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In this captivating episode of Space Nuts, host Andrew Dunkley and the ever-knowledgeable Professor Fred Watson delve into the latest discoveries surrounding water on Mars and innovative ideas for spacecraft re-entry. They explore a groundbreaking theory suggesting vast amounts of liquid water may exist beneath the Martian surface and discuss a revolutionary new cooling method for spacecraft during atmospheric re-entry.
Episode Highlights:
- The Water Beneath Mars: Andrew and Fred Watson discuss the findings from NASA's InSight mission, revealing that Mars may harbour significant amounts of liquid water trapped in porous rock beneath its surface. They explore the implications of this discovery for future Martian exploration and the potential for microbial life.
- Innovative Cooling Solutions: The duo examines a new approach to spacecraft re-entry that involves a 3D printed material capable of 'sweating' to cool down, potentially revolutionising how we protect spacecraft from the intense heat of re-entry.
- The Universe's Expiration Date: They also discuss a startling new theory from Dutch scientists that suggests the universe may end much sooner than previously thought, with calculations indicating it could be just 10 to the power of 78 years away, significantly shorter than earlier estimates.
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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 Andrew Dunkley and Fred Watson Watson
(01:20) Discussion on water beneath Mars
(15:00) Innovative spacecraft cooling methods
(25:30) New theories on the universe's lifespan
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 Andrew Dunkley: Hi there. This is Space Nuts, where we talk astronomy
00:00:03 --> 00:00:06 and space science. And my name is Andrew Dunkley, your host.
00:00:06 --> 00:00:08 It's good to have your company on this episode.
00:00:08 --> 00:00:11 We're going to Mars, uh, where we're going to
00:00:11 --> 00:00:14 talk about water. Now, water is a very common
00:00:14 --> 00:00:16 Martian topic, uh, but
00:00:17 --> 00:00:20 this story is going to throw a completely
00:00:20 --> 00:00:23 different light on Mars water. And we'll
00:00:23 --> 00:00:26 tell you why. Uh, there's also a
00:00:26 --> 00:00:28 great idea that's being put forward to
00:00:28 --> 00:00:31 help spacecraft, uh, re enter
00:00:31 --> 00:00:34 Earth's atmosphere. Because up until now, we've used heat
00:00:34 --> 00:00:37 shields and tiles. Now they think
00:00:37 --> 00:00:39 they've come up with something completely different. It's called
00:00:39 --> 00:00:42 Sweat and the
00:00:42 --> 00:00:45 Universe RIP Yep,
00:00:45 --> 00:00:48 we're going to see it all end much sooner than we
00:00:48 --> 00:00:51 expected. We'll talk about all of that on this episode
00:00:51 --> 00:00:52 of space nuts.
00:00:52 --> 00:00:55 Generic: 15 seconds. Guidance is internal.
00:00:55 --> 00:00:57 10, 9. Uh, ignition
00:00:57 --> 00:01:00 sequence start. Uh, space nuts. 4, 3.
00:01:00 --> 00:01:03 2. 1. 2, 3, 4, 5. 5.
00:01:03 --> 00:01:06 Uh, 4, 3, 2, 1. Space nuts. Astronauts
00:01:06 --> 00:01:07 report it feels good.
00:01:08 --> 00:01:09 Andrew Dunkley: And he's back again.
00:01:09 --> 00:01:12 For more it is Professor Fred Watson Watson, astronomer at
00:01:12 --> 00:01:13 large. Hello, Fred Watson.
00:01:13 --> 00:01:14 Professor Fred Watson: Uh, Andrew. How are you doing?
00:01:15 --> 00:01:18 Andrew Dunkley: I'm doing quite well, thank you very much. Are you.
00:01:18 --> 00:01:20 Professor Fred Watson: What a surprise to see it. Yeah, I'm very well, thank you. Yeah.
00:01:20 --> 00:01:23 Andrew Dunkley: Oh, it is a surprise to see you there. I mean,
00:01:24 --> 00:01:27 do you like my new background? I'm going to change the background every week
00:01:27 --> 00:01:28 on my studio.
00:01:28 --> 00:01:31 Professor Fred Watson: I think that's a good idea. Uh, and, um, I do like
00:01:31 --> 00:01:34 it. Uh, it's a, uh, place that's close
00:01:34 --> 00:01:36 to my heart as well as yours. It's a great place.
00:01:37 --> 00:01:40 Andrew Dunkley: Well, isn't that the saying, I left
00:01:40 --> 00:01:41 my heart in San Francisco.
00:01:42 --> 00:01:43 Professor Fred Watson: Yeah, you probably did.
00:01:45 --> 00:01:47 Andrew Dunkley: That's a photo I took after we crossed the
00:01:47 --> 00:01:50 Golden Gate Bridge looking back to San Francisco. So
00:01:51 --> 00:01:53 thought I'd use that as my backdrop today.
00:01:54 --> 00:01:56 Professor Fred Watson: The, um, second line of that song is a good one as well.
00:01:57 --> 00:01:59 I left my knees in old Peru.
00:02:02 --> 00:02:03 Courtesy of the goons.
00:02:04 --> 00:02:07 Andrew Dunkley: Yes, of course. Yeah. Beautiful
00:02:07 --> 00:02:10 city. Really beautiful city. I think I told you about
00:02:10 --> 00:02:13 the driverless taxis they've got. But there's so much more
00:02:13 --> 00:02:16 going for it. Those cable, uh, cars are
00:02:16 --> 00:02:18 fantastic. Um, we
00:02:18 --> 00:02:21 obviously did the tourist thing and did a ride on one of those
00:02:21 --> 00:02:24 and then, you know, did the walk down Lombard
00:02:24 --> 00:02:27 street, that, uh, zigzaggy street that, um,
00:02:27 --> 00:02:30 has become quite famous. And I don't know how many movies
00:02:30 --> 00:02:33 and TV shows it's been in, but, um.
00:02:33 --> 00:02:36 And it's like all of these things that when you see them on
00:02:36 --> 00:02:39 tv, you think, oh, wow, got to go see that. And then you get
00:02:39 --> 00:02:42 there and go, oh, it's. It's a lot smaller than
00:02:42 --> 00:02:45 I thought. Ah.
00:02:45 --> 00:02:48 But yeah, um, I don't know what the price of a
00:02:48 --> 00:02:51 house is on Lombard street, but it's, uh, beautiful homes
00:02:51 --> 00:02:51 there.
00:02:52 --> 00:02:52 Professor Fred Watson: Yes.
00:02:53 --> 00:02:56 Andrew Dunkley: But overall, a beautiful city. Beautiful city. I'd go back
00:02:56 --> 00:02:59 there tomorrow. Uh, we better get into it,
00:02:59 --> 00:02:59 Fred Watson.
