Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Astronomical Adventures: Exploring Titan's Ocean, Cassini's Legacy & the Future of Artemis

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Astronomical Adventures: Exploring Titan's Ocean, Cassini's Legacy & the Future of Artemis · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Heidi Campo: All right, Fred, let's light this candle.
0:02
This is the another episode of
0:06
space nuts.
0:07
Professor Fred Watson: 15 seconds. Guidance is internal.
0:10
10, 9.
0:12
Professor Fred Watson: Ignition sequence start. Space nuts. 5,
0:14
4, 3, 2. 1. 2, 3, 4, 5,
0:17
5, 4, 3, 2, 1. Space
0:20
nuts. Astronauts report it feels good.
0:23
Heidi Campo: And I am your host for, for this,
0:26
American summer, Australian winter, Heidi
0:29
Campo. And joining us is Professor Fred
0:31
Watson, astronomer at large. Hey
0:34
Fred.
0:34
Professor Fred Watson: Good to see you. Heidi. I can't remember
0:36
which astronaut that light this candle quotes
0:39
come from. Do you remember which one it was?
0:41
It was one of the early days of spaceflight,
0:44
I think.
0:44
Heidi Campo: Definitely early days. And you're testing
0:47
my history and I'm failing.
0:49
Professor Fred Watson: It's all right.
0:50
Heidi Campo: Fred and I, we discovered, a
0:53
new feature. So our, recording software is
0:56
updated and now it does a very exciting
0:58
countdown for us. So that was, that was kind
1:01
of fun, a way to launch into the episode, so
1:03
to speak.
1:04
Professor Fred Watson: Yep, we, we lit the candle.
1:07
That's the main thing we did.
1:09
Heidi Campo: We did. And so let's, let's, let's set this
1:11
off.
1:11
So our destination today for this first
1:14
episode is we're going on a mission
1:18
to some of the, outer planets
1:21
do we call. Well, Titan's not a planet, but,
1:24
it's a moon around Saturn. Saturn is a
1:27
outer planet.
1:28
Professor Fred Watson: Yeah, that's right. One of the four gas
1:30
giants in the solar system. The second one
1:33
out, for many, many centuries,
1:36
it was thought to be the edge
1:38
of the sun's family of planets, even
1:41
before the sun was known to be at the center.
1:44
Because it's the furthest of the naked eye
1:46
planets, the ones that you can see with the
1:47
unaided eye. M. Uranus just
1:50
makes it actually into the,
1:53
unaided eye category. But you really need to
1:55
know what you're looking at and you need good
1:57
eyesight and the dark sight. I've never seen
1:59
Uranus with my unaided eye. Anyway, Saturn
2:02
out there, one and a half billion kilometers
2:04
from the sun, doing its thing. And of course
2:07
from 2004 to
2:10
2017, Saturn was the star of the
2:13
Cassini show, the Cassini mission,
2:15
I think one of the most productive space
2:18
missions ever. NASA, with
2:21
an association with esa, the European Space
2:23
Agency, this fabulous mission. the spacecraft
2:26
was in orbit around Saturn for 13 years
2:29
doing marvelous things before it eventually
2:31
dived into the Saturnian atmosphere. And I
2:34
think some of the most exciting stuff, it's
2:37
actually hard to pick what was the most
2:38
exciting stuff to come out of the Cassini
2:41
mission? the rings, the moons, the planet
2:43
itself. But, for My money, Titan
2:46
really stole the show, actually,
2:49
I should say with Enceladus as a close
2:51
second. Enceladus was where we discovered
2:53
geysers of ice coming out of the, out of
2:56
the, subsurface ocean. But Titan, such
2:59
a weird, weird world. And we knew it was
3:01
weird before Cassini got there because there
3:04
was evidence, from radar measurements
3:07
from Earth that there was very smooth
3:09
surfaces on Titan. And it was
3:11
suspected that Titan would have lakes and
3:14
seas, not of liquid water. Because
3:17
the temperature out there is about minus 190.
3:20
That's the surface temperature. 190 Celsius.
3:23
So should specify the unit, shouldn't I?
3:26
And indeed it is known to have
3:29
lakes and seas, of liquid natural gas,
3:32
ethane and methane, which are predominantly
3:34
in the Northern hemisphere. One of the other
3:37
things that was an early discovery,
3:40
about Titan and this kind of links to the
3:41
story that we've got at the moment, was
3:44
that the surface, of
3:47
the planet is decoupled from the
3:49
interior. by that I mean that
3:52
the rocky core of Titan
3:56
rotates, in a certain way, but the
3:58
surface actually swishes around a bit.
4:02
you're kidding me. That's the conclusive
4:05
proof that you've got a global ocean
4:07
underneath the surface. It's a liquid
4:09
interface between the surface and the rock.
4:12
But if you're on Titan, your longitude
4:15
changes without you moving because
4:18
the surface of the ice moon
4:21
is moving.
4:22
Heidi Campo: So it's basically just a giant, what do they
4:25
call those, the little magic balls that you
4:27
shake up. And it's got the little globe
4:29
inside that rotates until the future.
4:32
It's just a giant.
4:32
Professor Fred Watson: Yeah, I've seen one of those, but I can't
4:34
remember what it's called.
4:35
Heidi Campo: The little, I think just the magic ball.
4:38
Yeah. Oh, wow. I didn't know that. That's
4:40
such a, that's such an incredible fact.
4:43
So it's not frozen then?
4:45
Professor Fred Watson: The ocean's not. No, that's right. The
4:47
surface is. And we don't know how thick the
4:49
ice layer of Titan's surface is. It's
4:51
probably many tens of kilometers. but
4:53
underneath that, I mean, Titan is a big
4:55
world. It's bigger than the planet Mercury.
4:57
It's the second biggest satellite in the
4:58
solar system. and so, a, significant
5:01
rocky core and this ocean, which, you
5:04
know, I don't think we've got any real
5:06
estimates of what its depth is, but it's
5:08
again measured in, tens or perhaps even.
5:11
Sorry, yeah, tens or tens of Kilometers is
5:13
probably the best, best guess for something
5:15
like that. Maybe even hundreds. anyway the,
5:19
this, the reason why this links to the
5:21
present story is that there's been a new
5:24
analysis of of
5:27
the spinning of Titan
5:31
and its atmosphere. Titan has
5:34
a thick atmosphere. It's 50% higher
5:36
atmospheric pressure than we have here on
5:38
Earth. So we probably feel like we were,
5:42
I read yesterday that we'd feel as though we
5:44
were in a depth of 5 meters. 5
5:47
meters of water, what's that? 6 meters is
5:50
20ft.
5:50
Heidi Campo: So you've so an average used in summer.
5:54
Professor Fred Watson: Yeah, probably. Yes, that's probably right.
5:57
so it's got this high pressure atmosphere,
5:59
mostly nitrogen and methane, and
6:02
they have clouds and rain and of liquid
6:05
natural gas. It's a bizarre, a
6:08
bizarre sort of parallel with the Earth where
6:10
water is the Earth's climatic cycle. We think
6:13
it's methane and ethane on Titan. but the
6:16
atmosphere has now been shown
6:19
to circulate around
6:21
Titan not in sync with
6:24
the surface like our atmosphere is
6:27
because we stand on the surface and we don't
6:29
feel any wind because the atmosphere is
6:31
moving with the rotation of the Earth Titans
6:34
actually the atmosphere rotates faster
6:37
than Titan does. So
6:40
it's decoupled from the ah, you know
6:43
from the surface which is a very strange
6:45
phenomenon in itself. I might give
6:48
a quote actually this, this story is actually
6:51
the one I've read is on Space.com. it's an
6:54
article written by Victoria Corliss. Very
6:57
nicely done. so it's
7:00
basically data from the
7:02
Cassini mission reanalyzing it.
