Andrew Dunkley: Hi there.
Andrew Dunkley: Thanks for joining us yet again. This is
Space Nuts. My name is Andrew Dunkley, your
host and it is so good to have your company
and I hope you're well. Uh, coming up on this
particular episode, Artemis 2.
Yes, the mission to the moon. Uh, we have an
update for you and it's really good news.
Could we have discovered a wormhole?
That's a big question. And an Einstein cross
has been spotted. They marked it with a cross
and then drew a circle around it. That's all
coming up on this edition of space nuts.
Generic: 15 seconds. Guidance is internal.
10, 9. Ignition
sequence star space nuts. 5, 4, 3,
2. 1, 2, 3, 4, 5, 5, 4,
3, 2, 1. Space nuts. Astronauts
report it feels good.
Andrew Dunkley: And he's here again to unravel
all the revelment of space space
science. His name is Professor Fred Watson
Watson, astronomer at large. Hello,
Fred Watson.
Professor Fred Watson: Hello, Andrew. I think actually we're
probably as good at, uh, ravelling it as we
are unravelling it. Really.
Andrew Dunkley: I, I tend to agree. Yes, you're
absolutely right.
Before we get into today's top topics,
you are, um, uh, in Melbourne, I believe, uh,
attending, uh, a conference.
Professor Fred Watson: I am, yes. Uh, sunny Melbourne, which
isn't at the moment, although it was briefly
this morning. Four seasons in one day is what
they say about Melbourne.
Andrew Dunkley: Uh, reputation for that.
Professor Fred Watson: I think we' already this week.
So, um, the conference I'm at is at Deakin
University here in Melbourne. It is called
Astro. Edu or Astro
Edu, um, for Astronomy Education
2025. And it's actually an international
conference, Uh, I think I'm right in saying
it's sponsored by the International
Astronomical Union. Um, so
it's a conference of international
astronomy educators. And so quite a
lot of it is about the
theory of education, as,
you know, applied to astronomy education.
Quite a lot of it is about the practise of
astronomy education. So there are real
teachers here, uh, who teach kids, um,
you know, from kindergarten to year
12, uh, and university as well.
Um, and um, one or two astronomers as well.
And we're there because we're interested in
education. I'm, um, only an amateur
educator, but a professional astronomer. So
my talk yesterday was about the
possibilities for using mega
constellations in astronomy education.
Because there's quite a number of ideas that
come out of, you know, what we and you and I
talk about routinely. Uh, the mega
constellations, um, a lot of astronomy
in that. And in terms of, um, trying
to, uh, perhaps,
uh, provide some, um,
background in astronomy education that might
otherwise, um, be missed. Um,
and I'm thinking of things like, you know,
how you measure the brightness of the
satellites. We use the star magnitudes the
same as we do in astronomy. Uh, why
satellites are bright themselves, why radio
telescopes are at great risk from satellite,
uh, constellations, all of the above.
Um, but um, my talk aside,
which was a minor contribution to this
conference, there have been some fantastic
presentations, um, really encouraging
about the state of astronomy education
in lands as far apart as
Chile, uh, and uh, Germany
and Belgium, Sweden,
Portugal, North America, Canada.
Inspiring presentation from Canada this
morning. Lovely chat from an educator in
Hawaii, uh, who I talk to later because I
used to work in Hawaii a lot. So a lot of
the folklore tales in astronomy he was
aware of and some, what some of his
colleagues were as well. But what was really
nice was getting a shout out from uh, from a
couple of, particularly a couple of this
morning's presenters. They did get a keynote
presentation, um, um, Mari Timms and
Sandra Woodward. Um, uh,
um, m mentioned, um, you know, stuff that
I do and that we do, uh, including a very
nice shout out about space nuts, which
apparently is um, very much
a source of inspiration to talk about with,
with kids in class.
Andrew Dunkley: Oh, wonderful.
Professor Fred Watson: Maybe we are useful after all, Andrew.
Andrew Dunkley: Possibly. Maybe we do contribute a little bit
to education. Or maybe it's pseudoscience.
Professor Fred Watson: No, it's not pseudoscience.
Andrew Dunkley: No, it's not, not at all.
