Andrew Dunkley: Hello again. Thanks for joining us on another
episode of Space Nuts. My name is Andrew
Dunkley. It's great to have your company. I
hope you're well. Uh, coming up in this
episode, some exciting storeys. And
one of them is a new
CSIRO map
developed in Australia of
magnetic fields. Now, it's been quite a while
since they updated this and they've got a new
one out. And, uh, it's quite extraordinary,
uh, the way it was done and what it shows and
what it can be used for. Uh, we've also got
a new report about the relationship
or otherwise between, uh, black holes
and dark matter. Now this is interesting
because it's only been a theory
until now. Now, this isn't absolute
proof, but it's a step closer to
proving there is something going on between
the two of them and they just don't want
anyone to know. And the world's first
trillionaire goes public. We'll talk
about all of that on this episode of space
nuts.
Professor Fred Watson: 15 seconds. Guidance is internal.
10, 9. Ignition
sequence start.
Professor Fred Watson: Space nuts.
Professor Fred Watson: 5, 4, 3, 2. 1, 2, 3, 4,
5, 5, 4, 3, 2, 1.
Andrew Dunkley: Space nuts.
Professor Fred Watson: Astronauts report it feels good.
Andrew Dunkley: And he's with us again for another dose of
whatever it is he takes before he talks to
me.
It's Professor Fred Watson Watson, Astronomer
at, uh, large. Hello, Fred Watson.
Professor Fred Watson: It's good cup of tea that I take
normally.
Andrew Dunkley: Uh, I've been drinking a bit more
tea of late. Um, only because, um,
by the afternoon I'm not really into coffee.
But today I did have coffee, so.
Do love my coffee.
Professor Fred Watson: I do too, but I make my own.
Andrew Dunkley: I got the whole barista thing going.
I'm even doing latte art, Fred Watson.
Professor Fred Watson: Oh, really?
Andrew Dunkley: Yeah. I don't know if you'll see this. I took
this photo, um,
today of my latte art. Can you see that?
Professor Fred Watson: That is brilliant.
Professor Fred Watson: Yeah.
Andrew Dunkley: Whoa.
Professor Fred Watson: That's real pro stuff. Self taught
barista.
Professor Fred Watson: Yes.
Andrew Dunkley: I don't know what it is. It's like some kind
of flower, like a lotus flower.
Professor Fred Watson: Well, it reminds me of ears of corn.
Andrew Dunkley: Oh, yeah, it does, doesn't it? Yeah, yeah,
yeah, that's what it was. Or just ducks
sitting on top of each other or something.
Professor Fred Watson: Could be your. Could be your corny latte.
Andrew Dunkley: Yes, it could be. Anyway, I've been working
on that.
Professor Fred Watson: That's very good. Yeah.
Andrew Dunkley: I was going to do a whole series and put them
on Instagram of my progression through being
really crap at it and to reaching a
point where it's, you know, something to look
at, but I didn't bother and now I wish I had
because I've had some epic fails.
But um, that one came out quite well today.
Professor Fred Watson: That's very nice. Well done.
Andrew Dunkley: M. Right, let's uh, let's get on with this
because, uh, we've got a lot to talk about as
always.
And our first storey comes from Australia,
mate. And it is the uh,
remapping of uh, the magnetic
fields of a, uh, large swathe of
um, uh, the universe. Or is it a large
swathe of uh, whatever piece of the backyard
sky someone can see out of. Not sure how much
of it they
Professor Fred Watson: got a good chunk of it
actually. I, uh, thought so because, um.
So these observations were made
at uh, uh, a site in
Western Australia known as Inyariman il Ghare
Bundara, which is Wajari for
sharing sky and stars. The Wodgery people are
the traditional owners there. And it's also
called the CSIRO Murchison Radio Astronomy
Observatory, but we tend to refer to it as
Inyarimana il Ghari Bundara because it's a
very nice name. Uh,
so what's there? There is, um, first of
all, um, it's the site for the
Low Frequency, uh, arm, um, of the
Square Kilometre Array. Uh, Square Kilometre
Array Observatory exists in three places.