7:05
and Lucy Wright who's the lead
7:08
author, not the leth order, the lead author
7:11
of the new research and is at the School of
7:14
Earth Scientists at the University of Bristol
7:15
in the U.K. Lucy said the behavior of
7:18
Titan's atmosphere tilt is very strange.
7:22
We think some event in the past may have
7:24
knocked the atmosphere off its spin axis
7:27
causing it to wobble. So not only does it not
7:29
rotate in sync with the surface but it also
7:32
wobbles. and m,
7:34
basically that's the best guess that it was
7:38
some sort of impact or some
7:41
you know, event in the in the
7:45
atmospheric history of Titan that's caused
7:48
not just this out of sync rotation but
7:51
also a tilt, a wobble of the
7:54
of the atmosphere.
7:57
Heidi Campo: that's incredible. If I
8:00
was Andrew and I had the soundboard I would
8:02
insert the little jingle from the X Files
8:05
right there. Do do do do.
8:07
Professor Fred Watson: Yeah well, that's right. Well, yes, very
8:09
strange. He sometimes does that. We manage to
8:11
keep him under control, though. That's all
8:13
right. But yes, it is. It's weird. and, you
8:16
know, it's a extensive study.
8:19
Ah, one of the.
8:20
Perhaps one of the consequences of this
8:23
though, is, if the atmosphere's,
8:26
not moving in sync with the surface, then it
8:29
means you've got high winds on the
8:32
surface. You're going to experience high
8:34
winds. and that has not really been,
8:39
deduced before. Although there is evidence
8:42
of wind ripples on, these lakes and
8:45
seas, the radar reflections
8:47
sometimes get very bright, which means
8:50
you've got radar bouncing off a rough
8:52
surface. If you get a very,
8:55
faint radar reflection, you're looking at a
8:57
smooth surface because most of the, radar has
8:59
been reflected off in a different direction.
9:02
it's like a mirror surface that will give a
9:03
very dark radar reflection. So a bright radar
9:06
reflection corresponds to a rough surface.
9:09
And that has been seen on some of the lakes
9:11
and seas of Titan. So maybe that itself was a
9:13
hint that, the winds are blowing
9:16
more quickly than we thought.
9:18
But what's really at stake here,
9:21
and this brings us back to NASA, the
9:23
Dragonfly mission, which is a
9:26
quadcopter, that is planned for
9:30
exploration of Saturn's moon Titan
9:33
sometime in the next decade, sometime in the
9:35
2000 and 30s. That is going to be a bit
9:38
like ingenuity was with, perseverance.
9:41
It's going to be a fantastic tool for
9:44
exploring Titan, for exploring its
9:47
surface, for investigating maybe what these
9:49
seas look like. I don't know whether
9:51
Dragonfly will dip its toes in the water, but
9:53
it's, going to tell us a lot more than we
9:56
know already. But here's the problem. If
9:58
we've got much faster winds than we thought
10:00
we had, and you're launching a quadcopter
10:03
into the atmosphere, then that could give us
10:05
all kinds of problems for the navigation of
10:08
the Dragonfly, drone, which might
10:11
lead to difficulties in actually making
10:14
the mission, succeed in all its goals.
10:17
you could argue the same thing with Mars. We
10:20
know that we get high winds on Mars and
10:22
that's what causes the dust storms. Ingenuity
10:24
managed to cope with that. But remember, the
10:26
atmosphere on Mars is only, it's less than
10:29
1% of the atmospheric pressure on Earth.
10:32
Whereas here we're talking about an
10:33
atmosphere that's 50% thicker than the
10:35
Earth's atmosphere. So there's probably more
10:38
at stake, I.
10:38
Heidi Campo: Think yeah, it was almost,
10:42
you almost need to look at more. You know,
10:44
I'm not, I'm not, an engineer rocket
10:46
scientist by a long shot. Far from it,
10:49
but it almost seems like you would need to
10:51
look at more amphibious designs than
10:54
aerospace designs. And it would need to be
10:56
able to navigate in that thick, thick
10:59
atmosphere. Almost like a, like a sub, like
11:02
a submarine in the
11:04
air.
11:06
Professor Fred Watson: Yeah, that's right.
11:07
Heidi Campo: I'm thinking of a zeppelin.
11:09
Professor Fred Watson: Yes. a submersible zeppelin. That's what you
11:11
need. I mean, something like a zeppelin will
11:13
get blown around even more because
11:16
they've got such a big surface area. But your
11:19
thinking's right, Heidi, because back in the
11:22
early 2000s, when we were first discovering
11:25
the, this extraordinary surface landscape
11:28
on Titan, with a surface
11:30
that's made of ice as hard as rock, but in
11:33
that rock there are depressions that have
11:34
these seas and lakes. when we're first
11:36
discovering that, people were suggesting
11:38
we've got to send a submersible to
11:41
Titan, we've got to send a submarine up there
11:43
to explore what's underneath the surface of
11:45
these lakes. Some of them are quite deep. I
11:47
think, if I remember rightly, the deepest one
11:49
is about 180 meters. That's a really
11:52
significant depth. and people
11:55
have conjectured that there may be life
11:58
forms in them, which use
12:00
liquid natural gas, ethane and methane
12:03
as its working fluid. Unlike every
12:06
life form on Earth, which uses water as its
12:08
working fluid. If you've got a world where
12:11
water's not common because it's frozen solid.
12:13
but, you've got other stuff that's a liquid.
12:16
Maybe, maybe, just maybe you've got
12:19
weird alien species that use liquid natural
12:22
gas, to make themselves work.
12:25
Heidi Campo: Yeah. Ah, there's just, there's so much,
12:26
there's so much to discover out there. And I
12:28
think we're, you know, I, I listened
12:31
to the show for a long time and I've been
12:33
helping out, for a little while now. But it's
12:35
interesting. It seems like there is
12:36
definitely an uptick in the
12:39
discovering a potential of life out there.
12:41
We're really, we're really learning so
12:44
much so, so quickly right now.
12:46
Professor Fred Watson: Yep, absolutely. I agree with you. I think
12:48
that's right.
12:50
Heidi Campo: And then, you know, our, our, our next story,
12:53
you know, we're talking about the, the
12:55
teams that are making these discoveries.
12:58
It's, you know, we're not just out there.
13:01
It's not just one guy in a room observing
13:03
these things. It is teams. And I
13:06
actually, I, I Wish I could have my, my book
13:08
sitting next to me. It's downstairs. I would
13:10
hold it up for those of you watching. I just
13:12
recently purchased a few books about NASA
13:15
teams and how they run their teams,
13:18
their programs and their robust
13:20
personality profiles and the things that they
13:22
do to create these teams.
13:23
But our next article is about the NASA
13:26
Artemis science team and inaugurating
13:28
their flight. Control room.
13:31
Professor Fred Watson: That's right, yeah. And this is not very far
13:33
from where you're sitting now is it? It's at
13:35
John Johnson Space center in Houston.
13:38
it's. That's where the Artemis
13:41
flights are going to be controlled from. when
13:44
they are ah, when they carry a human crew.
13:47
Artemis being, you know the,
13:50
the big initiative by NASA,
13:53
and other agencies actually to to
13:56
take astronauts back to the moon, in the
13:59
20, 20 twenties. We hope, we hope the first
14:02
landing will be 2027. It's already been
14:04
pushed back a few times. Artemis 2 is the
14:07
next mission, probably next year sometime
14:09
which will be basically a rerun of
14:12
Artemis 1 which was a flight around the moon,
14:15
but this time it will carry a crew of four
14:17
astronauts. So what's happened? Well,
14:20
at the Johnson Space center in Houston the
14:24
room which will contain the Mission
14:27
control for the Artemis 2
14:30
miss and subsequent ones has
14:33
been inaugurated. It is technically called
14:35
the Science Evaluation Room, the ser.
