Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / The Dinosaur Extinction Mystery Revisited: New Theories & Surprising Discoveries | #378

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The Dinosaur Extinction Mystery Revisited: New Theories & Surprising Discoveries | #378 · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Hello once again, thanks for joining us on Space Nuts. My name is
0:03
Andrew Dunkley, your host, and it's good to have your company. As
0:06
always. Coming up on this episode three hundred and seventy eight, what really
0:12
killed the dinosaurs? It was actually dental problems. I think that was pretty
0:17
much it. We're going to find out also some planets that are orbiting a
0:23
star that is kind of like ours and they're all doomed. Are we talking
0:29
about ourselves or somewhere else? We'll find out about that, and some audience
0:34
questions about Andromeda gravity. We never get questions about gravity, do we?
0:39
And a place called Tidbinbiller. We'll get into all of that very very soon.
0:44
On this episode of Space Nuts fifteen second Channel ten nine Ignition Squench Space
0:54
Nuts or three two one Space As when actually bought it? Neil's good and
1:03
joining us to unravel all of those mysteries is Professor Fred Watson, Astronomer at
1:07
Large. Hello Fred, Hello Andrew, Hello, good to see you looking
1:11
at today. But apart from that, you're all good. Yeah yeah,
1:15
and maybe you need new glasses. Oh it could be yeah, actually got
1:21
some new glasses not very long ago. Interesting and well I was going to
1:23
get new glasses, but then they found out something else was wrong, so
1:27
we're dealing with that. Actually, the optometrist said to me, I was
1:34
going to recommend new glasses because your visions deteriorate it slightly. But now I've
1:38
got a bigger fish, something bigger to deal with. Yeah, it's pressure,
1:45
you know, the pressure in your eyes. Yeah, apparently mine's gone
1:49
up, so we're looking into it. Bob. Anyway, you can solve
1:56
that, you can. You can solve that these days just by using drops.
2:00
Apparently well seems to be working. It's all a bit weird. Anyway,
2:05
I'm sure everyone needed to know that. That's all right. As long
2:09
as it stops at your eyes, we're quite happy. Yes, now you've
2:14
got some travels coming up, haven't you. You're a busy boy. Yes,
2:19
Actually I'm off to a place called Sea Lake in Victoria, which is
2:25
a state to the south of US here, although it's very rural Victoria.
2:30
I fly to Mildura and then drive for two hours and I get to Sea
2:34
Lake and there is an astronomy weekend there. It's a big festival actually,
2:38
with a few professional astronomers and lots of amateur astronomers and the general public,
2:44
and a good time will be had by all. So I'm doing talk,
2:50
I think, and discussion and all that stuff. But then actually the weekend
2:55
after that, I'm going off to another one, and I'm off again to
2:59
New Zealand and if I remember rightly, it is the one hundredth anniversary of
3:05
one of the astronomical societies. I can't remember, which might be the r
3:08
S n Z. Yeah, it might pay are there again? It might
3:12
be the Oakland dial check that I should find out should there before I go.
3:15
That's see, that's that's more than that's more than a week away.
3:17
So it's way below the horizon at the moment, but it will arrive very
3:22
soon. It just don't just don't do a US president and get Switzerland mixed
3:27
up with Sweden. That would you know, that wouldn't go down. Well,
3:31
No, I know, there's all that stuff. I was talking to
3:35
some Kiwis this week actually, or interacting with them in a meeting of Space
3:43
Agency personnel which took place down in Cameer. I was virtually joining that to
3:46
talk a little bit about dark and quiet skies. I didn't have much to
3:51
say, but it was very interesting. These are all space regulators. These
3:53
are the people who make the rules, and so they want to know what
3:58
what satellites are doing to astronomers. So that's what my parting that way.
4:02
Yeah, well that's a big issue at the moment. Just a little interesting
4:08
statistic about New Zealand and I hate to give them a hard time, they've
4:12
had a pretty rough time of its sporting wives of late. But I got
4:17
a news report the other day from the Australian Bureau and Bureau of Statistics.
4:21
This might interest people in other countries. But of the New Zealand population of
4:28
five million, what percentage of those live in Australia. I don't know the
4:38
outswids of that. I'd have to guess maybe twenty percent is probably something huge.
4:42
It's about ten percent, over five hundred thousand Kiwis live in Australia as
4:47
Australian residents. Yeah, which is ten percent of the population. That's that's
4:56
that's actually quite a surprising number. Yeah. But you know who's moving here
5:00
fastest. I don't know in the greatest numbers at the moment. The Nepalese.
