0:06

Man made black holes, low

0:08

energy vacuum bubbles, strange

0:11

lits. These are some of the

0:13

ways that an ill conceived physics

0:15

experiment could pose an existential

0:18

risk, not just for humanity,

0:20

but for all life on Earth and

0:23

possibly for every atom

0:25

in the universe if things go particularly

0:28

badly. Physics experiments

0:30

seem like an unlikely place to find

0:32

a clutch of existential risks, but

0:35

it makes sense. Really. There are

0:37

no other branches of science that explores

0:39

the places where something is magic. Is

0:42

accidentally creating a tiny black hole

0:44

could happen. Physics

0:46

is the purest branch of science. Back

0:49

in the thirties, physicist Ernest Rutherford

0:51

put it something like all science is

0:54

either physics or stamp collecting.

0:57

Physics, in particularly particle

1:00

physics, is the place where the leading

1:02

edge of science explores new frontiers

1:04

of the universe. It's as literal

1:06

as that. But we are still

1:09

at an early spot in our understanding of

1:11

particle physics, in the place

1:13

in human history where you and I live. Now,

1:16

those forays by the leading edge of science

1:19

are blind pokes in the dark, and

1:22

we face a dilemma because of this. We

1:24

can't understand the universe without

1:27

poking at it, but we can't

1:29

really say if poking at it is safe

1:31

until we poke it. The

1:34

idea that particle physics could end the world

1:36

sounds like nothing more than paranoid fantasy,

1:39

born from something like fear of science

1:42

and it's big, hulking machines that blast

1:44

invisible particles into one another, but

1:47

concerned that dangerous exotic stuff

1:50

could be created inside a particle collider

1:52

come from the physics community itself.

1:55

Physicists are aware that they know enough

1:58

about physics to build machines that can simulate

2:00

nature, but don't know enough

2:02

to say for certain just what will

2:05

happen inside those machines. We

2:07

don't know enough to know that those experiments

2:10

were running are existentially safe,

2:13

but we're doing them, pushing the envelope

2:15

anyway and hoping for the best. To

2:19

understand how things like low energy vacuum

2:21

bubbles and man made microscopic

2:23

black holes could accidentally be made here

2:26

on Earth, you have to know a few things about

2:28

physics first, and I will tell

2:30

you everything you need to know. To

2:32

start, I'll need you to hold your hand

2:34

up in front of your face. I

2:40

want you to focus on, say, the back of

2:42

your hand. Hold it up in front of you.

2:45

Gaze upon it, kind of lose

2:47

yourself in it. Let your

2:49

eyes come in and out of focus,

2:52

so that your hand becomes the only thing

2:54

in the world. Now, find

2:56

some little spot on your hand and focus

2:58

on it. Let your self be drawn into

3:01

that spot, drawn into your

3:03

hand. As you travel

3:05

into that tiny point on your hand, you

3:07

will grow smaller and smaller

3:10

and smaller, so that

3:12

you can pass easily through your

3:14

own skin, past your bone,

3:17

and into your veins, further

3:20

and further inward, growing smaller

3:22

as you descend, shrinking

3:24

through your blood and plunging into

3:27

one of the giant, gummy disc

3:29

red blood cells in it, growing

3:32

smaller and smaller, so that you pass

3:34

right through the cell walls untouched, smaller

3:37

and smaller among the galaxy

3:40

of a hundred and twenty trillion atoms

3:42

that make up a single red blood cell. Plunging

3:45

into the electric cloud that envelops

3:48

one single fuzzy oxygen

3:50

atom, you are surrounded

3:53

by the electrical field, like a fog that

3:55

encapsulates the nucleus and binds

3:58

the electrons to it A million miles

4:00

away. Here inside the

4:02

atom, you will learn the truth of

4:04

the universe. Everything

4:07

looks different than what you've always learned in

4:09

school. There is no atomic

4:11

solar system, with the nucleus as

4:13

the sun and the electrons like planets

4:16

in orbit. The electrons are everywhere

4:19

and yet nowhere at once and

4:21

at the center. There is no proton,

4:23

no neutron. There are no particles

4:26

like tiny pieces of matter, like crumbs

4:28

of the universe. There are

4:31

only vibrations of energy.

4:34

These are the true building blocks of the universe,

4:37

the corks and the gluons and

4:39

all of the other elementary particles that make

4:41

up everything that the material world

4:43

is built from. You are

4:46

here in the quantum world,

4:49

and now that you look around, you

4:51

see that there are vibrations everywhere.

4:54

All around you, you see fields of

4:56

different kinds of energy passing

4:59

through each other, interacting with

5:01

one another. And within those energy

5:03

fields are countless moving,

5:06

pulsating vibrations. Look

5:09

back upward, now up from your

5:11

place in the quantum field, pass

5:13

the atoms to the cells and out of your

5:15

hand. Look up to your own face

5:18

and to the sky and the sun behind you.

