0:00

This is a Triple J Podcast. Hello,

0:02

welcome back to another week of Science

0:04

with Dr Karl. This week we talked

0:06

about genetic modification in the womb. Could

0:08

it happen? Where is our

0:10

memory stored? And Dr Karl reveals

0:12

the best way to open up a jar or

0:15

a bottle. Hang out for that. I'm

0:17

Lucy Smith, let's get into it. What's

0:21

something you've learnt this week? That

0:25

there's a new microphone. Could this also

0:27

impact the world of music? Well, what

0:30

we did as humans, we just simply

0:32

followed evolution and looked at the human thinking,

0:34

hey, we're perfect, and the eardrum is really

0:36

nice. And when you're listening to the quietest

0:38

noise you can possibly hear, your eardrum is

0:41

moving back and forth the distance of a

0:43

hydrogen atom. Okay, so it's pretty sensitive. But

0:45

it's got a frequency response from 20 cycles a

0:47

second, up to about 20,000. Now,

0:52

we went looking elsewhere, and it turns

0:54

out that some spiders, they, here comes

0:56

a weird phrase, they outsource their hearing.

1:00

To who? To their web. So

1:02

your hearing happens inside your body.

1:05

So they make this web, they rest their

1:07

feet delicately on the web and the air

1:09

doesn't get stopped. So when the air goes

1:11

into your eardrum, it just stops. It's

1:13

not going nowhere. But the air

1:15

flows gently past the spider

1:18

web in part some energy to it.

1:20

And apparently they built one. And instead

1:22

of using spider web, which I just

1:24

love to piece, because spider

1:26

web is stronger than steel, weight

1:29

for weight and size for size. And yet it's made

1:31

from organic chemicals at room temperature. There's

1:33

none of this blast furnace stuff, right? And so

1:35

I love spider web and they couldn't use spider

1:37

web. So they used bits of silicon, one tenth

1:40

of the thickness of the human hair, the frequency

1:42

response, forget 20 to 20,000, one

1:45

to 50,000. Now,

1:48

the thing is that it gives

1:50

a very good, accurate representation of

1:52

what's out there, but it's

1:54

not particularly, it's not picking

1:56

up a lot of energy. So you'd need big amplifiers, but

1:59

they've just started using. In 10 years,

2:01

we might have completely different microphones.

2:03

Wow. Using this synthetic... Spider,

2:06

following the example of spider, it's called biomimicry. You

2:08

look around the world and you see what evolution

2:10

has done for you and you go, hey, that's

2:12

pretty cool. Wouldn't have thought of that. And then

2:14

off you go and you do it. That

2:16

is incredible. Yeah. Okay. No,

2:20

no, no, no, no. I have a huge,

2:22

terrifying, disabling fear of spiders there. I basically

2:24

turn into boiled spaghetti. That's how much structural

2:26

integrity I've got. And I can do his

2:28

lie on the floor like a jellyfish saying,

2:31

Mary, why can't you go to the

2:33

first moment? But at least

2:35

the webs are doing something good. Hey,

2:38

speaking of evolution, we've got a question here from

2:40

Jack in Hawkesbury. Jack, what do you want to

2:42

know? Welcome. Yeah.

2:45

G'day, doctors. How are you going?

2:47

Good. Oh, welcome. Yeah.

2:50

My question is, I'm wondering how an animal that doesn't have

2:52

wings, like a dinosaur, can turn into a bird that flies.

2:55

Obviously, I know through natural selection,

2:57

sort of a monkey

2:59

might get bigger thumbs so it can grab

3:03

onto branches better and stuff,

3:05

but I'm just wondering how they

3:07

can just get a different body part. Oh, yeah.

3:10

So, well, firstly, birds are dinosaurs. Yeah.

3:13

Yeah. The birds are dinosaurs that didn't

3:15

die out and we don't know why. And

3:17

you say, oh, because they can fly when the big rock happened 65 million

3:20

years ago. Sure. They can

3:22

fly. So, how come crocodiles

3:24

and alligators, which are not dinosaurs, they're different,

3:26

they're reptiles, they got their legs out to

3:28

the side instead of straight underneath, how come

3:30

they didn't die? That's a mystery.

