Join Andrew Dunkley and Professor Fred Watson in this engaging Q&A episode of Space Nuts, where they tackle a variety of intriguing questions from listeners around the globe. From the mysteries of black holes to the minimum temperature of space and the ambitious Starshot mission, this episode is packed with thought-provoking insights and lively discussions.
Episode Highlights:
- Black Hole Plasma Beams: Listener James from New Orleans sparks a fascinating discussion about plasma beams emanating from the M87 black hole and the recycling of matter in the universe. Andrew and Fred explore the implications of cooling plasma and its potential to change states.
- Minimum Temperature of Space: Buddy from Morgan raises a thought-provoking question about whether the minimum temperature of space will continue to drop as the universe expands. The duo dives into cosmic background radiation and its effects on the elements in the universe.
- Light and Gas Pressure: Jacob from Western Australia asks whether gas pressure can affect light. Andrew and Fred clarify the relationship between light, pressure, and the fascinating phenomenon of light refraction.
- Starshot Mission Hypotheticals: Ash from Brisbane presents a mind-bending hypothetical about launching a micro spacecraft to Alpha Centauri at a right angle to the galactic plane. The team calculates the time it would take to observe our galaxy from the outside, revealing the vastness of space travel.
For more Space Nuts, including our continually updating newsfeed and to listen to all our episodes, visit our website. Follow us on social media at SpaceNutsPod on Facebook, X, YouTube Music Music, Tumblr, Instagram, and TikTok. We love engaging with our community, so be sure to drop us a message or comment on your favorite 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.
00:00 - Introduction and audience questions
02:15 - Discussion on black hole plasma beams
10:30 - Minimum temperature of space and its implications
18:00 - Light behavior under gas pressure
26:45 - Starshot mission hypothetical and calculations
30:00 - Listener Ash engagement and closing thoughts
✍️ Episode References
Hubble Telescope Observations of M87
https://www.nasa.gov/hubble
Cosmic Background Radiation Studies
https://www.nasa.gov/cosmic-background-radiation
Starshot Mission Overview
https://www.breakthroughinitiatives.org/initiatives/starshot
Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-exploring-the-cosmos--2631155/support.
00:00:00 --> 00:00:03 Andrew Dunkley: Hi there. Thanks for joining us on a Q and A edition
00:00:03 --> 00:00:06 of Space Nuts. My name is Andrew Dunkley.
00:00:06 --> 00:00:08 It's always good to have your company. Thanks for joining
00:00:08 --> 00:00:11 us. All right, uh, what are we doing today? We're
00:00:11 --> 00:00:14 answering audience questions from all around the
00:00:14 --> 00:00:17 place. Well, mainly Australia, but one from New
00:00:17 --> 00:00:19 Orleans asking about black holes and plasma
00:00:19 --> 00:00:22 bursts. Uh, and Jordy wants to know where
00:00:22 --> 00:00:25 his food is. Uh, we're also talking about the
00:00:25 --> 00:00:28 minimum temperature of space, the effect of gas or on
00:00:28 --> 00:00:31 light and the starshot mission.
00:00:31 --> 00:00:33 That's all coming up in this edition of space
00:00:33 --> 00:00:34 nuts.
00:00:34 --> 00:00:37 Voice Over Guy: 15 seconds. Guidance is internal.
00:00:37 --> 00:00:39 10, 9. Ignition
00:00:39 --> 00:00:41 sequence start. Space nuts.
00:00:41 --> 00:00:43 Andrew Dunkley: 5, 4, 3. 2.
00:00:43 --> 00:00:46 Professor Fred Watson: 1, 2, 3, 4, 5, 5, 4, 3,
00:00:46 --> 00:00:49 2, 1. Space nuts. Astronauts report
00:00:49 --> 00:00:50 it feels good.
00:00:50 --> 00:00:53 Andrew Dunkley: And joining us along with Jordy, not Jaunty Joe
00:00:53 --> 00:00:56 Jordy. Uh, it's professor Fred Watson, astronomer at large.
00:00:56 --> 00:00:57 Hello, Fred.
00:00:57 --> 00:01:00 Professor Fred Watson: Hello, Andrew. Uh, yes, John. Um, John,
00:01:00 --> 00:01:02 Jordy's in the back.
00:01:03 --> 00:01:06 Johnty's not. Yeah,
00:01:06 --> 00:01:07 Jordy the dog.
00:01:08 --> 00:01:10 Andrew Dunkley: He's um, he's always welcome on the show.
00:01:10 --> 00:01:12 Always welcome on the show.
00:01:12 --> 00:01:15 Professor Fred Watson: Yeah, he had a good walk with me this morning. I, I'm
00:01:15 --> 00:01:15 good fettle.
00:01:16 --> 00:01:18 Andrew Dunkley: I'm sure he did. Um, now you're so
00:01:18 --> 00:01:21 tall and he's so small, I bet his legs go 20 to the
00:01:21 --> 00:01:22 dozen.
00:01:22 --> 00:01:24 Professor Fred Watson: M quite cute to watch.
00:01:25 --> 00:01:26 Andrew Dunkley: Be like a little wind up.
00:01:27 --> 00:01:29 Professor Fred Watson: It's what it's like. Yeah, absolutely.
00:01:29 --> 00:01:30 Andrew Dunkley: Oh, gosh.
00:01:31 --> 00:01:33 Um, now I, I, I, we, we, we've got some
00:01:33 --> 00:01:36 questions, a couple of text and a couple of audio.
00:01:36 --> 00:01:39 Now I uh, must, uh, preempt
00:01:39 --> 00:01:42 this by saying I had an eye check this
00:01:42 --> 00:01:44 morning and I had to have my pupils
00:01:44 --> 00:01:46 dilated. Right now what I'm looking at
00:01:46 --> 00:01:49 is absolute gobbledygook
00:01:49 --> 00:01:51 and it's very hard for me to read.
00:01:51 --> 00:01:53 Professor Fred Watson: So please, you want me to read it?
00:01:54 --> 00:01:55 Andrew Dunkley: I'll give it a go.
00:01:55 --> 00:01:56 Professor Fred Watson: Give it a go.
00:01:56 --> 00:01:59 Andrew Dunkley: Yeah, everything's, it's all double vision
00:01:59 --> 00:02:02 and blurry. Um, but anyway, let's, let's
00:02:02 --> 00:02:03 see what, uh, happens.
00:02:03 --> 00:02:06 Uh, this question comes from Jim in New Orleans.
