Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Unraveling the Phenomenon of Gamma Ray Bursts and Supernovae | #381

Transcript

Unraveling the Phenomenon of Gamma Ray Bursts and Supernovae | #381 · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Hi there, thanks for joining us. This is Space Nuts. My name
0:03
is Andrew Uncley, your host, and it's great to have you along again
0:07
for another episode, episode three hundred and eighty one. Coming up, we're
0:11
going to reveal the name of Australia's moon rover. Yes, we're building one
0:15
and we're sending it to the moon or nass there is in twenty twenty six.
0:19
I believe it's the plan, but what do you call it? Well,
0:23
I am going to prove beyond reasonable doubt that Australia has no imagination whatsoever.
0:28
We'll also be looking at something that affected our ozone layer not so long
0:33
ago, and this very strange galaxy that's been observed by the James Webb space
0:39
Telescope. Well it was observed and then it wasn't, and then it was
0:42
and then it wasn't. And we'll answer some audience questions about civilization types,
0:49
tidle locking, and much much more, all coming up on this episode of
0:54
Space Nuts fifteen Channel ten nine Ignition Space Nuts or three two one Space Nurse
1:08
Can I reported Bill Good and joining us to chat about all of that is
1:12
his good self, Professor of Fred Wat's an astronomer at large. Hello Brad,
1:17
Hello Andrew. It's drawing to a close. Is twenty twenty three?
1:22
Isn't sure as we speak? So yeah, we've bet to fit in as
1:26
much as we can. We we should do that, and yes and more.
1:32
I'm just I wanted to show you my my new toy. I bought
1:36
myself an early Christmas present. I don't know if you can see this,
1:41
can see that? Oh, look at that. That's the very elegant.
1:46
That's the Boulevard Luna Watch, Luna Watch, and that's that's a replica of
1:53
the one that went to the Moon with Apollo seventeen. I don't know if
1:56
you can see the on the back, but it names date and the astronauts
2:01
and the way it came about because they actually had commissioned a different watch company
2:07
to give the astronauts watches, and the fellow who and that was I can't
2:15
remember the brand off the top of my head now, but Amiga. Yeah,
2:21
with the Speedmaster. But one of the astronauts broke his so he took
2:27
his own watch, which was a Bullevar, and they were actually an improved
2:31
watch for the moon, but they didn't get the first option and they ended
2:37
up getting up there by accident, and so whila they became famous. So
2:43
got myself one. Yeah, I knew you were going to show me a
2:46
watch when you said you got yourself in an early Christmas present. I take
2:51
it you didn't buy on a ship though, No, not this time.
2:53
It was on I bought it through one of my son's my son's girlfriend's mother,
2:59
who works for a watch company. But they had a at a Black
3:06
Friday special, so I got it. I got it nearly half priced,
3:09
so I was very happy. Yeah, yeah, but I'm loving it.
3:15
Well, so you need to have to take half a mortgage to pea the
3:19
full thie. Yeah, that's right. I really need to get over my
3:23
watch fascination. But oh no, I think you're doing all right. I've
3:25
got about six of them now. Gosh, I don't know what should you
3:30
do. What we should do is get on with it because we've we've got
3:37
to talk about this. This rover plan. Australia has been commissioned to send
3:44
a or to construct a rover which will be sent to the Moon in twenty
3:49
twenty six on a NASA mission, one of the Artemis missions. Now,
3:53
apparently there were eight thousand submissions sent in to name this Rover, and twenty
3:59
thousand people voted on the top four selections. Now the top four will cool
4:04
them on Kakira Mateship, which I kind of like, and ruverav Er as
4:15
in Kangaroo Ruver, and the winner is Ruver. I mean, come on,
4:24
thirty five percent of the vote went for Ruver, so little imagination.
4:30
So I am so disappointed, Fred, I really am am. I can't
4:39
really comment because the Space Agency is very, very close to the astronomy branch
4:45
where I work, And in fact, the director of the Space Agency actually
4:50
asked me if I take part in the selection process. Oh, okay of
4:55
the name this. Didn't know that a couple of months ago, so he
4:58
asked me. I said, yeah, but delay to do that. He
5:00
said, yeah, it's stronger at large. I'd be great for you to
5:01
do it. Yeah, that'd be fantastic. And the next thing I heard,
5:05
the chosen the name. So so it just disappeared into the ether and
5:11
it never happened. I think, I think you dodged a bullet. I
5:15
might have done. Yeah, yeah, I might have done. I mean,
5:17
I'm surprised really because Kuliman was is Kulim on one of the indigenous names
5:21
for the moon. I think that's the case. Yes, that's right,
5:25
and made ship's obvious because that's an Australian thing. But and kakira is an
5:30
Indigenous word as well. Yes, yes, that's right. And I would
5:33
have Yeah, I would have. I was surprised with him yet one of
5:35
those Yeah, I am too. And there were a few others that I
5:39
liked, Matilda. I guess they were just sort of hanging on the on
5:42
the soccer team's success this year. Blue Now, I thought that was a
5:46
good name Bluey the cartoon character about the blue healer dog. But Blue is
5:53
a dog's name. Rover is like a dog's name. I thought maybe that
6:00
could work. Then they went with Skippy, like Skippy the bush kangaroo,
6:03
warm bat walk about. Now. I thought that was good, except the
6:06
thing doesn't walk. And my favorite Rover Mcrover face. I was going to
6:14
say, at least it didn't get mc face. And there was another clever
6:17
one, but people overseas won't get it. Rover McManus. Oh, yes,
6:24
after the TV host Rove McManus. Although he did work in for America
6:29
for a while so some people might know who I'm talking about. And Bert
6:31
Newton because his nickname as a TV host in Australia was Moonface Moon. So
6:38
that and then there's the obvious ones Steve Irwin, Sam Kerr, Red Dog
6:44
named after a famous movie character that was a dog, Mad Max, and
6:47
Blinky Bill, which is another cartoon character a kohalap. But yeah, it's
6:54
going to be called Ruver. I'm sorry. I just honestly, that would
7:00
have been the last thing I voted for, so all about personal taste,
7:06
isn't it. It's one of these things. Come on astral It's better than
7:11
you know, CEE ninety one forty two or something like that, which if
7:15
it had been an astronomer, that would have been what it was called.
