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Wait, you're listening? Okay.

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Alright. Okay. Alright.

0:38

You're listening to Radiolab. Radiolab.

0:41

From WNYC. See?

0:45

Yeah. What's

0:49

another word for a male frog

0:51

that has some children? What?

0:55

What's another word for a male frog that has

0:57

children? A daddy-wog. A dad-pole.

1:00

There you go! Yes! Okay,

1:02

sorry. I feel cash. Hey,

1:05

I'm Lulu. I'm Latif. This is Radiolab.

1:09

A host we are quite a big fan of. Allie, your show is awesome. It's

1:11

so great. Thank you. Her name

1:13

is Allie. She's a radio host. She's

1:15

a radio host. She's a radio host. She's a radio host.

1:17

She's a radio host. She's a radio host.

1:20

She's a radio host. She's a radio host. She's

1:22

a radio host. She's a radio host. So,

1:28

Allie Ward. I actually realized during our

1:30

conversation with her that she is my

1:32

neighbor. But we brought her in

1:34

because we wanted her to tell

1:36

you about her podcast.

1:38

So let the games begin. Ask me anything. What

1:41

is the name of your show and how would you describe

1:43

it? So Ologies is a

1:46

comedy-ish science podcast

1:48

where we explore a different ology

1:51

every episode. So it might be geology

1:53

one week and then a filamentology the

1:55

next, which is the study of kissing.

1:58

Allie has taken on. So

2:00

many ologies testudonology which

2:03

comes from the Latin testudo for

2:05

tortoise and a gmatology Hagfish

2:09

ology would it be raccoon ology

2:12

or would it be? meteorology

2:14

apiary ology

2:15

technology Melanin ology quantum

2:18

ontology chronobiology carnivorous

2:20

phytobiology flesh-eating plants

2:24

Your urology

2:26

episode was one of my favorites

2:29

and I did not think I would like I very

2:32

reluctantly clicked on that And

2:34

we brought Ali on because her show is

2:37

kind of like a kindred spirit

2:39

to our show But also

2:41

it's very different at the same time like for

2:43

our show we talked to a bunch of scientists but

2:46

it's usually in the context of a Story

2:49

or a big idea we're interested in and then

2:52

we try to make it all add up to something

2:54

Ali does not do that part She

2:57

just will be like oh this scientist is interesting

2:59

and then they will sit down and they will just

3:01

go to town and

3:02

Actually one of the things I love

3:05

about your show is like like

3:07

your what matters is totally different

3:09

than our what matters Like what

3:12

what does it matter when it's a random thing

3:14

that

3:14

that it seems like maybe only this one

3:17

Scientist you're talking to cares about I

3:19

love this question and I completely get it So

3:23

here's the thing science is everywhere

3:25

science is in How

3:27

you steam broccoli science is

3:30

in how you

3:31

park your car science is in who

3:33

you fall in love with science is why? You

3:36

sweat when you get a text message that freaks

3:38

you out like it's not just about

3:41

diagrams and textbooks and I think it's

3:43

also interesting that a lot of people

3:45

who are not scientists

3:48

think that scientists are jerks and

3:51

pedantic and are there with like a

3:53

huge book of facts to tell them that they're wrong about

3:55

things and I wanted to show that like scientists

3:57

are

3:58

curious little weirdos who found

4:01

their niche and whatever made

4:03

them passionate and they

4:05

make mistakes and they have hypotheses that

4:09

end up being wrong and they're

4:11

figuring it out too. And so humanizing scientists,

4:14

I feel like galvanizes people to care a

4:16

little bit more every time they see a research paper. They

4:19

think, I wonder why this person studied this or

4:21

I wonder how long it took to get this published.

4:23

And so the civic

4:25

duties that we have to protect things

4:28

and care about things become easier for people when

4:31

they have a little bit more context. But like,

4:32

okay, so like, how do you know how

4:34

to, that people will stay

4:37

with you for all of these, for your to

4:39

go down, like how far they'll follow you

4:41

before they'll just be like,

4:43

Ali just totally lost it. Lost

4:46

the plot. Yeah, lost the plot. Yeah, I

4:48

mean, it's really kind of more

4:50

of like a

4:52

lightning bug kind of darting around and just

4:55

following the light.

5:00

So for the rest of this episode of our show, we're

5:02

gonna follow Ali

5:05

into an episode of her show as she follows

5:07

the light bouncing around

5:09

like a little lightning bug like she does into

5:12

the dark. Oh, Scotto, high

5:14

lollogy Scotto means dark. High lollogy means matter.