00:02:59 --> 00:03:02 And our first topic, uh, today
00:03:02 --> 00:03:05 is the water on Mars. Or in this
00:03:05 --> 00:03:08 case, according to a new theory inside
00:03:08 --> 00:03:11 Mars. And we're talking about massive
00:03:11 --> 00:03:12 amounts of water.
00:03:13 --> 00:03:16 Professor Fred Watson: Indeed. That's right, we are. It's not just a
00:03:16 --> 00:03:19 few drips or drops. Uh, so the
00:03:19 --> 00:03:22 story, uh, the star of the story, Andrew,
00:03:22 --> 00:03:25 is NASA's InSight spacecraft,
00:03:25 --> 00:03:28 which it's almost. It's more
00:03:28 --> 00:03:31 than a decade ago now. I think that, uh, Insight landed, uh,
00:03:31 --> 00:03:33 you might remember it landed in the Arctic region,
00:03:33 --> 00:03:36 region of Mars. And, um, basically
00:03:37 --> 00:03:39 did one summer's worth of work.
00:03:39 --> 00:03:42 Because we knew that once it got into winter on
00:03:42 --> 00:03:45 Mars, the spacecraft would freeze and all the electronics
00:03:45 --> 00:03:48 would die and it would pass away, which it did.
00:03:48 --> 00:03:51 Uh, it's still there, of course, but it's inactive. Um,
00:03:51 --> 00:03:54 so a great, uh, mission,
00:03:54 --> 00:03:57 uh, it had one little, um,
00:03:57 --> 00:04:00 hiccup in that the thermometer that they were trying to dig into the
00:04:00 --> 00:04:03 ground didn't get dug in. You might remember we covered that on
00:04:03 --> 00:04:05 Spacenauts. But what worked a treat was the
00:04:05 --> 00:04:08 seismometer. Because it had a
00:04:08 --> 00:04:11 very sensitive seismometer able, uh,
00:04:11 --> 00:04:14 to listen to Marsquakes.
00:04:15 --> 00:04:17 Uh, and, um, Marsquakes are caused by
00:04:18 --> 00:04:20 a number of things. Um, impacting,
00:04:21 --> 00:04:23 uh, meteorites actually cause a little
00:04:23 --> 00:04:26 quake. And they also think there's some
00:04:26 --> 00:04:29 residual. Not exactly plate tectonics,
00:04:29 --> 00:04:32 but just slips and slides of fault lines and things of that
00:04:32 --> 00:04:34 sort, which also create seismic M data.
00:04:35 --> 00:04:37 Yeah. And so this is
00:04:38 --> 00:04:40 where the story really starts. Because,
00:04:41 --> 00:04:44 um, we know, uh, from other evidence
00:04:44 --> 00:04:47 that Mars, uh, Probably
00:04:47 --> 00:04:50 between about 4.1 and 3 billion years
00:04:50 --> 00:04:53 ago, was warm and wet. Uh, the
00:04:53 --> 00:04:56 evidence is in your face in many ways. You can see
00:04:56 --> 00:04:59 evidence of beaches and river channels. And,
00:04:59 --> 00:05:02 you know, the northern hemisphere of Mars is much smoother
00:05:02 --> 00:05:05 and flatter than the southern hemisphere, which we think is because
00:05:05 --> 00:05:07 there was possibly an ocean there. So all the evidence, science, uh,
00:05:08 --> 00:05:10 is that during that early period in Mars's
00:05:10 --> 00:05:13 history. And just remember that all the planets are
00:05:13 --> 00:05:16 4.6 billion years old or thereabouts.
00:05:16 --> 00:05:19 4.7, something like that. 4, uh.1
00:05:19 --> 00:05:21 billion years is only half a billion years after the
00:05:21 --> 00:05:24 origin of Mars. But, uh, we think that that
00:05:24 --> 00:05:27 was more or less the start of when it was a warm and wet
00:05:27 --> 00:05:30 world and that lasted for nearly a billion years. A little bit more
00:05:30 --> 00:05:33 perhaps. So um, the
00:05:33 --> 00:05:36 atmosphere, uh, uh sorry the water on
00:05:36 --> 00:05:39 Mars is now no longer on the surface.
00:05:39 --> 00:05:42 And uh, that's pretty evident because it's
00:05:42 --> 00:05:45 as dry as dust and in fact it's got humidity effectively
00:05:45 --> 00:05:48 not quite but effectively of zero. Very, very low
00:05:48 --> 00:05:51 humidity. Um so the questions have
00:05:51 --> 00:05:53 always been where did the surface water go? We
00:05:53 --> 00:05:56 know that uh because Mars does not have
00:05:56 --> 00:05:59 a strong magnetic field it's bombarded intensely
00:05:59 --> 00:06:02 by the solar wind, uh and that
00:06:02 --> 00:06:05 tends to separate any water
00:06:06 --> 00:06:09 uh, vapour uh into its component
00:06:09 --> 00:06:11 atoms, hydrogen and oxygen and they
00:06:11 --> 00:06:14 then basically waft off into space. And we know that's happening
00:06:15 --> 00:06:17 because there's uh, a spacecraft called Marvin or Maven,
00:06:18 --> 00:06:21 uh which is still active in uh, orbit around Mars and that can
00:06:21 --> 00:06:23 see this stuff all leaking away. So we
00:06:23 --> 00:06:26 know that was part of the story. But um, the
00:06:26 --> 00:06:29 planetary scientists who look at Mars in detail say that's
00:06:29 --> 00:06:32 not enough. We can't actually account for,
00:06:32 --> 00:06:35 for all the water that must have been there by
00:06:35 --> 00:06:38 it just disappearing into space. Um,
00:06:38 --> 00:06:41 we know some of it's frozen in the polar caps uh
00:06:41 --> 00:06:43 of Mars. Um, and
00:06:44 --> 00:06:46 probably you know, hydrolyzed minerals.
00:06:46 --> 00:06:49 There have been minerals on Mars surface have been
00:06:49 --> 00:06:52 affected by water. Uh that's still
00:06:52 --> 00:06:55 the case however uh, there must
00:06:55 --> 00:06:58 be more. And there was a calculation
00:06:58 --> 00:07:01 done um, I think by the research group
00:07:01 --> 00:07:03 that's uh, done this work with the Insights, um,
00:07:04 --> 00:07:07 lander which estimates that
00:07:08 --> 00:07:11 the water that's gone missing was uh,
00:07:11 --> 00:07:14 enough to cover the planet in an
00:07:14 --> 00:07:17 Ocean between 700 and 900
00:07:17 --> 00:07:18 metres deep.
00:07:18 --> 00:07:21 Andrew Dunkley: So that just blowed me away.