7:18
Yeah, I actually like that better than Ruther as well. Sorry, I
7:23
just think it's I think it's a shockup. But anyway, we're stuck with
7:26
it. The public has voted, and this is a democracy. Probably shouldn't
7:30
be after that, but anyway, maybe there'll be a coupdaeta before we launch
7:36
this thing and they can change their name. Let's move a line. I
7:43
think I'm overreacting for it. Well you are. You are turning out to
7:46
be a bit prickly about this. Have to say, does it say?
7:49
I can't really comment because I'm too close to the ocean. Not that I
7:53
had anything to do with it, although it was a near thing that I
7:56
didn't know anything. Like I said, I think you're lucky avoided it.
8:01
But let's talk about this other thing, this super and over explosion, the
8:05
gamma ray burst that heat Earth a couple of months ago now. But what
8:13
it did was extraordinary, And what's even more extraordinary is where it came Fromrew.
8:18
Yeah, So gamma ray bursts, as the name suggests, are bursts
8:24
of gamma rays. They actually were discovered first in an interesting way, Andrew,
8:28
because there were space Because gamma rays don't penetrate down through the atmosphere.
8:33
They interact with the atmosphere, but they don't penetrate the atmosphere. And so
8:39
back in the I think it was in the seventies, a flotilla of spacecraft
8:45
were launched to detect gamma rays coming from illegal nuclear tests at nuclear atmospheric tests.
8:54
It was all part of the Test Bound Treaty. The Atmospheric test Bound
8:56
Treaty. Satellites were put up to monitor the Earth to make sure nobody less
9:01
off a nuclear weapon clandestinely because you'd pick it up. And what they picked
9:05
up instead was, yes, was the the celestial version of a nuclear explosion.
9:15
They picked up gamma rays coming from from space, and bursts of gamma
9:20
rays, which which last minutes rather than seconds, are like fast radio bursts,
9:26
which are milliseconds. Gamma rays are a little bit longer, but they're
9:30
but they're typically a few seconds long. This particular one is called GRB two
9:35
two one zero zero nine A. That's a great name for a rover.
9:41
Yeah, yeah, that's right. Yeah, sure you could, yeah,
9:46
ground roving body gamma ray burst. Yeah, there you are. Yeah.
9:54
So it's and it is. It's unusual in two ways. First of all,
9:58
it was very bright in the gamma ray spectrum and also lasted a long
10:03
time. I think it lasted seven minutes, yeah, seven minutes long,
10:07
but was detectable. It's sort of you know, after glow, if you
10:13
can call it. That was still detectable for something like ten hours. And
10:18
that contrast with most gamma ray bursts because they are detected in gamma rays and
10:26
then they fade away very rapidly. And so basically a number of spacecraft have
10:31
been built that can respond to a gamma ray and this one was discovered actually
10:39
by two gamma ray space observatories, one called the Neil Gerrel's Swift Observatory and
10:46
the Faermi gamma ray space telescope both picked up this thing. And if so,
10:52
if you can do that, pick up a gamma ray burst before it
10:58
sort of starts sort of fading away, and that's usually a very short time.
11:03
What you can then do is alert the ground based visible light telescopes to
11:07
go and look at the place where where this thing was observed, and that
11:11
is what is usually the case, but means these telescopes have got to get
11:16
onto it very very quickly, whereas this one lasted for ten hours. And
11:20
in fact, there's actually a very nice time lapse set of footage that was
11:28
produced actually by the Fermi gamma race based telescope that shows the thing blasting off
11:33
and then you could see that it's still there for the ten hours later.
11:39
So it was you know, it was even observable in visible light by amateur
11:46
astronomers work that one out. So this is a really really bright object.
11:50
You know, you don't need the world's biggest telescope ground based telescopes to see
11:54
it. So if you had a telescope pointed at the right place at the
11:58
right time, you would have Yeah, you'd have seen it. That's right.
12:01
So now it's the fact that it could be observed in visible light means
12:07
you can pick up its distance, you measure its redshift, and it's two
12:13
billion light years away. So this is not on our doorstep significantly in the
12:18
depths of the universe, but it actually had made changes to the Earth's atmosphere
12:26
which were detectable for quite some time. It's actually the sort of ionization properties
12:37
of the atmosphere, and by that I mean atoms that have been stripped of
12:39
one or more electrons. These are iron artist particles, and it includes the
12:45
ozone molecules that we know so much about. They're the ones that absorb the
12:52
ultra violet radiation from the Sun. That's you know, we've talked a lot
12:56
about the hole in the ozone layer that came from the use of chlorofluoro carbons
13:01
in refrigeration all of that stuff. Well, this gamma ray burst affected the
13:05
ozone layer. It actually changed the levels. Yeah, fre it, it
13:11
does a bit, doesn't it. If you've got something two billion light years
13:13
away that can deplete ozone in the atmosphere, then it does. It just
13:18
underlines how vulnerable our our you know, our planet and its its surroundings are.
13:28
Apparently that's that effect. The depletion of the ozone lasted literally only minutes.