Uh, one is western, earlier where the Low
Frequency antennas are. The uh, other is
in South Africa where the mid Frequency
antennas are. And the other is near
Manchester where the headquarters are. Um,
that's Chodrell bank is where the
headquarters of SKAO are. Uh, uh, and
they've just got a new Director General, uh,
by the way, um, Jessica Dempsey I think is
her name. Somebody I've kind of run
into before over the years. Uh, is um,
uh, the new Director General of the SKAO
Observatory. Sorry, SKA Observatory. Anyway,
yeah, also on the site in Western Australia
is ascap, which is the
Australian SKA
Pathfinder. A s K a p.
Coincidence.
Andrew Dunkley: Uh, an ASCAP is also something you can wear
if you don't have any pants.
Professor Fred Watson: There's no answer to that, Andrew.
Andrew Dunkley: Uh, no,
no, that one. Can't we just let that one.
Professor Fred Watson: No, I might leave that one alone. Yeah.
Anyway, notwithstanding that.
See, you don't get this on other podcasts, do
you? It's why we're number one in Iceland.
Andrew Dunkley: That's right, we are. Thank you.
Iceland.
Professor Fred Watson: Absolutely. Go for it. Um,
I forgot. Yes. ASCAP,
not the garment, but the um,
Radio Telescope Array, 3612 metre
dishes which were built um, over
the. I guess 15 years ago was when they
started. It's been operational for probably
more than 10 years now and done some fabulous
work. Uh, but the latest piece of high
profile research that's come from ASCAP is
exactly as you've said, the largest
magnetic map of the universe ever produced,
five times larger than all previous efforts
combined. And it marks the beginning of a new
generation of research into the field of
intergalactic magnetism. And I'm reading
there from the CSIRO news release,
um, probably spot the hype but it's well
deserved type as well and a, uh, well
deserved kudos to the team leader Alec
Thompson of csiro. Um,
what they've done is used
the telescope uh, in a, I
suppose in an innovative way.
Uh, how do you measure magnetic fields? Well
you know normally to measure a magnetic field
we stick uh, a magnetometer in the way.
That's how magnetic fields are measured in
the solar system by various spacecraft
because they carry magnetometers which
measure the local magnetic field of where you
are. Um, and that gives us
some insights into not just the sun's
magnetic field, not the Earth's magnetic
field and the sun's magnetic field, but also
uh, courtesy of Voyager, the two Voyager
spacecraft. The galaxy's magnetic field
because we can sense the direction of that
with the magnetometers uh, carried by those
spacecraft which are now beyond the sun's
magnetic influence. But
uh, it's quite a long jump
from the environs of the
solar system to the universe as a whole,
uh, which is what these scientists have done.
And the basic technique
is uh, it's all about
um, polarisation and
we've talked about polarisation before, we
all know what it does when we
wear our uh, polarising sunglasses and you're
driving your car into the sunlight and
there's a huge reflection coming off the
road, especially if it's wet. Uh, and your
polarising sunglasses magically take away
that's happening because uh, the light waves
uh, have um,
if you think of them as just being wiggles in
space, which they are, ah, electromagnetic
wiggles, they have a preferred direction.
Um, normal light has a mix of all these
directions but uh, it turns out that
you can separate out them by using
well a polarising filter which is what we've
got in our sunglasses that only lets through
the vibrations that are vertical. That's the
vertical direction of the light that's coming
to you because the horizontal ones which are
very um, much reflected uh,
in the reflection from the wet road, they are
cancelled out and so you don't see them. Uh,
so we're kind of familiar with that idea of
the direction of vibration of
Light waves. Well, the same holds good
in, um, in radio waves. And
so ASCAP and many other radio
telescopes can actually sense the
polarisation of the radio
signals that they're receiving from deep
space. Uh, and so that's all
well and good, you can sense the
polarisation, but you can also
detect if that polarisation's
been twisted. And that's what happens
when the light passes through a magnetic
field. Um, it actually rotates,
called Faraday rotation. It's the plane of
the radio waves twists. And
you can detect that with an array like
ascap. And that is what has allowed
people to measure the magnetic field of the
universe. Because what you do
is you look at, uh, the light from
a distant galaxy and you look at the way
its polarisation changes, uh, as that
light comes towards us by using this
technique. And so what you're saying is
that you've got a kind of, um,
a beacon lamp in the distance and
what you can sense is what's happening to the
light coming from that as it passes through
magnetic fields on its way. And so
that's the basis of the map, as
far as I can tell from, because I'm not a
radio astronomer, which is pain, the obvious,
probably from the way I'm talking about it.