14:38
and it's been very cleverly
14:41
designed to be much more
14:44
maybe m. To allow much more integration
14:47
between the members of the team. you
14:49
and I, Heidi. Certainly. I have got in my
14:52
mind what the old mission control,
14:56
basically rooms or studios look like. I've
14:58
seen some of them actually at the
15:01
Kennedy Space center. and you've
15:04
got these rows of desks with screens and the
15:06
rows of desks are basically like a
15:09
classroom with rows of people all
15:12
doing their thing and talking as best they
15:14
can. This is different. This is set up in a
15:17
sort of U shape with the real nucleus
15:20
of the people who are key players
15:23
in the center and everybody else in this sort
15:26
of U shaped ah, array of tables around the
15:28
edge. And in order to test it
15:31
they've actually undertaken a dummy run.
15:34
They've basically simulated the
15:37
Artemis 2 mission. I don't know whether they
15:40
did the full 10 days of simulation or
15:43
just the key parts. but they've actually
15:45
simulated that mission to give them
15:49
an idea of how the scientific results will
15:52
come back to it, in what they
15:54
call a real world scenario. and so, you know,
15:57
the evidence seems to be that it's going
15:59
well. but I thought that was a very nice
16:01
story to relate. people ask us what is
16:03
happening with Artemis. It's a process that
16:06
is quite slow. it's
16:09
because NASA is progressing very
16:11
carefully with this mission, as you would
16:13
expect. but there are news items coming out
16:16
all the time and this is one of them. And I
16:18
think this is a big step forward, in the
16:20
Artemis, I won't say Race to the Moon,
16:23
because it isn't that, but the Artemis lunar
16:25
missions.
16:27
Heidi Campo: Yeah, the. We're going back. Yeah. You know,
16:29
and it's so funny, I'm looking at the picture
16:31
of the room and it's ah, I have the. I've
16:34
been to mission Control. It's so impressive.
16:36
I didn't know they were going to be
16:37
decommissioning that old room and moving to
16:40
this new room. you know, it's just like the
16:42
films you watch growing up, Apollo 13 and any
16:45
of them, there's this big impressive control
16:47
center. And this one almost looks like,
16:50
with everyone sitting around the table with
16:52
all their computers. And the other
16:55
crazy thing, there's so much more technology
16:58
in this room, but there's so much less in the
17:01
room. I think that's the most impressive
17:03
thing to me because you think of these older
17:06
control, centers and there's big, robust
17:09
machines. So you're thinking, wow, those big
17:12
powerful machines must be doing so much. And
17:14
these scientists are sitting around with a
17:16
laptop. So they almost look like college
17:18
students in a study, in a study,
17:21
study setting. there's some big flat screen
17:24
TVs, but it's, it's a lot more
17:27
bare bones than the, classic
17:30
mission control center. So I think that's the
17:32
most impressive thing to me is there's
17:35
so much more technology in here and
17:38
power in those machines, but it's just a
17:41
bunch of scientists with laptops compared to
17:44
the huge room of the big machines.
17:47
Professor Fred Watson: I think you've hit the nail on the head
17:49
there, Heidi. Absolutely. So we're seeing,
17:51
you know, 21st century technology, versus
17:53
1960s technology. and
17:57
that allows you to be much more
17:59
focused on the ergonomics of this
18:02
interaction. You know, the way the people
18:04
interact with one another and
18:07
how they communicate. it's probably going to
18:10
be in some ways a little bit more informal
18:12
because you do have folks sitting around
18:13
looking at their laptops. Hopefully that'll
18:15
have good outcomes for the mission.
18:18
Heidi Campo: Yeah. And that's something I don't want to
18:20
get too off track here. But that is something
18:22
that. The psychological, component to
18:25
how NASA forms teams and how any, you know,
18:28
if you're working in any corporation or
18:30
military teams is a very, very
18:32
interesting concept that I have. I have been
18:35
reading a lot of research on. I actually. I
18:37
don't know if I mentioned this on the show. I
18:39
was a final candidate for the
18:42
NASA HERA Analog, which is. The
18:44
HERA stands for Human Exploration
18:47
Research Analog. so I signed up to be, a
18:50
analog astronaut, which is. You are not
18:53
a real astronaut. You are a fake astronaut.
18:56
You guys can think of it, you're just larping
18:58
as an astronaut for a predetermined amount of
19:00
time. but this was a NASA, Johnson Space
19:03
center analog. So it's inside of Johnson
19:05
Space center and is run by NASA. But what
19:08
they're. They're doing a lot of different
19:10
tests in there, but one of them is, is
19:11
they're looking at crew dynamics. And some
19:14
really interesting research has come out of
19:16
that. so I'll just. I'll just paint a really
19:19
quick picture of this so we can move on to
19:21
our.
19:21
Our last story. But this is so fascinating to
19:23
me. So they look at
19:26
the crew of four. Four. There's four people
19:29
in this analog. And they give them simulated
19:31
scenarios that will allow for them to
19:35
build relationships a certain way. So they
19:38
might give two crew members a problem that's
19:41
hard enough to solve. That when they solve
19:44
it, they feel really accomplished and they
19:46
feel more bonded. But it's just easy enough
19:48
that they're guaranteed success. So they'll
19:51
artificially create a stronger bond between
19:54
those two crew members by doing something
19:56
like that. And then the other two crew
19:58
members, they might do this the same thing.
20:01
And then they might do other scenarios where
20:02
it's like, these crew members, these three
20:04
are closer. This third person, there's. This
20:07
fourth person is kind of cut out. And, I can.
20:10
I will give you guys the link so that you
20:12
guys can all read this research yourself.
20:13
Because I just. I. I'm obsessed with this,
20:16
this. This study. But basically what they
20:18
found is they have the integrated model where
20:21
all four crew members are working together.
20:23
And they're all in sync. And their mission
20:25
success was around 100% successful.
20:28
Then they have the subgroup models where,
20:30
okay, these two are closer, these two are
20:32
closer. Everyone still works together, but
20:35
these two subgroups have formed a closer
20:37
bond. Surprisingly, their
20:40
mission success would drop to around 80%
20:43
successful. And then the
20:46
isolated model where these three crew members
20:48
are working really closely together. And the
20:50
third crew member was kind of isolated. Their
20:52
mission success dropped to around 50%
20:55
successful. And they said that this
20:58
works across any
21:01
scale. So they've done a lot of research with
21:03
sports teams. So if your offense and
21:06
defense identifies more as offense and
21:08
defense rather than the whole team, the team
21:11
is less successful. And, you know, and then I
21:14
think you guys have figured out by now I'm
21:16
kind of a cheeseball here on Space Nuts. I'm
21:18
the, I'm the space. I'm a nerd. But it's
21:21
like, I think about it on a global scale.
21:23
What if humanity was thinking that
21:26
we're all on the same team instead of
21:29
I'm this company or I'm that company, or I'm
21:31
this this, or I'm that nation. If we were
21:32
all, if we were all playing for the same team
21:34
here and to see what our mission success
21:36
would be. But I don't know, that was, that's
21:38
just kind of what I get out of that. And so
21:40
there's, there's a level of informal that I
21:42
think sometimes really helpful because it
21:44
helps us form those bonds.
21:46
Professor Fred Watson: it's key to, I mean, it would be wonderful if
21:49
the whole world was on the same team. God
21:51
knows we need that, the way things are at the
21:54
moment. but, the,
21:57
idea of having the right
22:00
individuals and the right team structure for,
22:02
say, a Mars mission, where you've got
22:05
people cooped up in a small, place
22:09
millions of kilometers from Earth for six
22:12
months before you actually get to Mars,
22:14
and then you've got to do all the stuff there
22:17
that, that's going to be key to the success
22:19
of the mission. it's, you know,
22:22
notwithstanding all the technical issues, all
22:25
the habitat issues and all the rest
22:27
of it, just having people who get on and can
22:30
get on and work productively must be the
22:33
number one priority. So that's my guess
22:36
where that study, that sort of study is
22:38
heading. And, hopefully it will all be
22:40
100% successful.