5:17

We're gonna play her episode on dark matter for you. I

5:19

actually, that was a rare one where I worked with

5:22

theologists to be like, there needs to be a word for

5:24

this. How do you feel about this? And

5:26

he loved it. You coined a term. You coined

5:28

it. It's one of the very few conversations I've

5:31

heard that actually make dark matter

5:33

make sense to me. And even

5:35

feel like it matters. Yeah.

5:42

So we're gonna turn it over now to Ali with UC Riverside

5:45

theoretical

5:46

particle physicist and dark matter expert, Flip

5:48

T'Nato.

5:49

And just a quick heads up, the lovely Ali Ward

5:52

is not afraid to, dirty

5:55

her tongue. That's

5:58

not an expert.

5:59

She's not afraid to swear. So

6:03

there are a few swear words ahead. Here

6:06

we go.

6:07

Did you set out to become a theoretical

6:10

physicist? How does one land

6:12

in like what I feel like is the

6:15

hardest field possible?

6:16

All right. Here

6:18

is my origin story. I

6:22

wanted to be an author. Really? I

6:24

had no idea why, but I was

6:26

very passionate about writing

6:28

the idea that one can have a voice. And

6:31

so growing up, I was a huge

6:33

fan of LaVar Burton's because of Reading

6:35

Rainbow. Love, love, love, love. Reading

6:38

Rainbow, amazing. But you don't have

6:40

to take my word for it. So I

6:42

would watch Reading Rainbow

6:44

and at some point in the

6:46

back of my mind, I realized this person

6:48

who does Reading Rainbow is also on this TV show,

6:50

Star Trek. And

6:53

in high school, I started watching

6:55

Star Trek a little bit. It was still on at the time.

6:58

I picked up the book, The Physics of Star

7:00

Trek by Laurence Krauss.

7:02

And this was a really fun

7:04

ride because

7:06

it was the first time I thought about a scientific

7:08

subject

7:09

as something where there are open

7:11

questions and these open questions

7:13

are fun and creative and exciting

7:16

and any time that I lost track of it

7:18

being exciting, I just watch

7:19

LaVar Burton as Jodie LaForge as

7:22

a chief engineer. I know it well. Oh

7:24

my gosh. My sister and I used to watch The

7:27

Next Generation as well. It was the

7:29

best. Yeah. We can't change the gravitational

7:31

constant of the universe, but if we wrap a low-level

7:33

warp field around that moon, we could reduce its

7:36

gravitational constant. Make it lighter so

7:38

we can push it. So I think

7:40

that's what got me into this idea that, hey,

7:43

these black holes in the show, these are real. We

7:46

should understand these things. There are fundamental questions

7:49

that are not only abstract

7:52

and things you'd find in textbooks, but

7:55

they're fun ideas and it

7:57

was the creative spark that was really exciting.

7:59

could write a science fiction piece about

8:02

these actual things. And that's what got

8:04

me going with physics.

8:05

Do you write still at all? I

8:08

was never a great writer. And you can ask my collaborators

8:10

that my paper writing is slow and

8:13

tortuous. But I

8:15

would like to eventually write something

8:17

as a popular book.

8:18

Oh, yeah. I feel like that is in your future. But

8:21

when it comes to matter

8:24

and dark matter, I mean, slow

8:26

it way down for baby brains like mine.

8:29

But from what I understand, and the

8:31

first time I ever read this was like,

8:33

okay, all of the matter that we can see and

8:35

touch and feel and everything makes up about 15%.

8:39

Yeah, depending on how you're counting. But yeah, yeah, it's a

8:41

tiny fraction. Like a third

8:43

of that. So everything that you can

8:46

see and feel and touch

8:48

and smell, that's 5% of the universe's mass

8:53

and energy. There's another 95% of pure

8:55

mystery.

8:57

So

8:59

then what the fuck is everything else?