Professor Fred Watson: It's just um, you know, it's our take on the
universe which might not necessarily be the
same as some other people's, but I think
we're reasonably near the mark.
Andrew Dunkley: So that's so rare in science. Frick.
Professor Fred Watson: Yes. Um,
yeah.
So that's why I'm here in Melbourne in a
hotel room. Jordy is um, about a thousand
kilometres away, so you might not hear him
today.
Andrew Dunkley: I think we will hear him.
Professor Fred Watson: I think we will probably.
Andrew Dunkley: Oh, uh, wonderful. I'm glad it's going well.
And uh, a lot of people there.
Professor Fred Watson: Uh, there are 81 participants. Yes. Uh, some
of them are online but uh, there's quite a
good healthy handful. What, what I also
really like about it is the gender
balance. 50. 50.
Andrew Dunkley: Excellent.
Professor Fred Watson: Yeah. 50.
Andrew Dunkley: 50.
Professor Fred Watson: Um, that's um. Yeah, I think that's a very
important aspect of it.
Andrew Dunkley: Yeah, I, we can't claim M.50.50, but
this week we're running in Dubbo, uh,
the uh, New South Wales Veterans
State Golf Championships.
Professor Fred Watson: Oh yes, you said you were.
Andrew Dunkley: And we've got about 100 and let's say
120. 130
participants and about
nearly 50 of them are women. So.
Professor Fred Watson: Yeah.
Andrew Dunkley: That's pretty good.
Professor Fred Watson: That is great.
Andrew Dunkley: Yeah, I'm having a crack at the championship.
I've got, uh. I think the funny
story is, uh, I said to someone, look, I've
signed up for the state championships. I
don't know why. And he said to me, oh, no,
no, you gotta play. And I said, why do you
think that? He said, because they need at
least 40 players.
Thanks. Thanks for the vote of confidence.
I've actually played two rounds and I've done
all right.
Professor Fred Watson: Oh, that's great.
Andrew Dunkley: I'm not going to win. There's a couple of
guns that are just. But I'm hoping to finish
top 10 state championship.
Professor Fred Watson: Top 10 will be pretty damn good for golf,
which is not an easy game. No, but aren't you
organising the event? Isn't this a conflict
of interest?
Andrew Dunkley: Uh, yeah, I'm part of the committee, but, uh,
my only major role is to emcee the
presentation night.
Professor Fred Watson: So if you're getting an award.
Andrew Dunkley: Uh, I won't be giving the awards. I'm just
the mc. But I. Look, that's
not even going to be a problem.
Not unless I shoot the lights out in the
final round tomorrow. But we'll see.
Professor Fred Watson: Well, you might do. You might. You never do
that. Putting the lights out so was a good
move.
Andrew Dunkley: Yes, Golf's like that.
Could go the other way as well. I've got to
keep that in mind. Now we, we uh,
better get down to why we're here and uh,
that is to talk about things that are
happening in astronomy and space science.
And one of the things we've talked about, uh,
on a fairly regular basis is, uh, these, uh,
NASA missions to the moon, known as the
Artemis project. Um, Artemis
1 has been, and done its thing, ah, a
lap of the moon with nobody on board or maybe
a couple of plush toys. Um, but,
uh, now they're saying that they
think Artemis 2 will be on its way,
uh, at the latest. April, but possibly
sooner.
Professor Fred Watson: Well, it was, um, no sooner than April. That
was the deal, uh, so far. But
the news we've had today is that
the launch window, uh, in fact is being
brought forward and could be as early as the
5th of February.
Andrew Dunkley: Yes.
Professor Fred Watson: So we're looking now at ah,
Artemis flying much earlier than
we had expected. Artemis 2.
Um, and I think one of the reasons for that
is that we've, We've been seeing news
reports. I'm sure you've caught them as well,
Andrew, that um, the hardware is
ready to go, that the, you know, the space
launch system, which will take astronauts to
the moon. And um, the, the
Orion capsule, it's all ready to go.