22:43
Heidi Campo: Yeah. And that's what they do a lot in,
22:44
Chapia and Hera and a lot of these,
22:47
extended duration analogs. And I might still
22:49
do it. I told them that at the. I
22:52
was the one who dropped out. They, they were
22:54
ready to actually give me a mission, but I
22:55
dropped out because it just wasn't good
22:57
timing for me. but you know who's really
22:59
good? You love my segues. I don't know. This
23:01
is my thing is, you know, what species
23:04
is wonderful at working on A team.
23:08
Professor Fred Watson: Let me guess.
23:13
Yeah, isn't that is a lovely segue. And
23:17
you know, this is a story that. Yes, we're
23:19
going to talk about Wales. Wh.
23:22
Not. The country next to England
23:25
doesn't have the H. And we could talk about
23:27
that some other time probably.
23:28
Heidi Campo: I'm sure they're wonderful team players as
23:30
well.
23:30
Professor Fred Watson: Yeah, I think they are, yes. Yeah, they're
23:32
good singers too.
23:34
so this is a study about whale behavior.
23:37
And the reason why I thought this would
23:40
be a good one to talk about on Spacenauts is
23:43
that it's got, sort of overtones of
23:45
how we might deal with
23:48
communication with extraterrestrial
23:51
aliens. And you and I have mentioned already
23:53
the movie Arrival, which was a fabulous
23:56
account of exactly that problem.
23:58
Heidi Campo: Yeah, I love that movie so much.
24:00
Professor Fred Watson: Yeah, so this is the same sort of
24:03
thing, but you're not talking about people
24:05
who land in weird looking spaceships, you're
24:08
talking about whales. And there is a paper
24:10
now that has been. It's actually
24:13
reported in in Nature magazine, which is the.
24:16
One of the two leading journals in the world
24:19
for scientific results. But I think, there's
24:21
a publication in one of the, one of the
24:25
journals related to, you know, to living
24:28
organisms. But the bottom line is humpback
24:30
whales, we, we've known for quite a
24:33
long time that they use what are called
24:36
bubble rings as a trap for
24:39
the prey that they want to eat, probably
24:42
krill. I'm not sure whether humpbacks
24:45
eat bigger organisms, but krill is certainly,
24:48
part of their diet. And what they do is they
24:50
blow these bubble rings, which act as a sort
24:53
of net and then they swim inside it and
24:56
gobble up all the stuff that's been netted.
24:58
But it turns out that these bubble rings
25:01
actually, come in different shapes
25:04
and sizes. Some are
25:06
exquisitely circular. there's
25:09
actually an image, which is on this nature.
25:12
Heidi Campo: It's a perfect circle and it almost
25:15
looks like a whirlpool too. Like, I'm like,
25:17
how is this real?
25:20
Professor Fred Watson: That's right. Which is an
25:22
amazing. You know, it's like a foam in a
25:25
perfect circle a few feet in diameter.
25:28
But they also, sometimes make
25:31
multiples of these. So you get a ring of
25:33
perfect circles or a spiral
25:36
shape. And the
25:40
focus of this research is
25:42
that it turns out when you
25:45
look at the statistics of these bubble
25:48
ring appearances, that there are
25:51
more of them that
25:53
occur when humans are watching
25:56
than occur in the
25:59
natural world when there's nobody around.
26:03
And so this is they might be.
26:05
Heidi Campo: Trying to talk to us.
26:06
Professor Fred Watson: That's exactly it. This is the thrust of this
26:08
article. Are we seeing
26:12
ah, a behavior in Wales
26:15
that suggests that they are doing
26:18
something that is all about
26:22
whale to human communication
26:24
rather than, you know, rather than just
26:27
a random sort of thing. it's actually the
26:30
publication is Marine Mammal Science. That's
26:33
the, where this, where this paper appeared.
26:35
But I think it's been commented, I think this
26:37
commentary comes from Nature magazine.
26:39
and there's yeah some, some
26:42
lovely examples of
26:45
these. Ring, ring production. There's
26:48
one quote here that comes from the
26:49
researchers who've done this work. Out of the
26:51
12 episodes of Ring production reported here,
26:55
10 episodes were collected near a boat or
26:57
human swimmers, while six had more than
27:01
one whale present. Despite these ample
27:03
opportunities for intra and
27:06
interspecies aggression, there was
27:09
no evidence of antagonism towards
27:12
conspecifics. I think that's ah, a
27:15
marine mammal word for like minded
27:18
or aggression towards boats or swimmers in
27:20
any of the ring episodes. quite the contrary
27:22
in fact. Far from showing signs of avoiding
27:24
humans, eight of the nine of nine ring
27:27
blowers approached the boat or swimmers with
27:29
exceptions to when they were blowing bubbles
27:31
while feeding. So there's more
27:34
statistics in the article which I won't go
27:36
into but it does look as though there is a
27:39
predominance of these ring bubbles
27:42
of a particular kind. And these I think are
27:44
the most symmetrical and kind of elegant ones
27:47
in a way, being blown when there are humans
27:50
present. make of that what you
27:53
will. And you know I'm guessing
27:56
that a lot of the other others that have been
27:58
observed and I do know that quite a lot of
28:01
these ring bubbles that have been seen have
28:03
been observed by drones and you know, other
28:06
sort of remote sensing equipment so that
28:08
there weren't humans present in those
28:10
instances.
28:12
Heidi Campo: Well you know language in and of
28:15
itself is such a fascinating topic and
28:19
both verbal and written language is so
28:21
interesting and that was something to keep it
28:24
space related. That was something that was
28:26
widely discussed with Voyager and they
28:29
initially wanted to have a
28:31
map of Earth with an arrow pointing to Earth.
28:34
And there was a lot of discussion, well what
28:36
is an arrow? An arrow is a man made thing.
28:40
We can't say if ah, intelligent life
28:43
form would understand what an arrow meant. So
28:46
that's why they ended up doing more of kind
28:48
of like a little bit more of a
28:50
mathematical model because math is
28:53
universal. So that's that was the logic
28:55
behind that is math is A universal language.
28:58
and same thing with music. And they did also
29:00
include whale songs and a
29:03
number of other beautiful things. You can
29:05
actually find a lot of those tapes, on
29:07
Spotify. They have people singing from around
29:09
the world.
29:13
Professor Fred Watson: That's, the gold disc that was on,
29:16
each of the two voyages. The
29:19
Pioneer spacecraft also had. They just had
29:21
plaques, but they had sort of mathematical
29:24
representation of where the Earth was, which,
29:26
if I remember rightly, was in terms of the
29:28
direction to specific quasars, which
29:31
are very, distant. It might
29:34
even have been pulsars, I can't remember.
29:36
But, the idea was to.
29:39
To denote what the source of this spacecraft
29:42
was, using things that
29:45
would be recognized by an extraterrestrial
29:47
intelligence because they would make
29:49
astronomical observations as well. And so
29:51
they were trying to link, you know, the
29:53
directors, direct people to where this had
29:56
come from by the astronomical information
29:59
around us.
30:00
Heidi Campo: I, was speaking, with a friend of mine the
30:02
other day who's a mathematician, and she said
30:05
the reason why she loves music so much is
30:08
because music is math in motion.
30:11
Professor Fred Watson: It is, absolutely. I'm exactly the same,
30:13
Heidi. If I hadn't been an
30:16
astronomer, I would have been a musician.
30:18
Heidi Campo: Oh, that's beautiful. Yeah. I mean, it really
30:20
is. And whale song is something I think
30:22
everybody connects to. And it is really
30:25
incredible to see the
30:27
crossover between humans and animals and
30:31
intelligence and math and
30:34
maybe, who knows, maybe the whales are going
30:37
to help us figure out something. Maybe they
30:39
have it all figured out and they've been just
30:41
trying to tell us. Just need to listen
30:43
better.