Um, I think you probably
don't know how far away that magnetic field
is. And so, um, what you can
infer is, uh,
for example, how rapidly it changes, uh,
depending on the position
in the sky. Um,
when you look at this map, and I urge our
listeners to have a look at it, it's pretty
easy to find and largest magnetic map of the
universe yet. Um, you'll see lots of colours.
Um, the colours, I think, are colour coded in
that. I, um, think if I remember rightly,
red is with the North Pole
pointing towards us of the magnetism, and
blue is it pointing the other way. Um,
and so that, uh, lets you sense the
magnetism along that line of sight. And so
the biggest detail is actually in the
galactic centre, which is full of churning
magnetic fields. I guess you are having a
look at it now.
Andrew Dunkley: I'm looking at it right this minute. And
yeah, you're right that they're explaining
that just like, um, you've got blue shift and
redshift with light waves, the magnetic
fields have the same kind of qualities in
terms of north, south, um, on the
magnetic plane. And yes, the centre of the
Milky Way galaxy is probably the most
volatile part of this entire picture. Um,
which is not surprising. We live there.
Professor Fred Watson: That's right.
Andrew Dunkley: We know all about volatility.
Professor Fred Watson: Yeah. It's home from home.
Uh, and just going back to, um, what
you said a few minutes ago, um, there is a
hole in the, uh, map. And
that's because ascap, there's certainly
regions of the northern sky that ASCAP can't
see because they're permanently below the
horizon. They're relatively small, actually,
because ASCAP can look a long way down
towards the horizon, much further than we
can. In optical astronomy. In optical
astronomy, the atmosphere just gets too thick
when you're looking very low down until you
get all the distortions and everything from
the atmosphere. That doesn't happen, uh, with
low frequency radio waves. Um,
the gap that's missing because of the
Northern Hemisphere, uh, because it's not
visible to the telescope, that's actually
relatively small compared with if it was an
optical astronomy picture that you were
looking at. But yes, this map has
the line of the Milky Way across its equator,
across the middle. Um, lots of magnetic
turbulence in there, some really intriguing
features, things that look like magnetic
fingers just sort of pointing around. It's
a remarkable map which, um, yeah, I encourage
people to have a look at.
Andrew Dunkley: Now, just by way of, um, taking this a step
further. Uh, what can they now,
or what can anybody now do with a map like
this? Because it's been made publicly
available, hasn't it?
Professor Fred Watson: Yes, so that's exactly right. Those data, uh,
are now publicly available. By the way, I
do like the name of it, which is
Spice.
Andrew Dunkley: Spice Racks.
Professor Fred Watson: Yeah. Uh, so Racks is
the Rapid ASCAP Continuum Survey.
And I've forgotten what Spice is, but it's
something equally, equally delightful.
Uh, but the Spice Racks Survey, I think is,
uh, is. It's got its own, uh,
own. Own charm about it.
Andrew Dunkley: I was going to say something tongue in
cheek about a girl group named Something to
do with spice.
Professor Fred Watson: Oh, yes, I know that.
Andrew Dunkley: Then I thought, no, you can't really
associate that with racks. You could get
yourself smashed.
Professor Fred Watson: I would leave that well alone. I will.
Andrew Dunkley: I won't mention it.
Professor Fred Watson: Yeah, so, um,
it's. Yes, so it's so. And, and yes,
as data are already publicly
available, uh, research groups are already
actually digging through this to see
what it tells us about the, you know, the
magnetism of galaxies, for a start.
Professor Fred Watson: Uh,
Professor Fred Watson: and just the way the environment of a galaxy
is dominated by a particular magnetic field.
It's only recently that we've understood
that cosmic magnetic fields. That,
uh, is magnetic fields in space play a huge
role in so many areas of astrophysics,
but certainly in the way galaxies evolve
over the millennia. Millennia.