9:01

What is it? That

9:04

is the mind blowing thing. We've known

9:07

about dark matter indirectly for 100 years. And

9:09

I think it hasn't been until fairly recently

9:12

that this has come to the forefront of we really

9:14

ought to figure

9:14

out what this stuff is. Because

9:17

as you said, we spend all of our lives learning

9:21

science, art, history,

9:23

everything you learn from a textbook is basically

9:26

about that really tiny slice of

9:29

visible normal matter and

9:31

the history of that normal matter in this

9:33

universe and in this world and in our culture. But

9:36

it turns out for every, say,

9:38

what's the fraction? I think if

9:40

you look at the amount of energy, so energy

9:42

is a good

9:43

measure for stuff. 25% of

9:47

the universe is made of dark matter and

9:49

only 5% is made of the stuff

9:51

that we're used to. Wow. It's 5

9:53

times more dark matter than ordinary

9:56

stuff.

9:57

And in fact, it's so much more that...

10:00

We look at our galaxy and we think our galaxy is huge. Our

10:02

galaxy is almost everything. Everything we

10:04

possibly care about. Our galaxy

10:06

is only here because it is swimming

10:09

in an ocean of dark matter that provides a gravitational

10:11

pull to keep the galaxy there. The galaxy formed

10:14

because there was dark matter. So

10:17

where we are right now with Scotto-Hylology,

10:21

is that what we're doing? Yes. Nailed it. This

10:23

is the fish scientist discovering

10:25

for the first time that there's

10:27

this thing of water that we're swimming through. We should

10:29

figure out what this water is. Wow. And

10:31

now the other, let's say,

10:33

is the other 70% dark energy? Good.

10:36

Yeah. So that is a great. I

10:38

was both hoping and not hoping that you would bring

10:40

that up. 25% dark matter, 5% ordinary

10:42

matter. That

10:45

doesn't add up to 100%. And so the

10:47

rest is indeed dark energy.

10:49

And I'm excited that I have no idea

10:51

what dark matter is and that there are great

10:54

things to do in that field. I have no idea

10:56

what it is. Dark energy, I have no fucking

10:58

idea. There's a reason why

11:00

I don't work on it. It's

11:04

one of those shows, right? Of course, very

11:06

much so.

11:06

Especially this topic, there's going to be a

11:08

lot of boggling. Trust me. I

11:11

mean, OK. So

11:13

about 100 years ago, was

11:16

that when we realized,

11:18

I say we, the royal we hear, that

11:21

something is not adding up? That's right.

11:23

Yeah. When did we realize that? I

11:25

think this was about 100 years ago. The first astronomical

11:28

observations were, and

11:31

this is what's really, really trippy. The origins

11:33

of Scotto-Hylology were

11:36

really in astronomy. And people

11:38

would look at galaxies. And look

11:40

at how fast stars were moving in those galaxies.

11:42

And just using

11:44

ordinary, non-fancy,

11:46

Newtonian physics, the type of physics that

11:48

students grown over in high school, they

11:51

figured out that these stars moving

11:54

around these galaxies were going a

11:55

little bit too fast. It's as

11:57

if there was more gravity than.

13:59

observatory. She had to cut up a silhouette

14:02

of a dress and paste it on one of the men's

14:04

rooms. And then when she was done

14:06

crafting, then she pioneered some

14:08

giant theories about the existence of the universe. And

14:10

she died in 2016. She was never awarded the

14:13

Nobel Prize and they unfortunately do not

14:15

hand those out posthumously, which is a bummer.

14:17

But you can

14:18

name your dog Vera or your cat Reuben

14:21

and remember Vera Reuben that way. But anyway, dark

14:23

matter. It is, it's something else.

14:25

It cannot be the stuff that we're used to from chemistry.

14:27

And then

14:30

the fundamental particle physicists,

14:33

the elementary particle physicists, realized we've

14:35

been spending the past five decades trying

14:37

to categorize the elementary particles

14:39

of nature. We're trying to have the the most

14:42

fundamental periodic table. And you're

14:44

telling me that there is something that we're missing

14:46

that we definitely have to put on here? Wow.

14:49

And this became a big thing if you'll permit me

14:51

an aside.

14:52

Yes. I was hoping you'd say that.

14:55

So I'm gonna get the history a little

14:57

bit jumbled, but this is the moral history. This

14:59

is the way that we're gonna remember it. Okay. In the 80s and

15:01

90s, there was one

15:02

big hot question

15:07

in particle physics. And that question had

15:10

to do with the Higgs boson. So the

15:12

Higgs boson that in 2013 won the Nobel

15:14

Prize for its discovery. Big deal. Big

15:17

fucking deal.

15:17

And now that's sometimes

15:20

wrongly called the God particle. Yes.