30:44
Professor Fred Watson: Just look at these bubble circles, for
30:46
goodness sake, and then you'll work it all
30:48
out.
30:49
Heidi Campo: So if any of you guys can figure out the
30:51
math, formula that the whales are sending us,
30:54
please let us know.
30:55
Professor Fred Watson: Yeah.
30:56
Heidi Campo: Fred, this has been lovely. This is. This is
30:58
a really. This was a fun episode. A lot of,
31:00
uplifting and very interesting, conversations
31:03
today.
31:04
Professor Fred Watson: Thank you, Heidi. I think. I think so, too.
31:06
It's been fun talking to you, as always, and
31:08
we'll speak again very soon.
31:11
Heidi Campo: All right, see you later,
31:17
space Nuts.
31:18
Welcome back to another episode of Space
31:20
Nuts. I'm your host for this summer,
31:23
filling in for Andrew Dunkley. My name is
31:26
Heidi Campo, and joining us is Professor Fred
31:29
Watson, astronomer at large.
31:32
Professor Fred Watson: Good, to be here, Heidi, as always. And
31:35
you're also our host for this winter here in
31:38
Australia. So, yeah,
31:41
lovely to talk. And, I think we've got some
31:43
pretty great questions from our, listeners
31:44
for this episode.
31:46
Heidi Campo: We do. We have some. We have some really fun
31:49
not episodes. We have some fun questions.
31:52
our first question today is Martins
31:55
from Latvia. And here is
31:59
his question.
32:01
Speaker C: Hello, guys. It's, Martins from Latvia.
32:04
I've, been loving your show. Been listening
32:06
since 2017. And,
32:09
so I have a question about dark matter.
32:12
Okay, just kidding. I have a question about
32:15
speed, of light. So we have two objects.
32:18
One object is on Earth, and the other one is
32:20
traveling in space at the speed of light.
32:23
After some time, it comes back and the object
32:26
that's on Earth is older than the other
32:28
object. So why is that happening
32:31
again? Why? They aren't the same, age.
32:34
I mean, yeah, there's something to do
32:36
probably when you're reaching speed of light
32:38
that time slowing down or something. But why
32:40
it's slowing down? Why isn't it, like, yeah,
32:43
just curious. And, yeah,
32:46
and I have, some dad joke for
32:48
your, arsenal. Andrew. So,
32:52
how do you put a space baby to sleep?
32:54
Your rocket. So anyways, guys,
32:58
cheers, then. Yeah, have a good one.
33:01
Heidi Campo: Well, I think those space babies will be
33:04
sleeping well with those jokes. Thank you so
33:06
much, Martinez. That was a good one.
33:10
Professor Fred Watson: Yep. Space babies, always need to be
33:13
rocked. That's right.
33:15
So, now that's a great question. I have
33:18
visited Latvia, actually. some years ago. We
33:21
did a tour there. I do remember,
33:23
you know, Heidi, because we've talked about
33:25
it before. I'm very fond of trains. We
33:28
traveled on a little railway, through the
33:30
snow and through. Because we always visit
33:33
these places in winter, through snow and
33:35
woodlands. And it trundled along at
33:37
something like nine miles
33:40
an hour. Maybe it was a
33:43
fast walking pace because it was a very
33:46
old line, but it was a lot of fun. Anyway,
33:49
enough about Latvia.
33:50
let's get to the speed of light, which is
33:52
basically what Martin's question is about.
33:55
this is. It's one of the fundamental
33:58
aspects of relativity.
34:01
Einstein's two theories of relativity. One
34:03
was about motion, the other was about
34:05
gravity. It's the one about motion that
34:07
covers this. That's called the special theory
34:09
of relativity, dated 1905.
34:12
And it turns out that the thinking that
34:15
Einstein had had, leading up to this
34:18
was that we know
34:20
that the speed of light is a bizarre
34:23
quantity because in a vacuum, it's
34:26
always the same. We know also that
34:29
it's the maximum speed that anything can
34:32
attain. In fact, you can't actually achieve
34:33
the speed of light with an object because
34:36
you would have to put infinite energy in to
34:38
get it to the speed of Light. And we don't
34:40
have infinite energy. So light and its
34:43
other electromagnetic waves. They are the
34:46
only things that can travel at the speed of
34:47
light. But if you had something
34:50
that you are accelerating. Well, let me just
34:52
go back. The speed of light is,
34:55
almost like a magic number. It's not magic
34:58
because it's a very round number. It's about
34:59
300,000 kilometers per second.
35:03
it is, however, the fact that it
35:05
doesn't change in a vacuum. And it doesn't
35:07
matter how fast the source is moving. You'd
35:10
expect if you have a source that's moving.
35:12
That sends out a beam of light. The
35:15
source's speed would add to the speed of
35:18
light. And the speed of light would increase.
35:19
But it doesn't doesn't work like that. And
35:22
once you establish that, then it
35:25
turns out. And there's some
35:27
quite sort of simple ways of
35:31
seeing how this might work. Which we don't
35:33
really have time to talk about. But some of
35:35
the books about special relativity. That talk
35:37
about people looking at somebody moving on a
35:39
train. Show you how the geometry works. That,
35:43
Because the speed of light is always the
35:45
same. Then what it tells you is
35:47
perceptions of time and distance must change.
35:51
And so the key thing here. And the
35:54
point that, Martins is raising.
35:57
Is that if you've got an observer
36:00
who is stationary. Compared with somebody
36:03
who's moving at a very high speed. Nearly,
36:06
the speed of light or yeah. It doesn't
36:09
matter whether it's near the speed of light
36:10
or not. It's the effect works. But it's when
36:13
you get nearer the speed of light. That it
36:14
becomes noticeable. the time
36:17
that you observe that moving
36:20
person,
36:23
experiencing is slower. So your
36:25
time's ticking away as normal. And
36:28
the person who's moving past you. Their
36:31
time is ticking away as normal. But when the
36:34
stationary person. If you could see the clock
36:37
on the moving vehicle or whatever it is.
36:39
Train going at nearly the speed of light.
36:41
Just to mix a few metaphors there. what you
36:43
would see is their clocks would seem to be
36:45
going much more slowly than yours is.
36:48
And that's the time dilation effect.
36:51
And yes, it means that, if you can
36:54
then bring these two back together. The
36:56
moving person has experienced less
36:59
time relative to you than you have. And
37:02
that's the it's sometimes called the twins
37:04
paradox. Because if you take two twins. One
37:07
goes off at the speed of light, comes back
37:09
again. Or nearly the speed of light, comes
37:11
back again. There they have aged much less
37:14
than the twin who stayed put.
37:19
So that's the bottom line. And it's,
37:23
you know, it's such a counterintuitive
37:25
concept. That it is really hard to get your
37:27
head around. But we know it works. in fact,
37:31
the demonstration. the practical
37:33
demonstration of this phenomenon happening in
37:35
reality, I think it was just before the
37:38
Second World War. Might have been round about
37:40
the same time. But there are things called
37:42
cosmic rays. Which are bombarding the Earth
37:44
all the time. These are subatomic particles
37:46
that come from space. and they are,
37:49
predominantly a species of
37:51
subatomic particle called a muon. So these
37:54
muons were observed coming down through
37:57
space. At, nearly the speed of light.
38:00
And we know how long they take to
38:02
decay in the laboratory. But
38:05
their decay time was much longer. When
38:08
they were observed coming in at the speed of
38:10
light. Nearly the speed of light. The time
38:13
had dilated. So their decays were much
38:15
longer. Than what we observe in the
38:17
laboratory. When they're not stationary. But
38:19
they're going much more slowly. So
38:22
it is a proven fact this works.
38:25
if we could build a spacecraft that
38:27
would get us to. I can't remember what it is.