3:33

Getting back to what was happening. So, the thing is

3:35

called X-adaptation,

3:38

not just ordinary insemination. So, we'll go to

3:40

it. So, also, nature started

3:42

off with life on the planet about 4.5

3:44

billion years ago. And

3:48

from about 4.5 billion years... Sorry, 3.8

3:50

billion years ago. From 3.8

3:52

to about 1 billion years ago, all

3:54

life that we know of was just

3:57

single-celled creatures and roughly about a

3:59

billion years ago. still in the

4:01

oceans. We went to multi-celled creatures like you

4:03

and I, have 37 trillion cells on average

4:05

for your lung and your heart and your

4:07

liver and all those different things that we

4:09

do and see

4:11

as you go from a single-celled creature

4:13

to a multi-celled creature you're

4:16

in an environment where you want

4:18

to live and so different creatures

4:20

went down different pathways by

4:23

purely by chance like the roll of the

4:25

dice so some could survive better in

4:27

very salty in less salty

4:30

in hotter colder more oxygen

4:32

less oxygen and they try

4:34

to find different ecological niches

4:37

going specifically to feathers feathers

4:39

are really cool

4:41

for a really good for

4:43

insulation and then

4:45

later we think that they then

4:48

evolve for gliding and flying and

4:51

there's quite a few creatures

4:53

that do flying such as

4:55

birds besides

4:58

birds you've got spiders so

5:00

spiders on a day when the electrical

5:02

field is high they will extrude

5:05

a thread and they'll fly and

5:07

Charles Darwin was about 200 kilometers

5:09

out to sea when suddenly their

5:11

ship got invaded by flying spiders

5:13

that flew on these strands of

5:15

thread and they also have certain

5:18

mammals with floppy skin

5:20

that'll sort of fly from here to there so

5:23

it's firstly evolution trying to fit into

5:25

every ecological niche followed by the fancy

5:27

word of X adaptation where something that

5:30

was good for one thing like insulation

5:32

wow it's really light and strong maybe

5:34

I can glide with it and then

5:36

gradually then build up the muscles and

5:39

you can see over a period of

5:41

time the breast muscle coming forward so

5:43

you're familiar with you pump iron yeah

5:47

so you know about the pectoralis muscles right

5:49

yeah now what for a P what your

5:52

pectoralis muscles do is you put your arms

5:54

out to your side they pull your arms

5:56

forward so you can clap your hands together

5:58

in front of you now imagine So

12:00

the amount you fall is balanced

12:03

by moving across the surface of the round object,

12:05

the sun, and it curves away from you

12:07

by the distance you fall, so you always say the same distance

12:09

away. In the case of the Earth, about 150 million kilometres. Did

12:13

I leave anything out? Yeah,

12:15

right. No, you go pretty good. Yeah. So we're

12:18

just falling sideways as we're falling into it as well.

12:21

Yeah, we're travelling sideways and we're always falling.

12:23

And so here's a very handy hint, which

12:25

I actually tried once. So I

12:28

decided to try and invent levitation. So

12:30

what you do is you stand on a chair and you jump

12:32

off and you miss the ground. That's

12:35

the bit I can't do. But if you miss the ground,

12:37

you will be able to levitate. I've tried it for about

12:39

half a day. I've managed to convince my little nieces into

12:41

it. And they

12:45

can't levitate either. They keep on hitting the ground. We've

12:49

got Paul in Brisbane. Paul, what's your

12:52

question? Good morning. Good morning.

12:54

Good morning, doctors. I've

12:57

got a question about train travel. You

12:59

can picture two people facing each other

13:02

in a train heading from

13:04

Brisbane South into the city. Yep. And

13:07

my back is towards the direction of

13:09

travel. And we're actually travelling forwards or

13:11

backwards. Whoa. It

13:13

all depends on where you have, and this

13:15

is a very fancy term in physics, and

13:17

you have come across a very deep problem.

13:21

What is your inertial frame of

13:23

reference? So

13:26

Galileo is the first one to come across this

13:28

whole relativity thing when he's sitting in a ship

13:30

below decks and is sitting in a

13:33

bay and it's not moving anywhere because there's no

13:35

wind. He's working away doing stuff,

13:37

sciencey things. And then suddenly he looks up out

13:40

the window and he notices they're moving very slowly,

13:42

but they're moving and he has no idea. And

13:46

so he suddenly came up with the

13:48

idea that constant velocity is in

13:51

some ways, in terms

13:53

of what it does to your body, the same

13:55

as no velocity. You're not being pushed backwards or

13:57

forwards or left or right, and that started the

13:59

whole inertial frame. of reference, relativity,

14:01

etc. So your

14:04

body as a whole is

14:06

moving forward relative to where

14:08

you started and where you want to end

14:11

up, but with regard to the frame of

14:13

reference of your eyeballs, you are moving backward.