Um, and bearing in mind that this, this
mission is essentially a Repeat of the
11-22-2022 mission,
uh, which was a 25 day mission, it's actually
a shorter, shorter version of it. Uh but
Artemis 1, um, basically did what
Artemis 2 will do. It launched and
uh, sent this, the capsule into
orbit around the moon, um taking it actually
quite a lot further away than the moon's
distance, um, and then bringing it back re
entering and picking it up in, in the ocean.
So that was a very successful um,
dress rehearsal for what Artemis 2
will be like. And I'm sure the four
astronauts who are going to fly uh, trained
up to the gunnels, uh and it
will be really great to see them
stepping into the spacecraft in February I
think.
Andrew Dunkley: Yes, yes. Won't that be exciting? And the
first time in 54
years is it uh, we've
sent people to the moon?
Professor Fred Watson: Uh, yes, um, well 1970.
No, 72 was the last. 72,
that's right, yes it's, it will be 54. Yes,
you're right, 54 years. Um, um,
the thing that, a
point I didn't make is that um, these, the
astronauts will not land on the moon. That's
Artemis 3. Artemis 2 is
purely going around the moon, uh, and going
through all the required manoeuvres that will
be needed when um, they actually do
go to the moon in Artemis 3, for example, um,
this idea of you know,
undocking spacecraft ah from a, from a
module, a service module, turning it around
to be facing the way you want it to and then
re docking again. That kind of manoeuvre very
much the stocking trade of the Apollo era
astronauts. But of course now we've got new
technology, quite uh, different technology.
Um, a quick shout out to the crew. Uh,
Christina Koch, Richard Glover. Victor
Glover. Not Richard Glover,
Victor Glover, sorry Victor. Um, uh,
Reed Wiseman and Jeremy Hansen. They are
the ah, the Crew of Artemis
2. Heavily in training I'm sure
still and all ready to take their um, their
Orion capsule around the moon to give us
a fabulous view. So yes, the point um,
I think that you're making is that this is
the first time in 54 years that
astronauts will have gone out of low Earth
orbit which is where they've been uh, in the
International Space Station. We haven't had
anybody going, venturing out and of course
when you do that, when you go between the
moon and the Earth, you're in what we might
call deep space from A point of view of a,
uh, spacecraft, uh, which means that
you're uh, subject to the sun's radiation and
all of that other stuff. And uh. So there'll
be lots and lots of medical work done, um,
on analysing how these astronauts have
reacted to that and responded to that.
Andrew Dunkley: Yes, yes. And uh. I believe that they
will be, um.
Travelling further than any other human being
has ever gone in terms of space travel.
Because they'll be travelling
9,200 kilometres past the moon.
Professor Fred Watson: Yes, that's right, yeah. Yeah.
Andrew Dunkley: They still, they still won't be the most
isolated human humans in history. Michael
Collins still retains that because he was by
himself, uh, in orbit around the
moon. And uh, I believe in his
mission, Apollo 11, he was further out
than any of the others that were on the
command module.
Professor Fred Watson: Yes, I think that's correct. I mean all the.
All the Apollo, uh, uh, missions had a
command, a command module pilot.
Uh, as you said, Michael Collins was the one
for Apollo 11. But I think you're also right
that the orbit that Apollo 11 was uh,
in was further out from the moon's surface.
Andrew Dunkley: Then that's how I understand it. However,
the difference with this one is every, uh,
other mission we've sent to the moon has had
three astronauts. This has got four.
Professor Fred Watson: Yes.
Andrew Dunkley: Um, so that's a first.
Professor Fred Watson: Yep, it is. That's. That's right. That's a
big first. New technology. It's a much
more spacious capsule, the Orion capsule,
uh, which I think, uh, will
really be, um. It'll be luxury
compared with. With the Apollo.
Apollo capsules.
Andrew Dunkley: I imagine so. And we wish them well. Uh,
three representatives of NASA and one, uh,
Jeremy Hansen from the Canadian Space Agency.
So that's. That's pretty good too. Ah, we'll
watch with interest. And as you said,
Fred Watson, all the gear is ready to go.
This, uh, space launch system, the Orion
capsule, which had a couple of glitches
coming back to Earth, uh, on Artemis 1.
They've fixed that. I think it overheated.