5:21

All of those things, you, the

5:23

sky, the sun are made up

5:25

of spectacularly complex

5:27

arrangements constructed from

5:29

the energetic vibrations of complimentary

5:32

force fields, entangled by

5:34

irresistible forces until

5:36

time runs its course for them and

5:38

their arrangement collapses when

5:41

they break down and travel along

5:43

their fields until they are attracted

5:45

into some new arrangement. From

5:47

a frog as it dies, to the algae

5:49

of a pond that decomposing, to

5:52

the belly of a fish, to the mouth

5:54

of a mother, to the iris of a newborn

5:56

child. The cycle of life

5:59

and death is nothing more than

6:01

the movement of energy along a universe

6:03

of force fields. You

6:07

can see now that everything, every

6:09

site you've ever seen, everything you've

6:11

ever touched, everything you've ever

6:14

smelled or tasted, every

6:16

emotion you've ever felt, all

6:19

of it is made from the interaction

6:21

of the energy fields that make up our universe.

6:25

Even you, you can see now that you

6:27

are a bundle of discrete vibrations

6:29

held together by attractive forces

6:32

in the hyperlocal area of the universe

6:34

that until a few moments ago you

6:37

always thought of as your body. Pinch

6:40

your thumb and your index finger together tightly.

6:42

The sensation of pressure that you feel, there's

6:45

nothing more than the electromagnetic force

6:48

pushing back against itself. Physicists

6:52

have known all of this for more than a

6:54

century, and now you see

6:56

the true nature of the universe. Every

7:00

thing is energy.

7:09

All of the vibrations in the universe, and

7:11

so all of the matter in the universe are

7:13

remnants of the energy left over from the

7:16

Big Bank. Almost every vibration

7:18

unleashed, and the first trillions of a second after

7:20

the Big Bank came in equal and opposite

7:23

pairs, and they canceled each other

7:25

out. They annihilated each other, almost

7:28

all of them, but not all. This

7:31

is Don Lincoln. He's a physicist at

7:34

Fermi Lap near Chicago. Very

7:36

early on in the universe, there was some asymmetry,

7:39

some little difference between the two of them.

7:42

And what happened is there was

7:44

a very slightly larger

7:46

number of matter vibrations than antimatter

7:48

vibrations, something to the

7:51

tune of three billion to three

7:53

billion and one. And then the

7:55

three billions canceled and the

7:57

one was left over. And that's the matter of abrations

8:00

that are left that make up the

8:02

what we see now in our universe. Why

8:05

there is something and not nothing

8:07

is one mystery that particle physicists have

8:09

run across while plumbing the void. Another

8:12

is exactly where our universe came from.

8:16

It's looking increasingly likely that there

8:18

was nothing that came before that

8:20

our universe erupted randomly from an

8:22

aberration in an energy field, like

8:25

a bubble of steam rising in a pot

8:27

of boiling water, and in

8:29

fact, the basis of a theory by

8:31

physicist Roger Penrose from Oxford

8:33

University called conformal cyclic

8:36

cosmology, says that this

8:38

is just the way that universes are formed.

8:41

One bubbles up, lives, dies,

8:44

and leaves nothing behind but the remnants

8:46

of the black holes that formed in it, which

8:48

are scooped up in the structure of the

8:50

next universe that bubbles up to replace

8:53

the old one. To us living

8:55

in this universe, such a process

8:57

would take the longest scales of time

8:59

a man tenable, but to someone

9:02

with a different perspective of time, perhaps

9:04

watching universes bubble up, collapse,

9:07

and bubble up again might be like

9:09

watching a pot of water simmer. All

9:12

of this is to say that if our universe

9:14

arose from an aberration in an energy

9:17

field, or from the remnants of the collapsed

9:19

universe that came before ours, then

9:21

it could happen again. Our

9:23

universe could be reborn in a

9:25

different form within itself and

9:29

from a closer look at the Higgs field, it

9:32

appears that it's constantly trying to do

9:34

just that. One

9:42

of the energy fields that make up our universe

9:45

is the Higgs field. It is the field

9:47

that gives mass to other energetic

9:49

vibrations. Without the Higgs

9:51

field, nothing would have mass, which

9:54

means that the Higgs field is the energy

9:56

field that allows you and all other

9:59

matter in the universe to physically exist.

10:02

Without mass, there cannot be matter

10:04

to be bound together, and without

10:06

matter, there cannot be chemistry, which

10:08

binds that matter together and creates

10:10

new forms of matter. And so

10:13

without chemistry there can be no life,

10:16

which means without the Higgs field, there

10:18

can be no life, which

10:20

is one reason the Higgs boson. The

10:22

particle that carries the energy of the Higgs

10:24

field and interacts with other particles, is

10:27

called the God particle. The

10:29

other reason is that God particle

10:32

was originally short for the God damned particle,

10:35

which is what physicists called it because

10:37

it eluded them for so long. It

10:40

seems a bit heavy, but think of mass is

10:42

just another property that a vibration can

10:44

have, like how a ball can

10:46

be read, round and bouncy

10:49

all at the same time. When

10:51

you know what properties of ball has, you

10:53

can predict what it will do in any given situation.

10:56

Like if you drop the ball, you can say

10:58

that it will probably bounce a couple of times and

11:01

then roll away. And since

11:03

it's red and round, you know what

11:05

to look for when you go try to find

11:07

it in the grass to get it again. The

11:10

same goes for sub atomic particles

11:13

too. Their properties,

11:15

like their electrical charge and their mass,

11:17

let physicists predict how particles

11:20

will interact with particles from other energy

11:22

fields. And since everything

11:24

is energy, if you can understand

11:27

how every energetic particle interacts,

11:30

you can understand everything.