15:22

Okay. Right. That is the quote-unquote

15:25

God particle. Right. And if you asked physicists

15:27

in my generation, its discovery

15:30

was more like the second particle where

15:33

we had to really do some soul searching. Because

15:36

in the 80s and 90s, we had realized there's

15:38

probably a Higgs.

15:39

If there's not a Higgs, things get way more interesting.

15:42

But if there's a Higgs,

15:44

something isn't quite right in the theory.

15:47

Because for all the reasons that we needed

15:49

to have the Higgs, if the Higgs had the

15:51

mass and the properties that we needed it to

15:54

have, somehow it just didn't

15:56

seem right. It was far

15:59

lighter in mass, then

16:01

it really ought to have been. So we now

16:03

know it weighs about 125 times

16:05

the mass of a proton, which is pretty honking

16:08

for a fundamental particle. And

16:10

our prediction, naively, if I gave that

16:12

calculation to a first year grad student, they'd say

16:15

it's probably way heavier than that. It's

16:17

like balancing a pencil on its tip. The quantum

16:20

corrections to its mass would make the

16:22

Higgs heavier than it actually is.

16:24

And just some very brief background

16:26

on this. So Higgs particles make

16:28

up the Higgs field, which is this big cloud of

16:30

bosons or particles. So matter

16:33

started out zipping around like

16:35

photons, just unencumbered by mass. But

16:38

interaction with the Higgs field is what

16:40

makes matter interact with gravity and

16:42

have that mass be gravitationally attracted to

16:45

each other. But Higgs bosons, very

16:47

hard to find. You have to get like

16:49

a large hadron collider, say,

16:52

maybe 27 kilometers under Geneva.

16:55

And then you got to race protons at each

16:57

other. You got to explode them. And

16:59

then you got to measure what's left,

17:02

a.k.a. a decay signature. And if you're

17:04

looking through all those pieces and you have pieces

17:06

and parts for what could have been Higgs boson

17:09

that existed for a fraction of a millisecond, then

17:11

that's almost proof. But

17:13

for a long time, this possibility of the

17:16

Higgs particle had vexed science

17:18

for years. One leading scientist

17:20

wanted to call it the goddamn

17:22

particle. But his book publisher

17:24

was like, let's go softer and

17:26

naively made the facepalm

17:29

modification to just call it the god particle,

17:31

which has been making physicists cringe

17:34

for decades now. But yes, essentially,

17:36

things just didn't add up.

17:37

And so this was a huge

17:40

puzzle.

17:41

It's analogous to having an ice cube sitting in

17:43

an oven and you turn the oven on and the ice

17:45

cube is still there. So we

17:48

called this the hierarchy problem. For

17:50

people like me, we write it with a capital H

17:52

when we write our academic papers.

17:53

It was a big deal. It

17:55

seemed to be the reason why our

17:58

theory of particle physics just could not be complete. So

18:01

prior to 2013, they knew

18:03

something wasn't quite right. And

18:06

so we had these great exotic theories.

18:09

They had funny names, supersymmetry, extra dimensions,

18:11

compositeness. You know, maybe

18:14

the electron and its cousins are

18:16

not fundamental, but are actually

18:18

made of smaller things. Oh, wow. So

18:20

this was the heyday in the 90s of

18:23

doing particle physics. And right

18:25

around that time, as we were developing these really awesome

18:27

theories, people realized, hey,

18:31

in order for this theory to work, meaning

18:33

in order for protons not to decay too quickly, in order

18:35

for the universe to actually look like the way it does,

18:38

we need to tweak it a little bit. And

18:40

one output is we

18:42

get these new particles that stick around. They don't

18:44

decay. They're just around. That's

18:47

kind of weird. And

18:50

I imagine there's some particle

18:52

physicist sitting in his office saying this,

18:55

and an astronomer walks by and says,

18:57

you have particles just sitting around

19:00

contributing mass? Have

19:02

you heard about this anomaly

19:04

that we have? There's more mass in

19:06

these galaxies. And

19:08

so particle physicists were, I mean, were

19:10

kind of smug. Just

19:12

said, oh, yeah, OK, good. I

19:15

have discovered what your dark matter ought to be. You,

19:17

in 15 years, when we turn on this collider,

19:20

we're going to discover what this particle is. We'll measure

19:22

how heavy it is. And I will tell you exactly

19:24

what's in these galaxies that you've been looking at for the past hundred

19:26

years. This was the promise. Yeah. And

19:29

so

19:29

particle physicists didn't even care about the dark

19:31

matter because that was the output of this

19:34

elegant theory that solved the capital H

19:36

hierarchy problem. And just

19:37

a side note. So the capital S

19:40

standard, capital M model of particle physics involves

19:43

this uniform framework for

19:45

understanding electromagnetic

19:48

and weak and strong interactions. And

19:51

the hierarchy problem is the difference

19:53

between the way a weak force, which is a force

19:55

that allows protons to become neutrons and

19:57

then back and forth, vice versa. So that weak

19:59

force...