00:02:06 --> 00:02:09 I read where the Hubble telescope last
00:02:09 --> 00:02:12 fall. I assume you mean autumn for the people in the
00:02:12 --> 00:02:15 rest of the world. Um, I read where the Hubble
00:02:15 --> 00:02:17 telescope last fall observed what appeared to be a
00:02:17 --> 00:02:20 plasma beam of 3 light years emanating
00:02:20 --> 00:02:23 from, from the black hole at the center of Galaxy M
00:02:23 --> 00:02:25 M87 doing well so far.
00:02:26 --> 00:02:29 That black hole was estimated to be
00:02:29 --> 00:02:31 6.5 billion solar masses.
00:02:31 --> 00:02:34 I realized that questions concerning black holes
00:02:34 --> 00:02:37 are rather rare. Uh, on the
00:02:37 --> 00:02:40 podcast, however, I understand that When a
00:02:40 --> 00:02:43 plasma, uh, cools on Earth, it can either
00:02:43 --> 00:02:45 return to its original, original gaseous
00:02:45 --> 00:02:48 elemental state, or it can potentially
00:02:48 --> 00:02:51 reform into completely different elements. Given the
00:02:51 --> 00:02:54 near absolute zero temperatures in space,
00:02:54 --> 00:02:57 I believe that at some point the plasma beam
00:02:57 --> 00:03:00 from, uh, uh, the uh,
00:03:00 --> 00:03:03 black hole at M. M87 will eventually cool.
00:03:03 --> 00:03:06 Rather than being cursed as the ultimate destroyer
00:03:06 --> 00:03:09 of matter in the universe, perhaps black holes should be
00:03:09 --> 00:03:11 considered the ultimate recyclers of
00:03:11 --> 00:03:14 matter instead. Love the podcast.
00:03:14 --> 00:03:16 Uh, all the best. Cheers.
00:03:16 --> 00:03:18 Jim in New Orleans. Uh,
00:03:19 --> 00:03:20 is he on the money?
00:03:20 --> 00:03:23 Professor Fred Watson: Well, it's an interesting question. Yes. Uh, I mean, I think
00:03:23 --> 00:03:26 he's, he's right in the sense that
00:03:26 --> 00:03:28 the plasma, when it cools,
00:03:28 --> 00:03:30 um, will,
00:03:31 --> 00:03:33 uh, essentially turn, you know,
00:03:34 --> 00:03:37 what's a plasma? A plasma is an ionized gas.
00:03:37 --> 00:03:39 So it's a gas with an electrical charge. It's
00:03:39 --> 00:03:42 an electrified gas. When it loses its
00:03:42 --> 00:03:45 charge, it basically stays the same
00:03:45 --> 00:03:47 gas, uh, but is
00:03:47 --> 00:03:50 cooler. Uh, now the completely
00:03:50 --> 00:03:53 different elements idea would involve nuclear
00:03:53 --> 00:03:56 processes because, uh, that's the only way you can
00:03:56 --> 00:03:59 change the elements, despite what
00:03:59 --> 00:04:02 the, um, what the alchemists used to try and do.
00:04:02 --> 00:04:05 Uh, you can do it with accelerators. Uh, and
00:04:05 --> 00:04:07 it may well be that, uh, the conditions in
00:04:07 --> 00:04:10 some plasmas, like the one from the M87
00:04:10 --> 00:04:13 black hole, maybe they do, um,
00:04:13 --> 00:04:16 have collisions between the,
00:04:16 --> 00:04:19 uh, the ionized atoms, uh,
00:04:19 --> 00:04:22 that are of such high energy that you might split them
00:04:22 --> 00:04:25 or something of that. So I'm not familiar with that because
00:04:25 --> 00:04:28 I'm not a particle physicist, but in that regard, yes,
00:04:28 --> 00:04:30 if that happens, you've got, uh, a nice
00:04:30 --> 00:04:33 recycling process which, um,
00:04:33 --> 00:04:36 you know, is what goes on in a nuclear reactor as well.
00:04:36 --> 00:04:39 Uh, but nice to hear from you, Jim. Uh, glad you're enjoying
00:04:39 --> 00:04:40 the podcast too.
00:04:40 --> 00:04:43 Andrew Dunkley: Yeah, um, there's so much happening when it comes
00:04:43 --> 00:04:46 to black holes. I mean, there's just. Yes,
00:04:46 --> 00:04:48 you know, it's not just the plasma. It's,
00:04:48 --> 00:04:51 it's um, you know, the
00:04:51 --> 00:04:54 hunger, if I can use that term, black
00:04:54 --> 00:04:57 holes, uh, they get the munchies. They probably smoke
00:04:57 --> 00:04:58 too much pot.
00:04:59 --> 00:05:01 Professor Fred Watson: Um, is that what happens when you smoke too
00:05:01 --> 00:05:02 much pot?
00:05:02 --> 00:05:04 Andrew Dunkley: Apparently, I've been told, yeah. Yeah,
00:05:05 --> 00:05:07 Medical paper once,
00:05:08 --> 00:05:10 I spent a lot of time reading those.
00:05:11 --> 00:05:14 Um, but yeah, they're very active,
00:05:14 --> 00:05:16 um, parts of the, the
00:05:16 --> 00:05:19 universe. And there's so much we know that
00:05:19 --> 00:05:22 they do, but we don't know so much more about
00:05:22 --> 00:05:25 them. And we've, uh, only in recent times been
00:05:25 --> 00:05:28 able to image them. Yep, not so much
00:05:28 --> 00:05:31 photographs, but, um, it, uh, was infrared, wasn't
00:05:31 --> 00:05:31 it?
00:05:31 --> 00:05:34 Professor Fred Watson: That's Radio signals in the Event
00:05:34 --> 00:05:37 Horizon Telescope. That's right. And that's where this image comes from
00:05:37 --> 00:05:39 that, that Jim's talking about.
00:05:39 --> 00:05:42 Andrew Dunkley: Okay, so, um, yeah, the.
00:05:42 --> 00:05:45 And, and we get so very many
00:05:45 --> 00:05:47 questions about them. They. One of the great
00:05:47 --> 00:05:49 mysteries. Sorry.
00:05:49 --> 00:05:52 Professor Fred Watson: And I'll just correct what I just said. Uh, the,
00:05:52 --> 00:05:55 the Hubble telescope is certainly, um, what
00:05:55 --> 00:05:58 observed that, uh, plasma beam. Uh,
00:05:58 --> 00:06:00 but M87, of course, has had its,
00:06:01 --> 00:06:04 its structure, uh, imaged by the Event Horizon
00:06:04 --> 00:06:07 Telescope. Sorry, just. Just correcting myself there.