Uh, and a few other things that they've
sorted out. So they're good to go. So, um.
Yeah, just waiting for the right. Right
weather and the right data to set off. So,
um, yes, there'll be more to talk about as we
get into the early months of 2026
for the Artemis 2 launch. This
is Space Nuts. Andrew Dunkley. Oh, if you
want to read about that, of course, uh, it's
everywhere but BBC, uh, dot com has a good
story about it.
Generic: Three, two, one.
Andrew Dunkley: Straight Space nuts.
Now we'll keep the introduction to this one,
fairly short. Could we have discovered a
wormhole, Fred Watson?
Professor Fred Watson: Um, that's the usual answer.
Maybe.
Andrew Dunkley: I knew it.
Professor Fred Watson: Yeah, maybe. Um, so what we're
talking about is a gravitational
wave signal. Excuse me, a
slight frog in my throat there. Not a geordie
in my throat, just a frog. Um, it's
one that was recorded back in 2019.
So, uh, we've had access, ah, to
the gravitational wave sky, if I can put it
that way, for 10 years now. And in fact,
um, the first gravitational wave
signal was uh, on the
14th of September, 2015, Marnie's
birthday, as it happens. Uh, so the
LIGO people, the large Interferometric.
Sorry, a Laser Interferometric Gravitational
Wave Observatory, uh, they
have been celebrating their 10th anniversary
since operations came in. Um,
they have been joined by Virgo, uh,
another gravitational wave observatory. And
since then Kagura, which is in Japan.
Uh, so, um, these, uh, three
facilities are currently routinely
looking at gravitational wave science.
They're seeing exploding or
colliding neutron stars coming in ten a
penny. Um, uh, however,
this, and this goes back to when it was just
LIGO and Virgo. In 2019, there
was a very, very different
gravitational wave event detected
by uh, uh, the
two interferometers.
Um, you and I have spoken
before about the characteristic sound,
uh, because it is in the audio frequency
regime. Characteristic, uh, sound of two
neutron stars colliding or a neutron star and
a black hole or two black holes. It's that
chirp sound. It's uh,
with the frequency increasing as these things
spin together and then just vanishes when
they collide. It's when they undergo what's
called the ring down where the two black
holes actually merge. Yeah, but this one was
nothing like that. And I'm not going to
impersonate what it sounded like, but it was
more of a crack.
Andrew Dunkley: Uh, was it, Was it, Was it.
Professor Fred Watson: No, it could be something completely
different
because I'm sure there's a joke about Uranus
you can make with that, but I'm not, I'm not
even going to go there. So,
uh, the, um. Yeah, so it was more of a crack.
It was, it was less than, uh, a tenth
of a second in duration. These normal
signals take a few seconds to build up the
frequency and then they disappear with that,
you know, that chirp. Um, but this
one was over in 10 seconds.
So, um, there has been work done on trying
to explain this. It's got a name. All these
things have a name that starts with GW and
ends with the date spelled backwards. Uh, so
this was GW190521
for the date, which was the 21st of May,
uh, 2019. And, um,
the best interpretation,
which I guess is what you might call the
standard picture, is that. Yes, it is. Two
black hairs. Two black hairs.
Generic: Two.
Professor Fred Watson: Two black holes.
Andrew Dunkley: It's about all you've got on your head,
Fred Watson.
Professor Fred Watson: Uh, I'll have to look for the other one. Um,
there's two, uh. Two
black holes snaring each other. Not.
Not two black hairs snoring each other. Which
is, I think, is what I was going to say. Two
black holes snaring each other. Uh, in
passing, I'm reading the account that is, um,
on Science Alert, uh, written by Michelle
Starr, an old friend of Space nuts, uh, with
a name that tells it like it is. Um,
so, uh, that's the standard interpretation.
But there's a new paper that has come
from, um, astronomy, um,
astronomers, physicists actually,
uh, which is what you need to be to do
gravitational waves, I guess. But
astrophysics is probably the real name. A
physicist in China, University of Chinese
Academy of Sciences. Uh, we've seen a new
interpretation which is
that, uh, what this
event depicted was not two
black holes colliding in our
universe, but in another universe.
