0:02

The one sense in which

0:04

time is frustratingly different is

0:06

that I cannot extend equally

0:09

in each direction. I cannot

0:11

just turn around and go into the past.

0:14

Okay. And I seem to

0:16

be always driven forward into the future.

0:19

I can stand still in

0:21

space, but I can't seem

0:23

to stand still in time. Welcome

0:29

to How to Keep Time. I'm Becca Rashid,

0:31

co-host and producer of the show. And

0:34

I'm Ian Bogus, co-host and contributing writer

0:36

at The Atlantic. One

0:44

time I took a nap and I remember I woke up

0:46

at sunset, but it looked like dawn. And

0:49

I was like, I'm late for work. Like, what have

0:51

I done? And that's

0:53

why I avoid naps in

0:55

general. It's just, I'm so disoriented

0:58

every time. Oh yeah. When

1:00

you travel, you know, like I travel overseas and I'm

1:03

jet lagged and the time is all messed up and

1:05

I wake up in the middle of the night and

1:07

then I can't go to sleep or you start

1:10

falling asleep, you know, in the

1:12

middle of the day, you're so far away. Like what time

1:14

is it even? And you can't control it.

1:16

I love how I'm just napping and you're traveling

1:18

the world. Yes. But

1:20

I have napped like you described it. There

1:24

are all these ways that I

1:26

experienced these weird lags in my

1:28

space and time, not just with napping,

1:30

but sometimes if I'm really tired, like

1:33

a song sounds slower to me.

1:35

Like the beat feels like it's delayed

1:37

in some way, or if I'm really

1:39

caffeinated, it feels faster and same

1:42

thing with time. Like maybe I'm just getting

1:44

older or it feels like time is moving faster.

1:47

But I hate to tell you this, Becca, but I

1:49

think you may just be getting older because time

1:51

feels like it moves faster for me year

1:53

to year. And then sometimes

1:56

I'll look at myself in the mirror After

1:58

looking at a photo and I'm like, okay. The.

2:00

In not heard used to be that

2:03

color quite summer to Ryan's ah but

2:05

it doesn't feel like much time as

2:07

past you know there's a kind of

2:09

like funhouse mirror affects with times passes

2:12

were. You. Think you look a certain

2:14

way in time, but it turns out you're

2:16

all wonky. Ray A reminds. Me when I

2:18

used to go home as a

2:20

college student, than my little brother,

2:22

who's six years younger than me,

2:24

looked like a different person every

2:26

year I visited and. Now

2:29

the way I see my parents

2:31

aging, it's like ice. You're eating

2:33

at the same time with such as

2:35

them. It's also you are you don't

2:37

have as that sense of inside your

2:39

own head or you need some reference.

2:42

From outside of your body to remind

2:44

you. Oh yeah, time. Gemma

2:49

Are you a time Me personally think of yourself

2:51

as a timely person. As. I

2:55

am very often on time. I

2:57

really am. But. I can also. ah, I

3:00

can also get lost in time and

3:02

mean, I think if you're going to

3:04

do theoretical physics in, you're gonna hunch

3:06

over a blank online sheet of. Paper

3:08

which is what I liked with a. Pencil

3:11

for twelve hours such, you've gotta

3:13

be able to kind of turn

3:15

off some of the chatter. Saw

3:17

the internal by a rhythm. does

3:19

that make you so aware of

3:22

time passing? So Becca, I spoke

3:24

with the theoretical physicist down eleven

3:26

to understand what it means to

3:28

place ourselves in the universe in

3:31

particular, as it relates to time.

3:34

I'm Janna Levin and I'm a

3:36

professor of Physics and Astronomy at

3:39

Barnard College of Columbia University. Live

3:42

In specializes in black holes, actually.