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23:00

On

23:02

January 6, 2021, while

23:05

many of us watched news of the attack on

23:07

the U.S. Capitol in horror, Tasha

23:10

Adams watched knowing her estranged husband

23:12

was behind them. She was married to Stewart

23:14

Rhodes for more than 20 years, including

23:17

when he founded Oathkeepers. The first

23:19

words out of my mouth were, I helped start

23:21

this. And would

23:23

this have happened had I not supported

23:25

Stewart?

23:26

That's on the next episode of Deaf, Sex, and

23:28

Money, wherever you get podcasts.

23:36

Lulu. Latif. Radiolab. We

23:38

are back with Ali Ward on scop-to-hy-lology.

23:43

AKA the study of dark matter. With theoretical

23:46

particle physicist Flip Tonato. Here's

23:49

Ali. What about the

23:51

name dark matter and dark energy? Because

23:54

it's invisible at best, right? Absolutely.

23:57

Who decided that it would be called dark? Who decided

23:59

that it would have a spooky-

23:59

That is a great question. I think

24:02

it was Zwicky who was a famously

24:05

cantankerous physicist in the

24:08

early part of the 20th century.

24:10

So yes, this was 1933 with

24:12

Caltech's Fritz Zwicky. And

24:15

when you hear the words famously

24:17

cantankerous, I know you want the story time. And

24:20

among a lot of different legends and slander

24:22

and feuds and jealousy and what

24:24

sounds like a little maybe a touch of

24:26

old timey verbal abuse.

24:28

If his enemy stories were to be believed,

24:31

Zwicky would allegedly call his

24:33

colleagues scatter brains and

24:36

spherical bastards, spherical

24:38

because quote, they are bastards every

24:40

way I look at them. Oh, messy. I

24:42

love it. But a 2008 article in

24:45

Discover magazine features testimony from

24:47

Zwicky's daughter, Barbara Reina, that

24:49

Dr. Fritz

24:50

was just so brilliant that he had a lot

24:53

of haters. But he was the one who

24:55

coined the term dark matter. And what

24:58

he meant was that

24:59

it doesn't interact with light.

25:01

Yeah. So usually

25:04

we think things that are dark don't interact with light. But

25:07

actually, probably there's some junior high student out

25:09

there who'll say, no, no, no, things that

25:11

are dark absorb light. They're actually maximally

25:14

interacting with light. If you're an astronomer,

25:17

dark means you don't see any photons from it.

25:19

So I think that's why they use the word dark. And

25:21

to the best of my knowledge, I think dark

25:24

energy, which was discovered a little bit later,

25:26

as a big question mark, yeah, they

25:29

latched on to the to

25:30

the branding that we developed.

25:33

And they use the word dark to

25:35

mean just like dark matter, we don't know

25:37

what this is.

25:39

But at least dark matter, we had the idea

25:41

that this was stuff, these were particles, I'm 99.9%

25:44

sure dark matter is at least one particle.

25:47

Dark energy, definitely behaves

25:49

differently. And it's a much weirder thing.

25:52

Do you drive around in

25:54

traffic and think about this stuff? Like, can

25:56

you ever escape theorizing

25:59

about Oh, that is a

26:02

great question. I think the

26:04

the imposter syndrome in me says yeah, I escape

26:06

it way too much But traffic

26:09

in LA as you know is not not

26:11

a great place to have happy thoughts But

26:14

I often find myself thinking about physics in

26:16

the swimming pool

26:17

Really? So for example, there's this idea of we

26:19

are fish in an ocean of dark matter that

26:21

was something that I was I was thinking

26:23

about while swimming and I

26:25

guess being in a mathematical

26:28

discipline your

26:30

Sharpening your equipment like you having

26:32

having the finest equipment is really having

26:34

a clear mind And I can

26:36

sit at my desk and I can do a calculation

26:39

I can write a paper but the

26:41

creative spark is something that usually happens outside

26:43

of those environments. So Walking

26:46

around or having tea

26:48

on my patio that that that's that's

26:51

where the magic happens

26:52

and be honest with me without having A name names how

26:54

many astrophysicists out there

26:56

think that dark matter might be ghosts What

26:59

if dark matter is ghosts? What if dark energy is

27:01

ghosts? What if it's all ghosts?