00:06:07 --> 00:06:09 Andrew Dunkley: That's okay. It's all good. Thank you, Jim.
00:06:10 --> 00:06:10 Professor Fred Watson: Appreciate.
00:06:10 --> 00:06:11 Andrew Dunkley: Uh, the question.
00:06:11 --> 00:06:14 Uh, our next question comes from, uh, one of our
00:06:14 --> 00:06:16 regulars, Buddy. Uh, we'll see
00:06:16 --> 00:06:19 what, uh, he's got on his mind this time.
00:06:19 --> 00:06:21 Buddy: Well, hello. This is Buddy from
00:06:21 --> 00:06:24 Morgan. All right, guys, um, I
00:06:24 --> 00:06:26 got one more good one. I'll leave you alone
00:06:26 --> 00:06:29 for a while. Uh,
00:06:29 --> 00:06:32 is the minimum temperature of space,
00:06:32 --> 00:06:35 like, in the dark? Uh, is that gonna get
00:06:35 --> 00:06:38 lower as the universe spreads out? And
00:06:38 --> 00:06:40 if so, is that going to affect how things
00:06:40 --> 00:06:43 root in the universe react? Like, is that going to
00:06:43 --> 00:06:46 make the hydrogen or, you know,
00:06:46 --> 00:06:49 like helium turn into a liquid or something?
00:06:49 --> 00:06:51 Um, all right, thanks, guys.
00:06:52 --> 00:06:55 Andrew Dunkley: Uh, thank you, Buddy. Um, so as the
00:06:55 --> 00:06:58 universe is expanding, is the minimum temperature
00:06:58 --> 00:07:01 of space going to get lower? And what effect
00:07:01 --> 00:07:04 might that have on the elements? I think that's sort of the
00:07:04 --> 00:07:05 pricey.
00:07:05 --> 00:07:07 Professor Fred Watson: That's a nice pricey. Um, and,
00:07:08 --> 00:07:10 uh, Buddy's rice, it is getting
00:07:10 --> 00:07:13 lower. Uh, so, uh,
00:07:13 --> 00:07:16 the minimum temperature of space is
00:07:17 --> 00:07:20 essentially the temperature, uh, that we record
00:07:20 --> 00:07:23 from the cosmic background radiation, which
00:07:23 --> 00:07:26 is 2.7 degrees above absolute zero.
00:07:26 --> 00:07:29 Uh, so 2.7 degrees Kelvin is the temperature
00:07:29 --> 00:07:32 of space. Uh, and,
00:07:32 --> 00:07:35 uh, if you think about what that temperature
00:07:35 --> 00:07:38 was when the universe was much younger than it
00:07:38 --> 00:07:41 is now, certainly, uh, in the
00:07:41 --> 00:07:44 aftermath of the Big Bang, that temperature was, you know,
00:07:44 --> 00:07:46 5, 6, 7 degrees Kelvin.
00:07:46 --> 00:07:49 So as the universe has expanded,
00:07:49 --> 00:07:52 that temperature has fallen. And that
00:07:52 --> 00:07:55 2.7 degrees is what we have now. And
00:07:55 --> 00:07:57 as the universe continues to expand, it will continue
00:07:57 --> 00:08:00 to cool, but not at a rate that would ever be
00:08:00 --> 00:08:03 detectable by human instruments. But it is
00:08:03 --> 00:08:06 cooling. Um, whether that changes
00:08:06 --> 00:08:08 the, you know, the circumstances
00:08:08 --> 00:08:11 of clouds of gas or whatever is a
00:08:11 --> 00:08:14 different question. And I suspect the answer is no.
00:08:14 --> 00:08:17 Uh, it may, you know, it would have a
00:08:17 --> 00:08:20 superficial effect, but I don't think it's
00:08:20 --> 00:08:23 got any really fundamental effect on the
00:08:23 --> 00:08:25 makeup of the, of the cosmos.
00:08:25 --> 00:08:28 Andrew Dunkley: Okay, um, let's focus
00:08:28 --> 00:08:31 on the, the Kelvin scale for a
00:08:31 --> 00:08:34 moment. Ah, it's, it's a measure of
00:08:34 --> 00:08:37 temperature based on the absolute,
00:08:37 --> 00:08:39 absolute zero, lowest temperature.
00:08:39 --> 00:08:42 Professor Fred Watson: That's right. And
00:08:42 --> 00:08:45 that temperature is defined by
00:08:45 --> 00:08:48 being the temperature at which all
00:08:48 --> 00:08:51 motion of atoms stops. So
00:08:51 --> 00:08:54 temperature is um, a vibration of
00:08:54 --> 00:08:56 atoms. So as a solid gets warmer, the
00:08:56 --> 00:08:59 atoms vibrate more. As a liquid gets warmer,
00:08:59 --> 00:09:02 the atoms sort of slosh around more. And
00:09:02 --> 00:09:05 as a gas gets warmer, the atoms whiz around
00:09:05 --> 00:09:08 much faster, uh, in space. So um,
00:09:09 --> 00:09:11 the three states of matter there, uh,
00:09:11 --> 00:09:14 that, uh, that's to say that
00:09:14 --> 00:09:17 um, uh, at, at zero degrees
00:09:17 --> 00:09:20 Kelvin, uh, all atomic motion
00:09:20 --> 00:09:22 stops and we know it's absolutely
00:09:22 --> 00:09:25 zero. I think, um, some modern laboratories
00:09:25 --> 00:09:28 have got within a gazillionth of a degree of absolute zero.
00:09:28 --> 00:09:31 But it's one of those things you can never actually reach,
00:09:31 --> 00:09:34 uh, and get something that's whose
00:09:34 --> 00:09:37 atoms have stopped. As far as I know. Um, I might be wrong there, there might
00:09:37 --> 00:09:39 be physics laboratories where that's actually been done. But.
00:09:39 --> 00:09:42 Andrew Dunkley: Right, well, if you have, you know, chances are if you did achieve
00:09:42 --> 00:09:45 it, you'd never get home from work. Quite,
00:09:45 --> 00:09:46 you wouldn't be able to move.
00:09:47 --> 00:09:48 Professor Fred Watson: Yeah, yeah.