13:35
It was not something that you know, lasted for hours and suddenly you
13:39
radiated the surface of the Earth with ultra violet. It was a few minutes
13:45
and the ozone layer fixed itself. That you know, the atoms electrons reunited.
13:50
So it wasn't a serious event, but it does. It does suggest
13:56
that if you've got super and over explosion and that that's kind of basically what
14:01
gives rise to gamma ray bursts that's nearby, it's telling you that it can
14:07
make a significant difference to our planet and its environment. So I would not
14:13
have expected something that far away to have any impact on us whatsoever. Yeah,
14:20
that's right, so would I. It is being touted as a once
14:26
in ten thousand year event and is being called a boat boat the brightest of
14:33
all time is the same one we were talking about. I think it might
14:37
be, yes, because it was back it was last year as the ninth
14:39
of October twenty twenty two. I think we mentioned it before, but what
14:43
we haven't mentioned before is the fact that it was price enough to affect the
14:46
atmosphere of our planet. And that's the big news story that concerns this,
14:52
and it is really quite remarkable. Do we know its exact origin? Well,
14:56
these things, as I said, still a bit mysterious. I think
15:01
they're better understood than when they were first observed back in the seventies. That
15:07
what what you've got is effectively probably a super and ova. Uh, it's
15:18
this this still many different interpretations of gamma ray bursts. One one is,
15:26
okay, you've got a super and ova that is a star whose mass is
15:31
bigger than what would allow it just to collapse to a neutron star after the
15:35
explosion. Uh. And this you know this, if you've got something that's
15:41
more massive than that, then it'll collapse to a black hole. It's the
15:43
common formation mechanism for stellar mass black holes. And we know that they release
15:50
lots of energy, not just electromagnetic energy, but gravitational energy as well,
15:54
which is one of the reasons why they were getting so excited about the the
16:00
the Lego Gravitational Wave Observatory because it can detect these events as as can other
16:07
other detectors throughout the world. Virgo is the other one, and in Italy
16:11
and Kagra in Japan. If I remember rightly, I think I'm remembering the
16:15
names correctly. I might not be there, but you know what I mean.
16:18
It's it's it's the really high energy end of astrophysics. It's really extraordinary
16:26
that the processes that go on. And there are still some questions about gamma
16:32
ray burs we we I think it's true to say that we hadn't tied them
16:36
down yet as to what exactly the the basic mechanism is. We think that
16:45
there's that it's partly due to jets of material being emitted from this collapsing star.
16:52
Uh. And you know that jets have to point in the right direction
16:56
for you to see them. Yeah, that's of material. So there's all
16:59
that on into the mix as well. And you know, just to add
17:03
to the complexity, we've got fast radio burths, which seem to be something
17:07
quite different. They are probably flares on magnetars which are highly magnetized neutron stars.
17:14
But all these things that you know, Gosh, when I started my
17:17
career, we had no idea about We didn't even know that there was gamma
17:19
rays came from its face. Yeah, it's quite incredible. I suppose that
17:25
sort of spawns several questions, what if there's a super nova closer to us,
17:30
does that mean we're potentially more exposed? And beetlejuice once again comes to
17:37
mind. Yeah, yeah, that's right. Beetle juice is not five hundred
17:41
light years away something like that, which is a closer than two being it
17:45
is. Yeah, that's right. So a gamma ray burs from beetle juice,
17:48
yes, would be especially if it was a boat so arightest of all
17:52
time, it would be a bit catastrophic for the atmosphere. Yeah, yeah,
17:56
all right, Well, let's just how it's looking the other way when
18:00
it happens exactly. Yeah. If you're talking about the material that's being directed
18:04
out, you know, in relativistic jets, then you do want it to
18:07
be pointing the other way. Okay, Well, you can read all about
18:11
it online. It's everywhere. That story, it's made the New York Times,
18:15
it's it's on several websites. It's it's definitely worth a read. But
18:22
I imagine fred that someone somewhere or do a bit of a study and write
18:26
a paper about this at some stage that it seems like it's it's that sort
18:32
of topic. Yeah, they know that there are there are papers. In
18:34
fact, I should be able to give you the title of one of them.
18:37
Oh, there you are, let my hands on it. At the
18:38
moment, it was, I can't remember where it's published. I think it's
18:42
the Astrophysical Journal, and I can't let my hands on the reference to it.
18:51
It's it's a European discovery. Just to give you a bit of a
19:00
bit of a close ece. It is probably Astronomy Industrophysics, which is the
19:04
European jourbil Okay, very good, Yes, And if there's anything more to
19:10
learn about it going forward, we'll let you know. This is Space Nuts
19:14
Andrew Dunkley here with Professor Fred Watson. Let's just take a quick break from
19:21
the show to tell you about our sponsor, nord VPN. Now Virtual Private
19:26
Network is a great way to protect yourself from all sorts of nefarious situations from
19:33
hackers, to spammers to well just about anybody who wants to get hold of
19:40
your private information, your bank details, your passwords, your name, sell
19:44
it to the dark web, and your usernames and passwords are highly valuable commodities
19:51
and there's a great way to stop anybody getting hold of them, and that
19:55
is to use a virtual private network. And there is no better than nord
19:59
VP. Now as a space nuts listener, you get a special deal as
20:06
a Nord VPN customer. First of all, there's an exclusive deal available right
20:10
now for Christmas where you can save quite a few dollars and get extra time
20:17
on your service, so four extra months if you buy a NordVPN through our
20:23
special URL, which I'll give you in a moment, and don't forget,
20:26
nord always offers a thirty day money back guarantee. So the RL is NordVPN
20:34
dot com slash space Nuts. When you go to that, you'll see the
20:40
opening interface you click on get NordVPN and then you can go through all the
20:45
deals that are available, and there are all sorts of services that you can
20:49
add on, but it gets cheaper over the longer term of your or your
20:56
use. So when I signed on for NordVPN, i went with the two
21:03
year deal and I got everything and that worked out to be quite inexpensive,
21:07
so I'm pretty happy with the service. I'm very happy with the password manager.