5:06
Oh okay, not from New Zealand, No, No, the Nepalese
5:11
are the ones that are from Nepal. Yeah, and moving here faster than
5:15
any other nationality at the moment, which again quite surprised me. Enough of
5:23
that, that's our little planet. Let's sort of well, let's stick to
5:27
this planet, because sixty six million years ago, a big rock the size
5:32
of Mount Everest struck the planet at what is now the Gulf of Mexico.
5:39
And of course we all know that that was something that led to an extinction
5:44
level event which pretty well wiped out the dinosaurs. But there's been a lot
5:48
of debate fred about what exactly was it that finished them off? Was it
5:55
the tsunami that went around the planet three times? Was it the change in
5:59
environment? Was it the dental plaque problems created by the vegetation that changed.
6:06
Now there's a new theory which seems to have quite a bit of substance behind
6:12
it. It does, that's right, And this comes from astronomers in actually
6:18
most of them seem to be in Belgium. There's few UK names there as
6:21
well. It's a paper in Nature Geoscience which is entitled chick slob impact Winter
6:30
sustained by fine silicate dust and that really tells you the story in one.
6:36
So what these scientists have done have been to look very closely at some of
6:42
the deposits which we find in that boundary, which used to be called the
6:49
Cretaceous Tertiary boundary. It's now called the Cretaceous Paleogene boundary because I think that's
6:55
a bit more specific. It's a layer in the rock strata, and that's
6:59
actually what So it's that lair in which iridium was found now fifty years ago
7:04
nearly and sorry not quite fifty, probably more like forty one forty two years
7:10
ago. That iridium was what gave rise to the theory that this was an
7:16
asteroid, and it's because iridium is mostly found in extraterrestrial bodies, and so
7:25
that sort of gave the rise to it. So what's happened is a more
7:29
detailed investigation of that boundary has revealed that there's some stuff in that they didn't
7:36
really know about. Let me read the first little bit of the abstract for
7:43
this paper. So this is the real thing it. As I said in
7:46
Nature Geoscience, the chicks alb impact is thoughts that have triggered a global winter
7:50
at the Cretaceous Paleogene boundary, or sixty six million years ago, Yet the
7:57
climatic consequences of the various debris injected into the atmosphere following the impact remain unclear,
8:03
and the exact killing mechanisms of the mass extinction remain poorly constrained. So
8:11
here we present they say, palea climate simulations based on sediment sedimental logical constraints.
8:18
That means things they find in the boundary layer from an expanded boundary deposit
8:24
in North Dakota, United States, to evaluate the relative and combined effects of
8:30
impact generated silicate dust that's pulverized rock basically and sulfur as well as soot from
8:37
wildfires on the post impact climate. From what they've found is that the distribution
8:46
of silicate dust, which is fine dust about one michrome micrometer to eight micrometers
8:54
in diameter, and they say that's larger than has been previously previously estimated.
9:01
And they think that that dust, because it's sort of very fine dust,
9:07
could have stayed in the atmosphere for fifteen years and they are suggesting that that
9:13
would push down the average temperature on the surface by fifteen degrees celsius. And
9:20
that's significant because the average global temperature at the moment. The average, if
9:26
you average across the whole world, is fifteen degrees plus fifteen. So if
9:30
you push it down by fifteen degrees, you've got zero. Basically you've got
9:35
freezing. And they say this would have blocked This is another aspect of it.
