Andrew Dunkley: Hi there. Andrew Dunkley here. You're listening to or
watching Space Nuts, A, Q and A edition. Good to have
your company. And coming up, we have
got questions from all over the district.
or maybe all over the planet. we're going to be surfing
gravitational waves. Well, the question is,
can we. But I'll elaborate when
we get to that. the rotation of space time has come
up, firing, lasers into space. And
we've got a couple of jokes, which is nice, but
they're so funny nobody laughs because we
don't understand them. But, that's the nature of the
jokes because Judd wants Fred Watson to
explain why they're funny. So we'll get it. We'll
get to that and much more on this episode of
space nuts.
Generic: 15 seconds. Guidance is internal.
10, 9. Ignition
sequence start. space nuts. 5, 4, 3,
2. 1, 2, 3, 4, 5, 5, 4.
3, 2 dot Space Nuts.
Astronauts report. It feels good.
Andrew Dunkley: And he's back again. And he's reached a point in his
life where he can tell. Great dad
jokes. Great, great, great dad jokes.
Perhaps. Hello, Fred Watson.
Professor Fred Watson: yeah, no, I'm not a great granddad. I am a granddad, though.
yes, and, with a new. A new granddaughter who,
oh, we'll be seeing this week sometime.
Andrew Dunkley: Yeah.
Professor Fred Watson: Excellent.
Andrew Dunkley: It's very good news. yes. good to
see you, Fred Watson. By the way, thanks for joining us.
Professor Fred Watson: I was passing by, I thought might as well.
Andrew Dunkley: Yeah, I couldn't do this without you because, I
would have no idea about some of the answers to these
questions. But, we might as well just go straight to
it. And our first question comes from sunny
California.
Rennie wants to know, theoretically, can
gravitational waves pick up any kind of subatomic
particles or larger objects and carry them for a
certain period of time and drop them off as
they get weaker? Kind of like a surfer catching a wave.
Now, gotta tell you, in one of my science
fiction novels, I did this exact thing. Although it
wasn't a small object. It was a
space battle cruiser that got picked up
by a neutron bomb
explosion which created a gravitational wave. But that's another
story, and it's science fiction, so I could do whatever I like.
But, yeah, that's a good question. can they pick anything up
and carry it for a distance?
Professor Fred Watson: Well, no. apparently not. I checked
this one up, a while ago,
and, so
gravitational waves are a deformation
of spacetime. And,
objects, feel them, because
that's how we detect them. The fact that the
Shape of space changes slightly as a
gravitational wave passes through. it's, basically a
vibration of space time. and we
detect that by. Well, one way of detecting it is
by using two mirrors,
four kilometres apart in the case of ligo, the, Laser
Interferometer Gravitational Wave Observatory.
two mirrors whose separation can be
measured to, what is it? 1 10,000th of
the diameter of a neutron, I think a proton.
Andrew Dunkley: Wow.
Professor Fred Watson: It's ridiculous. Yeah, ridiculous.
But that's what you need, because the. As we've talked about
before, the, In fact, I think we mentioned this
last week, the flexibility of space is very, very low. It's
very stiff. 100 billion billion
times the stiffness of steel if you use Young's
modulus as a yardstick. so, But space
does vibrate. but, that's what happens.
So it vibrates as the wave passes
through, but you don't get surfed by
the wave. You know, it doesn't pick things up and carry them with
it. That's. Which is Rennie's point, I think,
things feel its presence, they feel it by the
vibrations that it sets up, but
they stay put. And that's just as well, because, you
know, the Earth's being bombarded by gravitational waves all the time.
We really wouldn't want to be carried away, from
our neat and tidy orbit around the sun by
passing through.
Andrew Dunkley: But, you know, what you've just done? You've debunked my book.
Professor Fred Watson: Well, that's. I, wasn't going to mention that.
Andrew Dunkley: However. However, I. I will. I will
qualify by saying it wasn't, you know, a
standard gravitational wave.
Professor Fred Watson: That was the neutron bomb. Gravitational.
Andrew Dunkley: Created by human action. So, you know,
I might get away with that one, but,
Yeah, So you did say they're
hitting us all the time. Because I remember when we first
talked about gravitational waves being discovered, it
seemed like a rare event, but it's not.
Professor Fred Watson: No, that's right. And in fact, you and I have spoken about the
sort of background noise of gravitational waves that
m. Swirling around,
the planet all the time. and yes, it's
just as well that space is so
stiff, because otherwise we'd be
getting rattled pretty badly all the time by gravitational
waves.
Andrew Dunkley: Nice. Well, okay, good.
Other things can rattle us.