I suppose they are uh, the way they evolve,
uh, is, um, very much
dominated by the local magnetic fields. And
one of the big puzzles in cosmology, the
science of the universe as a whole, is where
did these magnetic fields come from in the
first place? And it's actually
one of the things on the list of target
science. The Square Kilometre Array
itself was designed to address what's the
origin of the cosmic magnetic field, uh,
because we really don't know how they came to
exist. And more than that, we don't
know how magnetic fields have changed as, you
know, as the universe itself has evolved. All
this lets you do that because, of course, as
you look further out into space, you're
looking further back in time. So there's a
time dimension of this as well.
Andrew Dunkley: Yeah, there's a lot of magnetism out there.
And as you say, they don't know where it came
from. Uh, we probably would have solved it
except dark matter and dark energy came along
and we went, oh, well, this is more exciting.
But, um, yeah, it's just another one of those
mysteries.
Professor Fred Watson: It is. And I'm sure,
um, all the scientists who've been involved
with this have got magnetic personalities.
Oh, sorry. I do my best.
We aim to please.
Andrew Dunkley: Pretty good, that one. All right. If you'd
like to read up on it, you can do that
through the scene. CSIRO website. It's an
Australian website and you can download the
map. It's only 6 million megabytes. It's
a 6 megabytes. It's not a big file in the
modern age. Uh, you can also read the
paper in publications of the Astronomical
Society of Australia. This is
Space Nuts with Professor Fred Watson Watson
and Andrew Dunkley.
Space Nuts.
Professor Fred Watson: All right. Um, now, you
did press, didn't you?
Andrew Dunkley: I did press record. Yes. Um, yes,
the giant gap was a misfire.
Professor Fred Watson: Oh, good. That's good.
Andrew Dunkley: Okay, we get those.
Uh, now our next storey, it's a, uh, new
report about the relationship between
black holes and dark matter. Now this is,
this is something that our audience has quite
often thrown up. You know, there's got to be
a connection, uh, between black holes and
dark matter, et cetera, et cetera. Uh,
and now they've released a paper that's
suggesting just that.
Professor Fred Watson: Yes, this is really interesting stuff. And of
course, um, it covers
two of the most popular topics that we
discuss on, uh, Spacenuts. This is
research, uh, from Virginia Tech,
uh, in the United States. And
it's very neat because it uses a technique
that I've always found absolutely
fascinating, um, which
is it's got A fancy name, uh,
called reverberation mapping. Uh,
but we usually talk about light echoes.
Uh, and the easiest way to
envisage it is, uh, the one that
I think drew
everybody's attention to this phenomenon back
in the 1980s, uh, when
supernova 1987A,
the nearest supernova to us since
Kepler's supernova in 1604, I think it was,
um, that uh, became very much the object
of attention. Uh, it was in the Large
magellanic Cloud, to 165,000 light
years away from us as the crow flies.
And what was discovered as time
went on was the. So that the
supernova explodes. You've got this brilliant
flash of light. It was easily visible to the
naked eye. I remember looking at it. Uh,
and uh, then as time goes by, the light
fades. But what you get,
uh, uh, as time goes on is a series of
rings around the, apparently around
the site of the explosion. And those
rings are caused by light being
reflected off clouds of dust which
are between us and the supernova. And you
can do all kinds of really neat calculations,
uh, to discover how thick those clouds of
dust are, where they are in relation to the
supernova. Um, um, one of my
colleagues, now sadly no longer with us,
David Allen, was a past master,
uh, about working on this and writing about
it. And uh, those rings are called
light echoes because it's the echo of the
light of the supernova which has now faded
away. But you can still see it because it's
bouncing off clouds of dust in space.
So, so what this article is
about, the Virginia Tech work that we've just
mentioned is we know that black
holes, supermassive black holes, are
surrounded by swirling discs of
matter. Uh, they're called the accretion
disc. It's the stuff that's basically
swirling around the plug hole, um, before it
either gets sucked into the black hole or
shot out vertically from the poles of the
black hole. The rotation poles it in the form
of these jets, which we hear a lot about. But
the accretion disc itself is bright,
um, in X rays and radio radiation.
Uh, once in a while, um, a
larger dollop of matter enters the
accretion disc. And you get this
outburst, you get a brilliant outburst
of radiation. Um, and
that outburst is relatively short lived.
