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Time Dilation, Cosmic Questions, and the Nature of Space
In this enlightening episode of Space Nuts, hosts Heidi Campo and Professor Fred Watson dive into a captivating array of listener questions that explore the intricacies of time, light, and the universe itself. From the mysteries of dark matter to the philosophical implications of faster-than-light travel, this episode is a treasure trove of astronomical insights.
Episode Highlights:
- Speed of Light and Time Dilation: The episode kicks off with a thought-provoking inquiry from Martins in Latvia about why an object traveling at the speed of light ages differently than one on Earth. Fred unpacks the concept of time dilation as described in Einstein's theory of relativity, illustrating how time behaves differently for observers in motion.
- Ephemerides and Navigating Space: Art from Rochester, New York, poses a fascinating question about the navigation of rockets and the possibility of creating ephemerides for faster-than-light travel. Fred explains the significance of ephemerides in celestial navigation while addressing the theoretical challenges of faster-than-light journeys.
- Galactic Colors and Time Travel: David from Munich wonders about the different colors of galaxies captured by the James Webb Telescope and the implications of traveling to these distant realms. Fred discusses redshift, the nature of light, and how our view of the universe is essentially a glimpse into the past.
- Heat and Friction in Space: Daryl from South Australia asks whether objects in space produce heat as they move. Fred clarifies the role of friction in a vacuum and the conditions under which objects can generate heat through their motion.
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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) Welcome to Space Nuts with Heidi Campo and Fred Watson
(01:20) Discussion on time dilation and the speed of light
(15:00) Navigating space with ephemerides
(25:30) Exploring the colors of galaxies and time travel implications
(35:00) Heat and friction in the vacuum of space
For commercial-free versions of Space Nuts, join us on Patreon, Supercast, Apple Podcasts, or become a supporter here: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support
00:00:00 --> 00:00:03 Heidi Campo: Welcome back to another episode of space nuts.
00:00:03 --> 00:00:06 Voice Over Guy: 15 seconds. Guidance is internal.
00:00:06 --> 00:00:09 10, 9. Ignition
00:00:09 --> 00:00:12 sequence start. Space nuts. 5, 4, 3,
00:00:12 --> 00:00:14 2. 1, 2, 3, 4, 5, 5, 4,
00:00:14 --> 00:00:17 3, 2, 1. Space nuts. Astronauts
00:00:17 --> 00:00:19 report. It feels good.
00:00:19 --> 00:00:22 Heidi Campo: I'm your host for this summer, filling in
00:00:22 --> 00:00:25 for Andrew Dunkley. My name is Heidi Campo.
00:00:25 --> 00:00:28 And joining us is professor Fred Watson,
00:00:28 --> 00:00:29 astronomer at large.
00:00:30 --> 00:00:32 Professor Fred Watson: Uh, good to be here, Heidi, as always. And
00:00:32 --> 00:00:35 you're also our host for this winter here in Australia.
00:00:37 --> 00:00:40 So, yeah, lovely to talk. And um, I think we've got
00:00:40 --> 00:00:43 some pretty great questions from our, uh, listeners for this episode.
00:00:44 --> 00:00:47 Heidi Campo: We do. We have some really fun, uh,
00:00:48 --> 00:00:50 uh, not episodes. We have some fun questions.
00:00:51 --> 00:00:53 Um, our first question today is
00:00:54 --> 00:00:57 Martins from Latvia. And here
00:00:57 --> 00:00:59 is his question.
00:00:59 --> 00:01:02 Martins: Hello guys. It's, uh, Martins from
00:01:02 --> 00:01:05 Latvia. Um, I've been loving your show. Been
00:01:05 --> 00:01:08 listening since 2017. And, um,
00:01:09 --> 00:01:11 so I have a question about dark matter.
00:01:12 --> 00:01:15 Okay, just kidding. I have a question about speed,
00:01:15 --> 00:01:17 uh, of light. So we have two objects.
00:01:17 --> 00:01:20 One object is on Earth and the other one is traveling
00:01:20 --> 00:01:23 in space at the speed of light. After some
00:01:23 --> 00:01:26 time it comes back and the object that's on Earth is
00:01:26 --> 00:01:28 older than the other object.
00:01:29 --> 00:01:32 So why is that happening again? Why? They aren't
00:01:32 --> 00:01:35 the same, uh, age. I mean. Yeah,
00:01:35 --> 00:01:38 there's something to do probably when you're reaching speed of light that
00:01:38 --> 00:01:41 time is slowing down or something. But why it's slowing
00:01:41 --> 00:01:44 down? Why isn't it, uh, like. Yeah,
00:01:44 --> 00:01:46 just curious. And uh.
00:01:46 --> 00:01:49 Yeah, and I have, um, some
00:01:49 --> 00:01:52 dad joke for your, uh, arsenal,
00:01:52 --> 00:01:55 Andrew. So, uh, how do you
00:01:55 --> 00:01:58 put a space baby to sleep? You rock it.
00:01:59 --> 00:02:02 So anyways, guys, cheers then.
00:02:02 --> 00:02:03 Yeah, have a good one.
00:02:04 --> 00:02:06 Heidi Campo: Well, I think those space babies will
00:02:07 --> 00:02:10 being well with those jokes. Thank you so much, Martinez.
00:02:10 --> 00:02:11 That's a. That was a good one.
00:02:13 --> 00:02:16 Professor Fred Watson: Yep. Space babies, uh, always need to be
00:02:16 --> 00:02:17 rocked. That's right.
00:02:19 --> 00:02:21 So, uh, now that's a great question.
00:02:22 --> 00:02:24 Um, um, I have visited Latvia actually.
00:02:25 --> 00:02:28 Uh, some years ago we did a tour there. I do
00:02:28 --> 00:02:31 remember, um, you know, Heidi, because we've
00:02:31 --> 00:02:33 talked about it before. I'm very fond of trains. We
00:02:34 --> 00:02:37 traveled on a little railway, uh, through the snow and
00:02:37 --> 00:02:39 through, uh. Because we always visit these places in
00:02:39 --> 00:02:42 winter, uh, through snow and woodlands. And it
00:02:42 --> 00:02:45 trundled along at something like
00:02:46 --> 00:02:49 nine miles an hour. Maybe it
00:02:49 --> 00:02:51 was a fast walking pace
00:02:52 --> 00:02:54 because it was a very old line, but it was a lot of fun.
00:02:54 --> 00:02:56 Anyway, enough about Latvia.
