0:00

I'm Dr. Carl coming to you from

0:02

the lands of the Gadigal people of

0:04

the Eora nation. I acknowledge Aboriginal and

0:07

Torres Strait Islander peoples as the first

0:09

Australians and traditional custodians of the lands

0:11

where we live, learn and work. G'day

0:15

Dr. Carl, with part two of the standard model with

0:17

Professor Geraint Lewis. Good morning Carl, how are you? We've

0:20

sort of started off with atoms

0:22

which turn out can be cut.

0:25

We're now heading into quarks. So

0:28

the last thing you said was that electrons

0:32

are points, as far as we know,

0:34

but the protons and the neutrons are

0:36

not points. So they've got these

0:39

things called quarks in them. Yes. I

0:42

remember on one occasion you fixed up

0:44

one of my mini errors and let me thank

0:46

you for being so kind because I foolishly thought

0:49

that a proton was

0:51

what you got when you had a

0:53

neutron and you just shoved an electron

0:55

into it. Somehow the charges

0:57

cancel each other out. There's a slight increase

0:59

in mass and therefore you had this thing

1:01

which was just a neutron

1:04

and electron mushed together. And I

1:06

kind of thought there was an actual physical

1:09

electron there, but there

1:11

isn't. No. Tell

1:13

me how wrong I was so the audience

1:15

can appreciate this. You were quite wrong, but

1:17

you weren't the first person to have that

1:19

idea that a neutron is just a proton

1:21

with an electron inside because you

1:24

add those charges, they cancel and you get

1:26

something slightly more massive. People

1:28

have thought that in the past, but

1:30

there's no electron inside there. There's no

1:32

electron inside. A neutron does decay. So

1:35

a neutron does break down into

1:37

a proton, an electron

1:39

and another particle, which we haven't

1:41

mentioned yet called the neutrino. The

1:44

electron and the neutrino were not inside

1:47

the neutron before it decayed. They were

1:49

created as part of the decay process.

2:00

things. As long as you obey

2:02

the quantum electron

2:05

runs into the neutron, we're talking about a

2:07

free neutron decaying here, one just out in

2:10

space in an empty universe by itself, not

2:12

one in the middle of an atom somewhere.

2:14

You then create this neutron by running the

2:17

electron into a proton, but the electron and

2:19

proton no longer exists. There's something different that

2:21

we call the neutron. They're not magically buried

2:23

inside it that you pull out with a

2:26

set of tweezers. If you

2:28

take a proton and you fire an electron

2:30

into it, then one thing that

2:32

could happen is that one of the quarks

2:35

interacts with the electron and gets switched into

2:37

a down quark. So you've gone from

2:40

two ups and a down, which is a proton, to

2:42

two downs and an up, which is a neutron. But

2:45

the electron no longer exists. As part of

2:47

that process of changing the up to a

2:49

down, it vanishes.

2:52

Have we ever isolated

2:54

a free quark? Is it possible?

2:57

No. You mentioned previously about

2:59

Weinberg and the Standard Model. Yeah.

3:01

So let me just explain

3:03

where things started to go awry. Okay.

3:06

Oh, yeah. Okay. Everybody

3:08

was kind of happy with the

3:10

notion that you've got protons, neutrons,

3:13

and electrons, and they made up

3:15

stuff. But then

3:17

something was discovered and it

3:19

upset people. They discovered an

3:22

electron, except it

3:24

wasn't an electron. It

3:26

was a fat version of the electron. The

3:29

new one. All the

3:31

properties of an electron, except it was

3:33

just more massive. And it's

3:35

like, why? Why

3:37

is there this extra thing in the

3:39

universe, which don't exist very long after

3:42

about a millionth of a second, they

3:44

break down into electrons? So

3:46

why are they there? We don't need them to explain

3:48

the periodic table and this kind of thing. So

3:51

I think Rabi was one of the

3:53

physicists. Who ordered that? That's

3:56

not needed for anything. It just mucks up things,

3:58

get rid of it. Yeah. Okay. There's

4:00

already this realization that maybe this

4:02

picture of the electron, the proton,

4:04

the neutron, wasn't complete. But

4:07

things got really weird when

4:09

people started building particle accelerators. So

4:11

you have a particle accelerator, you

4:13

crash things together, things get spat

4:15

out, lots of different particles. And

4:17

before you knew it, as

4:20

well as the proton and the

4:22

neutron, there were other particles appearing.