38:29
I think it's 99.999998%
38:32
of the speed of light. Head off for
38:35
500 light years, come back again. you will be
38:38
10 years older. whereas everybody else on
38:40
Earth will be a thousand years older. So
38:43
it's that sort of thing, you know. Your time
38:45
has slowed down relative to what they've
38:47
experienced.
38:50
Heidi Campo: I had a weird nightmare about that the other
38:52
night.
38:52
Professor Fred Watson: Oh, did you?
38:54
Heidi Campo: It was the strangest thing. I had a nightma.
38:57
somebody put me in, like, some kind of a cryo
38:59
sleep.
38:59
And I woke up and so much time had passed
39:01
that everyone I knew had died. And so I had
39:03
them put me back in cryo sleep for thousands
39:06
of more years. Until we discovered the
39:08
technology to travel back in time. So I could
39:10
go back in time and link back up with
39:12
everyone I loved.
39:15
Professor Fred Watson: That's a pretty good one.
39:16
Heidi Campo: Is that I have a very active
39:20
dreamscape.
39:20
Professor Fred Watson: Ah.
39:20
Heidi Campo: At night I wake up exhausted.
39:23
Professor Fred Watson: Okay.
39:25
Heidi Campo: All right. Well, our next question, has a
39:27
little bit of philosophy in it. this. This
39:29
question is coming from Art from Rochester,
39:32
New York. And it's a. It's quite a long
39:34
question. So let's, grab a cup of tea here.
39:39
Art says, I was listening to the June 13
39:41
program concerning the Flying Banana. Which
39:44
prompted me to submit my first question to
39:47
Space Nuts. It is a question I had been
39:49
pondering for some time. You will be glad to
39:52
hear it is not A black hole question, but
39:54
rather a, what if question. The great
39:56
American philosopher Julius Henry Marx once
39:59
postulated, time flies like an arrow, fruit
40:02
flies like a banana. Based
40:05
on empirical evidence, I can confirm that
40:08
fruit flies like a banana. My question
40:10
revolves around time flying like an arrow.
40:14
To the best of my understanding, when we
40:16
shoot off rockets to the moon or Pluto,
40:19
in order to get there accurately, the rocket
40:21
scientists use an
40:24
infomeris. You'll have to correct me on the
40:27
pronunciations of that or possible
40:29
amphimerdes as a sort of a map.
40:32
If faster than light space travel were
40:35
possible, how could one navigate from point A
40:37
to point B? Is it possible to develop
40:40
an ephemeris for faster
40:43
than light travel? Thank you, Art from
40:46
Rochester, New York.
40:48
Professor Fred Watson: A great question, Art. And, yeah, your
40:51
pronunciation is correct. Ephemeris is what
40:54
these things are, and ephemerides is what a
40:57
lot of them are. So what's an ephemeris?
40:59
Well, the original
41:02
meaning, and I guess this really is still the
41:05
meaning of the word is, to
41:08
predict where, planets are
41:11
going to be, in the future, where
41:13
celestial objects are going to be. So, going
41:16
back to my master's degree,
41:19
back, you know, 150 years ago, my
41:22
work was on, the orbits of
41:24
asteroids. And so there were two
41:27
problems. First problem was how do you take
41:30
observations of an asteroid? And remember,
41:31
all we had in those days was
41:34
the direction that you could see measured
41:36
with a telescope. How do you turn that into
41:39
knowledge of the orbit of the
41:41
asteroid in three dimensions? And you can do
41:44
it. You need at least three observations to
41:46
do that. But you can do it. You can
41:48
mathematically deduce the orbit from just
41:50
three directions in space. But then once
41:53
you've got the orbit, what you want to know
41:55
is where it's going to be in the future,
41:57
what's its direction in space going to be?
41:59
And that is what an ephemeris is. It's how
42:02
the position of an object changes, in the
42:04
sky, over time. so it comes from
42:07
the word ephemeral, meaning stuff that's
42:10
temporary. so an ephemeris, is the.
42:14
Basically, it's a table, of where an object
42:16
will be over a given amount of time. And of
42:19
course, it's critically important these days
42:21
because we now know that, which we didn't
42:24
know when I did my master's degree. We now
42:26
know that the Earth's locality is pretty
42:29
heavily populated with asteroids. And
42:31
there's, you know, we might want to know
42:33
where they are just in Case, one's heading
42:35
our way. So, I, you know, I think the
42:38
question, Art's question is a good one in
42:41
the sense that, okay, he's saying, yes,
42:43
we, we use ephemera, ephemerides to,
42:46
to basically navigate
42:49
to objects. it's actually
42:52
a little bit more than that because we, we
42:55
use effectively a three dimensional map of
42:57
where these planets are, in order
43:00
to dictate where they're going to be when
43:03
your rocket arrives there. And that's
43:04
critically important of course, because you
43:06
want the rocket to get to the orbit of for
43:09
example Pluto, as Art mentions, when
43:12
Pluto is going to be, whereabouts the
43:14
rocket is. You don't want to reach the orbit
43:17
of Pluto and find Pluto somewhere else.
43:19
That's why you need an ephemeris. but
43:22
if you could travel faster than the speed of
43:24
light, and we've already shown that that's
43:27
impossible, in this episode because you need
43:29
infinite energy to do that, ah, to reach the
43:32
speed of light. But if you could, the
43:34
ephemeris would still work,
43:37
you would need to put in a negative
43:40
number for the I think
43:44
the speed of light actually goes into
43:46
ephemeris calculations. I remember it well,
43:49
but I think you put in a factor. It wouldn't
43:52
be a negative number. It would be a factor
43:53
that would allow for the fact that you were
43:55
traveling at faster than the speed of light.
43:57
So you could do it. It's not an impossible
44:00
mathematical problem.
44:04
For what it's worth.
44:06
Heidi Campo: Well, that was fantastic. I just about
44:09
understood that too.
44:11
Professor Fred Watson: Sorry.
44:13
Heidi Campo: no, you always do such a great job of
44:14
explaining these. my IQ is going up every
44:17
time I'm involved on these, these episodes.
44:20
And also great questions. We have
44:22
some of the smartest, smartest listeners.
44:25
I mean these people are, are brilliant.
44:28
our, our next question is another audio
44:30
question, from David from Munich. And
44:33
it's a little bit of a longer question as
44:35
well. So we are going to go ahead and
44:38
play that for you now.
44:40
Speaker D: Hey guys, David from Munich here.
44:43
Shout out to Andrew, Fred and
44:45
Jonti. And I heard that you're a bit
44:48
shorter in question, so I thought that my
44:50
chance to submit one.
44:53
I'm currently looking at the picture,
44:56
taken by the James Webb Telescope. You know
44:58
the first one, the first deep M space, which
45:00
was also presented by President Biden back
45:03
then. And I realized that the
45:05
galaxies do differ in
45:08
their color pretty much. So there are more
45:11
white ones, orange ones, and also reddish
45:14
ones. And I wonder how Is
45:17
that, is it due to the fact that or
45:20
is this like the redshift because they're
45:22
moving away, which I kind of
45:25
doubt, but I don't know what, what is it
45:27
else? Or is there so much material of a
45:30
different, of different kind in
45:33
the galaxy that he appears for us more red
45:36
or more blue. So
45:39
be nice if you could explain that. And
45:42
also I wonder a bit. Let's imagine we would
45:45
travel to this far distant galaxies.
45:48
if you could do it potentially,
45:52
would it not be some kind of
45:55
travel through, through the time? So
45:58
because when we look back there, right, we
46:00
see them on their early stages. So till
46:03
it, it's a long time until
46:06
the light reaches us. And if you would travel
46:09
to that far distant, galaxies you
46:12
would basically. Or what I imagine is
46:14
like you would travel through time, right? So
46:17
if you did, the moment you come closer and
46:19
closer the galaxy, or maybe let's
46:22
think of a single planet would then change
46:24
its appearance, right? So you would see that
46:26
it's alter, it shifts maybe its base
46:29
or it merges with another galaxy.