27:02

What if we're swimming in ghosts? there

27:05

is a famous quote from Nima

27:08

our Connie Hamed before the LHC

27:10

turned on and and The

27:12

quote was something along the lines of we

27:14

might turn it on and dragons might pop out.

27:16

We have no idea What's gonna pop what's gonna

27:18

happen? So in a March 2008 New

27:20

York Times article This particle theorist

27:23

who was at the Institute for Advanced Study in Princeton

27:25

told the paper that there was some probability

27:28

of almost anything happening even a minuscule

27:31

chance that quote the large hadron

27:33

collider might make dragons That

27:35

might eat us up. Maybe he was just

27:37

ahead of the curve and predicting the 2011 premiere

27:41

of game of Thrones, but either way people

27:43

were rightly pumped

27:44

and that kind of encapsulated a lot of the

27:46

the excitement there is something to be said

27:48

about maybe dark matter is something

27:51

much more exciting than particles and

27:54

There are theories where the

27:57

dark matter

29:58

it's probably

30:01

also not black holes. Okay. So

30:04

these are the other two like exotic things that you learned from

30:06

Star Trek. Yeah. So

30:09

it's not antimatter because if

30:11

we're swimming in the sea of dark matter and

30:13

if the dark matter were antimatter, it would keep

30:16

annihilating with ordinary matter and producing light.

30:18

So the fact that, I was going

30:21

to say that we're not a glow stick in the universe, but

30:23

really the

30:24

fact that our galaxy isn't just being burnt

30:26

up by the antimatter,

30:28

that means dark matter is not antimatter.

30:31

Nice. Until fairly recently, we would

30:33

say it's not black holes because black holes are a totally

30:35

different thing. But there have been some thoughts recently

30:38

that there might be little

30:41

tiny black holes that were formed in the universe that

30:43

would behave like dark matter. How tiny

30:46

are we talking? That's a good, there's a range

30:48

of sizes, but

30:50

the story of little black holes is funny.

30:52

For a long time, people were worried that turning on the LHC

30:55

would produce lots of little black holes that would eat the earth. Sounds

30:57

like fun. But we were pretty

31:00

sure that little black holes evaporate

31:03

and would be relatively harmless. Little black

31:05

holes are like little

31:05

particles. And do you

31:07

think that those could be just on earth

31:10

in just little pockets here

31:12

and there?

31:13

Chances are no. I would bet no, but

31:16

it is a theoretical possibility. It's attached

31:18

to a whole bunch of other weird things. I think to

31:20

make it work out gravitationally, you

31:22

need to have extra dimensions and maybe a few extra dimensions.

31:25

But it was a fun thing to think about 10 years

31:28

ago. Do you think that dark

31:30

matter could be extra dimensions? That is

31:32

a great question. That is what I spent

31:34

my summer vacation thinking about. So

31:38

extra dimensions are a really funny quirk

31:41

in the history of theoretical physics. I

31:43

think the modern way of

31:45

thinking about this is

31:47

the people who work on extra dimensions

31:50

don't necessarily literally believe

31:52

in,

31:53

if I could just step in the right way, I'm gonna be in

31:55

some parallel universe. But

31:57

in the mathematics, one

32:00

realizes that if I can write

32:02

a theory in

32:04

three dimensions of space plus one dimension of time, I

32:06

could write a theory in four dimensions of space plus

32:09

one dimension of time, or in five dimensions of space and

32:11

one dimension of time. No problem, right? It's

32:13

just, it's another number that you add onto

32:16

your mathematical expressions. And so

32:18

people, it was easy to play with. And

32:21

in the 1990s, one

32:23

of the huge revolutions in theoretical physics

32:25

was this observation that particular

32:28

types of theories with extra dimensions

32:30

end up giving mathematically

32:33

equivalent predictions. When

32:36

you were asked the right question to

32:39

a type of quantum theory that is really

32:41

hard to calculate. This is something called a duality

32:43

in physics. And it

32:46

meant that I could calculate something

32:48

in my wonky theory of extra dimensions.