Professor Fred Watson: Yes, they can. And that neutron bomb explosion
might, actually rattle us to the one you were talking about in your book.
But that would be a shockwave, not a gravitational wave.
Andrew Dunkley: Yes, indeed. All right, thank you,
Rennie. Lovely to Hear from you. Rennie's one of our regular
contributors.
Our next question comes from yet another regular contributor.
His name is Rusty.
Andrew Dunkley: G' day, Fred Watson and Andrew. It's Rusty
in Donnybrook. Now we know that in the realm of physics, human
logic often goes awry. Here's a
try anyway. Thinking about the Big
Bang, initially, no matter
came out of it. It was, was all energy.
And most of this was in the form of
space time. Looking at, black holes, which
is the opposite. This is matter going into
a black hole after the event horizon.
And when it finally gets to the singularity,
it can't exist as matter. So it must exist
as, matter's equivalent, which
is energy. We also know that space
time can rotate. We've seen, photographs
now of frame dragging. And we know that it even exists,
around the Earth. So we've got
some interesting things there about space time.
It has mass, it can rotate.
So is this energy dark matter?
It must also have a mass equivalence if
it's got energy. So, if it is
dark matter, could that be. Could it be the rotation
of space itself on a
galactic scale influencing the rotation
of spiral galaxies? That's my
question. Pretty difficult day. Okay, cheers.
Andrew Dunkley: Yeah, yeah. Rusty, you love asking
these curveball questions. I know. I, think you
sit there trying to figure out what to throw at
us next. this is an interesting one. We have talked about the
rotation of space time before or whether or not it does,
dark energy is always coming up. And we spoke about a
new theory on, dark matter
in our last episode. And we keep sort of cross
referencing dark matter and dark energy. But, yeah,
okay, so, does space time
rotate?
The mass of space
time, could that be dark matter?
I think I precede that too much. But anyway,
that was the guts of the question.
Professor Fred Watson: So, the energy
that the universe
contained at first, was photons. It was
electromagnetic energy, and
they then basically collapsed into
matter. So the Big Bang was very efficient at that
process. when things cooled down a bit.
when something crosses the event horizon, goes into a black
hole, it remains as matter,
even though it's now been squashed into an
infinitesimal point. so
the material
content of a black hole, is
mass. It's matter because it increases its mass.
we know that mass and energy are related by E equals MC
squared. Rusty certainly knows that.
so, I'm just,
I'm not sure I'm following the
logic there. We do know,
that, we've had
this issue with the asymmetric,
sorry, the unequal rotation of galaxies
clockwise and anti clockwise, that seem to be more one
way than the other. And that has raised the suggestion that
the universe is rotating. And it turns out if it
rotates once every 500 billion years, then
you can get rid of the Hubble tension.
I think that's the bottom line there.
And so, I mean, you
know, Rusty's points are all well made. I
don't think we get rid of dark matter and dark energy
though, by those considerations.
I think we're still stuck with puzzles that we don't
understand.
Andrew Dunkley: Yeah, I don't think he was talking about getting rid of dark
matter, but he was talking about the
mass of space time being dark matter.
Professor Fred Watson: Yeah, sorry, I'm using the wrong
words there. I'm using my words.
Andrew Dunkley: that's all right.
Professor Fred Watson: Very loosely, yes, that's right.
But dark matter, is,
you know, it's clumpy.
It's not, something that is
equal throughout the universe, which if it
was space time, it would be. I mean
space time itself doesn't have mass. It's
the fabric within which mass,
within within which it exists.
So I, think
it's an interesting suggestion, as
rusties always, are. But I'm not sure that
works out. Throwing the equation of
state there, that'll do it. Oh yes, Talking about that
last episode.
Andrew Dunkley: Yes. Oh, gosh, here we go. The
headache worthy material, this.
Professor Fred Watson: Yes, that's right.
Andrew Dunkley: when you talk about the universe and space time, like space
time, you said it doesn't have mass. It's just everything
that's in it is what's mass? Is
it strung out evenly across a,
universal plane or it's not
evenly spread
360 degrees in all directions, is it?
Professor Fred Watson: Well, it more or less is. But
you're right, it
changes from one place to another because math
matter changes the shape of space time.
so if you've got a lump of matter, then
you're distorting the space around it and yes, frame
dragging. Something, that Rusty mentioned. Frame
dragging is the way a rotating object drags
the space time around with it. But even if it's not rotating, it's
still deforming the space time around. It's how gravitational
lenses work. And so space
space time is this crinkled
pattern of
irregularity that comes from the matter
within it. And we think
what we call the cosmic web, this
entangled web of almost like a foam
of dark matter that itself has
mass and changes the shape of spacetime. That's how
we think the galaxies formed and how we think
we got the structure that we see today. but you
need mass within space time in order
to get those phenomena.