00:02:56 --> 00:02:59 Uh, let's get to the speed of light, which is basically
00:02:59 --> 00:03:01 what Martin's question is about.
00:03:02 --> 00:03:05 Um, this is, it's one of the
00:03:05 --> 00:03:07 fundamental aspects of
00:03:07 --> 00:03:10 relativity. Uh, Einstein's two theories
00:03:10 --> 00:03:13 of relativity. One was about motion. The other was about
00:03:13 --> 00:03:16 gravity. It's the one about motion that covers this. That's
00:03:16 --> 00:03:19 called the special theory of relativity. Uh, dated
00:03:19 --> 00:03:21 1905. And it turns out
00:03:21 --> 00:03:24 that the thinking that Einstein had had,
00:03:25 --> 00:03:27 uh, leading up to this. Was
00:03:27 --> 00:03:30 that we know that the speed of light
00:03:30 --> 00:03:33 is a bizarre quantity.
00:03:33 --> 00:03:36 Because in a vacuum it's always the same.
00:03:36 --> 00:03:39 We know also that it's the maximum
00:03:39 --> 00:03:42 speed that anything can attain. In fact, you can't actually achieve
00:03:42 --> 00:03:45 the speed of light with an object. Because
00:03:45 --> 00:03:48 you would have to put infinite energy in to get it to the speed of
00:03:48 --> 00:03:51 light. And we don't have infin infinite energy. So light
00:03:51 --> 00:03:54 and its other electromagnetic waves.
00:03:54 --> 00:03:56 They are the only things that can travel at the speed of light.
00:03:57 --> 00:04:00 But if you had something that you are accelerating.
00:04:00 --> 00:04:03 Well, let me just go back. The speed of light is
00:04:04 --> 00:04:07 almost like a magic number. It's not magic because it's a
00:04:07 --> 00:04:10 very round number. It's about 300 kilometers per second.
00:04:11 --> 00:04:13 Uh uh, it is, however,
00:04:14 --> 00:04:17 the fact that it doesn't change in a vacuum. And it
00:04:17 --> 00:04:20 doesn't matter how fast the source is moving. You'd expect
00:04:20 --> 00:04:23 if you have a source that's moving. That sends out a
00:04:23 --> 00:04:26 beam of light. Um, the source's speed
00:04:26 --> 00:04:29 would add to the speed of light. And the speed of light
00:04:29 --> 00:04:31 would increase. But it doesn't doesn't work like that.
00:04:31 --> 00:04:34 And once you establish that, then
00:04:34 --> 00:04:36 it turns out. And there's
00:04:37 --> 00:04:39 some quite sort of simple ways of
00:04:40 --> 00:04:43 seeing how this might work. Which we don't really have time
00:04:43 --> 00:04:46 to talk about. But some of the books about special
00:04:46 --> 00:04:49 relativity. That talk about people looking at somebody
00:04:49 --> 00:04:51 moving on a train. Show you how the geometry
00:04:51 --> 00:04:54 works. That, uh. Because the speed of light
00:04:54 --> 00:04:57 is always the same. Then what it tells
00:04:57 --> 00:05:00 you is perceptions of time and distance
00:05:00 --> 00:05:03 must change. And so the key
00:05:03 --> 00:05:06 thing here. And the point that, uh, Martins
00:05:06 --> 00:05:09 is raising. Is that if you've got
00:05:09 --> 00:05:11 an observer who is stationary.
00:05:12 --> 00:05:15 Compared with somebody who's moving at a very high
00:05:15 --> 00:05:18 speed. Nearly, uh, the speed of light or
00:05:18 --> 00:05:21 yeah. It doesn't matter whether it's near the speed of light or
00:05:21 --> 00:05:23 not. The effect works. But it's when you get
00:05:23 --> 00:05:26 nearer the speed of light. That it becomes noticeable.
00:05:26 --> 00:05:29 Um, the time that you observe.
00:05:29 --> 00:05:31 Um, that moving person,
00:05:33 --> 00:05:36 uh, experiencing is slower. So your
00:05:36 --> 00:05:39 time's ticking away as normal. And
00:05:39 --> 00:05:42 the person who's moving past you. Their time
00:05:42 --> 00:05:44 is ticking away as normal. But when the
00:05:44 --> 00:05:47 stationary person if you could see the clock
00:05:48 --> 00:05:51 on the moving vehicle or whatever it is. Train Going
00:05:51 --> 00:05:53 at nearly the speed of light. Just to mix a few metaphors there,
00:05:54 --> 00:05:57 um, what you would see is their clocks would seem to be going
00:05:57 --> 00:05:59 much more slowly than yours is. And
00:05:59 --> 00:06:02 that's the time dilation effect. And
00:06:02 --> 00:06:05 yes, it means that, um, if you can
00:06:05 --> 00:06:08 then bring these two back together, the moving
00:06:08 --> 00:06:11 person has experienced less time
00:06:11 --> 00:06:13 relative to you than you have. And
00:06:13 --> 00:06:16 that's the. It's sometimes called the twins paradox.
00:06:16 --> 00:06:19 Because if you take two twins, one goes off at the
00:06:19 --> 00:06:22 speed of light, comes back again, or nearly the speed of light,
00:06:22 --> 00:06:25 comes back again there they have aged much less
00:06:25 --> 00:06:27 than the twin who stayed put.
00:06:30 --> 00:06:32 So that's the bottom line. And
00:06:35 --> 00:06:38 it's such a counterintuitive concept that it
00:06:38 --> 00:06:41 is really hard to get your head around. But we know it works.
00:06:41 --> 00:06:44 Uh, in fact, um, the demonstration,
00:06:44 --> 00:06:47 um, the practical demonstration of this phenomenon
00:06:47 --> 00:06:50 happening in reality, uh, I think it was just
00:06:50 --> 00:06:53 before the Second World War. Might have been round about the
00:06:53 --> 00:06:56 same time. But there are things called cosmic rays which are
00:06:56 --> 00:06:59 bombarding the Earth all the time. These are subatomic particles that
00:06:59 --> 00:07:02 come from space. Um, and they are
00:07:02 --> 00:07:04 predominantly a species of
00:07:04 --> 00:07:07 subatomic particle called a muon. So these
00:07:07 --> 00:07:10 muons were observed coming down
00:07:10 --> 00:07:13 through space at, uh, nearly the speed of light.