Whoa. And what we're hearing, or what
we're sensing is the gravitational
disturbance, uh, of an event in
another universe that comes through a
collapsing wormhole that
was, um, basically, um,
formed in the merger and collapsed after
the end of it.
Andrew Dunkley: So, um, that's a huge claim.
Professor Fred Watson: Yes, it is, isn't it? So
let me quote from Michel's article, um, in
Science Alert. To be clear, the black hole
collision right here in our own universe is
still the preferred interpretation of the
strange signal. But that preference is not
strong enough to rule out the wormhole
model entirely. Uh, and that's, um,
basically a quote from the. The preprint that
these, um, uh, scientists in, In
China have published.
Um, so it's,
you know, it's, it's.
It's. It's a quite a remarkable thing.
Uh, Michel's article is relatively
short, although there's quite a lot of detail
in there. Uh, but the bottom line
is, you know, if. If it was.
If that was the correct interpretation,
uh, of, uh,
GW190521,
uh, and anything else we found that was like
it. If that was the, uh, the
confirmed interpretation that it was a
temporary wormhole, allowing us to sort of
hear the, uh, the echo of.
Excuse me, I'm gonna sneeze. Andrew. Sorry
about that.
Andrew Dunkley: It's. That Time of the year over here.
Professor Fred Watson: I think that was a, I think that was a
wormhole collapsing. Um, yeah, it
wouldn't, it wouldn't. If you could, if it,
if that was the preferred interpretation, it
wouldn't just suggest that these things
exist. Wormholes have been a feature of
science fiction as well as science writing.
The, the fact that they theoretically could
exist but we've got no evidence of them. Uh,
but what she says is it wouldn't just confirm
the existence of these, these things. Um, it
also gives uh, us a, ah, a new way
of, of investigating their
properties. Um, and you know, that might
lead to a whole new branch of astronomy,
wormhole studies. Well, wouldn't that be
extraordinary?
Andrew Dunkley: It would be, but it also opens up
um, another thing that's only theoretical
multiple universe theory. So if we've
detected the collision of two black holes
in another universe and detected it through
the opening up of a temporary wormhole, I
mean that's a double banger.
Professor Fred Watson: Uh, that is, uh, except that
you would need to rule out the possibility
that this wormhole was linking two bits of
our own universe because
that's one of the things that has been
suggested. But maybe the Chinese paper,
uh, actually uh, has ruled that out. I'm not
sure because I haven't looked at the
preprint. Um, but yes,
uh, it is, is really
rather remarkable. Uh, what the
uh, scientists in uh, China have done is
basically modelled what you would get
if you had a gravitational wave signal
from another universe coming
through a wormhole. Um, and they've
modelled that and they've compared that with
this particular event, um,
and uh, reasonably happy that their model
actually fits the data. Um, in fact
they say um,
that uh, you know, it's, it's comparable
with it. I don't think it's as
accurate as the black hole merger
waveform, uh, which is, would be a
conventional view that you've got two black
holes that have merged together in our
universe. Um, it's uh, that's
apparently just a very slightly
better fit to the observed signal than their
wormhole model. But it's still a
possible scenario. So
uh, I think uh, this
will be uh, very
much uh, a pathway
for further investigation of wormholes.
Uh, just generally. Um, so what
should we expect if wormholes do exist? What
should we expect? It's not, it's all very
well just talking about space worms I
imagine.
Yeah. Well there you go. You can, I think you
can get um, tablets for those.
Uh, anyway, um, it's, yes, it's,
it's a really interesting piece of work
obviously. Uh, quite controversial,
quite attention grabbing, headline grabbing.
Generic: Yeah.
Professor Fred Watson: And um, I'm gonna have a look at the
preprint, which I haven't had time to look at
yet. In fact I'm clicking on the link now.
Uh, and it's, it takes me to A paper called
IS GW 190521 A Gravitational
Wave Echo of a Wormhole Remnant from Another
Universe. What a great title.
Andrew Dunkley: That is a great title. And uh, hopefully it's
true. I think that'd be great. Uh, it would
give us something new to study and we might
even work out how to create our own wormholes
and travel long distances at the blink of an
eye.