21:12
That is one of the best things ever. I guess secure high speed
21:18
VPN, malware protection and tracker and ad blocker that comes with the basic service.
21:23
If you go to the next level up, you've got the password manager
21:26
and the data breach scanner. If you get everything, they'll throw in a
21:30
one terabyte cloud storage and the next generation file encryption, and it is great
21:37
stuff. I mean, I've been using it for quite some time now,
21:41
and as I've mentioned before, I've used it in places where I've been able
21:44
to get online, and my wife hasn't because she's not used the service at
21:49
that particular time. So it is quite remarkable, and I still don't know
21:55
how. Sometimes when you're on Nord VPN you get higher speeds than you actually
21:59
will would not being connected to it. So their servers are very very good.
22:03
They're all over the world. It is a fantastic thing to do for
22:07
peace of mind, especially if you're a traveler or if you use public Wi
22:11
Fi anywhere you go. Those are where people prow You think about it as
22:17
insurance. A virtual private network is just putting up a wall between you and
22:22
somebody who wants to use your information or something unsavory. That's going to see
22:29
maybe your bank account empty. You just don't know. These days, there's
22:32
so many scams around. So check it out nord vpn dot comash space nuts
22:37
and get the deal. I honestly think it's one of the best things I've
22:41
ever done. Nord vpn dot com slash space nuts. Now back to the
22:47
show, Space Nuts. Now Fred to our next story. And this is
22:55
sort of a telescopic revelation, initially involving the Hubble, but now with the
23:06
James web Space telescope up, they're doing all sorts of amazing things. They've
23:08
been able to nail this one down a bit better. The popular press is
23:14
calling this a ghost object because it sort of comes and goes, which is
23:18
just a popular way of getting people to read your article by putting the word
23:22
ghost in a headline. But yeah, what exactly are we talking about here?
23:29
So we're talking about an object. So you know, it's been called
23:36
the reappearing disappearing galaxy, which is what piqued my attention on the news media
23:42
because they got you too, they did, because they don't galaxies don't do
23:45
that. Hello, Hello, Hello, there's something Yeah, what's all this?
23:49
Then? What's all is that? But what it means is we're talking
23:55
about an object that is visible at some wavelengths and not at others. That
24:00
the bottom line and so this much much less exciting when you say like that,
24:04
it's all, yes, exciting is Ruver? You know, I'm going
24:10
to keep dumping on that. You are going to Yeah, poor old Ruver.
24:12
You know, you know, Andrew, you've got with a name like
24:15
that, something's going to go horribly wrong. You've got to Yeah, what
24:19
will go wrong is you'll decide in the end that you like it. You'll
24:22
face up to it, You'll think, oh, yeah, it's not going
24:26
to happen. Okay, Well I'll give you another name. Because this galaxy
24:32
is not called Ruver. It's called as Tech seventy one. Oh I like
24:36
that quite common. Yeah, so it's a TE double C seventy one.
24:41
I should have checked what that is an acronym for. It's one of the
24:44
survey is one of the many surveys that astronomers beloved off. They do surveys
24:52
and then they call the objects a number followed but preceded by the survey name
24:57
anyway, as TECH seventy one. So it was first found some years ago
25:03
by telescope I used to have a bit to do with, although I never
25:07
observed with it, the James Clark Maxwell Telescope in Hawaii on the summit of
25:11
MANORCAA that is a microwave telescope which was operated for many years by the Royal
25:19
Observatory in Edinburgh, which is where I used to work, and so my
25:23
colleagues were very much microwave engineers. They built the world's first microwave imager,
25:32
the world's first you know, image sensor for microwaves, which is called scuba,
25:37
and that was a big deal in Edinburgh and used on the JCMT,
25:41
the James Clark Maxwell telescope. Anyway, the object was detected first in those
25:48
wavelengths which are sort of sit between what we might call the far infrared,
25:53
the redder than red light that's very redder than the red, and the microwave
25:59
reached sorry millimeter wave region, that microwave region, and so that was when
26:07
as Tex seventy one was first found. But it was followed up by our
26:11
old friend Alma, the Alma Telescope in Chile, which is kind of super
26:15
deluxe version of the James Clark Maxwell telescope with an array of I think it's
26:19
sixty odd dishes at a ridiculous height place called shan yantor not far from San
26:27
Pedro to Atacama, where you're in the northern Ata Karma Desert, very very
26:33
dry, and that's why Alma's so good at what he does. So it
26:37
could be seen in the microwave spectrum that Alma looks at. Now, the
26:45
thing is that with an object like this, what you want to do is
26:48
see invisible light, and that's enter the Hubble telescope into the story. But
26:56
it ain't there in the hubble and that's why it's appearing disappearing galaxy. It's
27:06
not visible invisible lies. And that tells you that you're looking at an object
27:12
that is a bit peculiar because it shows up in the microwaves and I guess
27:21
what you might call the far infrared, the sort of stuff that Alma and
27:26
jessemt can see but not invisible lights. And the reason why it's coming to
27:30
the headlines now is that our new toy, the James Webspace Telescope, which
27:37
is an infrared telescope, has detected it and indeed given us some very nice
27:42
images of this object. It's only visible in the reddish that the reddest part
27:52
of the infrared spectrum that the James Web telescope is looking at. So it
28:00
but it is there, and it's the fact that we can now see it
28:06
with an infrared telescope as well as the microwave telescopes, but not in the
28:08
optical. What it does is that gives you a clue to what's going on
28:14
here, and it turns out that what you're seeing is a galaxy which is
28:18
basically enveloped in thick dust interstellar dust. Now we know about interstellar dust from
28:26
our own galaxy. That's what causes the dark streaks in the Milky Way.