00:07:13 --> 00:07:16 And we know how long they take to
00:07:16 --> 00:07:19 decay in the laboratory. But
00:07:19 --> 00:07:22 their decay time was much longer when
00:07:22 --> 00:07:25 they were observed coming in at the speed of light, nearly the
00:07:25 --> 00:07:28 speed of light, the time had dilated. So the decays
00:07:28 --> 00:07:31 were much longer than what we observe in the laboratory when
00:07:31 --> 00:07:34 they're not stationary, but they're going
00:07:34 --> 00:07:36 much more slowly. So it is a proven fact
00:07:36 --> 00:07:39 this works. Uh, if we could
00:07:39 --> 00:07:42 build a spacecraft that would get us to. I can't remember
00:07:42 --> 00:07:43 what it is. I think it's
00:07:43 --> 00:07:46 9998% of the speed
00:07:46 --> 00:07:49 of light. Head off for 500
00:07:49 --> 00:07:52 light years, come back again. Uh, you will be 10
00:07:52 --> 00:07:55 years older, whereas everybody else on Earth
00:07:55 --> 00:07:58 will be a thousand years older. So it's that
00:07:58 --> 00:08:01 sort of thing. Your time has slowed down relative to what
00:08:01 --> 00:08:02 they've experienced.
00:08:05 --> 00:08:07 Heidi Campo: I had a weird nightmare about that the other night.
00:08:07 --> 00:08:07 Professor Fred Watson: Oh, did you?
00:08:08 --> 00:08:10 Heidi Campo: It was the strangest thing. I had a nightma. Um,
00:08:11 --> 00:08:14 somebody put me in, like, some kind of a cryo sleep. And I woke up and so
00:08:14 --> 00:08:17 much time had passed that everyone I knew had died. And so I
00:08:17 --> 00:08:20 had them put me back in cryo sleep for
00:08:20 --> 00:08:23 thousands of more years until we discovered the technology to travel
00:08:23 --> 00:08:26 back in time so I could go back in time and link
00:08:26 --> 00:08:27 back up with everyone I loved.
00:08:30 --> 00:08:31 Professor Fred Watson: That's A pretty good one is that.
00:08:32 --> 00:08:34 Heidi Campo: I have a very active dreamscape. Uh,
00:08:35 --> 00:08:37 at night I wake up exhausted.
00:08:38 --> 00:08:38 Professor Fred Watson: Okay.
00:08:39 --> 00:08:40 Heidi Campo: All right.
00:08:40 --> 00:08:43 Well, our next, uh, question has a little bit of philosophy in it.
00:08:43 --> 00:08:46 Um, this, this question is coming from Art
00:08:46 --> 00:08:49 from Rochester, New York. And it's, ah, it's quite a
00:08:49 --> 00:08:52 long question. So let's, uh, grab a cup of
00:08:52 --> 00:08:55 tea here. Art
00:08:55 --> 00:08:57 says, I was listening to the June 13 program
00:08:57 --> 00:09:00 concerning the flying banana, which prompted me to
00:09:00 --> 00:09:03 submit my first question to Space Nuts.
00:09:03 --> 00:09:06 It is a question I had been pondering for some time. You
00:09:06 --> 00:09:09 will be glad to hear it is not a black hole question, but
00:09:09 --> 00:09:12 rather a what if question. The great
00:09:12 --> 00:09:15 American philosopher Julius Henry Marx once
00:09:15 --> 00:09:18 postulated, time flies like an arrow, fruit
00:09:18 --> 00:09:21 flies like a banana. Based
00:09:21 --> 00:09:24 on empirical evidence, I can confirm that fruit
00:09:24 --> 00:09:26 flies like a banana. My question
00:09:26 --> 00:09:29 revolves around time flying like an arrow.
00:09:30 --> 00:09:32 To the best of my understanding, when we shoot off
00:09:32 --> 00:09:35 rockets to the moon or Pluto, in order to get
00:09:35 --> 00:09:38 there accurately, the rocket scientists use an
00:09:40 --> 00:09:42 amphimerus. M. You'll have to correct me on the
00:09:42 --> 00:09:44 pronunciations of that or possible
00:09:45 --> 00:09:47 amphimerds as a sort of a map.
00:09:48 --> 00:09:50 If faster than light space travel were
00:09:50 --> 00:09:53 possible, how could one navigate from point A to
00:09:53 --> 00:09:56 point B? Is it possible to develop an
00:09:57 --> 00:09:59 ephemeris for faster than light
00:09:59 --> 00:10:02 travel? Thank you, Art from Rochester, New
00:10:02 --> 00:10:02 York.
00:10:04 --> 00:10:06 Professor Fred Watson: A great question, Art. And, uh, yeah,
00:10:07 --> 00:10:10 your pronunciation is correct. Ephemeris is what
00:10:10 --> 00:10:13 these things are, and ephemerides is what a
00:10:13 --> 00:10:15 lot of them, ah, are. So what's an ephemeris? Well,
00:10:16 --> 00:10:18 uh, the original
00:10:18 --> 00:10:21 meaning, um, and I guess this really is still
00:10:21 --> 00:10:24 the meaning of the word is, uh, to
00:10:24 --> 00:10:27 predict where, uh, planets
00:10:27 --> 00:10:30 are going to be, uh, in the future,
00:10:30 --> 00:10:32 where celestial objects are going to be.
00:10:33 --> 00:10:35 So, um, going back to my
00:10:35 --> 00:10:38 master's degree, uh, back, you know,
00:10:38 --> 00:10:41 150 years ago, my work was on,
00:10:42 --> 00:10:45 um, the orbits of asteroids. And
00:10:45 --> 00:10:48 so there were two problems. First problem was how
00:10:48 --> 00:10:51 do you take observations of an asteroid? And remember, all we had
00:10:51 --> 00:10:54 in those days was the direction
00:10:54 --> 00:10:57 that you could see measured with a telescope. How do you
00:10:57 --> 00:10:59 turn that into knowledge of the orbit of
00:10:59 --> 00:11:02 the asteroid, uh, in three dimensions? And you can
00:11:02 --> 00:11:05 do it. You need at least three observations to do that, but you
00:11:05 --> 00:11:08 can do it. You can mathematically deduce the orbit
00:11:08 --> 00:11:11 from just three directions in space. But then
00:11:11 --> 00:11:14 once you've got the orbit, what you want to know is where it's
00:11:14 --> 00:11:17 going to be in the future, what's its direction in space
00:11:17 --> 00:11:20 going to be? And that is what an ephemeris is.