11:34

And since Einstein showed the world with his

11:36

E equals MC squared equation

11:39

that mass and energy or just

11:41

two sides of the same equal sign, you

11:44

can just look at mass like it's just another

11:46

type of energy, which it is. When

11:50

a vibration arises, let's say

11:52

a cork from the cork field, it

11:54

interacts with the boson from the Higgs field,

11:57

almost like it's coded by it. And

12:00

now that cork has mass, so it

12:02

can be acted on by other fields

12:04

like the gravity field. These

12:06

fields, the cork field, the gravity field,

12:08

the Higgs field, all of the fields,

12:11

they are everywhere, at every point

12:13

in the universe. The

12:15

Higgs is the only field that can give mass

12:17

to other vibrations, and it has

12:20

another unique property too. It

12:22

is the only field that still has an

12:24

energy when it's turned down to zero,

12:28

which is surprising. If

12:30

you could turn down all of the energy fields in

12:32

the universe to zero on some master

12:35

universe style, there would be no

12:37

electrons at all in the electron field,

12:39

no corks, no glue ons,

12:42

all of the energetic vibrations would cease,

12:45

and yet energy would still persist

12:47

in the Higgs field. It's

12:50

like if you turn down the volume on this show

12:52

to zero, yet you could still

12:54

make out faint pops and crackles in your

12:56

headphones. It would lead you to believe

12:58

that there was some setting below zero

13:01

that you could turn the volume down to. Well.

13:04

Physicists have arrived at the same conclusion

13:06

about the Higgs field, but

13:08

this opens up an unsettling possibility.

13:11

If the Higgs field isn't currently at

13:13

its lowest energy state, and

13:16

the Higgs field is what gives matter mass,

13:19

then if the Higgs field ever slipped into

13:21

that lowest energy statement, the mass

13:23

of everything in our universe would suddenly

13:26

change. In other words,

13:28

we would all disintegrate. This

13:31

is theoretical physicist Ben Schlayer

13:33

from the University of Auckland in New Zealand.

13:36

Particle physics and the corresponding

13:39

chemistry would be suddenly very different, and

13:41

in particular, matter would no longer

13:43

be at the right size. The

13:46

different sizes of the atoms that make up

13:48

matter are based on the distance between

13:51

the electrons and the outer periphery and

13:53

the nucleus at the center. If

13:55

electron suddenly got heavier, adams

13:58

would shrink into smaller size,

14:01

which means everything in our universe would

14:03

suddenly shrink. All of the matter

14:05

around us would suddenly find itself unstable

14:08

to a great shrinking, and as

14:10

it shrank, it would give off a huge amount of

14:13

electromagnetic energy. So they'd

14:15

be an explosion of X rays and that

14:17

would be a pretty violent event. Two

14:19

theoretical physicists, Sidney

14:21

Coleman Frank DeLucia determined

14:24

back in that this

14:26

new lower energy state of the universe

14:29

would not support chemistry, which

14:31

means that life would not have the chance to

14:33

re evolve in this new version of our universe.

