Dunkley: Well, I've just looked now and I know this is
[26:09] being recorded. So by the time people hear
[26:11] this, the number will change. But at the
[26:13] moment, at this very moment,
[26:15] $192.50 in US
[26:18] dollars.
[26:18] Professor Fred Watson: All right, so they've already gone up then.
[26:21] Andrew Dunkley: They've gone up 19.6%.
[26:23] Professor Fred Watson: Yeah.
[26:24] Andrew Dunkley: In fact, they're up 31.55% today.
[26:27] Professor Fred Watson: So not a bad investment really, if you're
[26:29] into that kind of thing. Yeah, well, we're
[26:31] not into that kind of thing, but we're
[26:33] definitely into merge. Uh, and that's what
[26:35] this storey's about because,
[26:38] um. Uh, I guess the one
[26:41] thing you can not accuse Elon
[26:44] Musk of is lacking flair, um,
[26:47] because he's done this very nicely. You can
[26:49] buy a mission patch,
[26:52] Professor Fred Watson: uh,
[26:52] Professor Fred Watson: for the ipo, uh, which says
[26:55] the future is public. There's a lovely
[26:58] embroidered starship in the
[27:01] background. Uh, in the middle it says
[27:03] SPCX, which is SpaceX liftoff
[27:06] underneath it. And, uh, SpaceX
[27:08] 2026. Uh, and it's also got a four
[27:11] leaf clover on it, which I think is present
[27:13] on all Elon Musk. SpaceX.
[27:16] Andrew Dunkley: I think that's been his logo since day one.
[27:18] Professor Fred Watson: Yes. Yeah. M a sign of good luck.
[27:21] Maybe that's what's done it. But the thing I
[27:24] liked was, um, uh,
[27:27] you can have a souvenir bell.
[27:30] And I guess I don't know whether
[27:33] bells are normally associated. I know they're
[27:35] certainly associated with the stock exchange,
[27:37] but whether with, uh, public offerings,
[27:40] they're associated. But they certainly are in
[27:42] this case. And what he's chosen for the shape
[27:44] of his bell is something absolutely perfect.
[27:46] It's the bell, um, of,
[27:49] uh, a Raptor engine. These rocket
[27:52] motors have a very strongly bell shaped,
[27:55] uh, thrust chamber. I guess it's the, um,
[27:58] opening, uh, that lets all the gas out, uh,
[28:01] after it's been ignited in the combustion
[28:04] combustion chamber above it. And so it's a
[28:05] scale replica of the Raptor engines that
[28:08] actually power the Falcon
[28:11] Heavy, um. I beg your pardon, the super heavy
[28:13] Booster, which is the basis of starship.
[28:16] It's got 33 of these. And
[28:19] um, uh, this one's
[28:22] got a little clapper in the middle that lets
[28:24] you ring it as well as all the artwork. And
[28:27] apparently it rings. Yes, because there's a
[28:28] video on the website that shows you that, uh,
[28:31] they
[28:32] Andrew Dunkley: haven't released those yet to the
[28:34] public.
[28:35] Professor Fred Watson: That's right.
[28:35] Andrew Dunkley: They will be out probably. I think they're
[28:37] talking December. Yeah, um,
[28:40] yeah, they're sort of an 18 centimetre or
[28:43] 7 inch scale model of the, the
[28:45] SpaceX Raptor Bell. This
[28:48] one has a, you know, clunker in it that makes
[28:51] it ring. I don't know what that thing's
[28:53] called inside the bell, the dinghy thing.
[28:56] Professor Fred Watson: It's a clapper, is it? That's the technical
[28:59] name. Yeah, for.
[29:00] Andrew Dunkley: Anyway, so they're selling those, they're
[29:02] selling, uh, tote bag and
[29:05] um, as you said, mission patches, T shirts,
[29:08] caps, you
[29:11] Professor Fred Watson: know, he's um, he's the sort of
[29:13] Andrew Dunkley: bloke that never lets opportunity get away.
[29:15] Professor Fred Watson: None whatsoever. I, I did hear
[29:19] some of the things that he said publicly at
[29:22] the launch which made me cringe,
[29:25] uh, because,
[29:28] you know, I can, I can, can just about,
[29:32] um, believe that we
[29:34] might get humans to Mars in his lifetime.
[29:38] It won't be millions. And that's because
[29:41] that's immoral, apart from anything else.
[29:44] Um, but he was talking about,
[29:47] uh, you know, flying through,
[29:50] around the solar system and beyond.
[29:54] And at the moment that is off
[29:57] the agenda. Physics doesn't let you do
[30:00] that.
[30:01] Uh, just actually as a little footnote to
[30:03] that, I read a paper yesterday, uh, which
[30:06] is about, you know, the idea of
[30:09] using, um, photonic
[30:12] propulsion, or basically light, Ah,
[30:14] energy blasted at a light sail. You've got a
[30:17] laser, uh, you fire it at this light sail and
[30:20] the spacecraft accelerates because of that.