00:11:20 --> 00:11:22 It's how the position of an object changes,
00:11:23 --> 00:11:26 uh, in the sky, uh, over time. Um,
00:11:26 --> 00:11:29 so it comes from the word ephemeral, meaning
00:11:29 --> 00:11:31 stuff that's temporary. Uh, so an
00:11:31 --> 00:11:33 ephemeris, uh, is the,
00:11:34 --> 00:11:37 basically it's a table of where an object
00:11:37 --> 00:11:40 will be over a given amount of time. And of course it's
00:11:40 --> 00:11:43 critically important these days because we now know
00:11:43 --> 00:11:46 that, which we didn't know when I did my master's
00:11:46 --> 00:11:48 degree. We now know that the Earth's locality
00:11:48 --> 00:11:51 is pretty heavily populated with asteroids. And there's,
00:11:52 --> 00:11:54 you know, we might want to know where they are
00:11:55 --> 00:11:57 just in case one's uh, heading our way. So
00:11:57 --> 00:12:00 um, I, you know, I think the question, Art's uh, question
00:12:00 --> 00:12:03 is uh, a good one in the sense
00:12:03 --> 00:12:06 that, okay, he's saying, yes, we, we
00:12:06 --> 00:12:09 use ephemera, um, ephemerities to, to
00:12:09 --> 00:12:12 basically navigate to
00:12:12 --> 00:12:15 objects. Um, it's
00:12:15 --> 00:12:17 actually a little bit more than that because we, we
00:12:18 --> 00:12:21 use effectively a three dimensional map of where these,
00:12:21 --> 00:12:24 these planets are, uh, in order
00:12:24 --> 00:12:27 to dictate where they're going to be when
00:12:27 --> 00:12:29 your rocket arrives there. And that's critically important of course,
00:12:29 --> 00:12:32 because you want the rocket to get to the orbit
00:12:32 --> 00:12:35 of for example Pluto, as Art mentions,
00:12:35 --> 00:12:37 uh, when Pluto is going to be where,
00:12:38 --> 00:12:41 whereabouts the rocket is. You don't want to reach the
00:12:41 --> 00:12:44 orbit of Pluto and find Pluto somewhere else. That's why you
00:12:44 --> 00:12:46 need uh, an ephemeris. But
00:12:47 --> 00:12:50 uh, if you could travel faster than the speed of light,
00:12:50 --> 00:12:52 and we've already shown that that's impossible,
00:12:53 --> 00:12:56 uh, in this episode because you need infinite energy to do
00:12:56 --> 00:12:59 that, uh, to reach the speed of light. But if you
00:12:59 --> 00:13:01 could, um, the ephemeris would still
00:13:02 --> 00:13:05 work. Um, you would need to put
00:13:05 --> 00:13:07 in a negative number for the.
00:13:09 --> 00:13:11 I think the speed of light
00:13:12 --> 00:13:15 actually goes into ephemeris calculations. I remember it
00:13:15 --> 00:13:18 well. But I think you uh, put in a
00:13:18 --> 00:13:21 factor. It wouldn't be a negative number. It would be a factor that
00:13:21 --> 00:13:24 would allow for the fact that you were traveling at faster than the
00:13:24 --> 00:13:26 speed of light. So you could do it. It's not
00:13:26 --> 00:13:29 an impossible mathematical problem.
00:13:31 --> 00:13:32 For what it's worth.
00:13:33 --> 00:13:35 Heidi Campo: Well that was fantastic. Uh, I just about understood that
00:13:35 --> 00:13:36 too.
00:13:38 --> 00:13:38 Professor Fred Watson: Sorry.
00:13:39 --> 00:13:41 Heidi Campo: Uh, no, you always do such a great job of explaining these.
00:13:42 --> 00:13:45 Um, my IQ is going up every time I'm
00:13:45 --> 00:13:48 um, involved on these, uh, these episodes. And also
00:13:48 --> 00:13:50 great questions. We have some of the
00:13:50 --> 00:13:53 smartest, smartest listeners. I mean these people
00:13:53 --> 00:13:55 are, are brilliant.
00:13:59 --> 00:14:00 Speaker C: Space nuts.
00:14:01 --> 00:14:03 Heidi Campo: Um, our next question is another audio
00:14:03 --> 00:14:06 question, um, from David from Munich.
00:14:06 --> 00:14:09 And it's a little bit of a longer question as well. So,
00:14:09 --> 00:14:12 so we are going to go ahead and play that for you
00:14:12 --> 00:14:13 now.
00:14:13 --> 00:14:16 Speaker C: Hey guys, David from Unique here. Uh,
00:14:16 --> 00:14:19 shout out to Andrew, Fred and
00:14:19 --> 00:14:22 Jonti and I heard that you're a bit
00:14:22 --> 00:14:24 shorter in questions so I thought that's my chance
00:14:24 --> 00:14:27 to submit one. I'm currently
00:14:27 --> 00:14:30 looking at the picture from um, or taken by
00:14:30 --> 00:14:33 the James Webb Telescope. You know the first one, the first um,
00:14:33 --> 00:14:36 deep space which was also presented by President
00:14:36 --> 00:14:39 Biden back then. And I realized that the
00:14:39 --> 00:14:42 galaxies do differ in
00:14:42 --> 00:14:44 their color pretty much. So there are
00:14:44 --> 00:14:47 more white ones, uh, orange ones and also
00:14:47 --> 00:14:50 reddish ones. And I um, wonder
00:14:50 --> 00:14:53 how is that, Is it due to the fact that
00:14:54 --> 00:14:57 um. Or is this like the red shift because they're
00:14:57 --> 00:14:59 moving away, which I kind of
00:14:59 --> 00:15:02 doubt, but I don't know what, what is it else?
00:15:02 --> 00:15:05 Or is there so much material of a different,
00:15:06 --> 00:15:09 of different kind in the galaxy that appears
00:15:09 --> 00:15:12 for us more red or more blue.
00:15:13 --> 00:15:15 So would be nice if you could explain that.
00:15:16 --> 00:15:18 And um, also I wonder a bit.
00:15:18 --> 00:15:21 Let's imagine we would travel to this far
00:15:21 --> 00:15:24 distant galaxies. Um, if we
00:15:24 --> 00:15:25 could do it potentially
00:15:27 --> 00:15:29 would it not be some kind of
00:15:30 --> 00:15:33 travel through the time?