00:07:21 --> 00:07:23 Professor Fred Watson: Yeah, uh,
00:07:24 --> 00:07:27 it's gone um, where. And that's not an
00:07:27 --> 00:07:29 insignificant amount of water. Remember Mars is only half the
00:07:29 --> 00:07:32 diameter of Earth so it's not like uh, an
00:07:32 --> 00:07:35 earthly amount but it's a lot of water, 700 to
00:07:35 --> 00:07:37 900 metres deep across the whole planet.
00:07:38 --> 00:07:41 So uh, where's it gone? Uh
00:07:41 --> 00:07:44 and you know, if we can find it,
00:07:44 --> 00:07:47 what, what might it be like? So uh, now
00:07:47 --> 00:07:50 enter uh insight. Uh
00:07:50 --> 00:07:52 and actually I was wrong. It's not a decade ago. It was
00:07:52 --> 00:07:55 2018 when Insight landed uh and
00:07:55 --> 00:07:58 uh, did all that super work with its sensitive
00:07:58 --> 00:08:01 seismometer. Uh these
00:08:01 --> 00:08:03 scientists looked at the
00:08:05 --> 00:08:07 vibrations that come from
00:08:07 --> 00:08:10 um, any sort of marsquake caused
00:08:10 --> 00:08:12 by as I mentioned before, either
00:08:12 --> 00:08:15 slippage in the rock or uh, a meteorite.
00:08:15 --> 00:08:18 Uh but you can look very accurately at ah,
00:08:18 --> 00:08:21 the um, essentially the types of
00:08:21 --> 00:08:24 waves that you're getting because, uh,
00:08:24 --> 00:08:27 there are pressure waves and shear waves. I think they're called S waves and
00:08:27 --> 00:08:30 P waves in the, um. Uh, in the
00:08:30 --> 00:08:32 jargon of seismometry. But these
00:08:33 --> 00:08:35 waves, seismographic waves,
00:08:35 --> 00:08:38 tell you something about the material that they are
00:08:38 --> 00:08:41 passing through. And that is where
00:08:41 --> 00:08:44 this, uh, story has gone. Because these
00:08:44 --> 00:08:47 scientists estimate, uh, what they
00:08:47 --> 00:08:49 call a significant underground anomaly
00:08:50 --> 00:08:52 exists, uh, in a layer between
00:08:53 --> 00:08:55 five and a half and eight kilometres
00:08:56 --> 00:08:58 below the surface. Because they find that these
00:08:58 --> 00:09:01 shear waves move more slowly, uh, in that
00:09:01 --> 00:09:04 region. And the most likely
00:09:04 --> 00:09:06 explanation. And remember, that's. That's a layer
00:09:06 --> 00:09:09 that's, you know, it's two and a half kilometres,
00:09:09 --> 00:09:12 two and a half kilometres thick. Um,
00:09:13 --> 00:09:15 that layer they think is
00:09:16 --> 00:09:18 likely to be porous rock,
00:09:19 --> 00:09:21 uh, like we've got here on planet Earth,
00:09:21 --> 00:09:24 uh, filled with liquid water, just a little bit like the
00:09:24 --> 00:09:27 aquifers. And we've got a great one here in Australia, the
00:09:27 --> 00:09:30 great Artesian Basin, uh, which is.
00:09:30 --> 00:09:31 Andrew Dunkley: I'm sitting on it, right?
00:09:31 --> 00:09:34 Professor Fred Watson: You're sitting on it. That's right. You are. Are your feet wet, Andrew,
00:09:34 --> 00:09:34 or.
00:09:34 --> 00:09:37 Andrew Dunkley: No, no. We do have, as
00:09:37 --> 00:09:40 you know, several bores all over the city here
00:09:41 --> 00:09:43 because, uh, we can tap the Great
00:09:43 --> 00:09:46 Artesian basin and, and get that water for
00:09:46 --> 00:09:49 domestic use. So we. We kind of,
00:09:49 --> 00:09:52 um, take water from that source as well as from
00:09:53 --> 00:09:56 river. The river is fed by a huge dam
00:09:56 --> 00:09:58 upstream which is bigger than Sydney Harbour.
00:09:59 --> 00:09:59 Professor Fred Watson: Uh.
00:09:59 --> 00:10:02 Andrew Dunkley: And. Yes, that's right, Farendom Dam. So, uh,
00:10:02 --> 00:10:04 yeah, we, uh, definitely use
00:10:05 --> 00:10:08 the aquifer water from the great artesian
00:10:08 --> 00:10:11 basin to supplement the city supply.
00:10:11 --> 00:10:14 We are actually drought proof. As a consequence of that, we
00:10:14 --> 00:10:16 will never run out of water because
00:10:16 --> 00:10:19 we sit on the Great Artesian basin, which
00:10:19 --> 00:10:22 basically stretches north to south across the entire
00:10:22 --> 00:10:25 continent down, um, this sort of central, um,
00:10:25 --> 00:10:26 eastern section.
00:10:26 --> 00:10:28 Professor Fred Watson: That's correct, yeah.
00:10:28 --> 00:10:29 Andrew Dunkley: Yeah. It's massive.
00:10:29 --> 00:10:30 Professor Fred Watson: It is massive.
00:10:30 --> 00:10:33 Andrew Dunkley: It's like an underground ocean, basically. And that's what we're talking about
00:10:33 --> 00:10:34 with Mars.
00:10:34 --> 00:10:37 Professor Fred Watson: That's exactly right. And so it's a really nice,
00:10:37 --> 00:10:40 um, you know, connection that we have here in Eastern Australia
00:10:40 --> 00:10:43 with Mars. Uh, this sort of, you
00:10:43 --> 00:10:45 know, um. It's almost. The rock itself is
00:10:46 --> 00:10:49 sponge, like in the sense that it holds the water, the
00:10:49 --> 00:10:49 liquid water.
00:10:50 --> 00:10:52 And the thinking is, uh, that because
00:10:53 --> 00:10:56 it's at a depth, as I said, a
00:10:56 --> 00:10:59 few kilometres, between five and a half and eight kilometres,
00:10:59 --> 00:11:02 um, the temperature there is warmer than
00:11:02 --> 00:11:05 it is on the surface by quite a long way because of just the
00:11:05 --> 00:11:08 internal heat of the planet. Uh, and so they think
00:11:08 --> 00:11:11 it is actually liquid, uh, and that fits
00:11:11 --> 00:11:14 the bill in terms of the seismic
00:11:14 --> 00:11:17 waves that they've detected, uh, that you've actually
00:11:17 --> 00:11:19 got this liquid water in porous
00:11:19 --> 00:11:22 rock. Um, and what's
00:11:22 --> 00:11:25 really nice about this story is, uh, that
00:11:25 --> 00:11:28 if that is, um, a global,
00:11:28 --> 00:11:31 uh, layer of rock, and it may well be,
00:11:31 --> 00:11:34 um, they calculate how much water
00:11:34 --> 00:11:37 is in it, uh, and sure enough,
00:11:37 --> 00:11:40 it's enough to cover Mars in a global
00:11:40 --> 00:11:42 ocean between. Well, the figures they quote is between
00:11:42 --> 00:11:45 520 and 780 metres deep.