3:44

Oh, interesting, yeah, and black holes

3:46

are weird because time seems to

3:48

behave totally differently around them. So

3:54

what is it about Black Holes? What

3:56

is their role in helping us understand

3:58

that? the nature of time. The

4:01

nature of time seems to

4:04

go more and more out of sync as you get

4:06

closer and closer to the black hole. So let's say

4:08

you're an astronaut orbiting far from the black hole and

4:11

you have this beautiful clock and it's telling you

4:13

what time it is and your body is exactly

4:15

in sync with the clock and movies

4:17

run at a normal rate and music plays at

4:19

a normal rate and your companion,

4:21

another astronaut, has a perfectly

4:23

synchronized clock built by the

4:25

same manufacturer but they jump into the black

4:27

hole. What you find is that as they

4:30

get closer and closer to the

4:32

black hole, the astronaut from far

4:34

away will literally see the

4:37

ticks on the clock appear

4:39

to take longer, to be spaced

4:43

in a more elongated way so that it

4:45

says though time is running more slowly for

4:47

the astronaut who's falling towards the

4:49

black hole. Now it's not

4:52

just this clock, it's also the music they're

4:54

playing, the movies they're filming,

4:56

they all are running

4:59

slowly compared to the astronaut

5:01

far away. Now the one

5:03

who jumps in thinks their clock is normal, absolutely

5:06

normal experience. They just

5:08

think the astronaut left on this orbit

5:11

far from the black hole is running

5:13

very, very fast, racing through years of

5:15

their lives. All the movies are

5:17

fast, the music is fast and the clocks are all

5:19

speeding ahead and they

5:22

realize that they've

5:25

come out of sync as they get closer and closer

5:27

to the black hole. So

5:29

it's almost like the black hole is a

5:32

lens for physicists to ask difficult

5:34

questions about time. You can see it more

5:37

clearly through the subject of the black hole.

5:39

Yeah, the way the black hole distorts

5:42

slows time down as

5:45

you approach its

5:47

horizon relative to somebody very

5:49

far away. It makes the black

5:51

hole like a magnifying glass in some sense

5:54

so that you can look

5:56

on Higher and

5:58

higher energies in smaller and smaller time.

6:00

Keokuk. It's like this magnifying glass kind

6:03

of quality. Of the magnifying glass,

6:05

metaphor is really helpful. A

6:07

to me of but Jenna I'm

6:09

still not sure I understand what

6:11

time. Is. Like I kind

6:14

of have no idea what time is

6:16

when I stop and think about it

6:18

even though I understand what you're describing.

6:20

and I live in time all the

6:22

time. So once you once you use

6:24

this magnifying glass of the black hole

6:26

the said light on the nature of

6:28

time in the universe. What is the

6:30

answer? Like what is time anyway? Whom.

6:32

I'm not sure anyone can give you. A

6:35

fair answer to that. Oh no. As this and

6:37

that's a we would all love to I

6:39

could say let's go back and say what

6:41

is space Let's start there and see how

6:44

time is different sets I can say well

6:46

I know I can move. Extend my hands

6:48

of the last I can stand. Extend my

6:50

hand to the rights in space. I have

6:53

a kind of intuitive notion of that like

6:55

an awesome measure space with rulers. Of

6:57

how far. Away things are Mom.

7:00

Time. It he can be

7:02

very similar to spaces. What? Einstein

7:04

realize that there is sort of

7:07

a four dimensional space time. and

7:09

in some sense as the person

7:11

nears the black hole, it's as

7:13

though they're rotating what the astronaut

7:16

far away called space into what

7:18

they're calling time. It's as though

7:20

the rotating away in this four

7:22

dimensional space time. But the one

7:24

sense in which time is frustratingly

7:27

difference is that I cannot extends.

7:30

Equally. In each direction, I cannot

7:32

just turn around and go into

7:34

the past. And

7:37

I seem to be always

7:40

driven forward into the future.

7:42

Even if I'm standing stone

7:44

space. I can't stop the

7:46

next moment from passing. I

7:48

can't stop my. Body.

7:50

From Aging and we can always go forward

7:53

in this direction. He.

7:59

Knows In addition. the earliest memories I have from

8:01

childhood with my brother was operating

8:04

under the same schedules in a way.

8:06

Waking up, going to school together, putting

8:08

our backpacks on, getting yelled at to

8:10

put our jackets on, and then sort

8:13

of rushing out the door and then coming home

8:15

after three. Eat something. Eat something, have a

8:17

snack together. Drink some water. Yeah. The thing I

8:19

forget to do. And

8:23

now my brother recently moved to

8:25

Sweden for a grad school, fancy

8:28

fancy. That feeling that we're

8:30

kind of on the same rhythm

8:32

of each day, we're kind of

8:34

operating under the same clock and

8:36

sort of like moving through our

8:38

days together is completely not there.