14:36

They called this vacuum decay

14:39

and said that it was the ultimate ecological

14:41

catastrophe. But

14:44

things can actually get worse from there because

14:47

the shrunken universe is denser than it was

14:49

before. That means gravity acts

14:52

on all of the mass throughout the universe more

14:54

forcefully, too, so

14:56

that vacuum bubbles outward. Expansion

14:59

will eventually be and then

15:01

reversed as it's pulled backward,

15:03

returning to where it started, like an

15:05

implosion, forcing all matter

15:08

into an infinitely dense, infinitely

15:10

tiny ball, possibly the very

15:13

same place where our universe started

15:15

from. This is called the Big

15:17

crunch. It's the antithesis

15:19

of the Big Bang. Spacetime

15:21

ends and the universe ends. In a big

15:23

crunch, it would be like

15:26

our universe never happened. That

15:31

the Higgs field has balanced between its

15:33

current state and the lower energy version

15:35

of itself means that it poses

15:37

a natural existential risk to

15:40

us. If it moved into that

15:42

lower energy state, that would be

15:44

it for not just human existence,

15:46

but for everything in the universe. So

15:49

the Higgs field actually poses a universal

15:52

existential risk for

15:54

now and for the foreseeable future. At

15:56

least, the Higgs field is in a state

15:58

called meta stable. The

16:01

good analogy is a puddle in a valley

16:03

at the bottom of the hill. On

16:05

the other side of the hill, say there's an even

16:07

lower valley, and the Higgs puddle

16:10

would be happy to settle into that lower

16:12

one. But it would take a tremendous

16:14

amount of energy for the puddle to move

16:17

itself up the hill to the other

16:19

side, energy that the puddle

16:21

doesn't have, so the Higgs

16:23

field won't be moving up the hill. But

16:26

there's another way that it could slide into

16:28

that lower energy state. Unnervingly,

16:32

the Higgs is constantly trying to tunnel

16:34

through that metaphorical hill to get

16:36

to the lower valley on the other side, and

16:39

this attempt to tunnel through comes

16:41

in the form of indescribably small

16:44

pockets of this other lower

16:46

energy version of the Higgs field that at

16:48

every moment bubble up from it like a

16:50

simmering pot. But

16:52

these lower energy Higgs bubbles are too

16:55

weak to overcome the external pressure

16:57

or universe exerts on them,

16:59

so they wink out of existence just as

17:01

fast as they arise. The

17:04

trouble is that if one of those lower

17:06

energy bubbles ever does manage to

17:08

stick around long enough to stabilize and

17:10

grow, it would swallow our

17:13

universe and bring about that vacuum

17:15

decay that Coleman and DeLucia wrote

17:17

about and disintegrate our

17:19

version of the universe. It

17:22

would be a big crunching deal, you could

17:24

say, But probability

17:26

is on our side. Under normal

17:29

circumstances, the chances of one

17:31

of those lower energy version bubbles

17:33

growing are so low it's

17:35

not expected to happen over the estimated

17:38

lifetime of our universe, so

17:40

we appear to be in the clear again.

17:43

Though that's under normal circumstances.

17:46

We humans have a tendency to alter

17:49

normal circumstances, and

17:51

there's a way that the Higgs field campose

17:53

an anthropogenic existential threat.

17:56

A vacuum bubble could grow with

17:58

the help of a microscopic black hole, which

18:01

we might actually create. Inside

18:03

one of our particle colliders. Here

18:05

on Earth, m

18:25

about a hundred meters beneath the countryside

18:28

where Switzerland juts up from the southeast

18:30

into France. Above sits

18:33

the Large Hadron Collider, the

18:35

largest highest energy particle

18:37

collider in the world. Hadron

18:40

is a name for sub atomic particles

18:43

like protons and neutrons that are

18:45

made up of quarks and gluons.

18:47

Those energetic vibrations that

18:49

make up matter. If you

18:51

could go inside the LHC reduce

18:54

yourself back again to the scale of those

18:56

energetic vibrations, you would

18:58

see something spectacular. The

19:02

protons in the Large Hadron Collider

19:05

are created by passing a laser

19:07

through a cloud of hydrogen gas,

19:09

which breaks the atoms apart. Those

19:12

stripped protons are directed into

19:14

the LHC's vacuum tubes by

19:16

an electrical current, and they're separated

19:19

into two beams that are kept apart

19:21

and sent in opposite directions

19:23

around the elliptical collider. Over

19:26

the course of days, the beams are accelerated

19:29

until they reach unimaginably fast

19:31

speeds point

19:34

nine

19:34

nine nine one

19:37

percent the speed of light, where

19:39

a single proton can make the trip

19:41

around the seventeen mile circumference of

19:43

the collider more than eleven

19:45

thousand times in a single second.

19:49

At these speeds, the protons carry

19:51

with them as much as five trillion

19:53

electron volts of energy, an

19:55

extraordinary amount for something so small.

19:58

It's like a mosquito with the kinetic

20:01

energy of a planet. When

20:03

the beams are at their highest speeds, they're

20:05

directed into each other so that they cross

20:08

inside of one of the collider's enormous

20:10

sensitive detectors. Every

20:13

second a billion collisions take

20:15

place, and the energy from those impacts

20:18

turns into mass, which creates

20:20

particles for just a fleeting moment

20:23

that we're around right after the Big

20:25

Bang. So the LHC is

20:27

a way to rewind nature, to study

20:29

its origins. To me, it's like

20:32

I think of using particle colliders

20:34

to understand the universe as an exploration. We're

20:36

like looking for new stuff and you never know what you find.

20:39

You know, this is particle physicist

20:41

Daniel Whiteson from the University

20:43

of California, Irvine, And one

20:45

strategy we have to understand these things

20:48

is just to look for patterns among the particles.

20:51

And the way to look for patterns is to see more of

20:53

them. That's the goal of using the LHC

20:55

to explore the universe. We want to find

20:57

more particles, get more clues, see

21:00

sort of a larger window into

21:02

the reality that we're seeing currently, and

21:05

hopefully get some insight. The Large

21:07

Hadron Collider was first brought online in

21:09

two thousand nine after decades

21:11

of planning and construction, and

21:13

it woke up in a world where the field

21:15

of particle physics had hit a wall.

21:19

The LHC was designed to break through

21:21

that wall. It was designed,

21:23

you could say, to break physics.

21:30

The work of particle physics can be divided

21:32

between two groups. On the

21:34

one hand, you have theoretical physicists.

21:36

They come up with all the ideas about how

21:38

the universe might work, and on

21:40

the other hand, you have experimental physicists

21:43

who test those ideas in machines

21:45

like the Large Hadron Collider. The

21:48

work of these two groups forms in aura

21:50

borros, the mythical snake that

21:52

eats its own tail. The experimental

21:55

physicists find support for the

21:57

theoretical physicist theories, or

21:59

they say that they're wrong. The

22:02

experimental physicists also come up

22:04

with new data that the theoreticians

22:06

can use to create entirely new

22:08

theories that the experimental physicists

22:11

can then test. As a deeper

22:13

understanding of particle physics develops, the

22:15

snake grows fatter. In

22:19

the nineties, sixties and seventies, the

22:21

theoretical physicists dropped a huge

22:24

amount of new work on the desk of the

22:26

experimental physicists. A

22:29

group of theoreticians wrote down everything

22:31

science knew about the quantum world

22:34

and What they came up with is a set of formulae

22:37

known as the Standard Model of particle

22:39

physics. Over the decades,

22:42

the Standard Model has been proven correct

22:44

again and again. The

22:47

Standard Model does a really good job at

22:49

describing the particles that exist in the quantum

22:52

world and the forces that govern them.