4:25

Particles with more mass, particles with

4:27

more charge. One that I love

4:29

is called the delta plus plus

4:31

particle, which is like a big

4:34

proton, but with two charges on

4:36

it. Who are that? Exactly. And

4:39

so into the 1960s, there was this

4:41

zoo. And what people said

4:43

is that, you know what, this is

4:45

starting to look like that situation we had with

4:47

the periodic table. All

4:49

these different particles, and people

4:52

were getting Nobel Prizes for discovering the

4:54

next particle, and everyone was just going,

4:56

but it doesn't make any sense. Why

4:59

are there all these particles? So the question

5:01

was, is

5:03

there underlying simplicity? Can

5:06

we simplify what's being spat

5:08

out? And there was a realization

5:11

that you can't simplify

5:13

all these particles by just having

5:16

an up quark and a down quark. Because

5:18

there's only so many ways that you can arrange

5:20

that, right? You can have three ups, two

5:23

ups and a down, two downs and a up, and

5:26

three downs. And so people said, oh, what

5:29

if we add in another quark? What

5:32

if we hypothesize there's a quark called

5:35

strange? So

5:37

you can have an up, up strange,

5:39

an up down strange, a strange, strange

5:41

down, et cetera. And people realized that

5:44

you could start to do

5:46

what mostly had done, but now

5:48

by having quarks mixed together

5:50

to give us

5:53

what we saw coming out of the

5:55

Large Hadron Collider and similar colliders. And

5:58

what was discovered is that we can't do it. that

6:00

you need six different types

6:02

of quark, up,

6:04

down, strange, charm

6:08

and then, depending

6:10

on who you are, either top and

6:12

bottom or truth and beauty.

6:15

Now I prefer truth and beauty because that

6:17

comes from a Keats poem, which is so

6:19

it's nice, top and bottom are just boring,

6:22

right? With those six, you can imagine how

6:24

many different ways there are to arrange six

6:27

quarks together in groups

6:29

of three and there's another kind of particle,

6:31

the baryons that come in groups of three,

6:34

but then there's also these things called mesons which

6:36

come in groups of two and you

6:39

could suddenly explain all of these different

6:41

particles by just requiring

6:44

six different types of

6:46

quark. As you work

6:48

your way across from up, down, charm,

6:50

strange and truth and beauty, do

6:52

they get heavier as you go across? They do.

6:55

So this is one of the weird things. Up,

6:57

down and charm and

7:00

strange look very similar kinds of

7:02

particles. So the charm has a

7:04

charge of two thirds, strange

7:07

is a charge of minus one third, so

7:09

that matches the up and the

7:11

down, but they're heavier and

7:13

it's the same with truth and beauty,

7:16

top and bottom, is that they are

7:18

heavier again. So there

7:20

appears to be what people

7:23

call three generations of quarks.

7:25

Successively getting heavier? Successively getting

7:27

heavier, up, down, charm,

7:30

strange, truth, beauty. We'd

7:33

also seen that for the electron

7:36

there was a heavier electron, the

7:38

muon, which seems to be in

7:40

that second layer. Second generation equivalent?

7:43

Yeah. Was there a third generation

7:45

equivalent? There is. There is a

7:47

really chubby electron called the tauon.

7:50

Can we call them fundamental? Nine

7:52

fundamental particles, the six quarks and

7:55

the three electron variants? The

7:57

family name for the electrons.

8:00

are the leptons. Is

8:03

there anybody else in the lepton family besides

8:05

the electron, the heavy electron and the

8:07

really really heavy electron? Yes, there

8:10

are three neutrinos. I

8:13

love neutrinos but I don't understand them

8:15

and I love that they can go

8:17

through light years of lead and just,

8:20

it's nothing to them. Is that true?

8:22

Yeah, yeah, well that's very true. They're

8:24

stranger than that. So there are three

8:26

kinds of neutrino. There's an electron neutrino,

8:29

a muon neutrino and a

8:31

tau neutrino. And they go

8:33

up in mass as well but they've got barely

8:36

any mass, barely any. They're

8:39

the lightest particles other than things

8:41

like photons that have no mass

8:43

at all. Neutrinos have

8:46

next to nothing. Do they have a charge?

8:49

They carry no charge which is one of the

8:51

reasons that they can go through light years of

8:53

lead. They don't bounce off

8:55

atoms or anything. They can only

8:57

interact via one

8:59

of the fundamental forces, the weak force.