00:15:33 --> 00:15:36 So because when we look back there, right. We see them
00:15:36 --> 00:15:39 on their early stages. So till
00:15:39 --> 00:15:42 it's a long time until um, until the
00:15:42 --> 00:15:45 light reaches us. And if you would travel to that
00:15:45 --> 00:15:48 far distant uh, galaxies you would
00:15:48 --> 00:15:51 basically. Or what I imagine is like you would
00:15:51 --> 00:15:54 travel through time, right. So if you did, the moment
00:15:54 --> 00:15:57 you come closer and closer the galaxy or
00:15:57 --> 00:16:00 maybe let's think of a single planet would then change
00:16:00 --> 00:16:02 its appearance, right? So you would see that it's
00:16:03 --> 00:16:06 alter, uh, it shifts maybe its base or
00:16:06 --> 00:16:08 it merges with another galaxy. Um,
00:16:09 --> 00:16:12 is my thinking correct, Would it like the
00:16:12 --> 00:16:15 far. The closer you come the more it would
00:16:15 --> 00:16:18 change its shape and it, I
00:16:18 --> 00:16:20 don't know, colors maybe.
00:16:20 --> 00:16:23 Um, and things you would see.
00:16:23 --> 00:16:26 Um. Yes, thanks for taking my questions. Um,
00:16:26 --> 00:16:28 like the shop and, and um,
00:16:29 --> 00:16:30 till then.
00:16:30 --> 00:16:32 Heidi Campo: Well, thank you so much. Um,
00:16:33 --> 00:16:36 that was David from Munich. Thank you. That was a
00:16:36 --> 00:16:38 well thought out question. Fred, I'm so curious.
00:16:39 --> 00:16:42 Professor Fred Watson: They were great questions Heidi from
00:16:42 --> 00:16:44 David and in fact the answer to both his
00:16:44 --> 00:16:47 questions is yes. Um,
00:16:47 --> 00:16:49 so David's asking whether
00:16:50 --> 00:16:52 the color changes that we see in the
00:16:52 --> 00:16:55 images, uh, of these deep fields as we
00:16:55 --> 00:16:58 call them, uh, looking way back in
00:16:58 --> 00:17:01 time, uh, whether those different colors of
00:17:01 --> 00:17:04 galaxies is caused by
00:17:04 --> 00:17:06 the different redshifts of these galaxies.
00:17:07 --> 00:17:09 And that's the bottom line. But there's a few
00:17:09 --> 00:17:12 caveats here. Let me just explain what I Mean, um,
00:17:13 --> 00:17:15 redshift is the phenomenon that,
00:17:16 --> 00:17:18 uh, as light travels through an expanding universe,
00:17:19 --> 00:17:22 uh, the universe is expanding, light is making its
00:17:22 --> 00:17:25 way through the universe, but as it goes, the universe is getting
00:17:25 --> 00:17:28 bigger. And so the light's wavelength is
00:17:28 --> 00:17:30 actually being stretched. Uh, and,
00:17:31 --> 00:17:34 uh, as you stretch the wavelength of light, it goes redder. It goes to
00:17:34 --> 00:17:37 the redder end of the spectrum. And so that's what's happening.
00:17:37 --> 00:17:39 But the caveat that I mentioned is that these
00:17:40 --> 00:17:42 are actually false colors in the sense that
00:17:42 --> 00:17:45 the James Webb telescope is an infrared telescope.
00:17:45 --> 00:17:48 So it is looking at light that our eyes are not
00:17:48 --> 00:17:51 sensitive to. It's actually redder than red light that it's
00:17:51 --> 00:17:54 looking at. So what the mission
00:17:54 --> 00:17:56 scientists do is they,
00:17:57 --> 00:17:59 um, they take the shortest
00:17:59 --> 00:18:02 wavelengths that the Web can see,
00:18:02 --> 00:18:04 which are really beyond our.
00:18:05 --> 00:18:08 They're redder than red for us, for our eyes,
00:18:08 --> 00:18:11 but they're the shortest wavelengths that the red can detect, and
00:18:11 --> 00:18:14 they make that blue in their colors. And then the
00:18:14 --> 00:18:17 longest wavelengths that the Web can detect, they make it
00:18:17 --> 00:18:19 red in their colors and that. So that mimics
00:18:20 --> 00:18:22 what we would see with our eyes,
00:18:23 --> 00:18:26 uh, with visible, you know, visible light, but it
00:18:26 --> 00:18:28 mimics it moved into the infrared. So it does mean
00:18:29 --> 00:18:32 that as objects, uh, you
00:18:32 --> 00:18:34 know, get redder, uh, in the infrared spectrum,
00:18:34 --> 00:18:37 we see them redder, uh, in the James Webb telescope images.
00:18:38 --> 00:18:41 And that's exactly the reason the most
00:18:41 --> 00:18:43 distant objects are so highly redshifted,
00:18:44 --> 00:18:46 that you're seeing them as red objects compared with
00:18:46 --> 00:18:49 the white objects, which are the much nearer ones.
00:18:49 --> 00:18:52 So David's right on that front. His second
00:18:52 --> 00:18:55 question, uh, what would some of these galaxies
00:18:55 --> 00:18:58 we're looking back, you know, up to. I think the record is
00:18:58 --> 00:19:01 looking back 13.52 billion years at the moment,
00:19:01 --> 00:19:04 which is 280 million years after the birth
00:19:04 --> 00:19:07 of the universe. It's a big puzzle as to how
00:19:07 --> 00:19:09 galaxies got so
00:19:10 --> 00:19:13 big and so rich, um, in that short period
00:19:13 --> 00:19:15 of time. But that's for the
00:19:15 --> 00:19:18 cosmologists, not for us. Um, they'll work it
00:19:18 --> 00:19:21 out. It'll be okay. Uh, the bottom line, though, is
00:19:21 --> 00:19:24 that if you could forget about the journey, because
00:19:24 --> 00:19:27 we can't travel the sort of speeds that you need. But
00:19:27 --> 00:19:29 if you imagined yourself, uh,
00:19:30 --> 00:19:32 instantly transported from
00:19:33 --> 00:19:35 our, uh, vantage point here on Earth to
00:19:36 --> 00:19:38 one of These early galaxies, 13.52
00:19:38 --> 00:19:41 billion years, billion light years away, what you
00:19:41 --> 00:19:44 would see would be a galaxy that might look a lot like
00:19:44 --> 00:19:47 ours. It has evolved because
00:19:47 --> 00:19:49 you're seeing it. I mean, you've got to imagine
00:19:50 --> 00:19:52 we're being transported
00:19:52 --> 00:19:55 instantaneously. So that what we see is what's happening
00:19:55 --> 00:19:58 now. That galaxy will have had 13.52
00:19:58 --> 00:20:01 billion years of evolution. It'll be quite different. It might
00:20:01 --> 00:20:03 actually be quite a boring galaxy compared with the
00:20:04 --> 00:20:07 very, uh, energetic, uh, infant galaxy that
00:20:07 --> 00:20:10 we look at with the James Webb telescope. Complicated
00:20:10 --> 00:20:12 answer to a simple question, but David's
00:20:13 --> 00:20:13 right on the money.