It might last for a few weeks or even months,
but it's short lived. And so what you can
look for is a light echo
around it. Because that light radiates
outwards from the accretion disc. And if it
hits anything outside it,
it will reflect back to us. And we'll see it
at a later date from when
the bright event itself
happened. So you see the bright event in the
accretion disc and then at, uh, some time
later you see an echo of that
light which is being reflected off,
usually gas and D which is surrounding,
uh, the accretion disc. What this storey is
all about though, is that, uh, when you do
calculations about how
much material there
is in the accretion disc where the echo
is taking place, you get a much
higher mass than what you can see. And
that's always the, um,
that's always the um, uh, kind of
telltale signature of dark matter
when you can only see a limited, limited
amount of stuff. But gravity tells you
there's much more, there's more there. And
that's exactly the basis of this storey. So
it's just a new way of detecting
the dark matter, uh, around
black holes. But it looks as though black
holes, as you'd expect, not only
are a magnet for regular matter. I, uh,
mean a gravitational magnet. I guess it's not
magnetic in the sense that we've just been
talking about, uh, but a gravitational,
uh, pull from, for normal matter. It's also a
gravitational pull for dark matter as
well. And it looks as though the dark matter
actually congregates around black holes that
we've got, um, these buildups of dark
matter, ah, in the vicinity of a black
hole. Quite remarkable.
Andrew Dunkley: Now, the situation is that they
haven't absolutely proven it. They've
just come up with a way of suggesting that
this might be the case. But, um.
Yeah, it's not absolute. It's not.
Professor Fred Watson: It is in the sense that, um, they've looked
at this for 14 different
galaxies and all found
cases where, uh,
what you're looking for is the way the mass
changes with distance from the black hole.
And that mass is increasing because you're
looking at stuff swirling around. But the
increase in mass is faster
than the visible matter on its own can
explain. And that's the a. It's
a kind of smoking gun for dark matter,
really.
Andrew Dunkley: Yeah, I, I've, I've found the paragraph. It
says data limitations mean the results are a
proof of concept, not a definitive,
Definitive detection. Detection. But the
study outlines a clear path to confirmation.
Professor Fred Watson: That's right, yeah. So that.
Andrew Dunkley: We're almost there.
Professor Fred Watson: We're almost there. That's. That's exactly
right. We're almost there.
Andrew Dunkley: That is very exciting news. And, um, that
will stop probably 75% of the questions we
get on our Q A editions.
Professor Fred Watson: Well, it, it might, but I Bet it produces
another 150 about what it is that we're
finding and how do we know why? Isn't it mond
and things like that? Yeah.
Andrew Dunkley: Yes. Oh gosh, it will just. It'll never end.
It will never end. I hope it never ends.
Professor Fred Watson: I think it's great.
Andrew Dunkley: But if you want to read about it,
it's@fizz.org uh, they publish the paper
in the Physical Review D. Does that mean
there's an A, B and C that comes with.
Professor Fred Watson: Yes it does.
Andrew Dunkley: I assume so.
Professor Fred Watson: But um, that's a high profile journal though.
Physical Review. It's uh, definitely uh,
uh, you know it's, it's uh, ranks with Nature
and Science and these very high profile
journals. So it's not work that is
in any way secondary. It's not like Space
Nuts where it's adequate. This is top
ranked stuff.
Andrew Dunkley: Indeed it is. Uh, yes. So read about it
at Physical review or@phys.org this is
space Nuts. Andrew Dunkley here with
Professor Fred Watson Watson.
Professor Fred Watson: Okay, we checked all four systems.
Professor Fred Watson: Space Nets.
Andrew Dunkley: Our final storey. Fred Watson takes us
into the realm of um,
publicly offering your company up on the
stock exchange.
Professor Fred Watson: I wonder why we're going to talk about that.
Andrew Dunkley: I wonder why uh, the world's first
trillionaire has just done that in um, a
very interesting way. And to coincide with
the launch, um, he's selling stuff
like we do on the Space Nuts shop. All
sorts of little bits and bobs if you want a
piece of the action.
Professor Fred Watson: Yes, the IPO merch.
Andrew Dunkley: It really is a remarkable storey though. Uh,
elon Musk and SpaceX. Because uh,
as this article briefly um, mentions,
he didn't think the company would survive. He
didn't expect it to actually be a success.
He gave it a very low chance of lasting
and look at him now.