22:54

The strong nuclear force binds protons

22:57

and neutrons into the nucleus of an atom.

23:00

The weak nuclear force causes atoms

23:02

to decay over time. The

23:04

electromagnetic force binds atoms

23:06

together into higher structures like you and

23:09

meat, and the sun, and mosquitoes

23:11

and red blood cells. Every

23:13

particle that the Standard Model predicted

23:15

should exist by now has been discovered.

23:18

It is, as scientists put it, an

23:20

extremely reliable model to

23:22

describe the quantum world. The

23:25

last of the bunch was the Higgs boson,

23:28

which the LHC found in two thousand

23:30

twelve, and with that discovery the

23:32

experimental physicists exhausted

23:35

the theoreticians standard model. But

23:38

as good as the Standard Model is, as

23:40

reliable as it is, it's been

23:43

incomplete from the very beginning. It

23:45

has no place for gravity, and

23:49

vice versa. With Einstein's famous

23:51

theory of relativity. It's

23:53

proven extremely reliable at

23:55

describing how gravity governs the interaction

23:57

of large scale things like people

24:00

and planets. But the other three

24:02

fundamental forces, electromagnetism

24:04

and the weak and strong nuclear forces don't

24:07

fit into the equation partum field

24:09

theory. It really doesn't deal with

24:11

the universe as a whole, and

24:14

it's well known that general relativity does

24:16

not merge in mill well with

24:18

a quantum realm. So what physics

24:20

has on its hands are the standard model

24:23

and the theory of relativity too

24:25

totally accurate but totally

24:27

incomplete pictures of the universe that

24:30

won't fit together to form a cohesive

24:32

whole. It's almost like they repel

24:34

one another. Particle.

24:37

Physicists built the large hay Drown Collider

24:39

to figure out why that is. They

24:42

hope that the incredibly high energy collisions

24:45

will produce new particles that

24:47

don't fit into the standard model to

24:49

show where physics should start looking next.

24:53

One of the biggest mysteries of all that

24:55

physicists are hoping to solve is

24:57

why gravity is so weak compared

24:59

to the other three fundamental forces. It's

25:02

strange. Gravity is the force

25:05

that keeps planets in orbit around massive

25:07

stars and can catch light

25:09

by the ankles and prevent it from escaping a

25:11

black hole. Yet the other

25:13

three forces are stronger, and

25:16

you can see this for yourself if you just lay

25:18

a paper clip on a countertop and hold

25:20

a regular old refrigerator magnet over

25:22

it. As you bring the magnet closer,

25:25

the paper clip will eventually rise to

25:27

meet and stick to it. What

25:29

you've just seen is the electromagnetic

25:32

force and that tiny magnet overcoming

25:34

the gravitational force exerted

25:36

by the entire mass of planet

25:39

Earth. Like

25:41

I said, strange. To

25:44

make sense of this, and to unify relativity

25:46

in the standard model into a theory of everything,

25:49

some physicists have taken to adding

25:51

new dimensions to our universe. Some

25:55

models see our four dimensional world

25:57

of length, with height and

25:59

time as just a tiny membrane

26:02

floating within an infinitely larger

26:04

fifth dimension that we can't sense,

26:07

called the bulk. Others

26:09

include as many as eleven total dimensions,

26:12

most of which are curled up into extremely

26:14

tiny coils at the corners

26:16

of every point in the fabric of spacetime.

26:20

These models explain why gravity

26:22

is so weak by allowing it to

26:24

spread across all of the dimensions.

26:28

The other three forces, like us

26:30

are trapped within our four D world,

26:33

but gravity is not. And if

26:35

we could sense all five or eleven,

26:37

or however many dimensions there are, we

26:39

would see that gravity has the same

26:42

strength as the other three forces. It

26:44

just seems weak to us because it's

26:47

diluted by comparison inside

26:49

our four D world. So

26:51

one way that physicists are hoping that

26:53

the LHC breaks physics is

26:55

by revealing the presence of other

26:58

dimensions. And a really

27:00

good way to demonstrate that there are other dimensions

27:03

would be to create a microscopic

27:05

black hole. Those aren't supposed

27:07

to exist in our four D world until

27:16

the idea came along that's such a thing as

27:18

microscopic black holes could exist. We

27:21

used to think that we understood black holes

27:23

pretty well. It was sort of a golden

27:26

age of black hole understanding. We

27:29

learned over time that black holes were gaping,

27:32

all consuming, horrific abominations

27:34

in space time, with masses so

27:37

huge that they boggle the mind. Sure,

27:40

but we could feel good about them.