14:16

So both are true at the same time. So

14:19

it's often very handy to look at it from

14:21

different frames of reference and you can do the

14:23

thing of looking at another train

14:25

beside you and say, or your own train,

14:27

when does a station arrive at this train?

14:29

Your station and the earth is moving around

14:32

you because you are the most important thing.

14:34

So if you want to play with this

14:36

a bit more, check up Inertial Frame of

14:38

Reference on Wikipedia. That's deep. Okay. So the

14:41

other person that I'm facing, they're facing

14:43

forwards. Are they travelling forwards or

14:45

backwards? Once again, the whole thing. Same

14:47

thing. Yeah, and it all depends which way the

14:49

blood is pumping because at some stage the blood

14:51

will be pumping in the direction of travel away

14:53

from the direction of travel. There's many frames of

14:56

reference. This is a really good

14:58

topic to understand the universe around you on.

15:01

Okay. I've got some homework to do. Thanks

15:04

Paul. We got Amy here from Hall's

15:06

Gab. Amy, you tried

15:08

a bit of an experiment last night. What was it? Hi.

15:12

I was having a fire last night with some friends

15:14

and we cooked some potatoes on the fire and then

15:16

I burned the roof of my mouth really bad. Oh,

15:18

I hate that. I'm going to ruin that. So

15:21

I got some ice cubes. I was putting some ice cubes on

15:24

the roof of my mouth and then had

15:26

too many. And they're just like the standard ice cubes

15:28

you've got in your freezer at home, the little square

15:30

ones. And so I put

15:33

one on the log in the fire thinking

15:35

it would just immediately melt away and it

15:38

held its shape for 10 minutes and we were just

15:40

sitting on the log in the

15:42

fire surrounded by flames. Why

15:44

was it not melting? Ah, heat

15:46

can transfer by three main ways or

15:49

energy in general because heat is energy.

15:52

Conduction, convection and radiation. So

15:55

conduction, imagine you've got a

15:57

long, very long teaspoon. maybe

16:00

a very, very long one, and you put in

16:02

the end of the fire and

16:04

that end gets hot and the other end is cold.

16:06

And after a little while, the end that you've got

16:08

gets hot. And so the

16:10

heat energy has transferred along, making

16:12

the molecules move faster, and we

16:15

call that heat. So that's conduction.

16:17

Convection, you see that in the

16:19

stove when you're boiling water

16:21

and the water rises in the middle. So

16:23

the physically hot lump of water rises to

16:25

the surface. Once it gets

16:28

to the middle of the surface, it goes to

16:30

the outside because it's being pushed from underneath and

16:32

from behind, hits the wall, it goes down, and

16:34

it goes around and around. And then radiation, that's

16:36

how energy gets to us from the sun and

16:40

doesn't interact with matter in between because there is no

16:42

matter in between. There's another

16:44

factor in there called the leaden frost phenomenon.

16:47

And you can do this with an ice

16:49

cube, and if you heat your cast-iron fry

16:51

pan to the right temperature, you can put

16:53

the ice cube on the fry pan

16:56

and it will have a layer of

16:58

steam underneath it. Now, the steam is

17:00

very hot, but it is

17:02

not very good at transferring heat. And

17:05

so it'll skate around on top of the

17:07

fry pan for ages. When I'm talking about

17:09

it, not very good at transferring heat, think

17:12

about you get up on a cold morning

17:15

and you're on your cold carpet, which

17:17

is a 12-degree C because

17:19

it's been a very cold night, and

17:22

you don't feel cold at all because the carpet

17:24

is not very good at taking heat, the transferring

17:26

heat is a bit of an insulator. You walk

17:28

onto the tiles, which are at the same temperature,

17:30

a 12-degree C, and they're very good at transferring

17:32

the heat. So you've

17:34

got a bunch of phenomenon

17:36

acting there. Were there direct

17:38

flames licking onto the ice

17:40

cube? No, probably

17:43

like 5-10 centimetres around it.