Professor Fred Watson: Quite so. The world's world first
trillionaire. Ah yeah, it's um,
I mean I don't honestly I know virtually
nothing about the world of high finance.
Andrew Dunkley: Um, well you know more than me then.
Professor Fred Watson: When I see numbers like millions and
billions, I always expect there to be light
years after them rather than dollars.
But yeah, it's uh, the, the public,
the IPO initial public offering, um, has
valued this company at uh, something
absolutely huge. Compared with all the other
tech companies that are being floated or are
likely to be floated into public ownership.
It's enormous. Um, is it
170 billion? Am I thinking of the right
number there or is that light years? That
could be light years, I don't know.
Anyway, um, the bottom line so, yes, that
was, um, uh, over the weekend that
m offering IPO
happened, uh, and it was very successful.
Um, I heard people on Friday saying, oh, no,
it'll probably just fail because nobody will
actually believe what Elon Musk's saying.
Well, they might not have believed what he
was saying, but they put their money where
their mouths were. And um, yeah, so it's done
very, very well. Um, I think the number
I'm thinking of is $160.95,
which is the share price.
Andrew Dunkley: Well, I've just looked now and I know this is
being recorded. So by the time people hear
this, the number will change. But at the
moment, at this very moment,
$192.50 in US
dollars.
Professor Fred Watson: All right, so they've already gone up then.
Andrew Dunkley: They've gone up 19.6%.
Professor Fred Watson: Yeah.
Andrew Dunkley: In fact, they're up 31.55% today.
Professor Fred Watson: So not a bad investment really, if you're
into that kind of thing. Yeah, well, we're
not into that kind of thing, but we're
definitely into merge. Uh, and that's what
this storey's about because,
um. Uh, I guess the one
thing you can not accuse Elon
Musk of is lacking flair, um,
because he's done this very nicely. You can
buy a mission patch,
Professor Fred Watson: uh,
Professor Fred Watson: for the ipo, uh, which says
the future is public. There's a lovely
embroidered starship in the
background. Uh, in the middle it says
SPCX, which is SpaceX liftoff
underneath it. And, uh, SpaceX
2026. Uh, and it's also got a four
leaf clover on it, which I think is present
on all Elon Musk. SpaceX.
Andrew Dunkley: I think that's been his logo since day one.
Professor Fred Watson: Yes. Yeah. M a sign of good luck.
Maybe that's what's done it. But the thing I
liked was, um, uh,
you can have a souvenir bell.
And I guess I don't know whether
bells are normally associated. I know they're
certainly associated with the stock exchange,
but whether with, uh, public offerings,
they're associated. But they certainly are in
this case. And what he's chosen for the shape
of his bell is something absolutely perfect.
It's the bell, um, of,
uh, a Raptor engine. These rocket
motors have a very strongly bell shaped,
uh, thrust chamber. I guess it's the, um,
opening, uh, that lets all the gas out, uh,
after it's been ignited in the combustion
combustion chamber above it. And so it's a
scale replica of the Raptor engines that
actually power the Falcon
Heavy, um. I beg your pardon, the super heavy
Booster, which is the basis of starship.
It's got 33 of these. And
um, uh, this one's
got a little clapper in the middle that lets
you ring it as well as all the artwork. And
apparently it rings. Yes, because there's a
video on the website that shows you that, uh,
they
Andrew Dunkley: haven't released those yet to the
public.
Professor Fred Watson: That's right.
Andrew Dunkley: They will be out probably. I think they're
talking December. Yeah, um,
yeah, they're sort of an 18 centimetre or
7 inch scale model of the, the
SpaceX Raptor Bell. This
one has a, you know, clunker in it that makes
it ring. I don't know what that thing's
called inside the bell, the dinghy thing.
Professor Fred Watson: It's a clapper, is it? That's the technical
name. Yeah, for.
Andrew Dunkley: Anyway, so they're selling those, they're
selling, uh, tote bag and
um, as you said, mission patches, T shirts,
caps, you
Professor Fred Watson: know, he's um, he's the sort of
Andrew Dunkley: bloke that never lets opportunity get away.
Professor Fred Watson: None whatsoever. I, I did hear
some of the things that he said publicly at
the launch which made me cringe,
uh, because,
you know, I can, I can, can just about,
um, believe that we
might get humans to Mars in his lifetime.