00:11:46 --> 00:11:49 Just about the same as what they think is the missing
00:11:49 --> 00:11:50 water mass on Mars.
00:11:50 --> 00:11:53 Andrew Dunkley: So this is sense. Yeah, I mean, this
00:11:53 --> 00:11:56 is still a maybe, not a definite,
00:11:56 --> 00:11:58 but the numbers certainly support it.
00:11:59 --> 00:12:01 That's what's really interesting about this story.
00:12:02 --> 00:12:04 Excuse me. And, uh,
00:12:05 --> 00:12:08 yeah, the question is, if we go to Mars,
00:12:08 --> 00:12:10 and I know you don't like
00:12:10 --> 00:12:13 this, but they will probably establish colonies there. If
00:12:13 --> 00:12:16 one man has his way, um, will
00:12:16 --> 00:12:19 they be able to access it? Could it. Could it
00:12:19 --> 00:12:22 actually hold microbial life and could
00:12:22 --> 00:12:23 you drink it?
00:12:24 --> 00:12:26 Professor Fred Watson: Uh, yes, that's right. I mean, the middle question there,
00:12:27 --> 00:12:29 the. The fact that there might be life in it, that's the one
00:12:29 --> 00:12:32 that's so intriguing. Uh, I think, I
00:12:32 --> 00:12:35 suspect at that depth you'd struggle to get
00:12:35 --> 00:12:38 it. But we do know. And again, this comes from Insight.
00:12:38 --> 00:12:41 Um. Uh, no, it wasn't. Insight was. It
00:12:41 --> 00:12:44 was Phoenix. Yes, Phoenix was a spacecraft
00:12:44 --> 00:12:47 like Insight, uh, which was
00:12:48 --> 00:12:51 actually, uh, the one that was in the Arctic. And so. I beg your pardon,
00:12:51 --> 00:12:54 I said something incorrect before. The INSIGHT was in the
00:12:54 --> 00:12:57 Arctic. Martian Arctic. But it wasn't. It was Phoenix 2
00:12:57 --> 00:12:59 spacecraft which was very similar. Uh, one was for
00:12:59 --> 00:13:02 seismometry. INSIGHT was basically giving
00:13:02 --> 00:13:05 us sight of the inside of Mars and M.
00:13:05 --> 00:13:08 Phoenix was all about, uh,
00:13:09 --> 00:13:11 basically, um, sampling the surface rock.
00:13:12 --> 00:13:15 Uh, and, um, we remember
00:13:15 --> 00:13:18 those classic pictures, they scraped away the top layer.
00:13:18 --> 00:13:19 Andrew Dunkley: Of soil and there was ice.
00:13:20 --> 00:13:21 Professor Fred Watson: There's ice underneath it.
00:13:21 --> 00:13:24 Andrew Dunkley: Yeah, yeah, yeah. Um,
00:13:24 --> 00:13:26 it was like a kid had been up there with his
00:13:26 --> 00:13:29 Tonka tractor and he scraped the top of
00:13:29 --> 00:13:32 the dirt and turned white.
00:13:33 --> 00:13:36 Professor Fred Watson: That's right. So, uh, that is in the Arctic
00:13:36 --> 00:13:38 region, but that's telling you there's a permafrost of water
00:13:39 --> 00:13:42 and there is a huge amount there as
00:13:42 --> 00:13:44 well. Uh, but, you know, to find liquid water
00:13:44 --> 00:13:47 now, um, whether that's drinkable,
00:13:48 --> 00:13:51 probably if you purify it, might have minerals in it that you'd like to
00:13:51 --> 00:13:54 get rid of. But, uh, I think it will be drinkable.
00:13:54 --> 00:13:57 Um, but yes, the intriguing thing is, as you said, is
00:13:57 --> 00:13:59 whether it could harbour Martian
00:13:59 --> 00:14:02 Biology that's uh, really, really interesting.
00:14:02 --> 00:14:05 Uh, and, and in that regard, um, you
00:14:05 --> 00:14:08 know we've talked about the planetary protection rules before
00:14:08 --> 00:14:11 and uh, um, how
00:14:11 --> 00:14:14 much of spacecraft has to be sterilised before it's sent to
00:14:14 --> 00:14:17 Mars. If it's going anywhere where liquid water could exist,
00:14:18 --> 00:14:20 what it would do. This would mean that we would have to be doubly
00:14:20 --> 00:14:23 careful sort of no matter where you're going on
00:14:23 --> 00:14:26 Mars because deep under the surface there might well be Martian
00:14:26 --> 00:14:29 microbes that wouldn't like earthly microbes if they
00:14:29 --> 00:14:32 found their way down through the rocks, so. Oh, uh, absolutely.
00:14:32 --> 00:14:35 Andrew Dunkley: And, and we've got evidence on Earth of that kind of
00:14:35 --> 00:14:38 contamination when like the Spanish went to South
00:14:38 --> 00:14:40 America and the South American people
00:14:41 --> 00:14:43 um, were exposed to diseases
00:14:43 --> 00:14:45 that just didn't exist in there.
00:14:45 --> 00:14:46 Professor Fred Watson: Wipe them out.
00:14:46 --> 00:14:47 Andrew Dunkley: Wipe them out.
00:14:47 --> 00:14:50 Professor Fred Watson: Almost completely similar things happened in our own
00:14:50 --> 00:14:52 country. Andrew as well.
00:14:52 --> 00:14:52 Andrew Dunkley: Yep, absolutely.
00:14:52 --> 00:14:55 Professor Fred Watson: Smallpox and things like that. And I should just talking about our country,
00:14:55 --> 00:14:58 I should mention that some of this work has been carried out by
00:14:58 --> 00:15:01 Australian investigators at the Australian National University
00:15:01 --> 00:15:04 as well as um, uh, scientists at the Chinese
00:15:04 --> 00:15:05 Academy of Sciences.
00:15:06 --> 00:15:09 Andrew Dunkley: Well hopefully there'll be some follow up to um,
00:15:09 --> 00:15:11 maybe confirm what they think.
