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