9:41
This would have blocked photosynthesis for the amount of time that they say this
9:48
would have occurred would have been two years, effectively six hundred and twenty days
9:52
after the impact, And so that means things wouldn't grow if you don't have
9:58
any photosynthesis. First of all, you're not churning out oxygen from carbon dioxide,
10:05
because that's what photosynthesis does. But also you're stifling the plants. Basically,
10:11
things that live on plants don't like not to find any plants. And
10:16
they say that might have directly caused extinctions of dinosaurs and other groups that couldn't
10:22
adapt to the conditions, and accurting now from the Cosmos article rather than the
10:26
original article, which was written by Ja said so it's sorry, go ahead,
10:33
no no, I was just saying that this is probably not a huge
10:39
surprise in the scheme of things. I mean that that impact caused all sorts
10:43
of catastrophic things to happen, not just you know, the initial impact,
10:48
that rebound that happened in the Gulf of Mexico or whatever was there at that
10:52
time, and the tsunami I think went around the world what three times,
10:58
five times some massive number. Oh yeah, probably yeah. And was all
11:03
of that two miles aisles some horrible number. Yes, Yes, It's what
11:11
surprises me is it didn't wipe out life completely. Yes, exactly. I
11:18
was just going to make that comment. You're absolutely right, you know,
11:20
the trauma that the Earth suffered because of all that. Yeah. The the
11:26
another couple of quotes from the paper here simulated changes in photosynthetic active solar radiation
11:35
supported dust induced photosynthetic shutdown for almost two years. That's kind of what I
11:41
said, but in different language after the impact. But then and then they
11:45
go on to say, we suggest that, together with additional cooling contributions from
11:48
soot and sulfur, this is consistent with the catastrophic collapse of primary productivity in
11:54
the aftermath of the Chicksilab impacting. In other words, nothing was growing,
12:00
basically shut down growth. But there is a subtlety though, which is pointed
12:05
out in the Cosmos article as well, that the models that they that these
12:13
people just sorry about. It's two weeks in a row. Yeah, two
12:18
weeks in a row. Yeah, yeah, two different relatives. The models
12:24
are they suggest that the the recovery from that, so they've also modeled the
12:35
recovery as well as the kind of shut down. The recovery would have been
12:37
faster in the southern hemisphere, and that apparently matches, you know, the
12:45
evidence that when you look at the evidence from the geological record, the extinctions
12:52
were fewer in the southern hemisphere. So it's really a really interesting, you
12:58
know, an interesting little snippet that kind of I guess adds way to their
13:03
model that if you can suggest that there'd been a faster recovery in the south,
13:09
and that's what the evidence shows, then you've got some credibility with your
13:13
model. Of course, you know, the geography of the planet was different
13:20
then as well, because a lot of the continents, the stuff that's now
13:26
in the north was at that time heading northwards rather than being as far north
13:30
as it is. So the breakup of Gondwana, just to give you a
13:33
bit of context there, if I remember right, there was one hundred and
13:35
sixty million years ago, so that had already happened, but the map was
13:41
still not really like the Earth is today. Sixty six million years, there's
13:46
plenty of time for plate tectonics to shift the model to, you know,
13:50
shift the globe of the Earth. Yeah. Yeah, I imagine that impact
13:54
would have had a bit of an effect on plate tectonics too, Yeah.
13:58
Probably. I mean it's thought of stimulated volcanoes as well. That's one of
14:03
the other, you know, the other lines of research that we see in
14:07
that, Yeah, for sure, yep. So yeah, really interesting paper.
14:11
I mean, isn't it extraordinary that, you know, forty years after
14:16
it was suggested, we're still finding out about this impact and seeing different aspects
14:22
to it because of the devastation that it caused. Yes, absolutely, And
14:28
you mentioned it. The event basically took us out of the Cretaceous period into
14:33
the Peleogene period. Yep. I read a story the other day which is
14:41
of a similar ilk that we are now, according to some scientists, in
14:46
a new epoch, which they're calling the Anthroposyne Periodpathy, that's right, and
14:50
that is human induced climate change. They're saying we've reached the point of no
14:58
return and that we are now in a new epoch which has been created by
15:03
human intervention, so and future geologists will see evidence of that. They'll see
15:07
a boundary of exactly the same sort of thing, except it's all soot from
15:13
you know, industrial revolution call and fossils other fossil fuels, Yeah, fossil
15:18
fields. Yeah, that's right. So, yes, we're we're tinkering with
15:24
our pludet you know, We're sure, you know, And we can't wind
15:28
it back now, so we're going to have to learn to live with it,
15:31
by the sound of things. But yeah, that's a fascinating story.
15:33
You can read all about it in the on the Cosmos magazine dot com website
15:39
is Space Nuts. Andrew Dunkley here and Fred Watson there. Let's just take
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a little break from the show to tell you about our sponsor, Nord VPN.
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18:40
Now back to the show three space Nuts. Now Fred to our next
18:48
story, and this involves some planets orbiting a sun that is not like well
18:53
not unlike ours, a sun like star, if we want to call it
18:56
that, but there's a little bit of a difference kind of enjoying day in
19:00
the sun, these planets will not. That's right, You're absolutely right.
19:07
This is a story about sun like stars. So it's always you know,
19:11
stars come in many different varieties. But so whenever we talk about stars like
19:17
the Sun, you're kind of really talking about the Sun itself as well,
19:21
and you know, what might potentially happen to it, what's happened to it
19:23
in the past, and things of that sort, because what happens to one
19:26
star of one particular class and mass and luminosity is likely to happen to another
19:33
one as well, according to our best understanding of stellar evolution. The way,
19:37
what class is our star? Because I keep well, it's usually called
19:42
a yellow dwarf star, and that's you know, it's kind of not a
19:49
very complimentary description, but it's because it's not a giant star. Giant stars
19:56
are big, and the Sun will evolve into a giant star, but the
20:00
moment, it's not. It's a yellow dwarf and it's still growing up.