00:15:13 --> 00:15:15 As I said, the numbers are stacking up in that favour
00:15:16 --> 00:15:18 and it will mean that if uh, that's true,
00:15:19 --> 00:15:21 um, Mars is not a dry
00:15:22 --> 00:15:24 dead planet. It's probably a water world, but a
00:15:24 --> 00:15:27 different kind of water. And we're seeing more and more
00:15:27 --> 00:15:29 of that throughout the solar system.
00:15:30 --> 00:15:31 Professor Fred Watson: We are indeed. That's right.
00:15:32 --> 00:15:35 Andrew Dunkley: Very exciting indeed. All right, if you'd like to read up on that
00:15:35 --> 00:15:37 you can uh, see that@the
00:15:37 --> 00:15:40 conversation.com website. This is
00:15:40 --> 00:15:43 Space Nuts Andrew Dunkley with Professor Fred Watson
00:15:43 --> 00:15:43 Watson.
00:15:48 --> 00:15:49 Space Nuts.
00:15:49 --> 00:15:50 Professor Fred Watson: Speaking of water.
00:15:50 --> 00:15:52 Andrew Dunkley: Well not quite but uh, we,
00:15:52 --> 00:15:55 we've seen over the
00:15:55 --> 00:15:58 entire space ah, race to
00:15:58 --> 00:16:01 date, um, which began way back in the middle
00:16:01 --> 00:16:04 of the last century, uh, that if you wanted to get a
00:16:04 --> 00:16:07 spacecraft back into the atmosphere
00:16:07 --> 00:16:10 you had to be prepared for it to potentially
00:16:10 --> 00:16:12 burn up uh, unless you put a heat shield on
00:16:12 --> 00:16:15 it. And later those heat uh,
00:16:15 --> 00:16:18 absorbent tiles that were made famous by the
00:16:18 --> 00:16:21 space shuttle and my son has actually got one of those
00:16:21 --> 00:16:23 tiles at his place because he got it as a
00:16:23 --> 00:16:26 secret Santa through um, one of the uh, social media
00:16:26 --> 00:16:29 websites when they used to do that um, and
00:16:29 --> 00:16:32 the warning came do not lick the tile. Well apparently it's
00:16:32 --> 00:16:35 very toxic. Um, so
00:16:35 --> 00:16:38 um, that's how it's been done to date. But now
00:16:38 --> 00:16:40 they've come up with a new idea
00:16:41 --> 00:16:44 that basically involves spacecraft
00:16:44 --> 00:16:47 sweating to Stay cool as they come back
00:16:47 --> 00:16:49 into the atmosphere. This is really fascinating.
00:16:51 --> 00:16:53 Professor Fred Watson: Uh, it's extraordinary. Yeah. And what you've said
00:16:53 --> 00:16:56 is absolutely right. Um,
00:16:57 --> 00:17:00 uh, the traditional uh, heat shield
00:17:00 --> 00:17:02 is called an ablative shield because it ablates the
00:17:02 --> 00:17:05 heat, takes it away. Uh, and that means
00:17:06 --> 00:17:09 that you only use them once. So um,
00:17:09 --> 00:17:12 that's an issue for example with the Orion
00:17:12 --> 00:17:15 capsule which is um, going to be reused. Uh, this
00:17:15 --> 00:17:17 is the one that will take astronauts to the moon.
00:17:17 --> 00:17:20 Um, uh, and um, it's a pretty
00:17:20 --> 00:17:23 large piece of kit and every time you reuse it
00:17:23 --> 00:17:26 you've got to replace that ablative shield that's on there. Or
00:17:26 --> 00:17:29 ablative shield, however you pronounce it. It's on the back of
00:17:29 --> 00:17:32 the spacecraft. That's the bit that burns away, uh, as the
00:17:32 --> 00:17:35 spacecraft re enters. Uh, so, um,
00:17:35 --> 00:17:37 could you find a way of doing this, uh,
00:17:38 --> 00:17:40 which was essentially reusable
00:17:41 --> 00:17:44 something else, uh,
00:17:44 --> 00:17:47 that would actually protect the spacecraft from the intense heat of
00:17:47 --> 00:17:50 reentry. And it's a team at Texas A and
00:17:50 --> 00:17:53 M University, uh, partnering with a
00:17:53 --> 00:17:55 private concern called Canopy
00:17:55 --> 00:17:58 Aerospace. And they've basically
00:17:59 --> 00:18:02 developed uh, a 3D printed substance,
00:18:03 --> 00:18:05 um, that releases gas
00:18:06 --> 00:18:09 when you've got the heat of re
00:18:09 --> 00:18:12 entry. Uh and the reason
00:18:12 --> 00:18:14 that's interesting is that gas
00:18:15 --> 00:18:18 ah, has a very low conductivity of
00:18:18 --> 00:18:21 heat. Uh unlike you know, a piece of
00:18:21 --> 00:18:24 metal or something like that which conducts heat very, very
00:18:24 --> 00:18:27 well. Gas is pretty poor at conducting heat.
00:18:27 --> 00:18:30 Uh, and it's actually, you know, you've got
00:18:31 --> 00:18:34 a lot of uh, you know, why put it. Putting,
00:18:34 --> 00:18:37 putting air in the space between your inner and outside
00:18:37 --> 00:18:40 walls provides a bit of heat insulation and things of that
00:18:40 --> 00:18:43 sort. Uh, it's um, a um,
00:18:43 --> 00:18:45 good heat insulator. So if you
00:18:45 --> 00:18:48 can make something that will release gas
00:18:49 --> 00:18:52 as it enters the space, uh,
00:18:52 --> 00:18:55 as the spacecraft enters the atmosphere, then you might
00:18:55 --> 00:18:57 well find that you've got the situation
00:18:58 --> 00:19:01 where you've got uh, something that's effect
00:19:01 --> 00:19:04 reusable and that you don't have to replace every
00:19:04 --> 00:19:07 time. And it, and the material itself is a,
00:19:07 --> 00:19:10 it's a 3D printed silicon carbide,
00:19:10 --> 00:19:13 uh, and it is strong
00:19:13 --> 00:19:15 and I'm quoting here from the um,
00:19:16 --> 00:19:19 Space.com article about this, which is a very nice
00:19:19 --> 00:19:22 description, uh, written by Samantha
00:19:22 --> 00:19:25 Mathewson a few days ago or a day or so
00:19:25 --> 00:19:27 ago. Uh, uh, it's
00:19:27 --> 00:19:30 designed to be strong enough to withstand
00:19:30 --> 00:19:33 extreme atmospheric pressures, yet poor enough
00:19:33 --> 00:19:36 for the coolant to sweat through. Uh,
00:19:36 --> 00:19:39 and uh, she says prototypes are being tested at the
00:19:39 --> 00:19:42 university to evaluate the material's ability to sweat and
00:19:42 --> 00:19:44 how well, the gas that is released
00:19:44 --> 00:19:47 insulates a spacecraft. Uh, so
00:19:47 --> 00:19:50 it is. Yeah, um, it's a really interesting step.