8:41

And, you know, I don't know what time

8:43

of day he does his work or

8:45

I don't always know where he is

8:47

in space at any given time. Yeah,

8:50

I think I see what you mean, Becca. Like I

8:52

have two adult kids and they live

8:55

in a different city for me. And

8:58

I'd much rather be closer to them more of

9:00

the time. And you

9:02

know, in part, that's just about wanting to be close, like physically

9:04

close. Of course. But

9:06

when I do see them in person, then it

9:08

also feels different. It feels better, but in a

9:10

different way because we're occupying

9:13

the same time, not just

9:16

the same space. Even if nothing important

9:18

is happening, it's happening to

9:20

us together. I think that's exactly what

9:22

I miss is like that empty time we would share

9:24

with each other. So

9:26

Becca, there's space and there's time

9:30

and time is fundamental to existence,

9:32

just like spaces. But

9:34

our relationship with space and time as

9:37

human beings are very different from

9:39

one another. Right? Right. Like

9:42

you could go visit your brother in Sweden. You

9:44

could get on a plane and bridge that distance

9:46

if you wanted to or needed to. You

9:49

can move around in space If

9:52

you're like, you know, stuck in your car,

9:54

driving home, you know, and all I can

9:56

get home. But you will, you'll get home

9:58

eventually and then you'll be there. But you

10:01

can't really do that in time. He can't

10:03

move around in time. You can only go

10:05

in one direction. And. That's

10:07

forward. I

10:14

want to ask you more about the issue

10:16

and I was thinking about it as a

10:18

tried to prepare for our conversations. So I

10:20

have a I have three kids and to

10:22

them are grown up and one of them

10:25

as a lot is a lot younger and

10:27

before my youngest was born ah I did

10:29

I didn't think about her. At all.

10:32

Because he didn't exist. But

10:34

now. The. Idea of it. see

10:36

once. Didn't exist is kind

10:38

of impossible for me to to imagine

10:40

from him. and there's a name for

10:43

this. right is called the arrow of

10:45

Time isn't So what is that idea

10:47

mean? Well, arrow of Time just. In

10:49

response to that you just

10:51

described so beautifully is Sam.

10:54

We all feel this a

10:56

cemetery. Intuitively, we have a

10:58

great deal of anxiety about

11:00

the idea that we might

11:02

not exist in the future.

11:05

But. We're completely okay with the

11:07

idea that we did not exist

11:09

prior to some point in the

11:11

past. Not a semitism is just

11:14

built into us where we're not

11:16

to stress, see, believe that there

11:18

was some point before. Which your

11:20

daughter didn't exist. Yeah this.

11:23

Is just because we all fundamentally

11:25

seal the asymmetry. Wheatley Intuitive was

11:27

just part of our everyday experience.

11:30

Now we don't actually know. That

11:32

it's that farm. It is

11:35

conceivable many people have played with

11:37

this within the context of Einstein's

11:39

theory of Relativity that you could

11:41

find. A. Pass. Where

11:43

you did go backwards in time. And

11:47

they're all kinds of solutions that

11:49

we know exist mathematically. but we

11:51

think that at reality will forbid

11:53

these mathematical solutions. From ever

11:55

becoming actualized in the

11:57

universe. But we don't know.

12:00

For sure that the asymmetry it cannot

12:02

be violated. Does. That

12:05

contribute to our. Like.

12:07

Cultural obsession. With.

12:09

Time and the way that it slows for

12:11

I'm thinking here of like you know, Time.

12:14

Loops and their popularity and insane.

12:16

As soon as I wouldn't Senator

12:18

Doctor Strange likes the time dilation

12:20

effects in this domain. interstellar or

12:22

him or even like alternate timelines

12:24

are these examples and novels and

12:26

film of Playing With Time? What

12:28

do you make of those other

12:31

physicists like our cultural attempt to

12:33

wrestle with the arrow of time.