00:09:48 --> 00:09:51 Andrew Dunkley: So, so obviously this is a dumb
00:09:51 --> 00:09:54 question, but, um, if you like, when you
00:09:54 --> 00:09:57 freeze a tray of ice in your fridge,
00:09:57 --> 00:10:00 you've got an old fashioned fridge like me where you have to actually get the thing
00:10:00 --> 00:10:02 out, fill it with water and put it in and.
00:10:02 --> 00:10:03 Professor Fred Watson: Wait, you do that too?
00:10:03 --> 00:10:06 Andrew Dunkley: Yeah. Um, that's not
00:10:06 --> 00:10:08 absolute zero. So there's still
00:10:08 --> 00:10:09 movement.
00:10:09 --> 00:10:10 Professor Fred Watson: Yeah. In the atoms.
00:10:10 --> 00:10:12 Andrew Dunkley: In the atoms, yes, that's right.
00:10:12 --> 00:10:15 Professor Fred Watson: Even though the ice looks pretty inert, uh, the
00:10:15 --> 00:10:18 fact that it's probably, uh,
00:10:18 --> 00:10:20 well, absolute zero is minus 273
00:10:20 --> 00:10:23 degrees Celsius. So if you're cooling it down
00:10:23 --> 00:10:26 to, you know, -13 or something, then you've
00:10:26 --> 00:10:29 still got another 260 degrees to
00:10:29 --> 00:10:32 go before you get to absolute zero. So there's
00:10:32 --> 00:10:35 still plenty of movement in the atoms of your ice. Yeah.
00:10:35 --> 00:10:38 Andrew Dunkley: What about out in the depths of the solar system
00:10:38 --> 00:10:40 where the ice is so cold that
00:10:40 --> 00:10:43 it's the same as rock here?
00:10:44 --> 00:10:46 Is that anywhere near absolute zero?
00:10:46 --> 00:10:47 Professor Fred Watson: It's about um, uh,
00:10:48 --> 00:10:51 minus 190 on the
00:10:51 --> 00:10:54 surface of Titan, which is where ice is
00:10:54 --> 00:10:57 certainly effectively rock. It's as hard as rock,
00:10:57 --> 00:11:00 uh, hard as granite I think was the way, um,
00:11:00 --> 00:11:02 Jonti described it last week. Yeah, um,
00:11:03 --> 00:11:05 but even then you still, you know,
00:11:05 --> 00:11:08 83 degrees away from absolute zero.
00:11:08 --> 00:11:11 Wow. Uh, it's a very, very cold temperature.
00:11:11 --> 00:11:14 Andrew Dunkley: Sure is. Um, yeah, I,
00:11:14 --> 00:11:17 I, I, it's hard to imagine that kind of cold when
00:11:17 --> 00:11:20 the temperature outside here gets to 9 degrees. That's enough
00:11:20 --> 00:11:20 for me.
00:11:21 --> 00:11:23 Professor Fred Watson: Yes, yeah,
00:11:23 --> 00:11:24 yeah.
00:11:24 --> 00:11:27 Andrew Dunkley: Uh, so just to clarify one more
00:11:27 --> 00:11:29 point. Um, um, so absolute
00:11:29 --> 00:11:32 zero. Even though the universe is
00:11:33 --> 00:11:35 cooling, absolute zero is still absolute
00:11:35 --> 00:11:37 zero. That's not going to alter.
00:11:37 --> 00:11:40 Professor Fred Watson: That's right. Yes, that's right. And, and the universe
00:11:40 --> 00:11:43 isn't at, uh, that temperature yet. It's 2.7 degrees
00:11:43 --> 00:11:44 above it still.
00:11:44 --> 00:11:45 Buddy: Okay.
00:11:45 --> 00:11:47 Professor Fred Watson: Yeah. And that's the leftover heat of the Big Bang.
00:11:48 --> 00:11:50 Andrew Dunkley: Right. But it's slowly diminishing
00:11:50 --> 00:11:52 as, as the universe expands.
00:11:52 --> 00:11:53 Professor Fred Watson: That's right.
00:11:53 --> 00:11:55 Andrew Dunkley: But it could take a while to get down.
00:11:55 --> 00:11:58 Professor Fred Watson: Could it ever get down another degree? It
00:11:58 --> 00:12:01 will probably. If the universe
00:12:01 --> 00:12:04 carries on behaving as it does now. Uh, as it
00:12:04 --> 00:12:07 continues to expand. Yep. The temperature will continue to
00:12:07 --> 00:12:09 go down. Uh, it will never
00:12:09 --> 00:12:12 reach absolute zero. It might approach it
00:12:12 --> 00:12:15 asymptotically, which means it gets nearer and
00:12:15 --> 00:12:18 nearer, but takes longer and longer to do
00:12:18 --> 00:12:18 that.
00:12:18 --> 00:12:21 Andrew Dunkley: Right, okay. Very interesting. Great question,
00:12:21 --> 00:12:24 buddy. Thanks for sending it in. Good to hear
00:12:24 --> 00:12:25 from you as always.
00:12:25 --> 00:12:28 This is Space Nuts, Andrew Dunkley here with
00:12:28 --> 00:12:30 Professor Fred Watson.
00:12:32 --> 00:12:35 Professor Fred Watson: Three, two, one.
00:12:35 --> 00:12:38 Andrew Dunkley: Space Nuts. Now, if my eyes do not
00:12:38 --> 00:12:41 deceive me, I have a text question in front of me. Or it could just
00:12:41 --> 00:12:44 be a message from my wife that I probably shouldn't read.
00:12:44 --> 00:12:47 Uh, no, it's a question. We
00:12:47 --> 00:12:50 know that light travels at slightly different
00:12:50 --> 00:12:53 speeds in different mediums. Uh, we also
00:12:53 --> 00:12:56 see different mediums affect light via
00:12:56 --> 00:12:59 refraction since this is somewhat related
00:12:59 --> 00:13:01 to the density of gas. Can pressure affect
00:13:01 --> 00:13:04 this? Uh, if we go to the
00:13:04 --> 00:13:07 extreme case, is it possible for enough pressure,
00:13:07 --> 00:13:10 ah, of a gas, I assume cloud,
00:13:10 --> 00:13:12 or enough pressure of a gas in
00:13:12 --> 00:13:15 general to push back on light itself and
00:13:15 --> 00:13:18 stop it? That comes from Jacob in Western
00:13:18 --> 00:13:21 Australia. Um, I assume Western
00:13:21 --> 00:13:24 Australia. It could be an American state that has the abbreviation
00:13:24 --> 00:13:26 Wa I believe there is one, so
00:13:26 --> 00:13:29 could be either. But um,
00:13:29 --> 00:13:32 this reminds me of an experiment they did
00:13:32 --> 00:13:35 not so long ago where they actually did
00:13:35 --> 00:13:37 claim to have stopped light.