00:19:50 --> 00:19:53 You know, um, what struck me about this
00:19:53 --> 00:19:56 is we've been using these ablative
00:19:56 --> 00:19:59 shields since, well, the Mercury
00:19:59 --> 00:20:01 capsule back in 1960,
00:20:02 --> 00:20:05 whenever it was 62, I think, Mercury,
00:20:05 --> 00:20:08 maybe 63. Um, and
00:20:08 --> 00:20:10 they're still being used. They're still on the
00:20:10 --> 00:20:13 Orion capsule, which is just a giant version of
00:20:13 --> 00:20:16 Mercury in some ways. Uh, and it's great
00:20:16 --> 00:20:19 to see people thinking outside the box as to whether we can
00:20:19 --> 00:20:22 find better ways to do this and actually create, um,
00:20:22 --> 00:20:24 you know, create new materials, given
00:20:25 --> 00:20:28 where we've got to today in things like 3D printing,
00:20:28 --> 00:20:30 uh, create new materials that can do the job better.
00:20:31 --> 00:20:34 Andrew Dunkley: Yeah, I suppose the only way to really test this would be
00:20:34 --> 00:20:37 to create this, this new form
00:20:37 --> 00:20:39 of shielding and send one up and bring it back
00:20:39 --> 00:20:42 and see if it survives, basically. And
00:20:43 --> 00:20:46 you wouldn't want to sort of, um, go up there
00:20:46 --> 00:20:48 unchecked and go, okay, we're going to test this new.
00:20:49 --> 00:20:52 Professor Fred Watson: Yeah, no, you wouldn't, you wouldn't want
00:20:52 --> 00:20:54 that. Um, uh, they've used
00:20:55 --> 00:20:58 hypersonic, uh, uh, wind tunnels to
00:20:58 --> 00:21:01 test it. So, and these are things that blow the wind along at
00:21:01 --> 00:21:04 several times the speed of sound. And so they've got a good idea
00:21:04 --> 00:21:05 that this is going to work, I think.
00:21:05 --> 00:21:08 Andrew Dunkley: Yeah. As we've seen though, with the space shuttle, all
00:21:08 --> 00:21:10 it takes is a tiny little
00:21:11 --> 00:21:13 crack in a tile to cause a major
00:21:13 --> 00:21:16 catastrophe. I'll never forget that.
00:21:16 --> 00:21:19 Um, but, but, um, I would
00:21:19 --> 00:21:22 imagine with a heat shield type of approach like
00:21:22 --> 00:21:25 this, the gas that too could be
00:21:25 --> 00:21:28 exposed if one of the vents or whatever it is
00:21:28 --> 00:21:30 they use to release the gas fails.
00:21:30 --> 00:21:33 Professor Fred Watson: Yes, I guess that's right.
00:21:33 --> 00:21:36 There'll always be, um, some sort of failure,
00:21:37 --> 00:21:40 uh, possibility, uh, and the trick is
00:21:40 --> 00:21:42 to reduce those as much as possible.
00:21:42 --> 00:21:45 Andrew Dunkley: Indeed. Uh, well, uh, it will be really
00:21:45 --> 00:21:47 interesting to see how this develops. It could, could
00:21:47 --> 00:21:50 be one of the, um, the big leaps
00:21:50 --> 00:21:52 forward in terms of getting
00:21:52 --> 00:21:55 spacecraft back into Earth without having to
00:21:55 --> 00:21:57 constantly regenerate,
00:21:57 --> 00:22:00 um, shields. Because, uh, that's what happens at the
00:22:00 --> 00:22:03 moment. Once a heat shield has been used, you can't
00:22:03 --> 00:22:06 use it again. It's the same with the tiles on the space
00:22:06 --> 00:22:09 shuttle. You, you have to replace them after every
00:22:09 --> 00:22:12 mission. Apparently, uh, this could be a
00:22:12 --> 00:22:15 renewable resource, a renewable approach to the
00:22:15 --> 00:22:17 whole thing, which obviously would reduce
00:22:18 --> 00:22:20 costs ultimately. And it's still very expensive
00:22:20 --> 00:22:23 to get up there, send out your
00:22:23 --> 00:22:26 payload or whatever, and then get the
00:22:26 --> 00:22:28 hardware back to Earth. So, um,
00:22:29 --> 00:22:31 uh, it's Been a long time coming.
00:22:32 --> 00:22:35 We're coming up on 100 years of space flight and
00:22:35 --> 00:22:38 it's taken three quarters of that time to
00:22:38 --> 00:22:41 come up with a new idea. So fingers crossed that this
00:22:41 --> 00:22:44 is actually the answer and who knows what else they might
00:22:44 --> 00:22:47 figure out down the track that could do the job. So
00:22:47 --> 00:22:50 um, I suppose a question that pops to mind
00:22:50 --> 00:22:53 and this is sort of a very dumb question I
00:22:53 --> 00:22:56 suppose, um, why can't they just re, enter
00:22:56 --> 00:22:58 slowly to avoid the heat? I'm guessing
00:22:58 --> 00:23:00 you wouldn't get back in.
00:23:01 --> 00:23:03 Professor Fred Watson: Um, you're limited by, you know, the
00:23:04 --> 00:23:07 mechanics of space flight. So um,
00:23:07 --> 00:23:10 anything in space that's you know, that's not
00:23:10 --> 00:23:12 coming back to Earth is orbiting at
00:23:13 --> 00:23:16 uh, nearly eight kilometres per second. And
00:23:16 --> 00:23:19 uh, that's why you need such a big rocket to put
00:23:19 --> 00:23:22 things into orbit. Because you've got to not only get the height,
00:23:22 --> 00:23:25 uh, to two or 300 kilometres, but also to
00:23:25 --> 00:23:28 push it into this high velocity with respect
00:23:28 --> 00:23:31 to the Earth's surface. And when you come back
00:23:32 --> 00:23:35 you've somehow got to dump that velocity. You've got to kill it
00:23:35 --> 00:23:37 somehow. Now you know, I do remember
00:23:38 --> 00:23:41 when I used to read Dundeere, the uh, pilot of
00:23:41 --> 00:23:44 the future in the Eagle. They, they used
00:23:44 --> 00:23:46 um, what they called reactor rockets. So you had uh,
00:23:46 --> 00:23:49 the spacecraft was in orbit and
00:23:49 --> 00:23:52 then uh, the command that Captain
00:23:52 --> 00:23:55 Dan Dare said was blower reactors and that
00:23:55 --> 00:23:58 was forward firing rockets that slowed the
00:23:58 --> 00:24:00 spacecraft down. And that's what they still do.