00:20:14 --> 00:20:17 Heidi Campo: That is such an interesting way of thinking about that. I, um,
00:20:18 --> 00:20:20 I'm going to be spending, I'm going to be spending a while
00:20:21 --> 00:20:22 wrapping my head around that one.
00:20:25 --> 00:20:28 Professor Fred Watson: Okay, we checked all four systems and seeing where to go
00:20:28 --> 00:20:29 space nets.
00:20:29 --> 00:20:32 Heidi Campo: Um, our last, our last question of the evening is from
00:20:32 --> 00:20:35 Daryl Parker of South Australia.
00:20:36 --> 00:20:39 Daryl says, G' day, space nuts. I'm
00:20:39 --> 00:20:42 not sure of the best way to ask this question, so
00:20:42 --> 00:20:45 I'll just ask it the best way I can. That's
00:20:45 --> 00:20:47 usually, that's usually the, the best way.
00:20:48 --> 00:20:51 Uh, do objects, meteors, asteroids,
00:20:51 --> 00:20:53 comets, planets, stars,
00:20:53 --> 00:20:56 solar systems and galaxies
00:20:56 --> 00:20:59 produce heat as they move through space? Is
00:20:59 --> 00:21:02 it friction or is friction a thing
00:21:02 --> 00:21:05 in the vacuum of speed and the vacuum of space?
00:21:05 --> 00:21:08 Thank you in advance. And that's Daryl from South
00:21:08 --> 00:21:09 Australia.
00:21:10 --> 00:21:13 Professor Fred Watson: Uh, another great question. Um,
00:21:13 --> 00:21:16 so if space was a complete
00:21:16 --> 00:21:19 vacuum, and as I'll explain in a minute, it's
00:21:19 --> 00:21:22 not quite. But if it was a perfect vacuum
00:21:22 --> 00:21:25 with nothing in there, then, uh,
00:21:25 --> 00:21:27 there would be no friction,
00:21:29 --> 00:21:32 uh, as Daryl's calling, um,
00:21:32 --> 00:21:35 would be, uh, uh, you know,
00:21:35 --> 00:21:38 there'd be nothing to, uh, to limit the
00:21:38 --> 00:21:41 speed of motion, uh, of an object moving through it.
00:21:41 --> 00:21:44 And it wouldn't get hot. There would be no friction to heat it.
00:21:44 --> 00:21:47 And I think the way Daryl's thinking here, and it's quite right
00:21:47 --> 00:21:50 to, uh. When a spacecraft enters the Earth's atmosphere,
00:21:51 --> 00:21:53 uh, it's the friction between the spacecraft itself
00:21:53 --> 00:21:56 moving against the air molecules that causes it to be heated and
00:21:56 --> 00:21:59 gives us this heat of reentry. There are a few subtleties to
00:21:59 --> 00:22:02 that, but that's basically the way it works. So things moving
00:22:02 --> 00:22:05 through an atmosphere get hot. Um,
00:22:05 --> 00:22:08 now, uh, space
00:22:08 --> 00:22:10 beyond the Earth's, uh,
00:22:11 --> 00:22:13 atmosphere is not a vacuum.
00:22:13 --> 00:22:16 It's very nearly a vacuum. And that's why you can put a
00:22:16 --> 00:22:19 satellite up and it'll stay up for 200 years or
00:22:19 --> 00:22:21 whatever. And it's why, you know, the Moon doesn't come
00:22:21 --> 00:22:24 crashing down to Earth. In fact, the moon's going the other way. It's moving away
00:22:24 --> 00:22:27 from the Earth very slowly, but
00:22:28 --> 00:22:31 the, um, it's nearly
00:22:31 --> 00:22:33 a vacuum, but it's not quite so.
00:22:34 --> 00:22:36 Uh, there is basically, um,
00:22:37 --> 00:22:40 a very, very slight braking effect,
00:22:40 --> 00:22:43 uh, which in the Earth's vicinity, the Earth's
00:22:43 --> 00:22:46 atmosphere doesn't just stop, it sort of fades away. So
00:22:46 --> 00:22:49 even 10 kilometers away,
00:22:49 --> 00:22:52 there's still a little bit of residual atmosphere, which would have a
00:22:52 --> 00:22:55 slowing effect on a spacecraft. When you get into
00:22:55 --> 00:22:58 interplanetary space, there's a lot
00:22:58 --> 00:23:01 of dust and there's, there's also subatomic
00:23:01 --> 00:23:04 particles there. When you get to interstellar space, the space
00:23:04 --> 00:23:07 between the stars, there is something that we call the
00:23:07 --> 00:23:09 interstellar medium, uh, which is
00:23:09 --> 00:23:12 basically the radiation and
00:23:12 --> 00:23:15 particle environment of interstellar space.
00:23:15 --> 00:23:17 There are subatomic particles all through space.
00:23:18 --> 00:23:21 Now there, it's still so much of a vacuum
00:23:21 --> 00:23:23 that there's nothing really to heat a spacecraft.
00:23:23 --> 00:23:26 So Voyager, as it ventures through
00:23:26 --> 00:23:29 interstellar space, is on the brink of interstellar space.
00:23:29 --> 00:23:31 Now that, uh, won't get hot because of that,
00:23:32 --> 00:23:35 um, because the friction is far too small.
00:23:35 --> 00:23:38 But when you do see its effects, uh,
00:23:38 --> 00:23:41 they are on very big scales. And we do
00:23:41 --> 00:23:43 see, uh, when we look at
00:23:44 --> 00:23:46 some objects deep in space, for example in a gas cloud,
00:23:47 --> 00:23:49 uh, a nebula, where, um,
00:23:50 --> 00:23:53 maybe there are stars forming, sometimes you see objects which
00:23:53 --> 00:23:56 are moving through that gas cloud. And what you can see
00:23:56 --> 00:23:59 is a shock wave, uh, being generated.
00:23:59 --> 00:24:02 And sometimes that causes star formation,
00:24:02 --> 00:24:04 that shockwave of the gas cloud.
00:24:04 --> 00:24:07 Um, now, yes, that's Jordy agreeing with me there.