9:02

Yeah, they just happily stream through most of

9:04

the universe. I do

9:06

love to dream of a universe where everything

9:08

is made to a major degree from neutrinos

9:10

and this alternate universe exists around us but

9:13

we can't see it because it's so flimsy.

9:15

Rather, we are flimsy to them. They just

9:17

stream through us and we can write a

9:19

science fiction story so is there something weird

9:22

that they actually change or something? They travel

9:24

a lot? They do. This is one of

9:26

the weird things. It's a

9:28

thing called neutrino mixing and

9:30

neutrino can change its identity

9:33

as it travels. It

9:35

could be created as

9:37

an electron neutrino but

9:40

through its own sort of self-interaction it

9:42

can flip into a muon neutrino

9:45

or flip into a tau neutrino

9:47

and then flip back to an electron neutrino. I can

9:49

understand that it might flip one way so it's probably

9:51

going down an energy hill driving that. How can it

9:53

flip back again? Where are you getting the energy from

9:55

to make it go both ways? It's a good idea.

9:57

It's a good idea. It's a good idea. It's a good idea. in

10:00

motion, it's got that kind of energy. Nutrino

10:03

mix-in is one of those

10:05

really serial things that

10:07

neutrinos can do. We know

10:09

they do it because we know that

10:12

all of the neutrinos that we see

10:14

in the sun, that are created in

10:16

the sun, and for every nuclear reaction

10:18

produces a neutrino, they are all electron

10:20

neutrinos. But when the neutrinos

10:22

arrive at Earth, there's only

10:25

a third of the number that we expect

10:27

because they've just transitioned

10:30

and transformed into muon neutrinos

10:32

and town neutrinos, etc. They

10:35

definitely sort of morph from one

10:37

kind into another. And I was

10:39

reading a book by Renee James,

10:41

an astronomer in Texas, a thing

10:43

called Things Go Bump In The

10:45

Dark, and she's saying in some

10:47

cases, neutrinos from, say, a supernova

10:50

can arrive at Earth before

10:52

the photons do? Yes.

10:55

That's weird. I thought the photons held the

10:57

speed limit. Yeah, that was the speed of

10:59

light. Neutrinos were just a fraction slower. Yeah,

11:02

because you've got to think about the physics

11:04

of a dying star. You've got

11:06

a big star, and when it dies, it collapses.

11:09

It crushes down itself and crushes down

11:11

and crushes down. And in that crushing,

11:14

it produces a huge amount of

11:16

energy through nuclear reactions. So

11:18

those nuclear reactions release photons

11:21

and they release neutrinos. They're

11:24

both created at exactly the same time.

11:27

Now, as you already said, neutrinos can

11:29

happily skip through a million light years

11:31

of lead without worrying. So

11:34

the neutrinos can escape from

11:36

this star straight away. So they just run

11:39

straight to the edge and get

11:41

out. Now, the light travels

11:44

a tiny fraction of a millimeter

11:46

before it bounces off an atom

11:48

because the density is so high

11:50

and the light bounces around and

11:52

bounces around until the exploding star

11:54

has thinned out enough for it

11:56

to escape. They created

11:58

it exactly the same time. I'm. But.

12:01

The neutrinos get a head start because

12:03

to them when they created the star

12:05

doesn't exist. But to

12:07

the photo amongst, they stuck until the density

12:09

is low enough that they can stream out

12:11

of the star. Is a lot

12:14

years of lead to stop a neutrino had

12:16

used to take some. Well. I would

12:18

love to say to we have like years

12:20

of lead but we don't You send the

12:22

same what what you need to do is

12:24

you need to have. A lot

12:26

of target. As the

12:28

normally the targets that you do

12:31

is you either have a like a

12:33

big vat of very pure water in

12:35

the dark. This one of the same

12:38

sex marriage was done back in their

12:40

fifties and sixties but this a single

12:42

super cameo kinda in Japan is under

12:45

ground tank immense I'd hundred meters

12:47

across as something filled with water and

12:49

photo diodes round the side. Then in

12:51

Antarctica does this thing called ice cube

12:54

where they didn't build of tend to

12:56

just drill these holes down. Into

12:58

the ice and lower these folks to detect

13:01

is what happens is. You

13:03

have a hundred trillion trillion

13:05

trillion trillion trillion trillion neutrinos

13:08

stream through experiment. And.