17:46

OK. Yeah, so it was fully encircled by the

17:48

flames, but the cube itself was just sitting on

17:50

a hot log. Like, the log had been in the

17:52

fire for an hour. The log was hot to touch, and

17:55

it was surrounded by flames, but the

17:57

cube itself was just unfazed by all

17:59

of that heat. in fire around it. Was it

18:01

a big cube or a little one? Just

18:03

the standard one. Okay so the bigger the cube the

18:05

better it survives. So it was a combination of the fact

18:07

that the the energy was

18:09

there in a fire but it wasn't being able

18:11

to be efficiently transmitted to the ice

18:14

cube. If you were able to concentrate all in one

18:16

go, sure it'd melt, but in this case you were

18:18

just getting heat mainly by transferred by

18:20

radiation from the flames and there's not

18:22

a lot of energy in that in

18:24

this particular situation. Although the sun does

18:26

very well at giving us 1000 watts

18:28

per square meter but it's a much

18:30

bigger engine. Wow.

18:32

So even though it was all there it just wasn't applying

18:35

to the ice cube. It wasn't being transmitted

18:37

efficiently to the ice cube yeah that's a

18:39

really good physics problem for a year one

18:41

student. Wow good exam question. Thanks Amy.

18:43

Thank you so much. I hope you still enjoyed

18:45

your potatoes. Oh always

18:48

good. Seriously in the fire wrap them in

18:50

a bit before we open them up. Sour

18:53

cream. Oh so good. All

18:55

right Aaron in Terry Hills. What's

18:58

your question? Good day doctor. That's

19:00

another space related question for you. You

19:03

see that like a spacecraft might use

19:05

as the gravitational pull of a celestial

19:07

object in order to accelerate in and

19:09

out of its orbit and head off

19:12

in another direction. My question is

19:14

how does it actually accelerate if the gravitational pull

19:16

would be equal going in as going out? Ah

19:19

because the body is rotating. So

19:22

it was there

19:25

was a student who was a graduate

19:27

student in the late

19:29

60s who came up with this idea of

19:32

what we call the gravitational slingshot. NASA has

19:34

a really good home page on it and

19:37

he put forward the idea as a student to his teacher

19:39

who said ah you're a student what do you know. But

19:41

he kept on pushing and then finally

19:43

he gave a seminar going because he was a

19:45

mathematician not a physicist and he gave a seminar

19:47

to the physicist and he just went through the

19:49

mathematics and he said mate you're

19:51

right. And so they were

19:53

able to use this to slingshot one

19:56

of the pioneer spacecraft and

19:59

give it a bit of extra velocity. it's

22:00

calcium like when you're having a ham and

22:02

toasted or a hamburger with cheese. Yeah,

22:06

luckily part of

22:09

the answer comes from Richard Feynman who said

22:11

that if we lost all the knowledge of

22:13

our society and it all crumbled away, if

22:15

there's one sentence that you want to leave

22:17

for our descendants 10,000 years in the future,

22:19

what would that sentence be? And

22:21

the sentence he reckoned it should be is

22:23

everything is made of atoms. So

22:25

if you look at the cheese, it

22:28

has atoms of calcium and

22:31

in general they do not

22:33

leave the bulk of

22:35

that slab of cheese. They

22:37

stay there. So on one

22:40

hand I would say, no there's still just as

22:42

much calcium there as when you started assuming that

22:44

none drips off but there's another factor. You

22:46

talk to, now we're talking physiology, does

22:49

something happen to make it more

22:52

or less bioavailable. So

22:54

for example, you can have calcium in

22:58

milks and vegetables and some, even

23:00

though you might have the same

23:03

numbers of milligrams of calcium

23:05

per 100 grams of food, you'll

23:08

get more from one than the other. And so

23:10

the tricky word is bioavailability. So I do not

23:12

know and I would have to spend maybe half

23:14

an hour searching that up on our good friend

23:16

Google Scholar. So I'm guessing you still got the

23:19

same amount of cheese. I'm kind of guessing it's

23:21

probably just as bioavailable. So

23:23

it doesn't change like because the

23:25

fat, you know, how it changes

23:28

into more sort of a fattier

23:30

version. Well it's

23:33

kind of tricky. So what

23:36

happens, okay, so you got this married couple and then

23:38

the woman dies and the guy doesn't know how to

23:40

cook for himself and he kind

23:42

of survives for a while and then

23:44

suddenly he's fainting a lot and he's

23:47

gone iron deficient

23:49

because of a tea and

23:51

toast diet. So he

23:53

has one meal at the local RSL every day and it

23:55

gives him a bit of iron but the rest of the

23:57

time for breakfast and dinner he has tea

24:00

and toast. Tea has chemicals

24:02

in it called phytates and they chelate