00:13:37 --> 00:13:40 Professor Fred Watson: Yeah, that's right. Um, so you can
00:13:40 --> 00:13:43 stop photons. Um, and I'm
00:13:43 --> 00:13:45 not sure about the
00:13:46 --> 00:13:48 mechanism that is used to do that. It's not just
00:13:48 --> 00:13:51 pressure. There's more to it than that.
00:13:51 --> 00:13:54 I think it involves basically grabbing
00:13:54 --> 00:13:57 hold of photons using optical
00:13:57 --> 00:14:00 tweezers, uh, to stop the light.
00:14:00 --> 00:14:03 Uh, and so you can stop light. It's been done
00:14:03 --> 00:14:06 exactly as you've said, Andrew. But, uh, it's not just
00:14:06 --> 00:14:08 pressure. Pressures does have an interesting. I mean
00:14:08 --> 00:14:11 it does affect the gas. So refraction,
00:14:11 --> 00:14:14 the refraction of gas is invent, is
00:14:14 --> 00:14:17 affected by the pressure of the gas. Um,
00:14:17 --> 00:14:20 what also is affected
00:14:20 --> 00:14:23 Is if you send light of a single
00:14:23 --> 00:14:26 wavelength through a gas at
00:14:26 --> 00:14:28 high pressure, um, it will spread
00:14:29 --> 00:14:31 into adjacent wavelengths. It uh, means that,
00:14:32 --> 00:14:34 you know, the way we see it is as a spectrum line. If
00:14:34 --> 00:14:37 you send that light through a
00:14:37 --> 00:14:40 rain, sorry, a prism or something like
00:14:40 --> 00:14:42 that, you'll uh, end up with a single line of
00:14:42 --> 00:14:45 light corresponding to that color which corresponds
00:14:45 --> 00:14:47 to uh, a certain wavelength.
00:14:48 --> 00:14:50 Pressure actually broadens that and so these
00:14:50 --> 00:14:53 lines become wider. Uh, the process
00:14:53 --> 00:14:56 is called guess what? Pressure broadening.
00:14:56 --> 00:14:59 And um, um, that's what we see.
00:14:59 --> 00:15:02 Uh, and that's actually how we can
00:15:02 --> 00:15:05 use light, uh, from stars to
00:15:05 --> 00:15:07 measure the pressure in the atmosphere of the star,
00:15:08 --> 00:15:11 uh, by how much the line of
00:15:11 --> 00:15:12 light is broadened.
00:15:14 --> 00:15:16 Andrew Dunkley: Okay, okay. All right.
00:15:16 --> 00:15:19 Um, I was just reading something that,
00:15:19 --> 00:15:22 um, because we were talking about the fact that they have
00:15:22 --> 00:15:24 stopped light in a lab,
00:15:25 --> 00:15:27 um, the way they did it
00:15:27 --> 00:15:30 was um, they used, as you said, a
00:15:30 --> 00:15:33 special medium like um, a cloud of
00:15:33 --> 00:15:35 ultra cold atoms.
00:15:35 --> 00:15:36 Professor Fred Watson: Yes, that's right.
00:15:36 --> 00:15:39 Andrew Dunkley: Trapped the light's photons and it
00:15:39 --> 00:15:42 effectively brought the light to a complete standstill
00:15:42 --> 00:15:45 for a brief period. And that was work that was
00:15:45 --> 00:15:47 pioneered by physicists, um,
00:15:47 --> 00:15:50 uh, lean Howe, uh, from
00:15:50 --> 00:15:53 the Bose Einstein, um.
00:15:55 --> 00:15:56 Condensate. Condensate.
00:15:57 --> 00:15:58 Professor Fred Watson: Condensate, yeah.
00:15:58 --> 00:16:01 Andrew Dunkley: So, yes, your eyes aren't working.
00:16:01 --> 00:16:04 Professor Fred Watson: Yeah, well, you're doing well actually. You're doing very well. If I,
00:16:04 --> 00:16:07 um. The eyes that you've got at the moment, I couldn't read any of the stuff that
00:16:07 --> 00:16:09 you're looking at. A, um, Bose Einstein
00:16:09 --> 00:16:12 condenser is basically, uh,
00:16:13 --> 00:16:16 it says peculiar state of matter
00:16:16 --> 00:16:19 where it behaves as a single quantum object.
00:16:19 --> 00:16:22 Uh, so you know, you put all the atoms
00:16:22 --> 00:16:25 together and they all behave like one object. It's a bit like
00:16:25 --> 00:16:26 entanglement.
00:16:26 --> 00:16:29 Andrew Dunkley: Right. It's headache y stuff, isn't it?
00:16:29 --> 00:16:31 Professor Fred Watson: It is, yeah. A very headache, yeah.
00:16:33 --> 00:16:35 Andrew Dunkley: Um, we gave uh, Jonti a lot of headaches while he was.
00:16:36 --> 00:16:37 Professor Fred Watson: Oh, good. Well that's good. He
00:16:38 --> 00:16:40 complained his keep then every time.
00:16:40 --> 00:16:43 Andrew Dunkley: He was constantly having
00:16:43 --> 00:16:45 headaches. Um. All right, uh, so we
00:16:46 --> 00:16:48 covered Jacob's question effectively.
00:16:48 --> 00:16:51 Professor Fred Watson: I, uh, hope so. Um, it's uh, really all I've got
00:16:51 --> 00:16:54 to say about it. Unless you want to throw in a couple of.
00:16:54 --> 00:16:57 Andrew Dunkley: Oh no, you're getting into the realm
00:16:57 --> 00:17:00 of science fiction if you ask me to start talking about this.
00:17:01 --> 00:17:03 Professor Fred Watson: That's all right. That's perfectly acceptable.
00:17:04 --> 00:17:06 Andrew Dunkley: Thanks, Jacob. Great. Uh, question.
00:17:08 --> 00:17:10 Okay, we checked all four systems,
00:17:11 --> 00:17:14 space nets, and our final question
00:17:14 --> 00:17:17 today comes from Ash in
00:17:17 --> 00:17:17 Brisbane.