28:29
It's what causes the coal sack that blob, the black blob devoid of light
28:37
near the Southern Cross. It's in First Nations tradition, it is the head
28:42
of the EMU in the sky, a typical dusty region of space where there's
28:48
so much dust that you can't see the stars behind it. What's happening with
28:52
as Tex seventy one is that the whole galaxy is in a kind of coal
28:56
sack. There's dust around it. That means that you don't see the stars
29:00
within it what you see is the dust itself radiating infrared, because dust actually
29:07
does that, it gets heated up by the stars and radiates in the infrared.
29:11
So that's the interpretation of what we're seeing here. A paper published in
29:21
the Astrophysical Journal with a very very large number of authors that the paper draws
29:32
the inference from that because this object is not visible in optical and optical wavelengths
29:40
in visible lights, it's not seen in visible lights. It suggests that since
29:45
most of our surveys of galaxies are done with visible lights, maybe we're missing
29:51
a huge number of galaxies that are actually like this dusty galaxy, and there's
29:56
so dusty that they don't show up in the optical surveys. And so it's
30:02
kind of potentially opening up a new area of astronomy for scientists who have not
30:11
really considered this possibility that there's a there's all population of dusty galaxies that we're
30:18
missing, which is an important piece of work really, So University of Texas,
30:23
Austin and other institutions a very large number of authors of this paper,
30:30
which is entitled a Near infrared faint far infrared luminous dusty Galaxy at Z of
30:36
order of five in Cosmos web. So if there was no dust in the
30:41
way, we would see it invisible light. Yeah, exactly. Yeah,
30:45
if it wasn't sort of encased in a cocoon of dust, then we'd see
30:49
it. Okay, does that mean we are somewhat hidden from certain angles too,
30:53
because there's a lot of dust at the center of the galaxy our galaxy,
30:57
isn't it. Yeah, that's right, And so yes, if you
31:02
were looking at our galaxy from the outside, you would always see it,
31:06
because there's not that anything like as much dust as as tex empty one's got.
31:11
But if you looked at it sort of edge on, so you're looking
31:15
at the thick at the disk of the galaxy from the side, you would
31:18
definitely see dark markings throughout that disc, very strongly dark markings, which will
31:23
be the dusk in the sorry, the dust in the disc of the Milky
31:26
Way, not the dusk in the disc of the Milky Way, as the
31:29
other said, but the dust in the disc of the Milky Way. So
31:33
we're a galaxy that's still still sort of forming styles. A lot of the
31:38
material of our galaxy is actually hydrogen rather than being dust, which is the
31:42
case in this other one. So this could this discovery could open the way
31:48
for further investigations into other potential galaxies. Yeah, that we've now that we've
31:52
learned this kind of situation exists. Yeah, So what you do is you
31:57
get a telescope, well, well like the you know, the Alma or
32:01
the JCMT or the James Web telescope, and you do a survey. You
32:06
do as many, you know, as many as much of the sky as
32:08
you can because these things are visible in those telescopes. The problem is,
32:13
all of those instruments tend to be not what you call survey telescopes, for
32:16
which you need a wide field of view. So with a survey telescope,
32:21
you want to observe as much of the sky simultaneously as you can and then
32:24
go on to the next bit, rather than having this you know, kind
32:28
of drinking straw view of a little bit of sky, because then if you're
32:32
try to do a survey with that, you've got a tiny distance between that
32:36
field of view and the next one, and it takes you decades to cover
32:39
the sky, if not hundreds of years depending up. Okay, that's fascinating,
32:45
but yeah, if you'd like to worry about that you can find it
32:51
well, you can find it on the as TIC. If you do a
32:54
search for s TICK you'll find it as TICH seventy one with double s say
33:00
as tech seventy one. This is Spice Nuts Andrew Dunkley, Hey with Professor
33:06
Fred Watson, three Space Nuts Ready for some questions, Ran, why not?
33:17
Why don't we do that? For We've got one question and a couple
33:22
of text questions that have come in. We'll firstly be heading off to Germany.
33:29
Hello there, This is actually from Germany and I'm a huge fan of
33:32
the Space Nuts podcast. My question is a two part question. The Kardaship
33:37
scale is used to define the types of civilizations into type one, type two,
33:42
and so on. Humanity is considered to be zero point seven. It's
33:45
believed that we would be able to achieve this type one status in the next
33:50
one hundred years. So my first question is what do you think about the
33:53
scale and is it actually used in astrophysics and cosmology to search for other types
33:58
of civilizations? And as we know Tape two civilizations are the ones who can
34:04
harness the total energy of a star. This is hypot says, but constructing
34:07
a dacent sphere around the star. So my next question is that is it
34:12
actually possible to construct a mega structure that can cover the Sun. Would like
34:16
to know your thoughts. Love the podcast, keep up the good work,
34:20
Thank you, Thank you, Ashkara hap I got your name right, But
34:24
this is fascinating. We have talked about Dyson spheres before. We've talked about
34:30
different types of civilizations and where we sit in that spectrum. What do you
34:37
say we're at point seven with just a bit sure of being a type one
34:39
civilization? Do you want to expand on that, Fred before we try and
34:45
answer the question. Yeah, And I'm going to cheat because I did write
34:52
a little bit about this kind of thing in my kid's books. I saw
34:55
you reaching for that to grab it because it completely forgotten about it, and
35:00
that partly answers the question. Astrophysicists don't really think about this sort of thing.