Andrew Dunkley: Gotcha. All right, thank you Rusty.
stirring the pot as always. This is
Space Nuts Andrew Dunkley here and Fred Watson
Watson just he's right next to me.
Now let's take a quick break from the show to tell
you about our sponsor Insta360
and their brand spanking new top of the line
camera. The
Insta360X5.
This is as Fred Watson would say, a beautiful
piece of kit. It's the ultimate
360 degree action camera.
And it's designed for everybody, creators,
adventurers, professionals, but even
amateurs who just want a better job. this is
the camera for you and you can capture
the world in 8K resolution.
It's got dual sensors, it's
got 72 megapixel photos for ultra
clear pictures in true to life colour.
And it's got a very powerful triple AI
chip system which will give you exceptional
image quality even in low light conditions.
It's got everything. It's also got a pure
video mode so you can just capture everything
you want. And what I love about this camera is you
don't have to point it at something to get your footage. It, it
will just film 360 degrees and then
you figure out what you want later. It's so seamless,
so easy, so simple, you know, I don't think you'd be
disappointed at all. And whether or not you
you know, ah, out on holidays or
filming something for a professional finish,
you won't have a problem with the X5.
It's got incredible durability. it
can operate in just about any circumstances
including underwater. If you break a lens you can
replace it. Just pop one out, pop one. Really
quite simple. Up to 185 minutes of battery
life. so much going for this beautiful
insta360x5 camera.
And at the moment as a space nuts listener, there's a
special deal for you. If you sign up
for an Insta360 standard package and
one of the first 30 to do so, you
will also get a little bit of a, a
present, an invisible selfie stick.
So all you have to do is go to this URL
to find out more and sign up for
the, the standard package, the
insta360x5
and you do that at
store.insta360.com
that's
store.insta360.com
and don't forget the promo code Space Nuts.
with this special deal going right now on the
standard package for the
Insta360x5 camera, that's
store.insta360.com
and use the promo code Space Nuts. We've got
all the details in our show notes.
Now back to space nuts.
Generic: 3, 2, 1.
Professor Fred Watson: Space nuts.
Andrew Dunkley: Our next question comes from Dave.
Dave's in Indiana, which is also the name
of my sister in law's cat. if you fire.
I don't know why I said that. If you fire a laser into
space, would you the emission impart a force
in the opposite direction? If not,
could a broad beam be used on a space
sail to effectively move a spacecraft?
thank you, Dave. we have talked about this
concept before. They're talking about
experiments of
spacecraft using interstellar
sails or whatever you want to call them, being pushed
along by laser. I don't know if they've
actually done it yet or maybe they've tried it
in small scales. I can't remember. We
have come across this before.
Professor Fred Watson: There was some research that
was published and we talked about it on Space Nuts probably a
couple of years ago now in fact it might even be
longer which demonstrated that a light
sail will actually provide an
acceleration to a spacecraft. I think this was using sunlight
if I remember rightly. But there's a spacecraft
that was just an experimental one. They
used a light sail. They could tilt it in
different directions and it
basically provided accelerations exactly what they
expected from the transfer of momentum
from the photons to the sail
itself. so, yes. And the answer is
yes. So there is a whole study,
Dave, looking at this,
the project is called Breakthrough Starshot.
I'm not sure whether it's still running but the
idea was to do a
feasibility study,
funded by a Russian billionaire called Yuri Milner,
under the Breakthrough Foundations,
ah, Aegis. They were basically
doing a feasibility study to see whether
you could use powerful lasers to fire
photons at a light sail and accelerate a
spacecraft to maybe half the speed of
light, maybe a little bit less, but certainly a
significant fraction of the speed of light by bombarding
it with these photons all the time. to
see whether you could get it to Alpha Centauri, or
Proxima Centauri, the nearest star to our solar system,
in a reasonable time. In other Words, you know,
decade or so, rather than the
60,000 years it would take using conventional rockets.
So it has been well looked after. So,
your idea is good
and is already, you know, already in train and
in fact has already been demonstrated by this
experiment that was, carried out in Earth orbit.
Andrew Dunkley: And if you were to fire a laser into space, there would be
no recoil, there'd be no backwash or whatever you want
to call it.
Professor Fred Watson: I think that's correct, yeah. I need to check that, but I think that
is correct, because, yes, you wouldn't want your blazer
firing off in the opposite direction.
Andrew Dunkley: It's not, it's not like firing a bullet. it
shoots from shooting light. there's no
recoil from a torch or a flashlight.