00:17:17 --> 00:17:20 Jonti: G'day Fred and Andrew. Ash from Brisbane
00:17:20 --> 00:17:23 here. Um, got a bit of a mind bender
00:17:23 --> 00:17:26 question for you. I'm, uh, just wondering if we
00:17:26 --> 00:17:29 were to take one of the breakthrough star shot
00:17:29 --> 00:17:32 micro spacecraft that we're going to send through to Alpha
00:17:32 --> 00:17:35 Centauri, but launch it 90 degrees to the
00:17:35 --> 00:17:38 plane of our galaxy, how far, ah,
00:17:38 --> 00:17:41 and for how long? Going to have to travel before I can look back
00:17:41 --> 00:17:43 and see what our galaxy looks like from the outside.
00:17:44 --> 00:17:46 Interested to hear your thoughts. See you guys.
00:17:46 --> 00:17:48 Love the show. Bye.
00:17:48 --> 00:17:51 Andrew Dunkley: Thank you, Ash. I'm, uh, thinking that question
00:17:51 --> 00:17:53 came from one of the
00:17:54 --> 00:17:57 hypotheticals, um, that were thrown at us recently,
00:17:57 --> 00:18:00 asking if we could go anywhere in the
00:18:00 --> 00:18:03 universe and look at something, what would
00:18:03 --> 00:18:06 it be? And your answer was to go outside our
00:18:06 --> 00:18:09 galaxy and look back at it and see what it really looked like.
00:18:09 --> 00:18:10 Professor Fred Watson: Yeah, that's right.
00:18:10 --> 00:18:12 Andrew Dunkley: I think that's where that one's come from.
00:18:13 --> 00:18:13 Professor Fred Watson: Yeah.
00:18:13 --> 00:18:16 Andrew Dunkley: So if Starshot was able to do that, uh, how long
00:18:16 --> 00:18:19 would it take to get out there far
00:18:19 --> 00:18:22 enough for us to be able to look back and go, oh,
00:18:22 --> 00:18:24 look, there's our, oh gosh, we need to take the garbage
00:18:24 --> 00:18:26 out. Um.
00:18:28 --> 00:18:31 Professor Fred Watson: Um, so, uh, the
00:18:31 --> 00:18:33 answer, rather remarkably, Andrew,
00:18:33 --> 00:18:36 is a number that you quoted in our last
00:18:36 --> 00:18:39 400 years. That's right.
00:18:41 --> 00:18:44 So I'm doing that as a calculation in my head. So
00:18:44 --> 00:18:47 Starshot is the,
00:18:47 --> 00:18:50 it's breakthrough. Starshot is still
00:18:50 --> 00:18:52 just a concept investigator, uh,
00:18:52 --> 00:18:55 that the idea with the project Breakthrough
00:18:55 --> 00:18:57 Starshot was to look at the possibilities of
00:18:57 --> 00:19:00 accelerating a spacecraft smaller than your
00:19:00 --> 00:19:03 mobile phone, uh, to something like a
00:19:03 --> 00:19:06 quarter of the speed of light so that you get
00:19:06 --> 00:19:09 to Alpha Centauri maybe
00:19:09 --> 00:19:12 in, um, rather than in, you know,
00:19:12 --> 00:19:14 4.3 years. Um, you get there in 16
00:19:14 --> 00:19:17 years or something like that. 4.3 years is how long it
00:19:17 --> 00:19:20 would take for light to get to us. Uh,
00:19:20 --> 00:19:23 you could do it in 16 years if you were traveling at four
00:19:23 --> 00:19:26 times a, uh, quarter of the speed of light. With
00:19:26 --> 00:19:29 conventional rockets it takes about 60 years.
00:19:29 --> 00:19:32 So that's the difference. So if you. All right,
00:19:32 --> 00:19:35 so you accelerate your spacecraft to a quarter of the speed of
00:19:35 --> 00:19:38 light, I reckon you need to be 100 light years
00:19:38 --> 00:19:41 above the plane to see our galaxy in all
00:19:41 --> 00:19:43 its splendor. Because that's its diameter. It's
00:19:43 --> 00:19:46 100 light years in diameter. So you
00:19:47 --> 00:19:49 push back, um, push
00:19:49 --> 00:19:52 out one, uh, hundred thousand light years, you'll
00:19:52 --> 00:19:55 see the whole thing, um, at, uh, a quarter of
00:19:55 --> 00:19:58 the speed of light, that's going to take you 400 years. So
00:19:58 --> 00:20:00 it's not as quick trip.
00:20:00 --> 00:20:03 Andrew Dunkley: No, no. And, um, yeah, it makes
00:20:03 --> 00:20:05 it very hard to um, to arrange really, because by
00:20:05 --> 00:20:08 the time it's there, no one will have
00:20:08 --> 00:20:11 remembered it, why it was.
00:20:11 --> 00:20:12 Professor Fred Watson: Sent, what it was.
00:20:12 --> 00:20:15 Andrew Dunkley: And then of course it sends back the photo. It's
00:20:15 --> 00:20:18 800 years. 800 years.
00:20:18 --> 00:20:20 Professor Fred Watson: Yeah, that's right. No, um, actually it's
00:20:20 --> 00:20:22 not. It's
00:20:22 --> 00:20:25 500 because, because the light travels
00:20:25 --> 00:20:27 back at, you know, speed of light.
00:20:27 --> 00:20:28 Andrew Dunkley: Speed of light, of course.
00:20:28 --> 00:20:31 Professor Fred Watson: Half a million. Half a million years for the full mission.
00:20:31 --> 00:20:31 Andrew Dunkley: Yeah.
00:20:31 --> 00:20:33 Professor Fred Watson: That's doable, I think, Andrew, don't you?
00:20:33 --> 00:20:36 Andrew Dunkley: Oh, you know, I,
00:20:36 --> 00:20:38 I'm, I'm a fairly patient person. I'm just
00:20:38 --> 00:20:41 sure I'm patient. That, patient enough for that?
00:20:42 --> 00:20:43 Professor Fred Watson: No, me neither.
00:20:43 --> 00:20:45 Andrew Dunkley: Do you think Starshot will happen though?