Professor Fred Watson: Wouldn't that be great?
Andrew Dunkley: Wouldn't it be awesome?
Professor Fred Watson: Yes. We had a little certainly get you.
Andrew Dunkley: Out of jury duty.
Professor Fred Watson: Not necessarily. Because if you're in the
other side of the world they'd write to you
and say look, you've just got to use your
wormhole machine and.
Andrew Dunkley: Yeah, well, yeah, that's a possibility. All
this exciting stuff. Uh, if you'd like to
read about that, you can do that at the
Science Alert website, sciencealert.com
and read Michelle's article. Or you can go to
the source, the preprint server on
archive. This is Space Nuts with
Andrew Dunkley and Professor Fred Watson
Watson.
Generic: 0G and I feel fine.
Andrew Dunkley: Space Nuts, our final story.
Fred Watson, uh, takes us uh, into space
to see something very rare indeed. An
Einstein cross has been spotted.
Uh, X marks the spot and they drew a circle
around it.
Professor Fred Watson: Well that's kind of what you have to do. Yes,
uh, in uh, this case, uh, the observations of
the Einstein cross weren't made with visible
light telescopes or infrared telescopes,
but with our old friend alma, the Atacama
Large Millimetre Submillimeter Array, which
we're more used to seeing, uh,
connected to images of protoplanetary discs
and a high frequency radio radiation
from protoplanetary discs is something
that is very much the stocking trade of alma.
But now they've been observing, I mean they
do observe galaxies as well. What they've
observed is an Einstein cross.
This is usually uh, it's
four images of one object in a shape a
little bit like the Southern Cross in our,
ah, Southern Hemisphere sky,
um, which are all images of the same
object. Uh, but there's
something intervening, there's something
between them that creates a gravitational
lens, uh, that separates,
splits the light coming from the distant
object. And uh, as it passes through the
gravitational lens in the foreground, uh,
it's split into four components forming a
cross the reason why this one is particularly
rare is that it has a central image as well.
It's a five image
Einstein cross. And I think there's only one
other one that is actually known, uh,
with gravitational uh, lensing. Um, and
so uh, yeah the story is that um,
this object, uh,
the Einstein cross is the
multiple images of a uh,
background galaxy, uh, known as
hers three or her S3.
Probably her S3. Um, that's
a uh, galaxy which is 11.6 billion
light years away. So we've got a look back
time of 1.6 billion years. Well on the way to
the beginning of the universe. Yes. And
it's gone past uh, a group of
galaxies, a sort of
cluster of galaxies uh, which are in
the foreground and ah, they're only 7.8
billion light years from us, which is still a
staggering distance. But that is the gravity
uh, source that is bending the space and
forming these multiple images. Uh,
and so um, it tells us
about both objects, it tells us about the
distant galaxy of which this is a, a uh,
multiple image. It tells us about the
distribution of matter in the foreground
galaxy cluster. And the really interesting
thing is that what they've shown uh,
the scientists who've done this work,
um, it's ah, a Parisian
group based in Paris, uh, or the leader
is um, based in Paris. Uh,
what they've shown is that the
sort of centre of mass of the
galaxy cluster is not,
is off to one side of where the galaxies
are. And that in itself is
peculiar because we interpret that as saying
that the most of the mass in this cluster is
in the form of dark matter. Uh and it's the
dark matter clump uh, that is kind of
offset from the galaxies that we can see.
That's not um, unique. There are other
circumstances like that in the
universe but this is quite unusual that you
know we've got an Einstein cross created by
a cluster of galaxies whose centre of mass,
if I can put it that way, is off to one side
because of the distribution of dark matter
around it.
Andrew Dunkley: Fascinating. I suppose it also begs the
question that uh, we're looking at the same
thing in five different timelines.
Professor Fred Watson: Yes, that's right. And that actually adds
uh, something really interesting to this. Um,
uh, and certainly in the early days of
these kinds of observations, Einstein
crosses. And it goes back actually to the
1970s. I remember when the first double
quasars were being observed and they're
formed by a similar process. There's
something in between the quasar and yourself.