00:24:01 --> 00:24:03 They fire forward firing rockets
00:24:03 --> 00:24:06 to slow the spacecraft down. But unless
00:24:06 --> 00:24:09 you've got the same amount of fuel as you used to put it
00:24:09 --> 00:24:12 up there, you can't use that forward
00:24:12 --> 00:24:15 firing rocket to gently land it on the planet's
00:24:15 --> 00:24:18 surface. You've got to have something else. And uh, that something else is
00:24:18 --> 00:24:21 aero braking which is using the atmosphere to slow the
00:24:21 --> 00:24:23 spacecraft down. That's traditionally what
00:24:24 --> 00:24:27 has been used. It's the only way we have available at the moment until
00:24:27 --> 00:24:30 somebody invents something that doesn't need as much fuel
00:24:30 --> 00:24:32 to slow you down as uh, it takes you up there.
00:24:33 --> 00:24:35 Andrew Dunkley: Well that time will probably come. But
00:24:36 --> 00:24:39 for now making your spacecraft sweat could
00:24:39 --> 00:24:42 be uh, the new approach. And if you uh,
00:24:42 --> 00:24:44 are interested in that story, uh, as Fred Watson said,
00:24:44 --> 00:24:46 it's@space.com.
00:24:49 --> 00:24:52 okay, we checked all four systems and team with a go
00:24:52 --> 00:24:53 Space Nats.
00:24:53 --> 00:24:56 Okay Fred Watson, our final ah, story today
00:24:56 --> 00:24:59 is a very scary one because um, we
00:24:59 --> 00:25:02 might not be here next week or maybe it's a
00:25:02 --> 00:25:04 billion years. I always get the two mixed
00:25:04 --> 00:25:07 up. Uh, but um, on a serious
00:25:07 --> 00:25:10 note, uh, some Dutch scientists have come up with
00:25:10 --> 00:25:13 a new theory as to when the universe will end.
00:25:14 --> 00:25:17 And it is a heck of a lot sooner
00:25:17 --> 00:25:20 than we originally thought if they are right.
00:25:24 --> 00:25:26 Professor Fred Watson: Indeed it is. Uh, so here are the numbers,
00:25:26 --> 00:25:29 okay. Uh, because we might as well start with
00:25:29 --> 00:25:32 that. We used to think
00:25:33 --> 00:25:35 that the universe would die
00:25:36 --> 00:25:38 in 10 to the power 1100
00:25:39 --> 00:25:41 years. So that is a one with 1100
00:25:41 --> 00:25:44 zeros after it. It, that's how long we thought it would
00:25:44 --> 00:25:47 take to die. The new
00:25:48 --> 00:25:50 calculation uh, is only. It's a mere
00:25:50 --> 00:25:53 10 to the power 78 years. And
00:25:53 --> 00:25:56 that's 10 followed by, sorry one
00:25:56 --> 00:25:58 followed by 78 zeros.
00:25:59 --> 00:26:02 Look, that's ah, one heck of a
00:26:02 --> 00:26:05 difference, isn't it? It's a factor of more
00:26:05 --> 00:26:08 than 10 different uh, uh,
00:26:08 --> 00:26:10 it's a factor of more than 10 in exponent, which means that it's a
00:26:10 --> 00:26:13 very much different different. Um, so yes,
00:26:13 --> 00:26:16 the universe has only got really a brief period of 10 to
00:26:16 --> 00:26:19 the 78 years to last. Um but
00:26:19 --> 00:26:22 let's cut to the reason why these scientists are
00:26:22 --> 00:26:24 ah, uh, making these
00:26:25 --> 00:26:28 calculations. They're um, scientists actually in the
00:26:28 --> 00:26:30 Netherlands. Uh, and what they've
00:26:30 --> 00:26:33 done is they've looked at
00:26:33 --> 00:26:35 Hawking radiation. And
00:26:35 --> 00:26:38 that is the, the trick to this,
00:26:38 --> 00:26:41 this whole calculation. Hawking radiation
00:26:41 --> 00:26:44 is uh, as we know, the rad that
00:26:44 --> 00:26:47 leaks from a black hole. Uh which
00:26:47 --> 00:26:50 is a quantum physics effect because uh,
00:26:50 --> 00:26:52 relativity says nothing can come out of a black hole. But quantum
00:26:52 --> 00:26:55 mechanics says well they can evaporate very, very slowly.
00:26:56 --> 00:26:59 And they do. Uh, there's all the
00:26:59 --> 00:27:02 evidence suggests that Hawking radiation is a real thing.
00:27:02 --> 00:27:05 And so what these calculations are about is how long it
00:27:05 --> 00:27:08 takes everything in the universe to come to an
00:27:08 --> 00:27:11 end by Hawking radiation. Um, and they don't
00:27:11 --> 00:27:14 just cover black holes. They cover everything.
00:27:14 --> 00:27:17 They cover um, neutron stars which
00:27:17 --> 00:27:19 are kind of failed black holes. They cover white
00:27:19 --> 00:27:22 dwarf stars which are kind of failed neutron stars.
00:27:22 --> 00:27:25 Um, and these all have um, a
00:27:25 --> 00:27:27 Hawking age. And I think actually
00:27:28 --> 00:27:31 um, the original calculation of 10 to the 1100
00:27:32 --> 00:27:34 years was um, um,
00:27:34 --> 00:27:37 basically coming from just the lifetime of white
00:27:37 --> 00:27:39 dwarf stars does, but
00:27:40 --> 00:27:42 uh, the new calculation have
00:27:43 --> 00:27:45 uh, have um,
00:27:46 --> 00:27:48 essentially said uh, the,
00:27:49 --> 00:27:52 the decay time for white dwarfs is
00:27:53 --> 00:27:56 uh, sooner than we
00:27:56 --> 00:27:58 thought. Uh, I think actually the white dwarf decay
00:27:58 --> 00:28:01 time originally didn't include Hawking radiation. I think it
00:28:01 --> 00:28:04 was just how long it takes to cool down to a completely
00:28:04 --> 00:28:07 inert object. So um, the new calculation
00:28:07 --> 00:28:10 takes into account uh, the
00:28:10 --> 00:28:13 basics of Hawking radiation. Um,
00:28:14 --> 00:28:17 they've got some nice other
00:28:17 --> 00:28:20 figures as well because uh,
00:28:21 --> 00:28:23 they can Work out how long
00:28:23 --> 00:28:26 neutron stars take to decay. That's 10
00:28:26 --> 00:28:29 to the power 67 years. Um,
00:28:29 --> 00:28:32 they can work out how long. Long the
00:28:32 --> 00:28:35 moon will take to evaporate by human.