12:35

Yeah, I think it's a really

12:37

good way to challenge your belief

12:40

system. Our one of the things

12:42

we have to do and theoretical

12:44

physics is get over our intuitions

12:47

that are based on a very

12:49

limited experience of being a certain

12:51

size of alving under the sun

12:54

and having certain eyes as a

12:56

result of that and living a

12:58

certain duration and moving relatively slowly

13:01

so we don't really notice relativity

13:03

as an experience. So. With

13:05

beautiful actually to do it is

13:08

thought experiments in really challenge your

13:10

biases and try to break them

13:12

and see maybe we could go

13:14

backward in time. Maybe I said

13:16

i presume that just because it's

13:18

never happened to me said that

13:21

it couldn't have them. And

13:24

that there wouldn't be a physical, mathematically

13:26

realizable way to do them. And so

13:28

we we play those games all the

13:30

time. I

13:38

wondered in your job which is to

13:40

to think about Cosmic Sings how does

13:42

that impacts your daily life Week when

13:44

you're like you know commuting are going

13:46

to the grocery store, What is your

13:49

knowledge or understanding of the nature of

13:51

the universe? had a sick contribute to

13:53

your day to day life. Well

13:56

there's a lot of the scientists

13:58

who will say that. Whether

14:01

or not they're comfortable using

14:03

the word spiritual, that thinking

14:05

about these things gives them

14:07

a profound sense of meaning

14:09

and a connectedness. On to

14:11

something much faster than their

14:13

ordinary lives and I often

14:15

ah especially in our at

14:18

a time of. Great.

14:20

Pain and strife in trouble in

14:22

the world and I also and

14:24

lows meditate on the spurs. I

14:27

even beyond the bright side to

14:29

really imagine the earth under the

14:31

star. And the star

14:33

that's been burning for billions of

14:36

years and and then panning away

14:38

from the star and imagining this

14:40

entire solar system. all of us

14:43

silly little people warring together, orbiting

14:45

to gather around a supermassive black

14:47

hole twenty six thousand light years

14:50

away. And that that. Is.

14:52

Where we are, that is,

14:54

How. We got here and so do I think

14:57

about dance. If I get cut off on my

14:59

bike on my way over to the studio to

15:01

talk to you, ice, I don't. You

15:05

know, I'm shaking my fist in the

15:08

air and I'm impressed. Dated. But I

15:10

do believe that. In a

15:12

deep sense, it. Really has altered my sense

15:14

of who we are. In.

15:31

You know, people make like a five

15:33

year plan or like a ten year

15:36

plan. I've never, ever been that kind

15:38

of planner and that says he would

15:40

not. My experience of life or time

15:43

has ever been there. But I realize

15:45

that people can have this impulse control

15:47

their time because for her, your one

15:50

person in the universe had very little

15:52

control and all you can do is

15:54

map out. You know, maybe or weeks

15:57

may be or years in a way

15:59

that seals. It. It. Under your

16:01

control and hopefully at the end of

16:03

the day. feels like you've made the

16:05

most of whatever. Tongue tier devour? Yeah,

16:07

and you know, as down as explaining

16:09

that suing comes from the fact that

16:12

we can. I. We can go

16:14

forward and backward. And. Sideways and

16:16

space but we can't do the same

16:18

thing and time right and when it

16:21

comes down to it that sort of

16:23

this the fundamental puzzle and problem with

16:25

time that as as intellect normal sized

16:28

objects beings in the universe we cannot

16:30

go backward and so that feeling is

16:32

also weird you know but with like

16:35

black holes those are interesting to physicists

16:37

because there. There are exceptions

16:39

early potentially exceptions to that, the

16:41

normal rules of physics, and so

16:44

therefore, they offer this kind of

16:46

lenses through it's. Scientists.

16:48

Can look at time and understand

16:51

it better. You know that's great

16:53

for theoretical physicists, but. Not.

16:55

So great for the rest of us. Like

16:57

I don't have a black hole nearby Becca

16:59

that I can sort of ask questions about

17:02

truthfully? Yes, By. Wonder like are

17:04

there other lenses that ordinary people can

17:06

use to make sense of time? Re

17:08

I see like we humans need

17:10

a few ways to understand ourselves

17:13

better and even though it's not

17:15

directly related to physics in this.

17:17

Series. Called the Social Clock

17:20

which Bernice New Garden, a social

17:22

psychologist came up with in the

17:24

Nineteen sixties, can help explain that

17:26

fresher that we can seal that

17:28

we should be hitting certain social

17:30

markers at different stages of our

17:32

life at different ages. specifically. Okay,

17:35

Obviously the big things like

17:37

marriage, having children, but I

17:39

was thinking about how those

17:41

are norms dictated by society,

17:43

right? bus? Let's say you're

17:45

someone who. Was. Raised

17:47

with two cultures, then the social

17:49

class can have sort of different

17:51

terms depending. On when society or

17:54

which. Cultural norms you're trying to fit

17:56

into though. For keeping track a different time

17:58

zones if they keep track of. slow.