20:03
It's actually it's in it's it's not it's growing up phase. It's in its
20:10
midlife, right, it's almost exactly midlife, about five four point five seven
20:15
billion years old, and it's probably got a lifetime of round about ten billion
20:18
years. So, yeah, the stars go through a very energetic, youthful
20:22
phase where all kinds of things happen, and then they settle down to a
20:27
slow, steady hydrogen burning phase, which is what the Sun is in now.
20:33
If I remember rightly six million tons of hydrogen it burns every second,
20:38
turning into helium and energy. Yeah, so it's stopped stealing cars and getting
20:45
drunk, and now it's relaxed, that's right, relaxing at home. Indeed,
20:48
it's got its feet up and it's reading the paper and it will do
20:53
that for another probably four billion years or so before it does start turning into
20:57
a giant star. So what we have here that happens to humans too.
21:03
As you get you putting on all that white swell in all the wrong direction,
21:08
that's right, just like stars do and get rid of. Yes,
21:14
yes, that's right, sometimes that you do. So the star is a
21:22
star actually relatively close by, it's fifty seven light years away. It's one
21:26
that's very very well studied. There's a very famous UK schmid telescope image of
21:32
it and its surroundings. It is called row Corona borealiss in the constellation of
21:40
Corona Borealis. Uh. And it's it's as you said that the difference between
21:47
the start and the Sun is just one of maturity. So yes, we're
21:52
four point five seven billion years old, Corona Borealis is probably more like nine
21:59
billion. That means it's sort of in the last phases of its normal life.
22:06
So it's a normal star at the moment, but it will I mean,
22:08
well, it will continue to be a normal star, but it will
22:11
behave differently from a sun like star, so it will start to grow and
22:17
turn eventually into a red giant, possibly with a diameter in the region of
22:23
well, the Sun's diameter is a million kilometers, this one could reach ten
22:29
times that, you know, ten million kilometers or maybe even a billion.
22:33
It could go that far up to be a huge, bloated and bloated star.
22:40
So they estimate this will happen in something like a billion years. It's
22:45
actually a single author of paper which is in it's in the Astrophysical Journal,
22:51
one of the well known journals of astronomy. Stephen Kin is the author from
22:56
the Department of Earth and Planetary Sciences in the University of California, Riverside.
23:00
But what makes this start even more interesting, Andrew, is that it's got
23:04
four planets around it, or at least four planets. We know of four
23:11
planets which orbit Corona Borealis. They're all nearer to the planet than we are
23:18
to the Sun. The nearest one, in fact, the nearest two are
23:22
well inside what would be the orbit of Mercury in the Solar System, so
23:27
they're very close to Corona Borealis. So they're definitely doomed. There's one about
23:34
the distance of Mercury and the furthest one is eighty three percent of the distance
23:41
of the Earth from the Sun, eighty three percent from Corona Borealis. So
23:47
in that regard, Andrew, as that star sits at the moment that particular
23:52
planet. Row Corona or Corona borealist b D is the name of the of
23:59
the basically, sorry, it's Row Corona borealist d is the name of the
24:04
of the planet that's nearly at the same distance as the as the Earth is
24:08
from the Sun. That could be in the habitable zone, it could be
24:11
in the gold of a row coronat so interesting stuff. But what has been
24:21
the focus of this particular study is looking at what might happen to planets as
24:26
a star grows into a red giant. And it's not just a simple kind
24:33
of gobbling up, which is what you might expect. It's it's a lot
24:40
more nuanced than that. And it may well be that there are sort of
24:45
irregularities in the bloating of the parent star and that's going to have different gravitational
24:52
influences on the planets going around it. And so what they're suggesting is,
25:00
you know, yes, they may as the star grows simply spiral in towards
25:06
the star, but that would almost certainly mean that they would they just because
25:12
the temperature of the gaseous envelope that they're falling into is high, they just
25:18
basically evaporate. That They could also, you know, it depends just on
25:26
the geometry. There is something called the rochal limit, which is basically a
25:33
point around any object in space, and the Earth has a rochial limit as
25:37
well. You put something within that limit and it cannot stay in one piece
25:44
that the difference in gravity between one side of it and the other is going
25:48
to pull it to pieces. That's the basis of the Rochal limit. And
25:52
so it's almost like spaghettification in a black hole. Is that kind of phenomenon
25:57
the fact that things are getting stretched. So you try and stretch a planet
26:00
and he basically falls the bit so the yeah, that so that that they
26:07
may just evaporate or they may get torn apart by there by the you know,
26:15
by the by the gravitational effect of reaching the Rocial limit. There's there's
26:23
one caveat though, that is, if you've got bigger objects there, then
26:33
there's a chance that you might influence the orbit of that planet in such a
26:41
way that it actually gets thrown out of the system. It's possible then because
26:48
a rogue planet, yeah, that's right, that that it's it's orbit kind
26:52
of starts stretching and pushes it further away from the star, which may you