27:42

We understood them, and we

27:44

were here, and they were a way out

27:46

there. They had no way to touch

27:48

our world, let alone end it. From

27:52

studying them, we found that black holes

27:54

were created when some incredibly

27:56

massive star far larger than

27:58

our Sun, exhaust at its fuel

28:00

and collapsed under an unimaginable

28:03

force of gravity into an infinitely

28:05

dense, smaller version of itself

28:07

that actually pushed a bottomless

28:09

pit in the fabric of time and space.

28:13

Encircling the rim of this black hole is

28:15

the event horizon, the threshold

28:18

where the gravitational poll is so strong

28:21

that anything crossing it is doomed

28:23

to be forever trapped inside the black hole,

28:25

torn apart by the unimaginable

28:28

gravity with it. Over

28:30

time, we began to notice black holes

28:33

everywhere we could detect

28:35

them, ripping apart nearby stars, pulling

28:37

them into a ring of hot gas, and circling

28:40

the event horizon like water around

28:42

a drain. We began

28:44

to find them at the center of galaxies, including

28:47

our own Milky Way, which nourishes

28:49

a monstrous, supermassive black hole

28:52

the size of four million of

28:54

our sons. We saw

28:56

that black holes could cannibalize other black

28:58

holes, which forms even larger

29:01

black holes, and perhaps

29:03

the fate of our universe was to one

29:05

day be swallowed into one giant

29:07

black hole made up of every black

29:09

hole that's ever existed in every

29:12

universe that's ever existed, But

29:15

like any good golden age, this

29:17

one was not meant to last. It

29:20

ran from the time black holes were predicted

29:22

in Einstein's theory of relativity in nineteen

29:24

fifteen until about the mid seventies,

29:27

when a not yet world famous physicist

29:30

named Stephen Hawking proposed

29:32

some ideas about black holes

29:34

that suggested that maybe we didn't understand

29:36

them so well after all. For

29:40

starters, Hawking and his colleagues proposed

29:42

that black holes didn't have to be made of

29:44

something as big as a star. Black

29:46

holes could actually be incredibly tiny.

29:50

This was news. It's

29:52

true that anything with mass can

29:54

be turned into a black hole if it's made dense

29:56

enough. If the Earth were condensed

29:58

to do a black hole, it would have an event horizon

30:01

about as big around as your index

30:03

fingernail. But as far

30:05

as physicists understand it, the

30:07

Earth could never actually become a black

30:09

hole because it simply doesn't have enough

30:12

mass for gravity to collapse

30:14

it into that infinite density.

30:17

It takes a truly sincerely

30:19

massive object like an enormous

30:21

star to undergo that sort of

30:23

transformation. What

30:26

Stephen Hawking and his colleagues realized

30:28

back in the seventies is that there

30:30

are actually times in the universe's distant

30:33

past, say within trillions

30:35

of a second after the Big Bang, when

30:38

everything was much much

30:40

denser, and so during

30:42

this time, something with a mass

30:45

like the Earth's could have collapsed into

30:47

a black hole back then, and

30:49

much much smaller things could have two, maybe

30:53

even particles. Hawking

30:55

called these hypothetical particle sized

30:57

black holes that may have formed in the

31:00

very early universe primeval

31:02

black holes. Today people

31:04

call them microscopic black holes. In

31:08

addition to his theory that such a thing

31:10

as very tiny black holes could possibly

31:12

exist, there was another thing that

31:14

Hawking realized that brought our golden

31:16

age of understanding black holes to an

31:19

abrupt end. It

31:21

was actually possible for them to spit

31:23

matter out. He said this was

31:25

news too. Our understanding

31:28

of black holes at the time was that they did nothing

31:30

but consume, ceaselessly, growing

31:33

eternally. The idea that

31:35

they could spit stuff back out was pretty

31:38

revolutionary. The

31:40

idea that black holes could actually radiate

31:42

energy came to be called appropriately

31:45

Hawking radiation, and Hawking

31:48

showed that a black hole could emit photons

31:50

and gravitons, the particles that

31:52

carry electromagnetic energy and

31:55

gravitational energy, respectively. Normally,

31:58

these particles don't have matt mass,

32:00

they don't interact with the Higgs field. But

32:03

what Hawking figured out is that the

32:05

less massive a black hole is,

32:08

the hotter the temperature of the radiation

32:10

that it spits out, which

32:12

means a very very tiny, microscopic

32:15

black hole with a very very small mass

32:18

would actually have extremely hot

32:20

radiation because its mass is

32:22

so small that radiation

32:24

could be hot enough. Hawking realized

32:27

that the photons and gravitons

32:29

the black hole spit out could actually

32:32

have mass themselves. And

32:34

here's why temperature

32:36

is a measure of heat. Heat

32:39

is a form of energy, so

32:41

high temperature means high energy.

32:44

And since mass and energy are

32:46

two sides of the same coin, E equals

32:49

mc squared. Remember, mass

32:51

and energy are theoretically interchangeable,

32:54

which means that heat can be translated

32:56

into mass. Another

32:59

way you could put it is that if the energy

33:01

of a normally massless particle like

33:03

a photon or a graviton has

33:05

a high enough energy, it will

33:07

interact with the Higgs field and get coated

33:10

with mass, and a microscopic

33:12

black hole could produce photons

33:15

and gravitons with energies that high.