32:51

And that calculation would actually mean

32:53

something in an ordinary theory,

32:55

ordinary meaning three

32:57

dimensions of space, one dimension of time,

32:59

that is highly quantum mechanical,

33:01

but a perfectly plausible theory.

33:04

And it was a type of theory that we

33:06

really didn't know how to deal with until

33:09

we had tools like this. Tools like

33:11

the Large Hadron Collider. And so

33:14

one of the fun things to play with

33:17

is we have this really powerful

33:19

machine to make predictions where we couldn't make predictions 20

33:21

years ago. Maybe we can describe cool

33:24

theories of dark matter

33:25

that one could

33:27

explain why we haven't discovered dark matter,

33:30

and two could motivate interesting

33:33

different searches. Because this is

33:35

where we are right now. We need to figure out what is the best

33:37

way to test these different theories of dark matter.

33:39

It better happen in my lifetime. I

33:42

mean, I'm sure you think the same thing given that

33:45

this is your life's work. Yes, yes. Yeah.

33:47

And in fact, this is for

33:49

for me, this is a difference between dark

33:51

matter and dark energy. Both of them are

33:54

things we have no idea what they are. I certainly have

33:56

no idea what they are. Dark matter,

33:58

we have an experimental program.

33:59

and we know enough about it that I

34:02

have faith that we have a sporting chance

34:05

that we will learn something deep about dark matter in

34:07

my lifetime. Dark energy. I'm

34:09

not sure if we'll learn anything about it in the

34:11

history of humanity.

34:13

Hey, let them fear again. We're going to jump ahead

34:15

because Ali asked Flip so

34:17

many great questions. What

34:19

is dark matter look like in

34:21

your head? Time travel. Yes. No, maybe. What

34:23

is the best music to listen to while researching

34:25

dark matter? I would honestly just listen

34:28

to a podcast that was only Ali asking

34:30

questions. They are so great. How much dark

34:32

matter is in the room right now? We

34:35

actually know this. Oh, OK. In

34:37

your coffee mug, you have about one gram of dark

34:39

matter.

34:40

If you want to hear all of Flip's answers, you can listen

34:42

to the full episode. We'll link to it on the website. But

34:45

before we go, we will leave

34:47

you with one last question and answer

34:49

from Ali and

34:50

Flip.

34:51

What about your favorite thing about what you do? Oh,

34:53

gosh. I love that

34:56

on any given day, there are new

34:58

things to learn. And either

35:01

it's some experimental result that I want to understand

35:04

or some related field where

35:07

I never had the chance to take that class as a student.

35:10

But I see that there's an opportunity

35:12

where dark matter might be able to do something.

35:14

And then I can dig in and say, I

35:16

have an excuse to spend my time reading this textbook

35:18

or reading this this this recent article or talking

35:21

to my colleague from a different department. That's that's

35:23

the fun part.

35:24

That's great. I mean, I love that for

35:26

the rest of my life. I'm going to be walking

35:28

around thinking about a gram of dark matter

35:31

in my coffee cup and and sparkly

35:34

webs and maybe ghosts,

35:36

maybe ghosts. You

35:39

don't have to commit to that on the record. I just

35:41

for my own fun. Well,

35:44

I would add to my yes and would be thinking

35:46

about all of the dark matter scientists who are

35:49

thinking about us and we are the maybe ghosts.

35:52

I love that.

35:53

Thank you so much for doing this. This was a joy.

35:55

You know, oh my gosh.

36:05

Thanks to Allie Ward and her team for

36:07

letting us share her show with all of you. Hopefully

36:10

you'll go check it out. You can find it wherever you get podcasts

36:12

or at ologies.com. That's

36:15

O-L-O-G-I-E-S dot

36:17

com.

36:18

They also, by the way, make ones suitable

36:20

for kids where they rip out all the swears. Those

36:22

are called Smologies. Big

36:25

thanks again. This episode was produced by

36:27

Pat Walters with mixing help from Arianne

36:29

Whack.

36:29

And I don't think there are any special thanks,

36:32

so I'm just gonna thank you. Thank

36:34

you for listening. New episode in your

36:36

feeds coming up in a couple weeks and it is

36:38

a really good one. It's an

36:40

Odyssey. Catch you then.

36:48

Radio Lab was created by

36:50

Jad Abenrod and is edited by Soren

36:52

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36:54

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36:56

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37:02

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37:19

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37:22

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