The quasars are kind of delinquent galaxy,
uh, that's multiplying the image. Um,
there's a, um, a quote from,
uh, Tanu Dylan,
who's at Washington University in St.
Louis, wasn't, uh, involved in this research.
But a very nice quote that says the
magnification may allow
unusually detailed studies of
a star burst galaxy at redshift
3. And that's redshift 3 is
what tells you it's, uh, that far away.
11.5 billion years, light years,
uh, when the universe was less than a fifth
of its current age, including its gas, star
formation and possible outflows.
And what you really need,
um, is some visible
variation in the
light of the source
galaxy because the light path,
uh, to form each of these five individual
images of that object is different. And
so you expect these to be
delayed. Uh, and in fact, that was the
thing about the double quasars. You could see
variability in an object which
was mimicked by the second
image of it. This is how we knew that there
were two images of the same thing back in the
day. Uh, uh, an object would get brighter,
the quasar would get brighter, and there'd be
a delay between one image and the other. If
you could do that with five images, then you
can learn an awful lot. Um, there is another
quote, uh, from one of the investigators.
Usually people use quasars,
uh, for this purpose of time
delay, uh, since they
naturally vary, uh, very
rapidly as a function of time. But,
uh, uh, her, uh, s.
Uh three is star forming,
raising the prospect of detecting a
supernova, uh, whose light would arrive
at each image at different times, giving the
time delay. And from that you can actually
work out what the Hubble constant is. And the
Hubble constant is still, uh, a topic of
discussion. We've talked about the Hubble
tension several times. This will give us
another way of measuring that, and that will
be very interesting.
Andrew Dunkley: That would indeed be quite exciting. Gee,
we've covered some really interesting stories
today, Fred Watson, haven't we? Just if you'd
like to read more about that particular
Einstein cross story, you can do
it@skyandtelescope.org or you
can read the, uh, full paper which has
been published in the Astrophysical Journal.
Uh, we are just about done, Fred Watson.
Before we finish, I might just direct, uh,
people to the Space Nuts podcast group. This
is a Facebook page that was created
by our audience and has,
uh, quite a few thousand people. Uh,
2.7 is 20, uh, 700
members. It's got now, um, people who
discuss, uh, science and
astronomy together, publish stories that,
uh, they are interested in, um, ask
questions of each other, try to solve all the
mysteries of the universe. Uh, it's a great
little group, so if you'd like to join, it's
Facebook. Uh, um, yes, the Space
Nuts podcast group. That's what you've got to
put in your Facebook search engines. Uh,
Space Nuts page podcast group. There's also
an official Space Nuts Facebook group if you
want to join that as well. I think it's got
around, um, about the same number of members.
Probably all the same people. Very likely,
um, quite a few of them anyway.
Professor Fred Watson: Yes, I'm sure that's right. I am. I'll check
that out. I'm not a big Facebook
user, but once in a while I go online. I have
to first of all find out once again what my
password is because it keeps, seems to keep
getting changed. So, um, I'll get into
Facebook, um, or Face Ache as I call it. It's
what my dad used to call me. Yeah, um,
Facebook. Um, and have a look at SpaceNuts
podcast group and see what they're saying.
Andrew Dunkley: And I've got a shout out to our
administrators who do a great job of keeping
it all in ship shape condition. So thank you,
Paul, thank you Misty, and thank you Steve
and everybody else who's involved. There's a,
there's a few people who look after it for us
voluntarily too, I might say. Um, so,
yeah, excellent, Fred Watson, we're done.
Thank you very, very much.
Professor Fred Watson: Uh, it's a pleasure and good to see you
again, Andrew. And we'll talk again very
soon, I think.
Andrew Dunkley: Very soon, I expect.
Professor Fred Watson: Yes.
Andrew Dunkley: Uh, Professor Fred Watson Watson, astronomer
at large. And thanks to Huw in the studio,
who couldn't be with us today. His, uh, his
dog Einstein was naughty. He's very cross
with Einstein.
Professor Fred Watson: Oh, geez.
Andrew Dunkley: And from me, Andrew Dunkley, thanks for your
company. Catch you on the next episode as
well. Space Nuts. Bye Bye.
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