00:24:08 --> 00:24:10 Uh, he's just come back from his walk, so
00:24:10 --> 00:24:13 he's very enthusiastic about this idea. Uh,
00:24:13 --> 00:24:16 he's probably seen a shockwave. Um,
00:24:16 --> 00:24:19 and a shockwave is what you get when something moves rapidly through the
00:24:19 --> 00:24:22 atmosphere. You know, that's what causes the sonic boom of a
00:24:22 --> 00:24:24 supersonic jet. Um, so
00:24:25 --> 00:24:27 with very big objects in gas
00:24:27 --> 00:24:30 clouds in space, then you do get that sort of
00:24:30 --> 00:24:33 effect. The interaction between the moving object and
00:24:33 --> 00:24:36 its surroundings generates a shockwave and would generate
00:24:36 --> 00:24:39 heat as well. So under certain circumstances the answer is
00:24:39 --> 00:24:42 yes, Darrell, but probably for most things it's
00:24:42 --> 00:24:42 no.
00:24:44 --> 00:24:44 Heidi Campo: So.
00:24:45 --> 00:24:48 So, Fred, I don't know if you'd have time for a follow up question
00:24:49 --> 00:24:52 of my own. Yes, um, so
00:24:53 --> 00:24:56 I guess I never really thought of, um, the
00:24:56 --> 00:24:59 gravity atmosphere around planets having
00:24:59 --> 00:25:02 different layers. It's like, I knew there was layers, but it's like to really
00:25:02 --> 00:25:05 think, okay, you know, it gets thinner and thinner and thinner, but
00:25:05 --> 00:25:08 there's still particles, uh, being pulled into that atmosphere. But it
00:25:08 --> 00:25:11 just, it spreads out quite a ways well
00:25:11 --> 00:25:13 beyond our atmosphere. Are there points of space,
00:25:13 --> 00:25:16 and you may have already mentioned this, but are there points of space where there's
00:25:16 --> 00:25:19 particles floating around that are not being affected by
00:25:19 --> 00:25:22 any gravity at all? Or is every
00:25:22 --> 00:25:25 part of space affected by something's
00:25:25 --> 00:25:25 gravity?
00:25:26 --> 00:25:29 Professor Fred Watson: Um, yeah, pretty well. Um, the thing about
00:25:29 --> 00:25:32 gravity is it, it goes on for
00:25:32 --> 00:25:35 infinity. Um, it's, ah, it's a
00:25:35 --> 00:25:37 bit like actually light is the same. Electromagnetic
00:25:37 --> 00:25:40 radiation will not stop. It just keeps going until
00:25:40 --> 00:25:43 it gets too weak to be detected. You're talking
00:25:43 --> 00:25:46 about a dribble of, you know, hardly any photons.
00:25:46 --> 00:25:49 Gravity is the same. We don't know whether gravity
00:25:49 --> 00:25:52 has a subatomic particle equivalent. We think it might have, and
00:25:52 --> 00:25:55 we call them gravitons, but they haven't been discovered yet. But
00:25:55 --> 00:25:58 yes, uh, that's actually, you know, it's
00:25:58 --> 00:26:01 why, uh, an object like
00:26:01 --> 00:26:04 Pluto, way out there in the depths of the solar system,
00:26:04 --> 00:26:07 is still in orbit around the sun, even though
00:26:07 --> 00:26:09 it's all these, what is it, five, six billion
00:26:10 --> 00:26:13 kilometers away. Um, the gravity of
00:26:13 --> 00:26:15 the sun is still a force
00:26:15 --> 00:26:18 because gravity goes on forever.
00:26:18 --> 00:26:21 Uh, but of course, when you get way
00:26:21 --> 00:26:24 out into interstellar space, then you might feel
00:26:24 --> 00:26:27 the sun's gravity, but you'd also feel the gravity of other
00:26:27 --> 00:26:30 stars. Uh, and so I think you're
00:26:30 --> 00:26:32 right that there is always going to be a sort of gravity
00:26:32 --> 00:26:35 background, uh, because of the
00:26:35 --> 00:26:38 objects which are in the universe. Maybe
00:26:38 --> 00:26:40 it's pretty near zero in the space between
00:26:40 --> 00:26:43 galaxies, uh, which is pretty empty, although there are
00:26:43 --> 00:26:46 subatomic particles there too. Uh, but,
00:26:46 --> 00:26:49 uh, yeah, but no, it's a. It's a very, um,
00:26:50 --> 00:26:53 A very compelling force is gravity, which is just as
00:26:53 --> 00:26:55 well because otherwise we wouldn't exist.
00:26:56 --> 00:26:59 Heidi Campo: There's always something pulling. It's just going to
00:26:59 --> 00:27:02 be stronger or weaker. No matter if it's.
00:27:02 --> 00:27:04 No matter if it's the biggest gap in
00:27:05 --> 00:27:07 the known cosmos,
00:27:08 --> 00:27:10 there's still a little thread pulling us together.
00:27:10 --> 00:27:13 Oh, that's so beautiful. That's kind of cool. We're all connected
00:27:13 --> 00:27:14 somehow.
00:27:14 --> 00:27:16 Professor Fred Watson: That's a connection. That's right. Yeah.
00:27:17 --> 00:27:20 Heidi Campo: Um, Fred. Well, this has been a
00:27:20 --> 00:27:23 very enlightening Q and A episode
00:27:23 --> 00:27:26 of Space Nuts. Thank you so much for
00:27:26 --> 00:27:29 sharing your wealth of knowledge with us.
00:27:29 --> 00:27:32 Um, while your rooster. I'm sorry, your dog.
00:27:32 --> 00:27:34 Sings his song in the background.
00:27:35 --> 00:27:38 Professor Fred Watson: That's what he sounds like. I know. Um, his voice
00:27:38 --> 00:27:39 hasn't broken yet.
00:27:41 --> 00:27:43 Heidi Campo: It's kind of cute. It's endearing. Um, thank you so
00:27:43 --> 00:27:44 much.
00:27:44 --> 00:27:44 Professor Fred Watson: This has been, been.
00:27:44 --> 00:27:47 Heidi Campo: This has been fantastic. And, um, we
00:27:47 --> 00:27:50 will, we will, I guess, catch you guys next
00:27:50 --> 00:27:53 time. Please keep sending in your amazing
00:27:53 --> 00:27:55 questions. And, um, real quick, before
00:27:55 --> 00:27:58 we go, we are going to play a, uh,
00:27:58 --> 00:28:01 another, um, another
00:28:01 --> 00:28:03 update for you. So this is your little Treat for
00:28:03 --> 00:28:06 listening to the whole thing. We've got an update from Andrew,
00:28:06 --> 00:28:09 your beloved regular host. I know you
00:28:09 --> 00:28:12 guys probably miss him because your questions are still
00:28:12 --> 00:28:15 addressed to him, but, um, he's on his trip
00:28:15 --> 00:28:17 around the world. Going to let that, um,
00:28:18 --> 00:28:19 play back now.