33:18

If Hawking was correct, then that

33:20

means that over time a tiny

33:22

black hole could actually lose mass itself

33:25

as it spit out photons and gravitons

33:28

with their own mass, and at some

33:30

point, when the microscopic black hole

33:32

lost enough mass, it would wink

33:34

right out of existence. Black

33:37

Holes aren't supposed to do this. It

33:40

seems we didn't understand black holes nearly as

33:42

well as we thought we did. Are

33:44

comfortable Golden Age came to an

33:46

end. It's

33:53

about here where the story begins

33:55

of how cern, which actively messes

33:58

with the mass and energy of particles, took

34:00

up a long time quest to prove

34:02

that it's large hadron collider won't

34:05

do humanity. Actually,

34:07

wait, it begins a little before the

34:09

LHC came along. The story

34:12

really starts. In that

34:16

year was, as far as anybody knows, the

34:19

first time anyone seriously raised

34:21

the idea that a particle collider

34:23

might be able to end the world. Scientific

34:27

American Magazine published a letter from

34:29

a reader who wasn't so sure

34:32

that the relativistic heavy ion Collider

34:34

at the Brookhaven National Lab in New York

34:37

nicknamed the Rick, was entirely

34:39

safe. The reader was concerned

34:42

that the rick might produce a microscopic

34:44

black hole, the kind of thing that Hawking

34:47

proposed, when particles collided

34:49

inside of it. Scientific

34:51

American published the reader's letter along

34:54

with a response by a physicist named Frank

34:56

will Check, and will Check pointed

34:58

out classical six doesn't allow

35:00

for microscopic black holes to exist

35:03

at all. That's point one. Point

35:05

two was that even if the theories

35:08

that include additional dimensions,

35:10

theories that are beyond classical physics

35:13

and actually do allow for microscopic black

35:15

holes to exist, if those additional

35:17

dimensional theories turn out to be true, the

35:20

energies of the particle collisions in the rick

35:22

were still far too low to actually

35:25

create a microscopic black hole. So

35:27

no worries, Well, there

35:30

was one worry. At least. Will Check

35:32

did mention that it was much more

35:34

likely the Rick could produce an exotic

35:36

type of matter called a strangelet.

35:39

Strangelets are heavy particles made

35:42

of smaller vibrations called strange quarks.

35:45

Despite their heavier size, they're actually

35:47

lower energy than typical strange

35:49

quarks, which means that the universe

35:52

would prefer them over strange corps. It's

35:54

just that strangelets tended as all very

35:57

quickly because of their higher mass. The

36:00

concern over strangelets is that if

36:02

one of them didn't dissolve into elementary

36:04

particles, it could conceivably set

36:06

off a chain reaction, lowering

36:08

the energy but increasing the mass

36:10

of the matter that makes up Earth, converting

36:13

our planet and everything on it, including

36:15

us, into a massive, inert

36:18

dead bulk. Will

36:21

checks offhand comment at the end of his reply

36:24

set off a separate, years long tangent

36:26

of uneasiness and investigation into

36:28

strangelets and whether they have the goods

36:30

to pose in existential risk themselves.

36:33

But at least the microscopic black hole

36:36

terror was put to bed, or

36:38

so it seemed. The terribly

36:40

disconcerting idea of a man made black

36:43

hole has a habit of winking into existence

36:46

again and again. A

36:48

couple of years after the Scientific American

36:50

readers black hole question was asked

36:52

and answered, the looming specter of

36:54

a potentially world ending black hole

36:57

created in a particle collider rose

36:59

again, like a new universe

37:01

rising to replace an old one. This

37:04

time the collider in question was

37:06

the Large Hadron Collider, which

37:08

was beginning to be assembled in Europe. This

37:11

time around, the fears weren't quite so

37:14

unfounded, because the energies

37:16

of the collisions in the Large Hadron Collider

37:18

are an order of magnitude higher than

37:21

the ricks, high enough, in fact,

37:23

that if any of those multidimensional theories

37:26

are correct, the LHC should

37:28

be fully capable of producing microscopic

37:30

black holes inside of it. So

37:33

capable, in fact, that a two thousand

37:35

one paper by physicists Stephen

37:37

Gettings called the LHC a

37:39

black hole factory and calculated

37:42

that it could produce a microscopic black

37:44

hole every second it's proton beams

37:46

were crossed. Now

37:49

it's here where CERN began its long standing

37:51

quest to prove the Large Hadron Collider

37:53

is safe. On the one hand,

37:56

the idea that the LHC might be able to break

37:58

open the current understanding of the universe

38:00

and point theoretical physicists in a

38:02

clear new direction is intensely

38:04

exciting for the particle physics community.

38:07

But on the other hand, CERN was much

38:10

less excited about the idea of

38:12

everybody else seeing their machine as a

38:14

black hole factory that could end the world.

38:17

And it's pretty easy to understand why

38:20

the funding for certain at any given

38:22

point is precarious enough under the best

38:24

of circumstances, they

38:26

count on public funds from multiple nations

38:29

and work under the threat of those funds

38:31

drying up at any time, and

38:34

the stakes for keeping the Large Hadron Collider

38:36

funded are very high.