46:33
is my thinking correct? Would it like the
46:36
far, the closer you come, the more it would
46:38
change its shape and I
46:41
don't know, colors maybe, and things
46:44
you would see. yeah, thanks for taking my
46:47
questions. like the show and
46:50
till then.
46:51
Heidi Campo: Well, thank you so much. that was
46:54
David from Munich. Thank you. That was a well
46:57
thought out question. Fred, I'm so curious.
46:59
Professor Fred Watson: They were great questions, Heidi from
47:02
David. And in fact the answer to both his
47:05
questions is yes. so
47:07
David's asking whether the
47:10
color changes that we see in the images,
47:13
of these deep fields, as we call them,
47:16
looking way back in time, whether
47:18
those different colors of galaxies
47:21
is caused by the different
47:23
redshifts of these galaxies. And
47:26
that's the bottom line. But there's a few
47:28
caveats here. Let me just explain what I
47:30
mean. redshift is the phenomenon
47:33
that as light travels through an expanding
47:36
universe, the universe is expanding,
47:39
light is making its way through the universe,
47:41
but as it goes the universe is getting bigger
47:43
and so the light's wavelength is actually
47:46
being stretched. and ah, as you
47:49
stretch the wavelength of light, it goes
47:51
redder, it goes to the redder end of the
47:52
spectrum. And so that's what's happening. But
47:55
the caveat that I mentioned is that these are
47:57
actually false colors in the sense that the
48:00
James Webb telescope is an infrared
48:02
telescope. So it is looking at light that our
48:05
eyes are not sensitive to. It's actually
48:07
redder than red light that it's looking at.
48:10
So what the mission scientists do
48:13
is they, they take
48:16
the shortest wavelengths that the web
48:19
can see, which are really beyond
48:22
our. They're redder than red for us,
48:24
for our eyes, but they're the shortest
48:26
wavelengths that the red can detect, and they
48:29
make that blue in their colors. And then the
48:31
longest wavelengths that the web can detect,
48:33
they make it red in their colors and that. So
48:36
that mimics what we would see with
48:39
our eyes, with visible, you know, visible
48:42
light, but it mimics it moved into the
48:44
infrared. So it does mean that as
48:47
objects, you know, get redder, in the
48:49
infrared spectrum, we see them redder in the
48:51
James Webb telescope images. And that's
48:54
exactly the reason the most distant
48:57
objects are so highly redshifted that
48:59
you're seeing them as red objects compared
49:02
with the white objects, which are the much
49:04
nearer ones. So David's right on that front.
49:07
His second question, what would some of these
49:10
galaxies we're looking back, you know, up to?
49:12
I think the record is looking back 13.52
49:15
billion years at the M moment, which is
49:17
280 million years after the birth of the
49:20
universe. It's a big puzzle as to how
49:23
galaxies got so
49:26
big and so rich, in that short period of
49:28
time. But that's for the cosmologists,
49:31
not for us. they'll work it out. It'll be
49:33
okay. the bottom line, though, is that if you
49:36
could forget about the journey because we
49:38
can't travel the sort of speeds that you
49:41
need. But if you imagined yourself,
49:43
instantly transported from
49:46
our, vantage point here on Earth to one
49:49
of These early galaxies, 13.52 billion
49:52
years, billion light years away, what you
49:55
would see would be a galaxy that might look a
49:57
lot like ours. It has evolved
50:00
because you're seeing it. I mean, you've got
50:02
to imagine we're being
50:05
transported instantaneously so that what we
50:08
see is what's happening now. That galaxy will
50:10
have had 13.52 billion years of evolution.
50:13
It'll be quite different. It might actually
50:15
be quite a boring galaxy compared with the
50:18
very, energetic, infant galaxy that we look
50:20
at with the James Webb telescope. Complicated
50:23
answer to a simple question, but David's
50:26
right on the money.
50:27
Heidi Campo: That is such an interesting way of thinking
50:29
about that.
50:32
I'm going to be spending a while wrapping my
50:34
head around that one.
50:36
our last question of the evening is from
50:38
Daryl Parker of South Australia.
50:42
Daryl says G' day, space nuts. I'm
50:45
not sure of the best way to ask this
50:47
question. So I'll just ask it the best way I
50:50
can. That's usually the, the, the best
50:53
way. do objects,
50:55
meteors, asteroids, comets, planets,
50:58
stars, solar systems and
51:01
galaxies produce heat as they move
51:03
through space? Is it friction
51:06
or is friction a thing in the vacuum of
51:09
speed, in the vacuum of space? Thank you
51:12
in advance. And that's Daryl from South
51:14
Australia.
51:16
Professor Fred Watson: another, another great question. so
51:19
if this, if space was a complete vacuum,
51:22
and as I'll explain in a minute, it's not
51:24
quite, but if it was a perfect vacuum with
51:27
nothing in there, then, there would be
51:30
no friction, as, Daryl's
51:33
calling, would be,
51:36
you know, there'd be nothing to, limit
51:39
the speed of motion, of an object moving
51:41
through it. And it wouldn't get hot. There
51:43
would be no friction to heat it. and I think
51:46
the way Daryl's thinking here, and he's quite
51:48
right to, when a spacecra enters the Earth's
51:50
atmosphere, it's the friction between the
51:52
spacecraft itself moving against the air
51:54
molecules that causes it to be heated and
51:56
gives us this heat of reentry. There are a
51:58
few subtleties to that, but that's basically
52:00
the way it works. So things moving through an
52:03
atmosphere get hot. now,
52:07
space beyond the Earth's,
52:09
atmosphere is not a vacuum.
52:12
It's very nearly a vacuum. And that's why you
52:15
can put a satellite up and it'll stay up for
52:16
200 years or whatever. And it's why
52:20
the Moon doesn't come crashing down to Earth.
52:21
In fact, the Moon's going the other way. It's
52:23
moving away from the Earth, very slowly. but,
52:26
it's nearly a vacuum, but it's not quite
52:29
so There is
52:32
basically a very, very
52:35
slight breaking effect, which
52:37
in the Earth's vicinity. The Earth's
52:39
atmosphere doesn't just stop. It sort of
52:41
fades away. So even, you know, even
52:44
10,000 kilometers away, there's still a
52:46
little bit of residual atmosphere, which
52:47
would have a slowing effect on a spacecraft.
52:50
When you get into interplanetary space,
52:53
there's a lot of dust and there's
52:56
also subatomic particles there. When you get
52:59
to interstellar space, the space between the
53:01
stars, there is something that we call the
53:03
interstellar medium, which is basically
53:07
the radiation and particle environment
53:10
of interstellar space. There are subatomic
53:12
particles all through space. Now there, it's
53:15
still so much of a vacuum that there's
53:17
nothing really to heat a spacecraft. So
53:19
Voyager, as it ventures through
53:22
interstellar space, is on the brink of
53:24
interstellar space. Now, that won't get hot
53:26
because of that, because the friction is
53:29
far too small. But when you do see its
53:32
effects, they are on very big scales.
53:34
And we do see, when we look at
53:38
some objects deep in space, for example, in a
53:40
gas cloud, a nebula where,
53:43
maybe there are stars forming, sometimes you
53:45
see objects which are moving through that gas
53:47
cloud and what you can see is a shock wave,
53:51
being generated. And sometimes that
53:53
causes star formation, that shockwave of the
53:56
gas cloud. now, yes, that's Jordi
53:59
agreeing with me there. he's just come back
54:01
from his walk, so he's very enthusiastic
54:03
about this idea. he's probably seen the
54:06
shockwave. So, and a shockwave is what you
54:08
get when something moves rapidly through the
54:10
atmosphere. You know, that's what causes the
54:12
sonic boom of a supersonic jet.