26:59
know, it probably depends on there being other planets there that we don't know
27:03
about yet as well. You could have interactions between those which might then cause
27:07
this, you know, something to be thrown out. So, you know,
27:12
that would be a really interesting possibility. This paper actually looks in great
27:17
detail about the possibilities for planets to escape depending on their you know, depending
27:22
on their exact orbit. It's very detailed, the very detailed report in well,
27:30
first of all the original paper that I mentioned, but also there's a
27:33
Universe Today article on it, that excellent website which gives us space in astronomy
27:38
news, and it really pulls this whole thing to pieces in a very detailed
27:42
way. So what are the chances, Well, maybe maybe there'll be a
27:48
you know, I mean, the prediction for that system, which actually comes
27:53
from the original paper, is the evolution of stars through their progression on their
27:59
main sequence. That's just gobbledly goop. For normal star. Expansion into a
28:03
giant star and then final contraction into a white dwarf has profound consequences for the
28:08
obitting planets. Given the masses and semi major axis that's the distance from the
28:14
parent object. Of the four known planets, we predict that planet E will
28:18
evaporate within the stellar atmosphere, Planet B will spiral in and be tidally disrupted.
28:23
That means it will be pulled to pieces, and Planet C will be
28:27
evaporated within the star's atmosphere. Planet d's fate is a bit less certain.
28:34
That's the one that could spin out, but it will probably be destroyed too
28:40
at the end of the one of the phases of evolution. And as I
28:44
just mentioned, there is possible that there might be other planets that haven't yet
28:47
been detected. We don't know that they might survive, or do we know
28:52
what kind of planets these are? No, I think at least one of
29:00
them, I think is let me just check because there is a little table
29:03
here, right, but they're they're okay, So one of them is is
29:12
Jupiter sized. The others are super earths, basically some Neptune super earths.
29:21
Yeah, okay, so they're all bigger than us, Yes they are.
29:26
They're all bigger than the Earth. That's right. Okay, and yet they're
29:30
closer to the style and yes, that's right. That's often the case in
29:34
in what we see what we see in you know, in exo planet systems.
29:41
It's a really fascinating it's a fascinating paper because it does look at possible
29:45
scenarios for what might happen to us. Oh that's nice to know. Yeah,
29:52
in about five billion, four billion years time, So you diary when
29:56
it goes from being normal to cataclysmically large and then back on back a white
30:04
dwarf. How long does that process take. I think it's in the region
30:10
of you know, millions to ten millions of years, which is pretty fust
30:15
compared with the lifetime of the star of ten billion years. So, and
30:21
in fact, I think the earliest parts of that process start start maybe a
30:26
few hundred million years before it's really a fully fledged dread giant. So you
30:30
know, temperatures will change and things will start happening over a long period,
30:36
probably very slowly, so nobody notices at first, and then a few million
30:40
years later you think, oh, yeah, here we are. We're in
30:41
trouble now. But let's say there is a people on one of those super
30:47
earths and they're observing their star. Would they get any telltale signs that something's
30:53
about to change? Would there be a way of detecting the star saying all
30:59
right, i'm running out of patrol, I'm going to blow up. Well,
31:03
yeah, there are. And I'm not an expert on stellar evolution.
31:07
I've always got the basics of it in my mind. But it's a slow
31:14
process. There's just a slow indication of increased radiation from the star before it
31:22
really starts going pair shape. So should should we be putting out the welcome
31:26
sign or the nothing to see here sign or whatever? We can well fifty
31:32
seven light years away, you know, standard sort of spacecraft rate's going to
31:37
take them a few one hundred thousand years to get here if they if they
31:41
thought that the Earth looked like a nice, juicy place to settle on,
31:45
and you know, it's an interesting thought. Of course, these planets are
31:49
going to be much older than the planets in the Solar System, so they
31:52
might have because the star's older, So they could have had population of species
31:59
on them that's simply out there now because of already you know, not just
32:02
climate change, but maybe the drift of planets planet orbits to move very slowly
32:08
over periods of tens to hundreds of millions of years. So yeah, they
32:13
may have already had problems in terms of the way the Solar System has changed
32:19
shape. Okay, all we have to do is put a sign up saying
32:22
we've moved into the Anthroposyne period. So you know, if you want to
32:28
come here, it's up to you. But it's not going to be all
32:35
right, so doomed planets. Yeah, nothing to see there. That's another
32:38
one we can scratch off the visit list. You can really that story on
32:44
the Universe Today website Space Nuts. Andrew Dunkley here with Professor Fred Watson puts
32:55
Okay, now, Fred, time to tackle some questions. I've got a
33:00
couple of questions and then a really interesting email that came in from Duncan that
33:06
I think you'll enjoy. It's got a funny story behind it. But firstly
33:09
we'll go to a question from Yesh. Hello Andrew and Professor Fred Watson.