[30:22] That's all fine and dandy and will work,
[30:25] um, if you can make your spacecraft light
[30:27] enough. But it turns out that you're not ever
[30:29] going to get near the speed of light
[30:32] beyond about 75% of the speed of light.
[30:35] You, uh, get something called relativistic
[30:37] drag, uh, where space itself drags on the
[30:40] light sail as well as any kind of
[30:42] interstellar matter that you've got to plough
[30:45] through at 75% of the speed of light.
[30:47] So that's not going to get us touring around
[30:50] the galaxy.
[30:51] Andrew Dunkley: No, we'll have to find another way.
[30:52] Professor Fred Watson: Need another way? Yes.
[30:54] Andrew Dunkley: They need to go to science fiction, um,
[30:56] writers and see what they've come up with.
[30:59] Professor Fred Watson: Maybe that's what Elon's thinking of. Maybe
[31:01] he was suddenly in the realm of science
[31:03] fiction, but he didn't bother to tell us.
[31:05] Andrew Dunkley: No, maybe not, no. But there's no, Nothing
[31:08] fictional about his, um, ip.
[31:11] Professor Fred Watson: No, not at all.
[31:12] Andrew Dunkley: Uh, initial public offering that is out there
[31:14] and it is going gangbusters. It's burning
[31:17] like a raptor at the moment.
[31:20] Professor Fred Watson: Yeah, probably will. I mean, you know,
[31:23] you've got to give the guy credit. Uh,
[31:26] two of the biggest breakthroughs of our, of
[31:28] our generation, huh? Electric vehicles
[31:31] and, um, reusable booster rockets. And
[31:34] basically they've come from him.
[31:35] Andrew Dunkley: Yes, they have. It's quite
[31:38] extraordinary. Yeah, you can read about it at
[31:41] collectspace. Uh, dot com. We, um,
[31:44] won't tell you all the prices of everything
[31:46] he's selling because that's, you know, you go
[31:48] and have a look. Um,
[31:51] totally your call. Um, but I do like the
[31:54] idea of mission patches and I'm pretty sure I
[31:56] suggested that to Huw many years ago that we
[31:59] should have mission patches.
[32:01] Professor Fred Watson: Yes, yes, we do.
[32:02] Andrew Dunkley: Yes. I've got something we should. A new one
[32:05] for every episode.
[32:07] Professor Fred Watson: Oh, all right. Okay.
[32:09] Andrew Dunkley: No, that's a bit much.
[32:10] Professor Fred Watson: Look, the trouble is the mission patches,
[32:12] they would just be adequate and if you.
[32:15] Andrew Dunkley: Although, I think, ah, our logo would make a
[32:17] great patch.
[32:19] Professor Fred Watson: It would. Yeah.
[32:20] Professor Fred Watson: Yeah.
[32:21] Andrew Dunkley: Anyway, um, we'll, we'll do that one day
[32:24] maybe. I don't know. There's plenty of other
[32:25] stuff in the shop. Just go and have a look in
[32:27] our shop. It's on our website.
[32:28] Spacenutspodcast.com or
[32:31] spacenuts IO uh,
[32:33] click on the shop link and buy yourself a
[32:35] pair of socks or a notebook or a,
[32:38] um, or a coffee cup or a hat or a
[32:41] hoodie, stickers. Um,
[32:44] there's just all this great stuff there. I've
[32:46] got some of it. Look, I've got my car cup
[32:48] here. See, here's my cup.
[32:50] Professor Fred Watson: Oh, that's nice. Yeah, I might
[32:53] have one of those somewhere.
[32:54] Andrew Dunkley: I probably do, yes. And I've got the tote
[32:57] bag as well. So we thought of that before
[33:00] Elon. Probably using the same company that
[33:03] we do. But
[33:06] yes. Um, I think that brings us to the end.
[33:08] Fred Watson, thank you so much.
[33:10] Professor Fred Watson: A pleasure, Andrew, good to talk. And we'll
[33:12] speak again.
[33:14] Andrew Dunkley: We will indeed.
[33:15] Professor Fred Watson Watson, astronomer at
[33:17] large, and thanks to Huw in the studio,
[33:18] couldn't be with us today because he wants to
[33:20] be the world's second trillionaire and he's
[33:23] just put down five bucks and he's just
[33:25] watching to see what happens. And from me,
[33:27] Andrew Dunkley, thanks for your company.
[33:28] We'll see you on the next episode of Space
[33:30] Nuts.
[33:31] Professor Fred Watson: Bye. Bye.
[33:33] Andrew Dunkley: You've been listening to the Space Nuts
[33:35] podcast, available at
[33:38] Apple Podcasts, Spotify,
[33:40] iHeartRadio or your favourite podcast
[33:43] player. You can also stream on
[33:44] demand@bytes.com this has been another
[33:47] quality podcast production from
[33:49] bytes.com.

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