13:10

They all rushed through. That

13:12

owning see the experiments that. But

13:15

his chance? any chance that one of

13:17

them will interact with an atom, it'll

13:19

knock an electron off the atom the

13:22

most. them don't see a for one

13:24

am gets close enough. they hits and

13:26

electron like some gets the energy and

13:29

gets shot off at high speed. Traveling.

13:32

Faster than the speed of light

13:34

in the water. You.

13:36

Know what happens if you do that

13:38

and she was. You send an electron

13:40

through water the faster the speed of

13:42

light in the water. Sharon cough radiation

13:45

levels of radiation. Yes you produce a

13:47

flash of light and that flash of

13:49

light is picked up by the photo

13:51

detectors At this is a beautiful thing.

13:53

The flash as you can imagine is

13:55

made by high energy particle. Come in

13:57

in. The. Flash goes out.

14:00

I've been from a torch and so they

14:02

see a cone of light. Light.

14:05

Up in that tank, only fritz know

14:07

at the smallest fraction of a second.

14:10

And they just so oh. Neutrino. Detected.

14:13

It is a pretty cool experiments. Getting

14:16

back to. Twelve.

14:18

Can we call on particles that make up

14:20

what we call. Matter. The

14:22

three generations. As a

14:24

critically heavy a clocks and as

14:27

three generations the So the seats

14:29

are up down. Tab. Strange.

14:32

And Tuesday. And in the three

14:34

generations of the Lipton's increasingly getting heavier,

14:36

the electrons, the Muir home and in

14:39

the towel and then the electron neutrino

14:41

of that received. If you're neutrinos as

14:43

the tell you to assert best twelve

14:45

right it will have to twelve is

14:48

like have a cold particles a circle

14:50

of something else. yeah yeah everyone else

14:52

cause of particles but so romantic era

14:54

likes of it is in your other

14:57

half when you an astronomer aussie oh

14:59

he's is astronomer and will sit around

15:01

a campfire as somewhere expenses. And look

15:03

wistfully into the sky and sink of

15:06

wonderful things. But when he say particle

15:08

physics of Ziggy. Far. As go

15:10

Dust pan the city of a

15:12

bit of did as a very

15:14

romantic so look I already mentioned,

15:16

Keeps Keeps accused Newton Olds and

15:19

We've in the Rainbow didn't describe

15:21

the rainbow as a young. Some

15:23

like going through water droplets in

15:25

the atmosphere and that ruined the

15:27

romantic description of the rainbow for

15:29

Keats that that's why Keeps writes

15:31

poetry and that Newton didn't. The.

15:34

More I look at Sizemore think this

15:36

is beautiful and has his own ancestry.

15:38

Oh absolutely it would have done the.

15:41

Matter. Particles. That's.

15:44

Six for six Clarkson lived

15:46

on and in there are

15:48

other size source carriers. Both.

15:51

Zones as is a cynical bows on saw this

15:53

it is is a says on a bus yes.

15:56

The. sultan which is involved as

15:58

any gods z weak

16:00

nuclear force bosons and then the gluon

16:02

and the Higgs boson. This

16:05

is a zoo of, tell me where to start.

16:07

Take me through it. Assume I know nothing. The

16:09

particles that you've said are particles of matter. The

16:12

question is how do you stick them together

16:14

and how do they interact with each other?

16:16

And that's where the bosons come in. So

16:19

the, the bosons are the force

16:21

carriers. What we mean by that is, you

16:24

know, in Newtonian picture of forces, you

16:26

push on something forces in

16:28

the quantum world occur when you exchange

16:31

particles and the electromagnetic

16:33

force is carried

16:36

by the photon. Think of two electrons,

16:38

Carl. They're both negatively charged. In your

16:41

classical picture, you'd sort of say, oh,

16:43

they're negatively charged. So they repel each

16:45

other. So they push each other away.

16:48

When you go to the quantum picture,

16:50

they do repel each other, but that

16:52

repulsion is carried from one

16:55

electron to the other by the

16:57

photon. So the photons involved in

16:59

static electricity. Yeah. Yeah. In the

17:01

quantum level. Yep. The photon is

17:03

it's, it's called a force mediator.