33:16
My name is Yash and I'm living in Toronto, Canada, although I'm originally
33:23
from India. I've been a big fan of your podcast for a while now,
33:29
enjoying every single episode. I have a question for you. In the
33:36
unlikely event that I find myself alive during the impending collision between our Milky Way
33:42
and the Andromeda Galaxy, I'm curious to know what I am actually going to
33:50
see at that time. Also, will the collision be a lightning fast spectacle
33:59
or a slow motion celestial dance off? Moreover, is there any possibility of
34:07
the or surviving amidst this celestial encounter? Assuming that our planet remains intact so
34:20
can't bear to hear the answer, Thank you, Thanks Yash. Great to
34:24
hear from you. I think we've had a question from Yash before. I
34:28
can't it just seems familiar to me, But we have been asked about the
34:31
Andromeda collision numerous times. I thought maybe we should revisit it, because,
34:39
yeah, there's a there's a few people wondering what might happen. His middle
34:46
questions probably answer the question outright and yes, look, if you are around
34:55
for that event, please let me know, Hey, you doing it,
35:00
because that could be important for all of humanity. This is not going to
35:07
happen for around until week after next now a bit longer. Yeah, from
35:15
three to four billion years, which think about billion years. So yeah,
35:21
so two big galaxies careering towards one another at high speed a couple of hundred
35:25
kilometers per second. If I remember ADI something like that, maybe three hundred.
35:30
It's it's an inevitable collision. We believe we've we had results from GAYA
35:38
that tally with the radial losty results that we've got GAYA measures the accurate positions
35:45
of stars are on the sort of face of the sky, as it were.
35:47
The transverse velocities can be deduced from that. In other words, you
35:52
can work out the true velocity of something not just along the line of sight,
35:57
which is what we call a radio velosty, and it looks as so
36:00
it's an inevitable collision. It's not going to miss. So the bottom line
36:06
here, Andrew, is that the scale of things that will happen in this
36:12
collision, in terms of the length of time that's involved, is much much
36:19
slower than stuff on human time scales. So over a human lifetime, or
36:24
even a lifetime of human history, which is, you know, maybe a
36:29
few thousand years, nothing happens. Even at the heart of the collision,
36:35
nothing happens. The bottom line is the space between the stars is so big
36:43
that the stars themselves almost certainly won't collide. There might be a few instances
36:47
where stars are captured into binary orbits, or where one star steals another stars
36:52
planets, but they would I think be quite rare because of the amount of
36:57
empty space. What's not empty, though, is the spiral arms of both
37:04
these galaxies, which are pretty rich in hydrogen. And so the thinking is
37:09
that as the collision evolves, there will be gravitational disturbances of this hydrogen,
37:16
which will cause clouds of hydrogen to collapse and start forming stars very rapidly,
37:22
and high mass stars will live for a short time and then they'll explode as
37:28
supernova, so we might see we might start to see more super and ova
37:32
explosions that we do at the moment. So the last super and over explosion
37:39
in our own galaxy that we could see. There are probably others that have
37:43
been hidden from us by the dust in the Milky Way, but the last
37:45
one we saw was four hundred years ago. The last one in a nearby
37:51
galaxy was in nineteen eighty seven that was super and over nineteen eighty seven a
37:55
in the large Magelanic Cloud. All of all of that, uh, you
38:04
know, could could produce some differences to the environment. But my guess is
38:12
that you know, in general terms, the Earth would be likely to be
38:17
relatively unscathed by this, unless one of the stars nearby turned into a super
38:22
and ova and you know, irradiated us with sub atomic particles. That's not
38:28
impossible. But the the the odds are that as a as an observer,
38:35
it will be very spectacular. At any given time. You know that this
38:39
nearby galaxy and getting closer and closer, you wouldn't we wouldn't see it changing.