24:04

or grab. Chelate is a fancy word

24:06

meaning they grab the iron. So the

24:08

iron is there in his bloodstream but

24:10

it is not available to him, it's

24:12

not bioavailable. So he eats the same

24:14

amount of iron as he did before

24:17

and wheat has also got phytates. Now

24:19

tea has got tannin, wheat has got

24:21

phytates. They each grab the iron and

24:23

even though it's physically there inside his

24:26

body, it will not be picked up

24:28

by his body. It will stay in his gut and it will

24:30

go out through his bowel and

24:32

out into the toilet bowl. So

24:34

the bioavailability thing is a complicated

24:36

thing so we really need a

24:38

dietician to tell us if melted

24:41

cheese has a different bioavailability. Claire

24:43

Collins where you at? Claire Collins where you at?

24:45

Yeah Claire Collins where you at? Alright thanks Gabby.

24:47

Thank you Gabby. That's a deep one. We'll try

24:49

and get to the bottom of this. Why does

24:51

it taste better? So good. But hang

24:53

on does blue cheese taste better if you melt

24:55

it? I haven't been game to do it. Cheddar

24:58

does. I don't have it on a pizza and stuff.

25:00

If you get a little Quattro for Margie sometimes they'll

25:02

put a blue cheese on there. Quattro for

25:04

Margie? Four cheeses babe. Hey

25:07

Quattro for... Quattro for

25:09

Margie cheese. Is that Italian for four

25:11

cheese? Yeah. Hang on. Have

25:13

I just been missing out on cheese

25:16

a piece of with four cheese for all

25:18

my life? So good. Why didn't you send

25:20

me an email about this? Why

25:22

didn't I miss out on an email? I

25:25

was talking earlier about how I've been

25:27

having histamine allergy issues and apparently cutting

25:29

out or looking to cut out gluten

25:31

and dairy can be good. I don't know again

25:33

it's something to put to Claire Collins and

25:35

I'm like I can't cut it out

25:38

and here and maybe that's why maybe because I'm eating

25:40

a four cheese pizza. Maybe that's why my

25:42

histamine issues. I'm

25:44

eating a four cheese pizza soon. Yeah. Do

25:47

it. I have a new goal. Yeah. Cam in the

25:49

Yarra Valley. Dr Cam come on down.

25:51

What's your question? Morning doctors.

25:53

So I've got a question about memory.

25:57

I've got like this weird ability to like

25:59

pretty much remember. anyone that I meet.

26:01

And so like for example like someone came

26:04

into our work the other day and I

26:07

pretty much like said

26:10

his exact order and sort of looked at me

26:12

sideways because like

26:14

last time we came in was four years ago. Right.

26:18

So this happens a lot like it happens

26:20

with pretty much everything I

26:23

meet. And yeah

26:25

I was just wondering like what's the sort

26:27

of mechanism behind that like why can I

26:29

remember names and faces but like seems like

26:31

no one else can. Okay

26:34

there's different types of memory. You

26:37

and I you've got a bit

26:39

of the meat it appears. So one

26:42

sort of memory is they say what

26:44

are the 15 countries

26:46

of the world that have something or other and

26:48

you can just generate that list out of your

26:51

brain. And the other one is where

26:53

you look at those 15 countries and it's

26:55

presented to you and say oh yeah they all

26:57

export wheat. Right. Yeah. So you've

26:59

got that second sort of memory and

27:01

I remember a case with

27:04

a incredibly smart

27:06

woman who was doing three honors degrees at the

27:08

same time when I was in the University Medical

27:10

Service and she was changing a tire on her

27:12

way back home to the country and a truck

27:14

went past and blew off the road and she

27:16

fell over and land on her head and she

27:18

came in and said I'm not so smart anymore.

27:20

And we checked her IQ was just as astronomical

27:22

and what she had lost it was still the

27:24

same but she dropped from being able to do

27:26

three honors degrees effortlessly to being

27:28

just able to get through one honors degree three

27:31

at the same time. Oh my god she was

27:33

a mega genius. Right. And so what she had

27:35

lost was the ability to generate lists but she

27:37

still had the ability to recognize and you've got

27:39

that. And so she went for the public service

27:42

and now she's a very high ranking Australian public

27:44

servant and a very nice person. And

27:46

so because in the exam

27:49

they give you lists of things and she

27:52

can recognize and work out what's in and what's not as

27:54

opposed to give me the 15 countries

27:56

that export wheat. Right. So you have got that

27:58

to a very high degree. Why. waste

30:00

of my entire life when I was a laborer. What

30:02

do you mean? Well, you know, the bit where you curve

30:04

in above your hips instead of bulging it. Oh yes. Once

30:07

upon a time I used to have a beautiful, slim girly

30:09

waist. Oh my God. You still do, babe.