00:20:45 --> 00:20:48 Professor Fred Watson: No, I think, I think
00:20:48 --> 00:20:51 the results that are coming out are promising. But
00:20:51 --> 00:20:54 uh, the Starshot is only a project
00:20:54 --> 00:20:57 to investigate whether it's feasible. Uh,
00:20:57 --> 00:21:00 so that will wind up. Then somebody's got to put the money
00:21:00 --> 00:21:03 in to not just build the
00:21:03 --> 00:21:06 spacecraft, which is probably quite cheap because
00:21:06 --> 00:21:09 it's small, uh, but to arrange for that
00:21:09 --> 00:21:12 Mylar, uh, light sail that's going to catch the light of
00:21:12 --> 00:21:15 the laser. And the big ticket item is the
00:21:15 --> 00:21:17 laser itself. Yeah, we currently
00:21:18 --> 00:21:20 don't have a laser that's anywhere near powerful enough
00:21:21 --> 00:21:24 to uh, accelerate something to the quarter of the speed
00:21:24 --> 00:21:24 of light.
00:21:24 --> 00:21:27 Andrew Dunkley: Which leads me to um, uh, um,
00:21:28 --> 00:21:30 a question without notice because we've actually, I think
00:21:30 --> 00:21:33 in recent weeks or months had two or
00:21:33 --> 00:21:36 three questions directly related
00:21:36 --> 00:21:38 to sending a mission to
00:21:38 --> 00:21:41 Alpha Centauri using Laser
00:21:42 --> 00:21:44 United spacecraft. Um,
00:21:44 --> 00:21:47 this is not science fiction. This is
00:21:47 --> 00:21:50 feasible and
00:21:50 --> 00:21:52 doable. We've uh, been doing all sorts of experiments with
00:21:53 --> 00:21:55 spacecraft sending up wooden
00:21:55 --> 00:21:58 satellites and things like that. But this
00:21:58 --> 00:22:01 would probably be one of the most
00:22:01 --> 00:22:03 efficient ways to send a long haul
00:22:03 --> 00:22:06 spacecraft to another place.
00:22:06 --> 00:22:08 Professor Fred Watson: Yeah, so you're quite right. It is doable, it's
00:22:09 --> 00:22:09 feasible.
00:22:09 --> 00:22:10 Andrew Dunkley: Yeah.
00:22:10 --> 00:22:13 Professor Fred Watson: Uh, but you need the technology which we don't have at the moment.
00:22:13 --> 00:22:15 And um, uh, I mean we should
00:22:16 --> 00:22:18 put a footnote in that. It has been done.
00:22:18 --> 00:22:21 There's light sail experiments have already been
00:22:21 --> 00:22:24 done, uh, in orbit around the Earth
00:22:24 --> 00:22:27 just by the spacecraft deploying a very large
00:22:27 --> 00:22:29 sheet of Mylar, uh, and
00:22:29 --> 00:22:32 the ground controllers noticing the change
00:22:32 --> 00:22:35 in the acceleration of the spacecraft as a result of that.
00:22:35 --> 00:22:38 That's, that's been done and I think you and I covered it
00:22:38 --> 00:22:40 actually on one of the shows. Um,
00:22:41 --> 00:22:43 so the principle works. Uh,
00:22:43 --> 00:22:46 light sail, that's a principle that
00:22:46 --> 00:22:49 will actually work well. But uh,
00:22:50 --> 00:22:53 for the kind of figures that you were talking about
00:22:53 --> 00:22:56 sending a spacecraft to Alpha Centauri. You
00:22:56 --> 00:22:59 need such a big laser, uh, that we
00:22:59 --> 00:23:02 simply don't have at the moment. And it may even. You might
00:23:02 --> 00:23:05 even have to uh, put it into orbit
00:23:05 --> 00:23:08 around the Earth, uh because if you had it on the ground it
00:23:08 --> 00:23:10 might fry the atmosphere or something like that.
00:23:10 --> 00:23:11 Andrew Dunkley: Oh, that'd be fun.
00:23:11 --> 00:23:13 Professor Fred Watson: Yeah, yeah, we do.
00:23:13 --> 00:23:15 Andrew Dunkley: Yeah, we really need that.
00:23:15 --> 00:23:18 Um, yeah, I love that it's
00:23:18 --> 00:23:21 feasible. I have a
00:23:22 --> 00:23:24 sneaking suspicion that we could never do it out of Australia
00:23:25 --> 00:23:28 because of electricity prices and you're talking about leaving a light
00:23:28 --> 00:23:30 on for 16 years. I mean let's face it.
00:23:30 --> 00:23:31 Professor Fred Watson: Yes, and it's a big light too.
00:23:31 --> 00:23:33 Andrew Dunkley: Not feasible in Australia.
00:23:35 --> 00:23:36 Not with what we pay for.
00:23:36 --> 00:23:37 Professor Fred Watson: You get a bill.
00:23:38 --> 00:23:41 Andrew Dunkley: Um, another thing that uh, has fascinated me in
00:23:41 --> 00:23:44 recent times, uh, and I read a couple of stories like this
00:23:44 --> 00:23:47 when you were away, Fred was
00:23:47 --> 00:23:49 uh, the ongoing development
00:23:50 --> 00:23:52 into new engine technology for
00:23:52 --> 00:23:55 space travel. And I know NASA's been working on
00:23:55 --> 00:23:58 something called the Deep Space Engine.
00:23:59 --> 00:24:02 Um, um, it's a thruster,
00:24:02 --> 00:24:05 uh, that uh, is showing a heck of a lot of
00:24:05 --> 00:24:07 promise in terms of its power.
00:24:08 --> 00:24:10 Uh, it's a low cost chemical compound
00:24:10 --> 00:24:12 engine. Uh, it's lightweight,
00:24:13 --> 00:24:16 uh, and it promises to do some pretty amazing things if
00:24:16 --> 00:24:19 they can perfect it. We're on the cusp
00:24:19 --> 00:24:22 of probably achieving breakthrough
00:24:22 --> 00:24:25 technology in terms of speed and
00:24:25 --> 00:24:28 long haul space travel by the sound of it.
00:24:28 --> 00:24:30 Professor Fred Watson: Yeah, I think we covered um,
00:24:31 --> 00:24:33 some stories last year about EU
00:24:33 --> 00:24:36 ion drives and plasma drives and things like that which
00:24:36 --> 00:24:38 are all very promising.
00:24:38 --> 00:24:41 Andrew Dunkley: Yeah, I, yeah, I think it's uh, it's a pretty exciting
00:24:41 --> 00:24:44 time and uh, there's a lot of development going on, a
00:24:44 --> 00:24:47 lot of money being poured into it because there
00:24:47 --> 00:24:50 are rewards to be gained if you can get out there.
00:24:50 --> 00:24:50 Professor Fred Watson: Yeah. Ah.