17:05

It carries the force. And so

17:07

it carries electromagnetism and

17:09

then you've got to have similar particles for

17:12

the other forces. So the,

17:14

the easy one, what's known as the

17:16

strong force that occurs inside the proton

17:18

and neutron, and it's also a glues,

17:20

the protons and neutrons together. And that's

17:23

called the gluon. And

17:26

then the weak force has to

17:28

be odd. The weak

17:30

force has three particles. It

17:32

has two W's, a W plus

17:34

and a W minus and

17:37

a Z zero particle. And

17:39

they tend to be very massive particles. The

17:43

weak force is really

17:45

responsible for an aspect of

17:47

radioactivity. It's a weak

17:49

force that takes the neutron and allows it

17:52

to decay into the proton. Is

17:54

that important? Well, it is if you're a

17:56

neutron. Right. And I'm guessing in some ways

17:59

fundamental to. The Workings of

18:01

the Universe. Dre of haven't thought about the

18:03

weak force. it doesn't get much publicity of.

18:05

I have heard about the Social On, but

18:07

I haven't heard about the weak force. Actually,

18:09

the weak force is a throttle. Inside

18:12

the Sun that controls the

18:14

rate at which nuclear energy

18:16

is released. Are now

18:18

we're talking important Yeah ah. Iraq has

18:21

something called the deuterium bottleneck and it

18:23

slows down the rate at which the

18:25

sun burns. It's fuel. I'll take his

18:28

the whole fundamental error of those belt

18:30

which I need to learn I guess.

18:32

Oh it. With were hitting through our

18:34

standard model and we've got the So

18:37

on and then we got the week

18:39

use of force, the W plus w

18:41

modest and doesn't know what and in

18:44

their the gluons. Plural

18:46

is more than one. Yes, there

18:48

are eight different gluons operated, so

18:50

they have very similar properties. But

18:52

the way that they interact with

18:55

the clocks and some data particles

18:57

is subtly different. but you can

18:59

just take it the city glue

19:01

on as a. Catch

19:03

all name for them for an

19:05

he said eight Clausewitz is six

19:07

tops of kwok yes because glue

19:09

on of related to something at

19:11

that and know this is going

19:13

to open up a new can

19:15

of worms called color. Oh god

19:17

I awesome. There's a quantum number

19:19

called color which is either red

19:21

or green or blue. It's got

19:23

nothing to do with red, Green

19:25

or blue. Would you make a

19:27

particle? The next color has to

19:29

be white says to be a

19:31

red particle a green. Particle and of

19:34

blue particle or rate and on T

19:36

rex. The. Said with you make a

19:38

particle and did Color has to be white.

19:41

Yes, Imagine your proton.

19:44

You've. Got three clocks in there to

19:46

up costs and down clock. So for

19:48

those three clocks one of the clock

19:50

says read. One. Of them is. Green.

19:53

The other is blue. The. color charge

19:56

as it's known is zero

19:58

it's it's white I

20:00

should have realised that you were opening a

20:02

can of worms or a box of frogs

20:04

as we like to say in Australia when

20:06

you said the numbers of these colours are,

20:08

instead of giving numbers you gave me colours

20:10

of the rainbow. Yes. I'm

20:12

guessing that when an electron runs into

20:15

a positive proton then things are happening

20:17

to the quarks and the gluons are

20:19

deeply, deeply involved at a level that

20:22

is like second or third or fourth

20:24

the aesophysics? The answer is yes. Think

20:27

about it this way. The electron

20:29

approaches a proton. Yes. Okay.

20:33

So the electron and one

20:35

of the up quarks

20:37

inside the proton, they

20:40

have a little conversation and they

20:42

agree that they're going to exchange

20:45

a W boson. They

20:47

exchange the W boson and

20:50

so if you imagine the electron emits a

20:52

W boson and in the act of emitting

20:54

that W boson it gets

20:56

changed into a neutrino. That's

20:58

what happens. The W

21:01

boson then goes to the up

21:03

quark and when it arrives it

21:05

flips the up quark into a down quark.