35:07
A few astrobiologists they do, but the consensus of astrophysics generally and astrobiology
35:16
is that we could be unique, certainly in our galaxy. So it's not
35:20
really much point in talking about these civilizations. But let me just read a
35:24
little paragraph. Because my space warp had lots of little breakout boxes, which
35:32
we call techno. I'm just throwing something before you start to please, just
35:37
in time for Christmas, right, thank you for space work. Yeah,
35:43
yes it is. Yeah, it's interesting time because it's a great book full
35:45
of cartoons, full of pictures of Yeah. Anyway, never mind, this
35:47
is not an advert. What I said was because this is to remind me,
35:52
because I can't remember all this stuff. It says. One measure of
35:58
what an advanced civilization work can do is the amount of energy it can use.
36:04
The idea was proposed by astronomer Nikolai Kardashev in nineteen sixty four, who
36:09
devised a scale of civilization based on energy resources. For example, imagine a
36:15
civilization that gathers all the energy from its parents star by building a sphere of
36:22
solar panels around it. This so called megastructure is known as a Dyson sphere,
36:27
named after the physicist Freeman Dyson, who popularized the idea in nineteen sixty.
36:31
If Dyson spheres exist, they should be detectable by their infrared radiation.
36:37
So far, no one has found anything like this. Now I'm not going
36:44
to go into the different types because can't remember all that stuff. Type ones
36:49
and type twos and things of that sort. But the question about, you
36:53
know, are we as a civilization anywhere near the idea of building megastructures.
37:01
I think the answer is no. Well, i'd agree because we can't even
37:06
name rhaders. That's going to cut. There's got to be a clever name
37:14
for a megastructure that's got kangaroos in it, please know. Yeah. Anyway,
37:21
so Dyson spheares goe not go one. Mob mentality. Oh I love
37:25
it. Yeah, I love that, Yes, love that. For those
37:30
I know, a group of gank kangaroos is called a mob. Indeed,
37:34
that's the collective noun. Yeah. So, I mean, you know,
37:37
all these are really interesting concepts. The Kardashief civilization scheme. Check it out,
37:43
you know, to our listeners, check it out. It's very easy
37:45
to find that stuff online. But it's uh, there's nothing in astrophysics that
37:52
leads us to believe that any of this is actually real, and and a
37:59
lot of it comes from this idea, which I think is pretty prevalent among
38:05
the people who really know about living organisms and evolution and all the rest of
38:09
it. That the step from a single celled organism, which might be relatively
38:15
common through the universe, from that to even an amieba. You know,
38:21
a multi celled organism is huge. And one of the pieces of evidence for
38:25
this, if I can kind of get on a bit of the hobby horse
38:29
here, is that the first single celled organisms appeared on Earth within the first
38:35
billion years of the Earth existence. So it's a very long time ago.
38:38
And we see them, you know, their relics stromatolites over there in Western
38:42
Australia. These are mats of microbes and they came into existence probably about four
38:50
three point eight four billion years ago, but the first multi celled organisms we're
38:54
only about seven hundred million years ago, So there was this long, long
38:59
period three billion years where there was nothing but slime on Earth. You know
39:05
why it took so long because Australians had to vote on what Australian microbes couldn't
39:15
Yeah, that's right, well that could You could be right there because a
39:20
lot of these microbes that we you know, the evidence for them we actually
39:23
see in Australia waweather are some very you rest your case exactly. But yeah,
39:30
so going back to it, you know, yes, it's really interesting
39:36
to hypothesize on what advanced civilizations might do, and perhaps if we managed to
39:43
survive, what we might do as a species down the track. But I
39:47
think we are millennia away from anything remotely describable as a megastructure. We've got
39:57
a very very long way to go. And yeah, you know, you
40:01
never know once we start pulling helium three back from the moon. If that
40:07
happens, we might not need any of these weird and wonderful things because you
40:10
could build something the size of a toaster and use nuclear fusion of helium three
40:16
quite harmlessly to produce electricity. That meands like exaggeration, but that's the bottom
40:22
line is it's a it's a possible possibility for nuclear power, very clean nuclear
40:29
power that might come down the track. MM. Fascinating. And actually I
40:34
said, we're at point seven on that civilization rating scale. I can't know
40:39
what that means. Actually, yeah, well it's it's a mute point at
40:44
the moment, because after the Rover vote went back too point five. Yes,
40:52
Okley, thanks actually lovely to hear from you. Let's go to a
40:58
question from Ti Hi, Fred, and Andrew. The podcast is brill notwithstanding
41:06
the names of rovers. He says here, Tim from Villages Hills, Sussex,
41:09
UK. My question is why do planets and moons become tidally locked?
41:15
Is it because one side of the planet or moon has more mass egen mountains?
41:21
Will the Earth's ocean tides gradually slow down the Earth's rotation by friction and
41:27
then it will become tidally locked to the Moon or the Sun. I'm lining
41:31
up some black hole questions for the next time. Many thanks, and of
41:36
course keep up the awesome work. Tim. I like this question. Yeah,
41:40
it's a great question. As we talk about tidal locking all the time.
41:44
The Moon's tidally locked to Earth, it's drifting away bit by bit.
41:50
So he's sort of asked a what if question, But it's real life.