It won't be millions. And that's because
that's immoral, apart from anything else.
Um, but he was talking about,
uh, you know, flying through,
around the solar system and beyond.
And at the moment that is off
the agenda. Physics doesn't let you do
that.
Uh, just actually as a little footnote to
that, I read a paper yesterday, uh, which
is about, you know, the idea of
using, um, photonic
propulsion, or basically light, Ah,
energy blasted at a light sail. You've got a
laser, uh, you fire it at this light sail and
the spacecraft accelerates because of that.
That's all fine and dandy and will work,
um, if you can make your spacecraft light
enough. But it turns out that you're not ever
going to get near the speed of light
beyond about 75% of the speed of light.
You, uh, get something called relativistic
drag, uh, where space itself drags on the
light sail as well as any kind of
interstellar matter that you've got to plough
through at 75% of the speed of light.
So that's not going to get us touring around
the galaxy.
Andrew Dunkley: No, we'll have to find another way.
Professor Fred Watson: Need another way? Yes.
Andrew Dunkley: They need to go to science fiction, um,
writers and see what they've come up with.
Professor Fred Watson: Maybe that's what Elon's thinking of. Maybe
he was suddenly in the realm of science
fiction, but he didn't bother to tell us.
Andrew Dunkley: No, maybe not, no. But there's no, Nothing
fictional about his, um, ip.
Professor Fred Watson: No, not at all.
Andrew Dunkley: Uh, initial public offering that is out there
and it is going gangbusters. It's burning
like a raptor at the moment.
Professor Fred Watson: Yeah, probably will. I mean, you know,
you've got to give the guy credit. Uh,
two of the biggest breakthroughs of our, of
our generation, huh? Electric vehicles
and, um, reusable booster rockets. And
basically they've come from him.
Andrew Dunkley: Yes, they have. It's quite
extraordinary. Yeah, you can read about it at
collectspace. Uh, dot com. We, um,
won't tell you all the prices of everything
he's selling because that's, you know, you go
and have a look. Um,
totally your call. Um, but I do like the
idea of mission patches and I'm pretty sure I
suggested that to Huw many years ago that we
should have mission patches.
Professor Fred Watson: Yes, yes, we do.
Andrew Dunkley: Yes. I've got something we should. A new one
for every episode.
Professor Fred Watson: Oh, all right. Okay.
Andrew Dunkley: No, that's a bit much.
Professor Fred Watson: Look, the trouble is the mission patches,
they would just be adequate and if you.
Andrew Dunkley: Although, I think, ah, our logo would make a
great patch.
Professor Fred Watson: It would. Yeah.
Professor Fred Watson: Yeah.
Andrew Dunkley: Anyway, um, we'll, we'll do that one day
maybe. I don't know. There's plenty of other
stuff in the shop. Just go and have a look in
our shop. It's on our website.
Spacenutspodcast.com or
spacenuts IO uh,
click on the shop link and buy yourself a
pair of socks or a notebook or a,
um, or a coffee cup or a hat or a
hoodie, stickers. Um,
there's just all this great stuff there. I've
got some of it. Look, I've got my car cup
here. See, here's my cup.
Professor Fred Watson: Oh, that's nice. Yeah, I might
have one of those somewhere.
Andrew Dunkley: I probably do, yes. And I've got the tote
bag as well. So we thought of that before
Elon. Probably using the same company that
we do. But
yes. Um, I think that brings us to the end.
Fred Watson, thank you so much.
Professor Fred Watson: A pleasure, Andrew, good to talk. And we'll
speak again.
Andrew Dunkley: We will indeed.
Professor Fred Watson Watson, astronomer at
large, and thanks to Huw in the studio,
couldn't be with us today because he wants to
be the world's second trillionaire and he's
just put down five bucks and he's just
watching to see what happens. And from me,
Andrew Dunkley, thanks for your company.
We'll see you on the next episode of Space
Nuts.
Professor Fred Watson: Bye. Bye.
Andrew Dunkley: You've been listening to the Space Nuts
podcast, available at
Apple Podcasts, Spotify,
iHeartRadio or your favourite podcast
player. You can also stream on
demand@bytes.com this has been another
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