30:11

Darling, you're too kind. We

30:14

got Richard in In-A-Loo. Richard, you heard something

30:16

interesting on hacks this week. What was it?

30:20

I heard about the microplastics

30:23

ending up in men's testicles and

30:26

dogs' testicles. I'm wondering,

30:28

you know, what's going on with, you

30:30

know, what else in parts in the

30:33

body could microplastics be affecting? Like mental

30:35

health potentially, given how much you

30:37

see about that stuff these days. Ah,

30:41

well, the situation is that we recycle about

30:43

5% of our plastics and

30:45

we could easily recycle 95%. And

30:49

there's actually been moves to stop recycling because

30:51

that would cut to the profits of the

30:53

people who sell the raw feedstock. So we

30:57

could have virtually no microplastics if

31:00

it was a decision at a political level, but we're

31:02

stuck with it at the moment. In 2021, the word

31:05

plastic centre got discovered

31:07

or invented because, or coined, because

31:09

we found microplastics in a majority of a

31:11

sample of human female placentas after the babies

31:14

had been delivered. Now we've found them in

31:16

testes. The bottom line is this. There's

31:18

three bodies. Oh, by the way, one

31:22

litre of water in a plastic bottle

31:25

has 100,000 microplastic particles, right?

31:27

Okay, this is the bottom line. They are

31:29

present in us all. And unfortunately, we don't

31:31

have a control group to

31:33

sue people without microplastics to see what would happen. So

31:35

we're just going to have to do it by what

31:37

they call an observational study and we'll see what will

31:39

happen with time. Will they

31:41

have endocrine hormonal effects on mental? We

31:44

don't know. We're looking for it now.

31:46

Ashley and Tazzy, what's your question? Hi,

31:49

doctors. I was just wondering if genetic

31:52

modification within the womb will be a

31:54

possible thing in the future. We're

31:57

heading towards that. Ashley, are you

31:59

familiar with the... Ah,

34:01

it was a slushy. So it wasn't solid, but it was

34:03

slushy and it expanded in volume enough to force it out

34:05

of the neck. That's a beauty. That's good. Okay,

34:07

what you saw then was a change in state

34:10

from liquid to solid. The inside of the freezer

34:13

is minus 18 degrees and so

34:15

the beer liquidy goodness went down to

34:17

say minus 5 minus 10

34:19

and the water wanted to freeze

34:22

because beer is 95% water, but it couldn't

34:25

because it hadn't been

34:27

disturbed and if you keep it still it

34:30

won't freeze. But if you give it a bit

34:32

of what they call a nucleation center which can

34:34

be the little bubbles when you open it. So

34:36

you open it, the pressures are leave to get

34:38

these little bubbles and the bubbles will trigger it

34:40

to go from liquid into solid, but

34:42

not a full solid, just like a slushy solid.

34:44

But the one bubbling out of the mouth like

34:46

an elephant's toothpaste, you've been very lucky. I'd almost

34:49

drink a beer to that one. Awesome.

34:53

Thanks, Lyndon. If I'd given it a little

34:55

shake, it would have frozen in the bottle. It

34:57

can, but you don't want to break the

34:59

bottle. So you do this thing. So suppose

35:01

you're sanding paper on a hot day and

35:03

you're sanding some wood with 2000 grade paper

35:05

and you've got this very fine dust in

35:07

the air and then you breathe on it

35:09

with your mouth and out comes water which

35:11

normally is invisible in the air, but it

35:14

lands on the tiny particles of dust in

35:16

the air and they

35:18

act as a fancy word, nucleation

35:20

center. And then it does the

35:23

changing state from gas into

35:25

a liquid. So

35:27

what you're getting is nucleation centers

35:29

in the bottle, nucleation centers in

35:31

Wikipedia. Thanks

35:34

so much for listening to this episode of

35:37

Science with Dr Karl and we always want

35:39

more people to join the Science with Dr

35:41

Karl fam. So the best way to get

35:43

us in other people's feeds is to like,

35:45

rate, subscribe, follow, do what you

35:47

got to do on whatever platform you listen. And

35:50

we really appreciate it. My name

35:52

is Lucy Smith. This episode was produced by Sarah

35:54

Harvey and we'll catch you next week. Bye.