38:45
On a human timescale, we simply wouldn't see that. We would just
38:47
see a snapshot of the of of the events. But yes, imagine the
38:52
Andromeda galaxy in covering the whole of the of the southern sky, sorry,
38:58
the northern sky. It would be it would be pretty phenomenal, and it
39:01
would cover a lot of the southern sky as well, so and that would
39:07
get more and more spectacular. But you wouldn't, on a human timescale worry
39:12
about it. If you could see it, you'd say, well, yeah,
39:15
that's amazing. Yeah, and maybe it means we're colliding and maybe things
39:19
will get a bit hairy down the track, but for us, it's not
39:22
going to affect us. So it's certainly not lightning fast, which is what
39:24
Yash was saying. It's a long, slow process. And just a final
39:29
footnote to this, there are simulations online you can check and see a video
39:36
of what actually happens, what will happen, And it looks as though,
39:40
you know, you know, there'll be a collision the two the stars of
39:44
the two galaxies will pass through one another and then the spiral arms will start
39:50
getting disrupted. It won't be a neat and tidy spiral galaxy anymore. But
39:54
then it rebounds and you've got you know, the things sort of squashing around
39:59
it. They passed through each other again, maybe two or three more times
40:02
before settling down to a galaxy which will be devoid of hydrogen by then because
40:09
the gravitational interaction will use up all the spare hydrogen, and so all the
40:14
stars start popping into supernova. But at the end of it, of course,
40:19
you get a galaxy which we now call milk What is it? Milk
40:22
commeda milk commodot. I love that, all right, thanks Yash. There's
40:28
a there's a follow up question. I just noticed that came in on an
40:31
email from Jarra, who wants to know, in regard to the combination of
40:38
the Milky Way and Andromeda, what happens to their respective black holes? Will
40:43
they merge? And he's got a dad joke final line that says, you'd
40:47
think that Jarrah would know, Jara would Jarrow would know? Good one,
40:57
So what happens to the black holes in the end, they would merge.
41:02
I think that's the the general understanding that they would merge because of that relative
41:07
gravitational attraction. Okay, so yeah, so well, Jara, it should
41:14
know now, Yes, fascinating thing to look forward to or not. Boom
41:20
boom. Okay, thanks Jarah and thanks to Yes. Let's move on to
41:24
a question from Buddy. I threw this one in because I thought that's an
41:30
interesting question because it creates a question in my mind which I will ask after
41:35
we hear from Buddy orient again. Okay, here here's my part of the
41:43
day. If nothing about hockey radiation is supposed to speak more black hole?
41:49
How does gravity eskie? Thanks guys, Love Michelle. Yeah, that's an
41:54
interesting It's an interesting thought because we talk about grab in black holes a lot,
42:04
and my question after listening to Buddy is does gravity actually escape from a
42:08
black hole? That's it's a well thought question actually, and I think the
42:19
way Buddy is thinking is running is that gravity is one of the four fundamental
42:24
forces that operate the universe. It's by far the weakest. It's clearly different
42:30
from the other three, which are electromodetic, radiation in the strong and weak
42:37
nuclear forces. So the fourth fundamental force gravity. Some people have thought that
42:45
there must be a quantum version of gravity, where gravity is spread by gravitons,
42:51
and so gravitons will be sub atomic particles, and you're right, sub
42:57
atomic particles don't escape from black holes then, not if they're photons. And
43:02
so it's a very good question. And I think what it because clearly gravity
43:07
does it escape from black holes. But what it I think what it underlines
43:14
is that when it comes to gravity, it's a force field. And normally
43:20
with a force field you associated some atomic particle with it, But the graviton
43:24
has never been discovered. We know it's a force field because we know it
43:28
works. It's we're all sitting in that force field now as we sit or
43:32
stand on the surface of Earth. But if there are such things as gravitons,
43:38
they clearly can escape the clutches of a black hole. And so that's
43:44
a you know, it's an interesting question, buddy, And I'll try and
43:46
read up a bit more on that, because I think it is quite intriguing,
43:50
quite an intriguing idea. Yeah, it is probably start another aval anche
43:54
of black hole questions. You know, why not we'd been able to escape
44:00
them for a whole week. Nothing escapes a black colle We'll always be talking
44:06
about black Yes, that's very true, very true, Thank you, buddy.
44:10
We will do some homework on that one for you and we'll see how
44:15
we go. Duncan has sent us in a text. This is a bit
44:19
wordy, but it's worth it because there's a great story here. William Rudd
44:22
was a mechanic servicing the backup generators at Tidbinbilla during the Apollo program. He
44:28
was also a member of the local Highland band and a skilled piper, and
44:31
he would often take his bagpipes to work and practice when it was quiet.