00:28:35 --> 00:28:38 Uh, Sorry, By Hawking radiation.
00:28:38 --> 00:28:41 And how long it will take a human to evaporate.
00:28:41 --> 00:28:44 And those figures are respectively. Well, they're the same
00:28:44 --> 00:28:47 10 to the power 90. So you and I, as we sit
00:28:47 --> 00:28:48 here, Andrew.
00:28:49 --> 00:28:49 Andrew Dunkley: Yeah.
00:28:49 --> 00:28:52 Professor Fred Watson: Uh, we will evaporate in 10 to the power 90
00:28:52 --> 00:28:55 years, which means we actually outlast the
00:28:55 --> 00:28:57 universe because the universe is going to
00:28:57 --> 00:29:00 evaporate in. In 10 to the 78 years.
00:29:01 --> 00:29:04 Uh, so we're, we're doing well there. How can we
00:29:04 --> 00:29:06 outlast the universe? I'm not sure what the answer to that
00:29:06 --> 00:29:07 is.
00:29:08 --> 00:29:11 Andrew Dunkley: Yeah, well, nothing, um, could. If the
00:29:11 --> 00:29:14 universe comes to a grinding halt, that's the end of everything,
00:29:14 --> 00:29:17 isn't it? Ah, to qualify this, you've
00:29:17 --> 00:29:20 got to accept that, um, they're talking about the, the, uh,
00:29:20 --> 00:29:23 fading out of everything. That's correct. But the
00:29:23 --> 00:29:24 universe will still be there. It'll just be dead.
00:29:26 --> 00:29:28 Professor Fred Watson: Unless, uh, the, you know, the
00:29:28 --> 00:29:31 accelerated expansion of the universe results in the Big Rip,
00:29:31 --> 00:29:34 which could come a lot sooner than those evaporation
00:29:34 --> 00:29:37 times. So you're quite right. This is assuming
00:29:37 --> 00:29:40 nothing else happens in the universe. The universe is as boring as
00:29:40 --> 00:29:42 anything. Uh, and things just
00:29:42 --> 00:29:45 evaporate by Hawking radiation. That's
00:29:45 --> 00:29:46 the numbers that you get.
00:29:47 --> 00:29:50 Andrew Dunkley: Yeah. And there was one other thing we left out of that, and that was
00:29:50 --> 00:29:52 the, um, um, evaporation of brown
00:29:52 --> 00:29:55 dwarfs, um, because they're failed Disney
00:29:55 --> 00:29:58 actors, so got to take that into
00:29:58 --> 00:30:01 account too. And that only takes 88 years.
00:30:01 --> 00:30:04 Professor Fred Watson: Okay. Very good.
00:30:04 --> 00:30:07 That's a neat calculation. I think you should write. That's up to the
00:30:07 --> 00:30:08 conversation, Andrew.
00:30:10 --> 00:30:13 Andrew Dunkley: It's terrible, Jack. Horrible. Yeah. Um,
00:30:13 --> 00:30:16 no, but it is, uh, rather fascinating. Um, so do we
00:30:16 --> 00:30:19 know. I don't know if you said it in number of years, what 10
00:30:19 --> 00:30:22 to the 78 actually means for the
00:30:22 --> 00:30:22 universe.
00:30:25 --> 00:30:28 Professor Fred Watson: Yeah, well, yes, uh, just means one followed by
00:30:28 --> 00:30:30 78 zeros. It's a long time.
00:30:30 --> 00:30:31 Andrew Dunkley: Still a long time.
00:30:32 --> 00:30:34 Professor Fred Watson: Yeah. And, um, we should be right to.
00:30:34 --> 00:30:36 Andrew Dunkley: Pay the, the water rates next week then.
00:30:36 --> 00:30:39 Professor Fred Watson: That's right. I mean, you know, put it in perspective.
00:30:39 --> 00:30:41 Uh, the Earth is probably going to get melted
00:30:42 --> 00:30:45 within maybe 4 billion years.
00:30:45 --> 00:30:48 What's that? 4 times 10 to 9 years. So.
00:30:48 --> 00:30:50 Yeah, yeah, yeah, that's, uh.
00:30:51 --> 00:30:53 That's. That's going to be a much more immediate
00:30:54 --> 00:30:57 problem, uh, for us than the evaporation of everything by
00:30:57 --> 00:30:57 Hawking radius.
00:30:57 --> 00:31:00 Andrew Dunkley: That's assuming humanity has actually survived that long, which
00:31:00 --> 00:31:02 is totally different.
00:31:02 --> 00:31:03 Professor Fred Watson: Yes, we might.
00:31:03 --> 00:31:05 Andrew Dunkley: Argument, theory, whatever you like.
00:31:05 --> 00:31:06 Professor Fred Watson: M yeah.
00:31:06 --> 00:31:09 Andrew Dunkley: All right. Uh, that story available through
00:31:09 --> 00:31:12 fizz.org p h y s.org
00:31:12 --> 00:31:15 if you want to read up on it. It's really, really interesting.
00:31:15 --> 00:31:18 Uh, and that brings us to the end. Fred, thank you very
00:31:18 --> 00:31:19 much.
00:31:19 --> 00:31:22 Professor Fred Watson: Pleasure, Andrew, as always. And we'll speak again soon. I'm sure
00:31:22 --> 00:31:23 we will.
00:31:23 --> 00:31:26 Andrew Dunkley: And, uh, looking forward to it. And don't forget to visit us
00:31:26 --> 00:31:29 online at our website and visit the shop
00:31:29 --> 00:31:32 while you're there or just have a look around. And that's
00:31:32 --> 00:31:34 at, uh, spacenutspodcast.com or
00:31:34 --> 00:31:37 spacenuts IO. Uh, I would
00:31:37 --> 00:31:40 have said thanks to Huw in the studio, but he couldn't be with us
00:31:40 --> 00:31:43 today because he reached the age of 10 to the
00:31:43 --> 00:31:45 78. And that was the end of that
00:31:46 --> 00:31:49 from me, Andrew Dunkley. Thanks for your company. We'll see you
00:31:49 --> 00:31:51 on the next episode of Space Nuts. Bye. Bye.
00:31:53 --> 00:31:55 Generic: You've been listening to the Space Nuts Podcast,
00:31:57 --> 00:32:00 available at Apple Podcasts, Spotify,
00:32:00 --> 00:32:03 iHeartRadio or your favourite podcast
00:32:03 --> 00:32:04 player. You can also stream on
00:32:04 --> 00:32:07 demand at bitesz.com This has been another
00:32:07 --> 00:32:09 quality podcast production from
00:32:09 --> 00:32:11 bitesz.com