21:07

So it turns the proton into a neutron

21:10

and then a neutrino is sent off

21:12

into the universe. Apparently

21:15

they thought that we would never be able

21:17

to detect neutrinos in the same way we

21:19

would never be able to detect gravitational waves

21:22

and they were wrong in each case. Is

21:24

that correct? So the person that proposed the

21:26

neutrino first of all was Wolfgang Pauli. He

21:29

wrote this paper because the problem

21:32

was again radioactivity, you

21:34

know, beta decay when atoms spit out

21:36

electrons from their nucleus. All

21:38

of the experiments were done. People were measuring accurately

21:40

the speeds of electrons that were

21:42

being spat out and they were coming out

21:45

at different speeds and that shouldn't

21:47

be the case. If it was

21:49

only the electron being spat out, it must be

21:51

the same in each case. So why was some

21:53

coming out slower than others? Pauli

21:55

said there are two options. Either

21:58

energy is not conserved. or

22:02

there's an invisible particle which is carrying

22:04

away the energy. So

22:06

he proposed that there was this thing

22:08

called the neutrino and he apologized because

22:10

he said, oh, I've invented something which

22:12

will never be detected. In

22:14

the 1950s people realised that if you

22:17

build a target big enough, enough targets

22:19

in there, eventually you will see one

22:21

or two of these neutrinos. Now

22:24

let's get our last bows on. The

22:26

bearing in mind we haven't done these in any

22:28

depth at all and I still don't know enough

22:30

about gluons and the weak force, the Higgs bows

22:32

on. Tell me how wrong I am

22:34

in my understanding. You physically have volume and

22:36

we kind of understand that when you put

22:38

your foot into a bathtub full of water,

22:40

it flows out, it alchemides and you have

22:42

optical properties like light lands on you and

22:44

some is absorbed and some is affected, we

22:46

kind of understand that and you have a

22:48

property called mass and my

22:51

very primitive understanding is that mass

22:53

is somehow conferred upon you, whatever

22:55

you are, via the Higgs

22:57

bows on. Tell me how wrong I am. Pretty

23:00

wrong. Good. Thank God.

23:02

So the important thing for your mass is

23:04

not the Higgs bows on, it's the Higgs

23:06

field. Okay. The

23:09

idea that was proposed back in the 50s and

23:11

60s is that the universe is filled with this

23:13

energy which is known as the Higgs field. You

23:16

can think of the Higgs field a bit like

23:18

treacle. The fundamental

23:20

particles feel that treacle.

23:23

Some of them do. The photon doesn't feel it.

23:25

The photon doesn't have mass so

23:27

it doesn't feel it. All the

23:29

other particles do. So what that means is

23:31

that they have this property that if you

23:33

push on them, there is a resistance to

23:35

that push, inertia, right? Why is it easier

23:37

to push a mouse than an elephant? So

23:40

it's the Higgs field that

23:43

provides that mass

23:46

to fundamental particles. The

23:49

Higgs bows on is

23:51

a ripple in the Higgs field.

23:54

The Higgs bows on is a

23:57

ripple in the Higgs field. Yes.

24:00

came across this a while ago, you told me before that we

24:02

can think about mass particles

24:04

as just being ripples in a

24:06

field. I'm liking that.

24:08

Absolutely. If you want to understand

24:10

how that works, you need to

24:13

go to Archill's fourth year course

24:15

on quantum field theory. It

24:17

takes three years of university undergraduate to get you ready

24:19

to do the course where that is sort of explained.

24:22

So we shouldn't try to explain it in a trivial way

24:24

because it's not trivial. But

24:26

yes, everything is represented by fields

24:29

and particles are ripples in those

24:32

fields. So as we come to

24:34

the end here, I'm beginning to realise that

24:36

while in my own brain I have slightly

24:38

increased the ball of knowledge

24:40

I have, that ball has got bigger and

24:43

it interacts with everything I don't know, which

24:45

because it's got more surface areas, there's more

24:47

things I don't know than a little bit

24:50

before. But that's fine. That's my day. I've

24:54

been a professional physicist for

24:56

30 years or something like

25:00

that. Every day it's just like there is

25:02

more that I need to learn. Thank

25:04

you so much for taking us on this little

25:06

hint of a guided tour. A pleasure, Carl. Happy to

25:08

chat. One last thing before we say goodbye. Have

25:10

you got any books out because I haven't? Well,

25:13

I've still got my usual books out.

25:15

So I have A Fortunate Universe, Cosmic

25:17

Revolution's handbook and Where Did the Universe

25:19

Come From and Other Cosmic Questions. If

25:21

I can pull my finger out, I'm trying to get

25:24

to work on two books at the moment. Hopefully in

25:26

a year maybe at least one of them will appear.

25:28

And with a bit of luck I'll get

25:31

through my autobiography trying to find interesting things

25:33

in the desert that is my life. I'm

25:35

sure it'll be a wonderful read, Carl. Shirtloads

25:37

of science is washed, spun and aired by

25:40

the University of Sydney.