54:15
so with very big objects
54:18
in gas clouds in space, then you do get that
54:21
sort of effect. The interaction between the
54:23
moving object and its surroundings generates
54:26
a shockwave and would generate heat as well.
54:28
So under certain circumstances the answer is
54:30
yes, Darrell. But, but probably for most
54:32
things it's no.
54:35
Heidi Campo: So, Fred, I don't know if you'd have time for
54:37
a follow up question of my
54:40
own. so
54:43
I guess I never really thought of, the
54:45
gravity atmosphere around planets
54:48
having different layers. It's like, I knew
54:50
there was layers, but it's like to really
54:51
think, okay, it gets thinner and thinner and
54:54
thinner, but there's still particles being
54:56
pulled into that atmosphere. But it just, it
54:58
spreads out quite a ways well beyond our
55:01
atmosphere. Are there points of space, and
55:03
you may have already mentioned this, but are
55:05
there points of space where there's particles
55:06
floating around that are not being affected
55:08
by any gravity at all? Or is every
55:12
part of space affected by something's
55:14
gravity?
55:16
Professor Fred Watson: yeah, pretty well. the thing about gravity is
55:19
it, it goes on for infinity.
55:21
it's it's a bit like actually light is the
55:24
same. Electromagnetic radiation will not
55:26
stop. It just keeps going until it gets too
55:29
weak to be detected. And you're talking about
55:31
a dribble of hardly any photons.
55:34
Gravity is the same. We don't know whether
55:36
gravity has a subatomic particle equivalent.
55:39
We think it might have, and we call them
55:40
gravitons, but they haven't been discovered
55:42
yet. But yes, that's actually,
55:45
you know, it's why, an object like
55:48
Pluto, way out there in the depths of the
55:50
solar system, is still in orbit around the
55:53
sun. Even though it's all these, what is it,
55:55
five, six billion kilometers away,
55:58
the gravity of the sun is still a force
56:02
because gravity goes on forever.
56:04
but, of course, when you get way out into
56:07
interstellar space, then you might feel the
56:10
sun's gravity, but you'd also feel the
56:12
gravity of other stars. and so
56:14
I think you're right that there is always
56:16
going to be a sort of gravity background
56:18
ground, because of the objects which are
56:21
in the, in the universe. Maybe it's pretty
56:23
near zero in the space between galaxies,
56:26
which is pretty empty. Although there are
56:28
subatomic particles there too. but,
56:31
yeah, but no, it's a, it's a very, a, very
56:34
compelling force is gravity, which is just as
56:36
well because otherwise we wouldn't exist.
56:40
Heidi Campo: There's always something pulling. It's just
56:42
going to be stronger or weaker. No matter if
56:45
it's. No matter if it's the biggest gap in
56:48
the known cosmos,
56:51
there's still a little thread pulling us
56:54
together. Oh, that's so beautiful. That's
56:55
kind of cool. We're all connected somehow.
56:58
Professor Fred Watson: That's a connection. That's right. Yeah.
57:01
Heidi Campo: Fred, well, this has been a
57:04
very enlightening Q and A episode
57:06
of Space Nuts. Thank you so much for
57:10
sharing your wealth of knowledge with us.
57:13
while you're. Rooster. I'm sorry? Your dog
57:15
sings his song in the background.
57:18
Professor Fred Watson: That's what he sounds like. I know. It's, His
57:20
voice hasn't broken yet.
57:23
Heidi Campo: It's, it's kind of cute. It's endearing.
57:25
thank you so much. This has been, this has
57:27
been fantastic. And, we will, we will, I
57:30
guess, catch you guys next time. Please keep
57:32
sending in your amazing questions. And,
57:35
real quick before we go, we are going to play
57:38
a, another, another
57:41
update for you. So this is your little treat
57:43
for listening to the whole thing. We've got
57:45
an update from Andrew, your beloved
57:48
regular host. I know you guys probably miss
57:50
him because your questions are still
57:52
addressed to him, but, he's on his trip
57:55
around the world, so we're gonna let that,
57:57
that, that playback now.
57:59
Andrew Dunkley: Hi, Fred. Hi, Heidi. And hello, Huw
58:02
in the studio.
58:03
Andrew, back again, reporting from the Crown
58:05
Princess on our world tour. since I spoke to
58:08
you last, our cruise has made news all
58:11
over Australia. You might have seen some of
58:13
the reports or heard some of the news about
58:15
some of the, the conditions we've had to deal
58:17
with. When I last spoke to you, I was
58:19
explaining how we were heading into rough
58:21
weather. We got off to a pretty rocky start.
58:24
Well, it got much, much worse. We
58:27
were having lunch in one of the restaurants
58:30
at the back of the ship ship and we got hit
58:33
by a weather front. It felt like we'd been
58:35
rammed and the, the ship tilted
58:38
over 7 degrees and it stayed there for the
58:41
rest of the day. It just hit us out of
58:43
nowhere. The captain had to do some heavy
58:46
maneuvering to get us into a, you know,
58:48
better position and they had to move the
58:51
ballast to keep the ship
58:53
balanced and upright. Fight as much as they
58:56
could. yeah, it was pretty harrowing. And
58:59
the weather never got better until
59:02
we got into Adelaide and were in protected
59:04
waters. But the Adelaide was fantastic. Went
59:06
to Handorf as I mentioned, that little German
59:09
village where the, the German people came in
59:11
all those years ago. They were they were
59:14
basically escaping Prussian oppression when
59:17
they came out here in the 1800s. And yeah,
59:19
made it, made a German town town which is
59:20
fantastic. had a good look around Adelaide
59:23
although the weather was terrible. We went to
59:24
Mount Lofty which is one of the best views in
59:26
Australia. And all we saw was cloud and
59:30
very strong winds. It was it was quite
59:32
nasty. Got back on board. We had to stay the
59:35
night in Adelaide because of the conditions,
59:37
hoping they'd settle down. And we, we did
59:39
have some good sailing until we got to the
59:42
West Australian border and then another
59:44
weather front hit us and it got
59:47
rough again and yeah, gosh.
59:50
And just to top it all off, we had a galley
59:52
fire in the middle of the night at one point
59:54
which they dealt with very, very quickly. So
59:56
it's been a bit of a dog's breakfast of a
59:59
cruise in some respects. But we're still
1:00:01
having a fantastic time. We stopped at
1:00:03
Fremantle again, because of the weather. We
1:00:06
were very late and so we stayed the night. We
1:00:08
have friends in Fremantle so we spent the
1:00:11
evening with them. It was fantastic. And we
1:00:14
set sail again yesterday, headed west.
1:00:16
We leave Australia now, headed for Mauritius.
1:00:19
That'll be a seven day crossing of the Indian
1:00:21
Ocean. So that's where things are at with
1:00:24
our current tour. we're really
1:00:27
enjoying ourselves, I must confess. The crew
1:00:30
here is fantastic and you
1:00:33
know, with over 2,000 Aussies on on board, we
1:00:35
outnumber everybody about 10 to 1 which is,
1:00:38
which is good. But so many nationalities.
1:00:41
Hope all is well back home and in Houston of
1:00:44
course. Heidi, look forward to talking to you
1:00:46
next time. no, Aurora Australis missed out
1:00:48
completely. Couldn't see that. So hopefully
1:00:51
when we get up north, we'll see the other end
1:00:53
of the, country and see if there's any
1:00:56
lights up north. So until next time,
1:00:58
Andrew Dunkley signing off. Off.
1:01:01
Voice Over Guy: You've been listening to the Space Nuts.
1:01:03
Podcast, available at
1:01:06
Apple Podcasts, Spotify,
1:01:08
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1:01:11
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1:01:13
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1:01:16
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1:01:20
Heidi Campo: see you later, Fred.
1:01:21
Professor Fred Watson: Sounds great.