41:53
It's not a speculator, it's not it's actually happening. It's happening. So
42:04
probably the way to think to deal with this is to actually answer the second
42:07
part of this question. First, is the Earth gradually slowing down in its
42:12
rotation so it will eventually be tidal locked to the moon? Tidally locked to
42:15
the Moon, And the answer is yes, And it's why one reason why
42:20
we have to keep inserting leap seconds into the length of the day, which
42:27
we've done since the nineteen seventies. I think, if I remember rightly,
42:30
about twenty five times, either on the thirty first of December or the thirtieth
42:35
of June. There's actually, at the moment, the Earth's rotation is speeding
42:37
up slightly because there's other forces at play. There's a lot of sloshiness going
42:43
on in the Earth's core and mantle, but the mechanism for that slow down.
42:49
So just think of it in terms of the Earth. To start with.
42:52
What you've got is our planet that's spinning once every twenty four hours.
42:55
It's got the Moon relatively close by, which is going around it once every
43:01
twenty seven and a half days. And the revolution of the Moon in its
43:08
orbit is in the same direction as the spin of the Earth. In fact,
43:13
most things in the Solar System are. They're anti clockwise, as seen
43:15
from the north above the North Pole. So think about this. Here's the
43:21
Moon in space, Here's the Earth. I'm drawing a diagram on my desk
43:25
with my fingers. The Earth, here's the Moon. The Earth is spinning,
43:31
and the Moon is it's gravity. It's pulling up a tidal bulge on
43:37
the Earth. Now that but the Earth is kind of spinning underneath that,
43:43
if you can imagine it, this tidal kind of directed towards the Moon.
43:47
The Earth's still turning, and what it does is because of friction between the
43:52
oceans and the Earth itself. And you actually don't need oceans for this to
43:58
happen. It can happen in solid rockers. Well. But what's happening is
44:01
that the bulge of the tides pulled by the Moon actually drifts slightly in the
44:07
same direction that the Earth is rotating. And what that does is that adds
44:15
a bit of gravitational acceleration to the Moon, which speeds up the Moon in
44:19
its orbit. To respond, the Moon moves further away. So that's why
44:22
the Moon is drifting away. And it's that friction between the you know,
44:28
the tidal bulge of the Earth and the Earth itself spinning underneath. That is
44:32
the friction that causes tidal locking, because it's gradually over time slowing down the
44:37
Earth's rotation. And so the same thing would have happened the other way around
44:43
with the moon. Very early in the moon's history, as the Moon was
44:46
spinning, the Earth would have raised a bulge. Actually not in the moon
44:51
it's not in the oceans of the Moon because it didn't have them, but
44:53
in the rock itself, which acted as a break on the rotation of the
44:59
Moon, and so it became tidally locked, probably quite quickly in the first
45:04
certainly the first billion years, maybe even the first few hundred million years of
45:07
the solar system. So that's how that process takes place. And yes,
45:12
eventually in probably more than ten billion years, by which time the Earth might
45:16
not exist anyway, because the star Sun will have turned into a red giant
45:20
star. But over time, if nothing else happened, the Earth would be
45:24
tidally locked to the Moon. If I remember rightly, the Moon and the
45:30
Earth would rotate, would revolve around one another, always facing the same to
45:37
each other. I think it's forty forty two days, forty five days,
45:40
it's about that, rather than the twenty seven and a half days at the
45:44
moment that is the month. So the month and the day become the same
45:47
length of time because the Earth's rotation has slowed down, it's matched the Moon
45:53
rotating around it, by which time, by the way, the Moon will
45:57
be half a million kilometers as well the way, but it will be a
46:00
stable situation so we'd never lose the moon altogether. It would wind up in
46:07
this state. But as I was just saying, the super and ova effect
46:09
will probably overtake it. Yeah, yeah, so is it? Sorry,
46:15
Red Giant, Red Giant, Yeah, I knew what you meant. So
46:17
we don't really we don't want a super and ova. We don't want to
46:20
sup We won't get one with us. It's not massive enough. So the
46:23
only good thing about a super and oval like that would be it would get
46:27
rid of the ruver. Uh dear, But I wanted to ask you,
46:32
is it a coincidence or is it a part of the effect of tidal locking
46:37
that our rotation and the rotation of the Moon creates that situation we're always seeing
46:43
the same part of the moon. Is that part of the same effect.
46:46
It is just the fact that the Moon norse faced is the same way towards
46:51
us. That was not a coincidence. It's actually a part of the Yes,
46:54
it's exactly the effect, that's right. And so eventually, as I
46:58
said that the Earth will be the same, the Earth will always present the
47:00
same face to the Moon, just like the Moon presents the same face to
47:04
Earth. So on what side of the Earth. You'll well to see the
47:07
moon at all, you'll ever see it? Yeah, okay, so not
47:12
nothing to do with mountains, Tim, It's all to do with that other
47:15
stuff he was talking about. See how much I listen's still too. You're
47:22
fretting about that ruver still, you know, pucket it out of my head
47:24
for it can't still really bothering me. Thank you, Tim. Let's move
47:30
on to our final question for this week from Daniel. Hey, guys,
47:32
I am mediating a question from my father per discussion we had regarding time and
47:37
space. We all talk about that at dinner. He's from Nottingham, England,
47:43
so trying not to be biased. His question relates to relativity. How
47:47
is it possible to measure the speed of anything if an object is relative to
47:52
many points of reference. Eg. Two trains moving in different speeds to someone
47:55
standing in the person on the ground, the speed is different, or more
48:00
expansively said, trains are traveling at this at a speed across Earth. Earth
48:07
is orbiting the Sun at one hundred thousand kilometers, And how the Solar system
48:09
orbits the galaxy substantially faster, and the galaxy vastly faster than that, and
48:14
so on? So how does one measure the speed of the train relative to
48:19
anything? I guess the point is to calculate speed of objects. Does one
48:22
always need a fixed point of reference? But what is that reference point when
48:28
calculating velocity and distance of objects on an Earth or intergalactic scale. Is the
48:35
reference point always Earth? If so? Why, thank you kindly, Daniel
48:38
and Peter. I hope Dr Watson gets proofread it, gets to proof read
48:45
this before the show. No he didn't. I just gave it to him.