44:36
One particular shift, while NASA's astronauts were busy on the Moon, Tidbinbilla was
44:40
the station relaying the signal from Houston to the Moon. The story. The
44:45
story goes that the phone line between the control room at tidbin Biller and the
44:50
generator room was open, unbeknownst to mister Rudd. While merely practicing the pipes,
44:55
William was told, in no uncertain terms, they can he you on
45:00
the moon. It sounds improbable. It sounds improbable. They probably could without
45:06
having a radio. It sounds improbable. And the people of Tidbinbilla said it
45:09
didn't happen, But the people of Parks were not quite so sure. So
45:15
I have a theory. In those days, there would have been a manual
45:19
patch board at Tidbinbilla with all its plugs and cables leading in and out of
45:22
the facility. I imagine the internal communications were also patched via the same board.
45:29
The feed to and from Houston was via the intel Stat satellite, But
45:36
did it go through the manual patch board to Tidbinbiller control room, And if
45:39
it did, was the internal telephone system at Tidbinbilla also set up via the
45:45
same board. Could it be possible that the distant and eerie sound of Williams
45:50
pipes was heard on the mood? That great question. I love those little
45:55
pieces of folklore. If you like it's good. Yeah, well, you
46:02
know, anything's possible. It's the answer to the question. I have heard
46:07
this story before, have you not? In quite as much detail? Yes?
46:10
I have yet bagpipes on the moon. It's so I can't remember who
46:17
told me. I do know, you know, passing acquaintance. Some of
46:24
the people who worked at Timberbilla during the Apollo era, one in particular,
46:29
who came from the same part of Britain as I do. In fact,
46:32
we used to get the same bus to school. His name is mister Dinner.
46:38
I can't remember his first name. That's terrible. Anyway, we used
46:40
to get the same bus to school, but ten years apart, so because
46:44
he's older than me. Right so, but it's yeah, So there's lots
46:51
and lots of stories. I I don't know the you know, the veracity
46:55
of it. I my probably my best contact is actually John Sarkissian, who
47:02
is a long term member of staff at Parks, very very prominent amateur astronomer
47:09
as well as a professional radio telescope engineer and support astronomer. And he's written
47:19
extensively on the Apollo era work of Parks and timber Miller. So you might
47:22
know a little bit about it. Next time I see him, I'll ask
47:25
him about it. What about the bagpipes, John, Yeah, well,
47:30
yes, that's right, the bagpipes on the moon. It's a great story.
47:35
I hope it's true, just like I hope the mister Gorsky story is
47:38
true. Yes, right, the famous words that Daniel Armstrong was supposed to
47:45
have said when he set foot on the mood good luck, mister Gorsky.
47:49
I'm not going to tell you why I said it. In fact, it's
47:52
been proven that he didn't but it's such a great story. I wish it
47:57
was true. Yes, but we're not going there. It's too dangerous.
48:02
We put out the pasture. If we hopefully say that, I think our
48:06
listeners can find you, if some will know to someone know, there's plenty
48:10
there's plenty of evidence online about that one. All right, thanks Duncan.
48:15
That's great. That's worth investigating for sure. I don't forget. If you
48:20
want to send us an email, or you would like to send us a
48:22
voice message, you can do that on our website spacenuts podcast dot com or
48:27
spacenuts dot dot io. There's an Ama tab at the top where you can
48:30
send us emails and voice messages, or the button on the right hand side,
48:35
that little purple one. And have a look around while you're there,
48:37
to the various pages we offer Astronomy Daily, et cetera. It's worth a
48:43
look. I don't forget the shop. Christmas is coming up. Yeah,
48:47
that's all I can say. Really, why would you give something from space
48:52
Nuts to somebody and smile while you're doing it? That's what I want't know.
48:59
Gosh, no more to say. That's they're good Christmas present, they
49:04
are well. I love them. You could, you could buy a book
49:07
and use that to put your coffee on or something. Yeah, all right,
49:14
Fred, thank you so much. We're done for another day. That's
49:17
great. We made it through another day and we will look forward to other
49:21
days in the future. Thanks again, Undrew to take care. Okay,
49:23
you too. Fred Watson, astronomer at large part of the team here at
49:28
Space Nuts. And thanks to here in the studio for and that's it from
49:34
me. Thanks for your company. We'll catch on the very next episode of
49:37
Space Nuts. Bye bye. You'll be listening to the Space Nuts podcast available
49:45
at Apple Podcasts, Google Podcasts, Spotify, iHeart Radio, or your favorite
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49:54
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