20:00

If it was true to time,

20:02

whatever that could possibly mean, you

20:05

would not have any scientific way of

20:07

measuring the passage of time. Johnny,

20:10

you mentioned change. Is

20:12

that all time really is, just change? We

20:16

do, yes, measure time through

20:18

change. If I were to,

20:20

a classic example,

20:23

take this glass of water I have

20:25

here and smash it to the

20:27

floor and film this for you.

20:30

You would absolutely believe the

20:32

movie had run forward in time

20:34

because you know that individual pieces

20:36

of glass everywhere and water splashed

20:38

everywhere, that that's the

20:41

logical way things unfold. They don't,

20:43

if I were to show you

20:45

the movie running backwards, reassemble into

20:47

a seamless glass with water inside

20:49

it naturally. That's not something we

20:52

see. What we

20:54

do see is we see change in

20:56

the direction of greater disorder. We

20:59

do not see change in

21:01

the direction of increased

21:03

order. That's also part of

21:06

the arrow of time conversation. If I were

21:08

to show you movies, you're always going to

21:10

be able to guess that one's running forward

21:12

in time if you see things going towards

21:14

greater disorder, like smashing

21:16

apart, more disordered. You're

21:18

always going to know they're

21:21

running backwards if you see

21:23

things perfectly reassembling. We

21:25

do seem to measure the

21:27

passage of time as tightly

21:30

correlated with the increase

21:32

in disorder. This

21:34

is making me feel a little more at peace

21:36

with the chaos in my own life, I think.

21:39

It reminds me of the fact that time

21:42

feels different at different times. A long

21:44

flight can feel really slow, but then

21:47

the vacation that you're flying to goes

21:49

by really quickly. Is

21:52

there a physical reason why

21:54

time feels different, or is that a

21:56

psychological thing? I think one of the explanations

21:59

could be just one. at

24:00

the end of their lives, a

24:02

lot of those sentiments have to

24:04

do with regret, with things that

24:06

those people are happy that they did or

24:09

things they wish they'd done. A few years

24:11

ago in a story for The Atlantic, the

24:13

writer Michael Arard explained how the dying

24:17

often use these metaphors of travel

24:20

to talk about their impending

24:22

death. Just trying to make

24:24

sense of what's happening to them.

24:26

Like... Wow. The

24:28

sentiment like if I could just find the map,

24:30

I'd know where to go next. The

24:33

way I understand that sentiment is that even

24:35

at the end of life when you know

24:37

there's no more moments left

24:39

and there's no choice but

24:42

to face the forward flow of

24:44

time into oblivion, people

24:46

still haven't, they still aren't fully come to terms with

24:48

it. They're still yearning to go back to

24:51

make changes or take comfort in the fact that

24:53

they can't go back and make changes but they

24:55

recognize that pull or that tension. My

24:58

own fascination with

25:00

the social clock stuff I think came from a

25:03

similar yearning to turn back the clock

25:05

and make the changes to my life

25:07

that would put me in line with

25:09

what I should have done and that's

25:12

the scary time thing. Ian, we're

25:15

all coping with that fact in

25:17

different ways. Everything

25:19

that no action, no sort of

25:22

doing anything can turn back the

25:24

clock. Almost

25:27

everything else we do involves going

25:30

back to some capacity as well.

25:32

Editing an email before we send

25:34

it, revising a text. We

25:37

can kind of do everything forwards and

25:39

backwards to elicit a

25:42

different result. Time

25:46

is just this sort of train I feel

25:48

like I'm on that's moving along

25:50

without my consent and

25:53

I just have to be okay with that. Yeah, that's what Jana

25:55

is saying. You're on the train. You're on the train,

25:57

Becca. It's like the constant

25:59

tragedy. of time that you

26:01

from 10 years ago will never return,

26:04

neither will you from yesterday, but it's

26:06

also like the great comfort of time.