Professor Fred Watson: Well, but yes, I mean, there might be.
Yeah, I think that is correct. I think that's correct.
Andrew Dunkley: Yeah.
Professor Fred Watson: You'd never detect it in a torch anyway.
Andrew Dunkley: No, definitely not. I have just done a bit of
a search and I found a website called
planetary.org and this
is an organisation that is working
on light sail technology, through
the Planetary Society. And,
they're doing a light sail programme and they
demonstrated that solar, sailing is a
viable means of propulsion. And for small
satellites, solar sails, use
sunlight instead of rocket fuel for propulsion.
they are one of the few technologies that could be used for
interstellar travel. Their Light Sail
2 spacecraft was, in
space from June, 2019 to November
2022 and successfully used sunlight,
alone to change its orbit around Earth. So
that's probably what you were thinking of.
Professor Fred Watson: It is, yes, that's right, yeah.
Andrew Dunkley: So that's a website worth
visiting, Dave, if you want to check it out.
Planetary.org but there are
so many other stories about lightsail technology
and lots, of people giving this
very, very serious thought. So,
worth worth chasing up if you want to find out more
about it. And thank you, Dave, for the question.
Andrew Dunkley: Space nuts.
Andrew Dunkley: Now, final question is not a question at all.
Excep. It's a question that needs to
be answered. Doesn't make sense. But, Judd,
who, is in Brisbane, formerly Sydney,
the traitor. Traitor, says. G' day,
Andrew and Fred Watson. Heidi did a great job of, co hosting while
Andrew was away. It could take years for her to bring
her dad jokes to Andrew's level, though. Yes,
that's very true. you know, there's
no comparison to how bad I am. I, came
across this zinger online. He says, if
you use it, maybe Fred Watson could explain why it's funny.
that always goes down, down well with my wife. He
says.
All right, here we go. Two spinal. spinal.
Two spiral galaxies walk into a
pub. The first one goes up to the bar and asks for
two drinks, one for him and one for his friend. The
barman looks suspiciously at the second spiral
galaxy and says, I'm sorry, but I can't serve your friend.
He'll have to go. The first spiral galaxy
complains, why can't you serve him? The barman
replies, he's barred
deafening silence. Why is that,
Fuzzy?
Professor Fred Watson: I'm chuckling away to myself here.
Ho, ho, ho, ho,
ho, ho. So, it's really interesting.
There's three different, three different
uses of the word bar here. Ah,
the bar. The barman's got, and
a bar being something that prevents
you from doing something new Bard. But also,
we talk about spiral galaxies having a bar.
Andrew Dunkley: I kind of figured it was something.
Professor Fred Watson: Like that by that sort of bar. think of a chocolate bar
this time. spiral
galaxies that rather than just having
a central bulge with
spiral arms coming from them, they've got the central
bulge, but they've also got a bar across. And the spiral
arms start with the. From the ends of the bar.
indeed. Our own galaxy has one which has
been observed and measured by the Gaia spacecraft and
many others. So our galaxy has one. We sort of
look at it sideways from our vantage point, or obliquely,
if I can put it that way.
it's a, you know,
it's a phenomenon that is very common
among galaxies. We, call them barred
spirals.
Andrew Dunkley: There you are.
Professor Fred Watson: They are spirals. So your friends are bad.
Your friend's bad. That's because he's a bad spiral. Sorry,
it took a long time to get that through. No.
Andrew Dunkley: Well, it certainly required
explanation. I'm sure some people immediately went, oh, yeah, I get
it. but, others like myself would have gone, I
don't. Yeah, I'm scratching my head. although it's
prompted another dad joke. You ready for this, Judd?
so the Milky Way
can't. Here we go. Is non
alcoholic. Because it's. It's barred.
Professor Fred Watson: Yes, it's bad spiral.
Andrew Dunkley: Yeah. Terrible,
horrible joke. thanks, Judd. Oh, he had a bonus
joke. the. The bartender says, I
don't serve anyone. Faster than light,
a neutrino walks into the bar.
Why is that funny?
Professor Fred Watson: So that was when, it's a story.
It's quite an entertaining story, which we covered. This
is going back maybe even a decade, right? there
is A particle detector at Gran Sasso
in Italy, northern Italy, which
detected neutrinos that were being emitted
by the Large Hadron Collider on the French Swiss border. Now,
I remember neutrinos barely interact with anything,
so they travel through rock, cheerfully go right through the,
Earth, no problem. But the,
problem was these neutrinos
seemed to arrive at Gran Sasso,
in a time that was less than what it would
take them if they were travelling at the speed of light, which is about the
speed that they do travel. They travel very close to the speed of light.