00:24:50 --> 00:24:53 Andrew Dunkley: And um, you probably don't like the idea
00:24:53 --> 00:24:56 but they're. You know, we've already spoken
00:24:56 --> 00:24:59 about uh, in the last episode or two about uh,
00:24:59 --> 00:25:02 asteroid mining. That's a, um, that's a
00:25:02 --> 00:25:05 mission test that's been um. Well as we
00:25:05 --> 00:25:08 talked about in the previous episode, has fallen uh,
00:25:08 --> 00:25:11 foul unfortunately. But that, that's just the beginning.
00:25:11 --> 00:25:14 That's just going to be. Yes, it will continue on and of course
00:25:14 --> 00:25:17 mining the moon for that um, that, that mineral
00:25:17 --> 00:25:20 that's not so common on Earth. Can't remember the name of it.
00:25:20 --> 00:25:22 Professor Fred Watson: Something called water, I think.
00:25:22 --> 00:25:25 Andrew Dunkley: No, no, there's something else up there. Something else up there that
00:25:25 --> 00:25:25 they.
00:25:25 --> 00:25:27 Professor Fred Watson: Well, helium 3 is it?
00:25:27 --> 00:25:30 Andrew Dunkley: That's it. So there's a lot going on
00:25:30 --> 00:25:33 and um, yeah, I'm sorry to
00:25:33 --> 00:25:36 say that profit's uh, probably the driving
00:25:36 --> 00:25:37 force behind.
00:25:37 --> 00:25:39 Professor Fred Watson: It in the end. That's right.
00:25:39 --> 00:25:40 Andrew Dunkley: It's a very human thing to do.
00:25:41 --> 00:25:44 Yep, essentially.
00:25:44 --> 00:25:47 All right, thank you, Ash. Thanks, uh, for the question. Great
00:25:47 --> 00:25:50 to hear from you. And don't forget, if you've got questions for
00:25:50 --> 00:25:53 us, you're always welcome to send them to us via
00:25:53 --> 00:25:56 our website, spacenutspodcast.com
00:25:56 --> 00:25:58 or spacenuts IO
00:25:58 --> 00:26:01 and you just click on the little thing at the top called
00:26:01 --> 00:26:04 ama. Now, I know some time ago someone said, can you change
00:26:04 --> 00:26:07 it to something else so that we know where to
00:26:07 --> 00:26:10 send questions? Still working on
00:26:10 --> 00:26:13 that. Not sure where that's up to. I'll have to check with
00:26:13 --> 00:26:16 Huw in the studio, uh, as to where that's up to. But,
00:26:16 --> 00:26:19 uh, yeah, the AMA M button @ the top is the one you
00:26:19 --> 00:26:21 click on. When you click on that, which I'm doing right now,
00:26:21 --> 00:26:24 you can send us a text question just, um, with your
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00:26:27 --> 00:26:30 click start recording. If you've got a device with
00:26:30 --> 00:26:33 a microphone. It's really quite simple.
00:26:33 --> 00:26:36 And while you're on the website, um, just randomly click
00:26:36 --> 00:26:38 on, oh, I don't know, shop.
00:26:40 --> 00:26:43 Speaking about profitable humans. And, uh, look at
00:26:43 --> 00:26:46 all the, uh, Space Nuts paraphernalia. You can get
00:26:46 --> 00:26:49 stickers, you can get T shirts, you can get mugs,
00:26:49 --> 00:26:51 you can get, uh, polo shirts, dad
00:26:51 --> 00:26:54 hats, bucket hats. Uh, for those
00:26:54 --> 00:26:57 of you that live in those northern cold latitudes,
00:26:57 --> 00:27:00 um, you can get a ribbed beanie, all with
00:27:00 --> 00:27:03 the Space Nuts logo. You can even get Space
00:27:03 --> 00:27:04 Nuts socks.
00:27:05 --> 00:27:07 Professor Fred Watson: I need one of those beanies for the next time we go up to the
00:27:08 --> 00:27:08 Arctic.
00:27:08 --> 00:27:11 Andrew Dunkley: Yes, yes. Well, when
00:27:11 --> 00:27:14 we're up above the Arctic later this year, even though it'll be summer,
00:27:14 --> 00:27:16 the temperatures that we don't get down to here in winter,
00:27:17 --> 00:27:19 essentially. So we've bought ear muffs.
00:27:19 --> 00:27:22 So we should get some Space Nuts earmuffs, I reckon.
00:27:23 --> 00:27:26 Uh, there's also the, uh, the Space Nuts hoodie.
00:27:26 --> 00:27:29 That's a fun item if, you know, if you want to scare
00:27:29 --> 00:27:32 people. Not just Space Nut, but you've got a Space
00:27:32 --> 00:27:34 Nut hoodie on that'll freak people
00:27:34 --> 00:27:37 out. Yeah, that's all
00:27:37 --> 00:27:40 on the Space Nuts website and plenty of other things to see and
00:27:40 --> 00:27:43 do there. And if you want to become a Space Nut supporter,
00:27:43 --> 00:27:46 you can do that on the Space, uh,
00:27:46 --> 00:27:49 Nuts website as well. And thank you to all of our
00:27:49 --> 00:27:51 patrons. Uh, um, we think you are
00:27:51 --> 00:27:54 awesome. Um, thanks for getting behind
00:27:54 --> 00:27:57 us. Uh, and did I say goodbye,
00:27:57 --> 00:27:57 Fred?
00:27:58 --> 00:28:00 Professor Fred Watson: Uh, I'm not sure whether you got there or not, actually.
00:28:00 --> 00:28:01 Andrew Dunkley: Thank you, Fred.
00:28:01 --> 00:28:02 Professor Fred Watson: Nice.
00:28:04 --> 00:28:07 Good to talk to you, Andrew. And we shall speak again
00:28:07 --> 00:28:07 soon.
00:28:07 --> 00:28:10 Andrew Dunkley: We will indeed. And, uh, that's Professor Fred Watson,
00:28:10 --> 00:28:13 astronomer at large. And thanks to Huw in the studio, who couldn't be with us
00:28:13 --> 00:28:16 today because, uh, he actually thought Starshot
00:28:16 --> 00:28:18 was real. And, um, he went, bought a
00:28:18 --> 00:28:21 ticket, and it cost him a million
00:28:21 --> 00:28:24 bucks. So he's out, uh, doing his second
00:28:24 --> 00:28:27 and third job to pay it off from me, Andrew Dunkley. Thanks for your
00:28:27 --> 00:28:30 company. Catch you on the next episode of Space Nuts. Until then,
00:28:30 --> 00:28:31 bye bye.
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