26:09

Time allows change to happen. It allows

26:11

you to change. I

26:20

very much feel part of a vast

26:23

ecosystem going back to the Big

26:25

Bang. I really remember

26:27

learning that, and I

26:29

remember being floored at

26:32

the idea that there are atoms in my body

26:34

that are primordial. And of

26:36

course, many people say, you know, we're made of

26:38

stardust, and some of that primordial material went through

26:40

stars and had to be cast back out in

26:42

the universe and are in my body right

26:45

now, from a star. And

26:48

I know that that's something lots of people

26:50

know now and talk about, but there are

26:52

times where, yes, I can suspend

26:55

the feeling of that being just

26:57

an intellectual fact. And

26:59

actually feel a real

27:02

sense of comfort that there

27:04

will be a future where we

27:06

will all be part of that larger

27:09

ecosystem again. Okay, well, speaking of being

27:11

part of that larger ecosystem, it's almost

27:13

like a euphemism for a difficult topic

27:15

that we nevertheless have to talk about,

27:18

which is that if time

27:21

is change, part

27:23

of the change that we experience as

27:25

human beings is death. Like

27:27

we're gonna die someday, or even

27:30

before that, my kids will grow up and leave

27:32

the house and they won't be around anymore. Do

27:35

physicists have something to say about

27:37

that, about how humankind can

27:40

grapple with our minor role in the universe?

27:42

And you're kind of touching on that with

27:44

your own personal experience, but is there something

27:46

in physics that gives us

27:49

clues about how to live

27:51

without checking out or without

27:53

falling into existential despair? That's

27:56

a very difficult question, but I

27:58

have already left. behind a part

28:01

of myself that will never exist again. There

28:04

will never be seven-year-old me again.

28:06

There might be some deep sense

28:09

in which that does exist

28:11

seven-year-old me. It's just not one of

28:13

the movie frames I can make my way back to. There

28:17

are all these deaths along the way.

28:19

I have children and they'll

28:21

never be babies again. I will

28:23

never hold my little babies.

28:27

I think that when we kind of see it

28:29

that way and we begin to ask, what does

28:31

it mean to be me? I

28:34

left so much of that behind. Am

28:36

I still the same person? These are

28:38

philosophical questions. I think you're wondering,

28:41

what does a physicist have to

28:43

say about that? I think it's really

28:46

going to sound quite difficult, but the

28:48

physicist is likely to go as

28:50

far as to say, there

28:52

really is no self. You

28:56

are a collection of quantum particles

28:58

and interactions and

29:00

they change. We

29:02

see this all the time. I certainly

29:04

could take a chemical that would completely

29:06

change my chemistry and completely change my

29:08

personality. In what sense am I still

29:11

me? I could have an injury

29:13

to my brain and the tissue

29:16

is reoriented and

29:18

reconfigured. In what sense is that still me?

29:20

In what sense was it ever me? We

29:22

are just a collection of particles.

29:24

One day we will

29:27

go back into the

29:29

galaxy. What then is

29:31

the purpose or value of

29:34

your and my time on Earth in that

29:36

context? Well, this

29:38

is back to taking that astronomical

29:40

view of the Earth and why

29:43

people are so stirred by

29:45

things like the International

29:48

Space Station taking

29:50

a photograph of the Earth rising.

29:53

Earthrise, I believe it

29:55

helps us to understand that

29:58

so much that we take so seriously

30:00

is completely devoid

30:03

of any meaning. And

30:07

most of all, this kind of

30:09

notion of our differences, I think,

30:11

has been kind of historically catastrophic.

30:14

To think of all of us in this way

30:17

can be transcendent and it can

30:20

be quite unifying. And I

30:22

think it's okay to still say, I really

30:24

love the color green, even

30:27

if I believe it's only in my mind. I

30:30

can live with that. I can sit with

30:32

that. I

30:34

have one last question for you. In a

30:37

sentence, how do you define time? One

30:43

last question that people

30:45

have been wringing their hands

30:47

over for centuries and will for

30:50

centuries to come. If

30:54

forced, I would say,

30:56

to the best

30:59

of my present understanding, time

31:03

is a measure of change.

31:07

And I'm very unsatisfied with that answer. I almost

31:09

should be more rebellious and say, I can't do

31:11

that and I don't want to do that because

31:14

if I were to do that, I'd be saying

31:16

something so tricky. So for instance, it

31:18

would be very easy for me to argue

31:20

with that statement and say,

31:23

well, what do you mean change? Change happens

31:25

over time. We're caught in a little loop.

31:28

I could say something like time is a

31:30

dimension, but it's a dimension

31:32

that has an arrow where

31:35

you're forced to always move in a

31:37

particular direction. So it's a dimension just

31:40

like north, south, east,

31:42

west, up and down spatial dimension.

31:44

But it has this weird

31:46

restriction that I can

31:48

only move in one direction in

31:51

that dimension. Why does

31:53

it have the arrow of time? Well,

31:55

that is a hotly debated topic that

31:57

will continue to go on, but some

31:59

signs