48:49
Then that's all right. But yes, it's a great question because you
48:53
know, we're taught in relativity. Everything's relative to something else, So is
48:58
there an absolute The question really is is there an absolute frame of reference?
49:00
You know, is there something that you could say this is the stationary reference
49:06
frame of the universe itself, And in a sense there isn't There isn't they
49:15
have I put it that way so exactly as Daniel says, we tend to
49:21
measure everything with respect to everything else. And it goes back to you know,
49:25
when I was professionally measuring star velocities by the hundred, which we did
49:31
with the uk shmid telescope. Here Siding Spring Observatory not far from you,
49:37
Andrew. We always corrected for the Earth's motion around the Sun, so what
49:44
we were doing was measuring those star velocities with respect to the Solar System itself.
49:51
And that's fine. But we know from other considerations what the velocity of
49:55
the Sun is going around the galactic center exactly as Daniel said. So if
50:00
we're talking about looking at other galaxies, we correct for our motion around the
50:06
galactic center, and you could, in theory, correct for the motion of
50:12
our galaxy with respect to the Andromeda galaxy to get another frame of reference.
50:19
So there isn't really an absolute frame of reference in the universe. There is
50:25
one thing that did make people wonder if there was, and that is that
50:30
when you look at the cosmic microwave background radiation, which is as you know,
50:35
the flash of the Big Bang, when you look at that, you
50:38
find that we've got a velocity with respect to it. I can't remember what
50:40
it is. Actually it's some hundreds of kilometers per second, and that makes
50:45
you wonder if what we're really seeing there is the motion of our whole galactic
50:52
network with respect to the universe itself, and that might be slightly you know,
51:00
it's just a slightly speculative interpretation, but it has been put forward as
51:07
being an absolute frame of rest for the universe, the frame of rest of
51:10
the flash of the Big Bang, because it's as fundamental as we can get.
51:15
But the bottom line is that you know the speed of light three hundred
51:20
thousand kilometers per second. That's been measured many, many times, and in
51:23
fact it was kind of predicted as the speed of light before relativity came into
51:32
being by James Clark Maxwell. These name's cropping up twice in there in this
51:37
episode. Was James Clark Maxwell, a physicist, a Scottish physicist. He
51:45
had a theory of electromagnetism which popped out this number. See. That's why
51:51
it's called see because it comes from Clark Maxwell's theory. And it turns out
51:58
that that was the speed of light. And it turns out that the prediction
52:00
is three hundred thousand kilometres per second, and that matched actually all our measurements
52:05
of the speed of light, which by the way, go back to the
52:07
sixteen eighties with the Danish astronomer by the name of Wurma, who measured the
52:13
speed of light by looking at the way Jupiter's moons behave, and he figured
52:16
out that some of the things that were a bit peculiar about Jupiter's moons came
52:22
came about because if the moons were on the far side of Jupiter, the
52:27
light was traveling for a longer distance than if they were on the near side
52:30
of Jupiter, and he could work out what that distant difference was, so
52:32
he got a good estimate of the speed of light. Well well, well,
52:37
well, well, well, yes, that's enough about that. But
52:39
yeah, interesting, you know, relative, it is a good question and
52:45
well framed. Indeed, I love that they're having those kinds of conversations.
52:51
So and I'm glad they came to us to see if we could or you
52:54
could come up. I am too. And look, I don't know Daniel,
53:00
whether your dad wins the argument or your your your self wins the argument.
53:07
But give my regards to Nottingham. It is where my niece lives.
53:13
Oh lovely, lovely, thank you, Daniel, Thank you, Peter,
53:15
lovely to get your question, and don't forget. If you have questions for
53:20
us, you can send them to us fire our website, space nuts podcast
53:22
dot com or space nuts dot I O. And while you're there, don't
53:27
forget to check out the Space Nuts shop because you might be able to pick
53:30
up a Christmas edition of Space War by someone who shall remain name us.
53:37
But if you want a real book, there's other ones in there too.
53:40
No, it's good, it's good stuff. It's a good it's aimed at
53:45
children. That's the one that you wrote for kids, isn't it so that
53:46
they can Yeah? Twelve twelve and upwards. People have said it's it's the
53:50
best kid kid's book for adults on astronomy. I think that's the problem is
53:55
is well, I'm gathering everyone who wrote it is also voted for ruver or
54:01
read it. Read it. Sorry but anyway, but yes, I do
54:06
log on our bit website to send us questions, visit the shop. We'll
54:08
become a patron if you would like to do that and help us keep the
54:13
lights on. Yes, mine's still on. Just got my electricity bill so
54:16
I wasn't sure. That just about wraps it up. Thank you very much,
54:21
Fred, great pleasure, Andrew. Good to have a nice, juicy
54:24
episode to get our teeth into. We've got some great ground today. We
54:29
sure did, all right. Thanks for We'll catch you next time. Sounds
54:31
good. See you Fred, thank you very much. And to here in
54:35
the studio who didn't appear today, well shame on you. The reason he
54:39
didn't show up is because he voted for Ruvera And from me Andrew, thanks
54:45
for your company. We'll catch you on the very next episode of Space Nuts.
54:50
Bye bye. You'll be listening to the Space Nuts podcast available at Apple
54:57
Podcasts, Google Podcasts, Spotify, iHeartRadio, or your favorite podcast player.
55:04
You can also stream on demand at bites dot com. This has been another
55:07
quality podcast production from fights dot com.