Andrew Dunkley: Right.
Professor Fred Watson: And so, this was,
it really hit the headlines big time. Faster than
light neutrinos. And,
you know, people commented on it. There were
relativist theories, people
digging up what could be going on here. They were all
trying to think of how the theory of relativity could be
modified to accept this, to make it work.
And a few other people were saying, I bet it goes away. I bet there's something
wrong with the equipment. About a month
after that experiment had
been reported, they fessed up at Gran
Sasso that they had discovered a faulty connector.
and it was that faulty connector, that
was giving the, mistaken
impression that these neutrinos was travelling faster than the speed of
light. It's to do with their clocking. And it was
so embarrassing that the director is.
He resigned to. Resigned, yeah.
Andrew Dunkley: Wow. I mean, we've, we've talked
about certain gaffes in
science, discoveries, etc in the past, but that,
that's a, that's a big price to pay, isn't it?
Professor Fred Watson: It is, yeah. Yeah. He was, I think he felt that, he'd have
put Italy on the scientific map for the wrong
reasons because they had a faulty connector.
But it does remind me of another joke that was going
on round about the same time. This was back in 2012 when
the Higgs boson was discovered,
which I always liked. and it's very
quick. A Higgs boson walks into a bar
and. No, let me start again.
That's the wrong joke. Wrong
joke.
Andrew Dunkley: That was funny.
Professor Fred Watson: That was funny. That was good, wasn't it? A Higgs boson, a
Higgs boson walks into a church
and the priest says, I'm sorry, we don't allow Higgs
bosons into this church. And the Higgs boson said, well, how do
you have mass there, then?
Andrew Dunkley: Love it. I have heard that before.
Professor Fred Watson: Yes, I'm sure you have, yeah. Was doing the round.
Andrew Dunkley: I've got a, somewhat spacey joke because,
GPS operates using global positioning
satellites. I'm going to
buy you one of these, Fred Watson. This is, a GPS
navigation system for seniors.
Professor Fred Watson: Okay.
Andrew Dunkley: It, not only tells you where to
go, is how to get there. It tells
you why you wanted to go there in the first place.
Professor Fred Watson: Yeah, that's a good one. It probably needs to tell you where you've come
from as well and how to get back.
I'm, not quite at that stage yet. My GPS
gets used a lot and I always know why I'm going
there. Although sometimes I do wonder.
Andrew Dunkley: Well, it's reached a point where we wonder how we
dealt without.
Professor Fred Watson: It is amazing, isn't it?
Andrew Dunkley: We used to have those big, thick roadmap books in the
car.
Professor Fred Watson: Yeah. I used to have them on the passenger
seat with page markers in them so I
could, you know, when I got to that end of. End of one map,
I could turn it over and find where I was on the next.
Terribly dangerous.
Andrew Dunkley: Yeah, the way it was. You're not allowed to touch your phone
in a car, but you can read a book.
Professor Fred Watson: Yes, that's right.
Andrew Dunkley: Yes. Yeah, it's, it's. Yeah.
And, for all you young people, they used. It was made
of paper with coloured maps inside.
It was very, very.
Professor Fred Watson: Some of them anyway.
Andrew Dunkley: And in.
Professor Fred Watson: Great.
Andrew Dunkley: And instead of it following you along on your phone,
you just ran your finger along the red line.
Okay, I gotta turn left there. Yes,
all right, we're done. Fred Watson, thank you so much.
Professor Fred Watson: It's a pleasure. and we will talk again soon, I hope.
Andrew Dunkley: Yes, yes. I think I've got one more recording session before I
head off and hand over to Heidi again for a while. But,
I will be reporting in from my various
destinations around the world. So, we'll, tell you
more about that down the track. Don't forget to visit us online too,
because we need some more questions. we are desperately short, as it
turns out. Cleaning out the closet of questions
was probably a bad idea. But anyway, it got done.
SpaceNutspodcast, uh.com Space Nuts
IO is where you can send us your questions on
the AMA link, audio or text. Either
way, tell us who you are and where you're from. We love to know
that. And, Huw in the studio.
well, I think you'll know where this is going. He couldn't be with
us today because he's barred
and from. From me, Andrew
Dunkley. Thanks for your company. We'll see you on the
next episode. Goodbye.
Generic: 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 at bitesz.com This has been another
quality podcast production from
bitesz.com
Andrew Dunkley: I love getting a Wait for this one. A barb in
Professor Fred Watson: The good ones. Yes, I like that too. You should have.
Should have thrown that in somewhere.
Andrew Dunkley: Well, I haven't stopped recording yet, but I'm going to press stop now.