00:28:19 --> 00:28:22 Andrew Dunkley: Hi, Fred, hi, Heidi, and hello, Huw
00:28:22 --> 00:28:23 in the studio.
00:28:23 --> 00:28:26 Andrew back again, reporting from the Crown
00:28:26 --> 00:28:29 Princess on our world tour. Uh, since I spoke to you
00:28:29 --> 00:28:32 last, our, uh, cruise has made news all over
00:28:32 --> 00:28:35 Australia. You might have seen some of the reports or heard some of
00:28:35 --> 00:28:38 the news about some of the conditions we've had to
00:28:38 --> 00:28:41 deal with. When I last spoke to you, I was explaining
00:28:41 --> 00:28:43 how we were heading into rough weather. We got off to a pretty
00:28:43 --> 00:28:46 rocky start. Well, it got much,
00:28:46 --> 00:28:49 much worse. We were having lunch in
00:28:50 --> 00:28:52 one of the restaurants at the back of the ship and
00:28:53 --> 00:28:55 we got hit by a weather front. It felt like we'd
00:28:55 --> 00:28:58 been rammed and the. The ship
00:28:58 --> 00:29:01 tilted over 7 degrees and it stayed there
00:29:01 --> 00:29:04 for the rest of the day. It just hit us out
00:29:04 --> 00:29:06 of nowhere. The captain had to do some heavy
00:29:06 --> 00:29:09 maneuvering to get us, uh, into. Into a, you know, better
00:29:09 --> 00:29:12 position. And they had to move, um,
00:29:12 --> 00:29:15 the ballast to, uh, keep the ship,
00:29:15 --> 00:29:18 uh, balanced and upright as much
00:29:18 --> 00:29:20 as they could. Uh, yeah, it was pretty harrowing.
00:29:21 --> 00:29:24 And the weather never got better, uh,
00:29:24 --> 00:29:26 until we got into Adelaide and were in protected
00:29:26 --> 00:29:29 waters. But, um, the Adelaide was fantastic. Went
00:29:29 --> 00:29:32 to, uh, Handorf, as I mentioned, that little German
00:29:32 --> 00:29:35 village where the German people. People came in all those
00:29:35 --> 00:29:38 years ago. They were, um, they were basically
00:29:38 --> 00:29:41 escaping, uh, Prussian oppression when they came out
00:29:41 --> 00:29:43 here in the 1800s. And, um, yeah, made it, made a German
00:29:43 --> 00:29:46 town, which is fantastic. Had, uh, a good look
00:29:46 --> 00:29:49 around Adelaide, although the weather was terrible. We went to Mount Lofty,
00:29:49 --> 00:29:52 which is one of the best views in Australia. And all we saw was
00:29:52 --> 00:29:55 cloud and very strong winds. It
00:29:55 --> 00:29:58 was, uh, it was quite nasty. Got
00:29:58 --> 00:30:01 back on board, uh, we had to stay the night in Adelaide because
00:30:01 --> 00:30:04 of the conditions, hoping they'd settle down. And we did have
00:30:04 --> 00:30:06 some good sailing until we got to the
00:30:06 --> 00:30:09 West Australian border and then another weather front hit
00:30:09 --> 00:30:12 us and it got rough again
00:30:13 --> 00:30:16 and. Yeah, gosh. And just to top it all
00:30:16 --> 00:30:19 off, we had a galley fire in the middle of the night at one
00:30:19 --> 00:30:21 point, which they dealt with very, very quickly. So it's been
00:30:21 --> 00:30:24 a bit of a dog's, uh, breakfast of a cruise
00:30:24 --> 00:30:27 in some respects, but we're still having a fantastic
00:30:27 --> 00:30:29 time. We stopped at Fremantle again,
00:30:30 --> 00:30:33 um, because of the weather. We were very late and so we
00:30:33 --> 00:30:36 stayed the night. We have friends in Fremantle so We spent the
00:30:36 --> 00:30:39 evening with them. It was fantastic. And we
00:30:39 --> 00:30:41 set sail again yesterday, headed west.
00:30:41 --> 00:30:44 We leave Australia now, headed for Mauritius. That'll be
00:30:44 --> 00:30:47 a seven day crossing of the Indian Ocean.
00:30:48 --> 00:30:50 So that's where things are at with our uh, current
00:30:50 --> 00:30:53 tour. Um, we're really enjoying
00:30:53 --> 00:30:56 ourselves. I must confess. The crew here
00:30:56 --> 00:30:59 is fantastic. And uh, you know, with
00:30:59 --> 00:31:02 over 2 Aussies on board, we outnumber everybody
00:31:02 --> 00:31:05 about 10 to 1. Which is, which is good.
00:31:05 --> 00:31:08 But so many nationalities. Hope all is well back home
00:31:08 --> 00:31:11 and in Houston of course. Heidi, look forward to talking
00:31:11 --> 00:31:13 to you next time. Uh, no, Aurora.
00:31:13 --> 00:31:13 Heidi Campo: Australa.
00:31:13 --> 00:31:16 Andrew Dunkley: Australis. Missed out completely. Couldn't see that.
00:31:16 --> 00:31:19 So um, hopefully when we get up north we'll see the other
00:31:19 --> 00:31:22 end of the uh, country and ah, see if
00:31:22 --> 00:31:25 there's any lights up there. North. So until next
00:31:25 --> 00:31:26 time, Andrew Dunkley signing off.
00:31:27 --> 00:31:30 Voice Over Guy: You've been listening to the Space Nuts. Podcast
00:31:32 --> 00:31:35 available at Apple Podcasts, Spotify,
00:31:35 --> 00:31:38 iHeartRadio or your favorite podcast
00:31:38 --> 00:31:39 player. You can also stream on
00:31:39 --> 00:31:42 demand at bitesz.com. This has been another
00:31:42 --> 00:31:44 quality podcast production from
00:31:44 --> 00:31:45 bitesz.com
00:31:47 --> 00:31:48 Heidi Campo: See you later, Fred.
00:31:48 --> 00:31:49 Professor Fred Watson: Sounds great.