38:39

This is law professor Eric Johnson,

38:41

who has written extensively on the risks

38:43

that come along with high energy physics

38:46

experiments. It's really hard to

38:48

downplay the amount of money and the amount

38:51

of professional lives that

38:53

are involved with the Large Hadron

38:55

Collider. Uh. CERN

38:57

is a multibillion dollar institution. UH

39:00

there's thousands of people who work there and

39:02

in the field of particle physics. In

39:05

the field of particle physics, there really aren't

39:07

It's not like everyone's off doing

39:09

their own experiments. Particle physics

39:12

tends to be dominated by the big

39:14

collider of the day and the data

39:16

that it's producing. And if that collider

39:18

doesn't come online, then

39:21

there's nothing to study for a whole

39:23

lot of people. Protecting certains

39:25

enterprise is made all the more difficult by the fact

39:27

that what it is doing is pure science.

39:30

There's no obvious research and development

39:33

that can be turned into useful products

39:35

that the nations involved can expect to make back

39:37

some of their investment with instead.

39:40

The LHC is as unadulterated

39:42

as scientific experiment as you will find

39:45

on Earth. It was designed

39:47

and built solely so that we can

39:49

better understand the universe in our place

39:51

within it. A genuine, noble

39:54

public good to benefit all

39:56

humankind. It can be

39:58

tough to make money off of else. That

40:01

is not to say that the Large Hadron Collider

40:04

hasn't already produced dividends well beyond

40:06

physics. You could argue and

40:08

plenty do. That's certain paid for itself

40:10

many times over. Back in the late nineteen eighties,

40:13

when one of its computer scientists, a

40:15

British man named Tim berners Lee,

40:18

created a method for linking text files

40:21

so that they could be shared universally

40:23

over computer networks. Burners

40:26

Lee called it the Worldwide Web,

40:30

so that it could protect its funding, calm

40:32

fears among the non scientific public, discover

40:35

whether the LHC actually is an existential

40:38

threat or all of those things. CERN

40:40

took up its quest to demonstrate

40:43

that the Large Hadron Collider will not

40:45

doom humanity, who

40:47

would be a long and circuitous

40:49

route so at that point cern

40:52

couldn't rely on the

40:55

not having enough power to produce black Hall's

40:57

argument for safety, and they

41:00

they acknowledge the need for

41:02

a new examination of hazards,

41:05

and uh they went back and

41:08

did some new work on that, and

41:11

then they said in two thousand

41:13

three that Hawking radiation

41:16

will ensure that any black

41:18

hole that's produced will evaporate almost

41:21

as soon as it's produced, so that

41:24

that will be safe. Because any

41:26

microscopic black holes the colliding particles

41:28

inside the LHC might manufacture

41:30

would have extremely small masses. Hawking

41:33

radiation says that they would emit particles

41:36

and lose their mass at a blinding

41:38

speed, winking out of existence

41:40

instantaneously. Just

41:42

how fast that would happen, called the rate

41:45

of decay, would be a fraction

41:47

of a fraction of a second, something

41:50

like ten to the negative

41:53

power of a second, a decimal

41:55

point, followed by zeros,

41:58

and then finally all the way down

42:00

in the position a single

42:02

one that fraction of a second.

42:06

In this unimaginably short time, the

42:08

microscopic black hole would have no chance

42:11

to absorb any matter and grow larger.

42:14

On this infantism le small scale

42:16

matter is just too few and far between,

42:19

so the microscopic black hole would be gone

42:22

before we knew it was ever there, but

42:24

it would leave telltale traces behind

42:26

that the LHC's detectors could find and

42:29

show the world that there are dimensions

42:31

beyond our own. But

42:33

this argument that suggests the Large Hadron

42:35

Collider is safe comes with some

42:37

baggage. Between the time

42:40

that the research began on the safety

42:42

paper and when CERN released it,

42:44

the physics community's faith in the

42:46

existence of Hawking radiation was

42:48

shaken. In the early two

42:50

thousands, the trickle of papers began

42:53

to question it. It wasn't disproven,

42:55

just question enough

42:57

to erode it as the kind of thing that

43:00

CERN could fet the survival of the planet

43:02

on. So

43:05

CERN looked for another way to show the Large

43:07

Hadron Collider was safe, and this time

43:10

they settled on cosmic rays. Cosmic

43:15

rays aren't exactly what they sound like. They're

43:18

actually tiny energetic particles

43:20

that travel at incredibly fast speeds

43:22

through space and smash into other

43:24

particles, creating a spectacular

43:27

cascade of energy converted temporarily

43:29

into mass. And if this

43:31

sounds a lot like the collisions inside the Large

43:33

Hadron Collider, you're absolutely

43:35

right. A particle collider is,

43:37

if anything, a laboratory for

43:40

stimulating cosmic ray collisions, and

43:42

because they're so similar, means that since

43:45

cosmic rays bombard everything in the universe

43:47

all the time and have for billions

43:49

of years, then the fact that the universe

43:52

still exists proves that

43:54

even if particle collisions can create

43:56

microscopic black holes, that microscopic

43:59

black holes must be harmless, because

44:02

again, the universe continues

44:04

to exist. That

44:06

is the cosmic ray argument, and it's

44:09

the second thing that's certain pinned the safety

44:11

of the Large Hadron Collider too. But

44:14

there's a problem with the cosmic ray argument

44:16

as well. Cosmic rays

44:19

aren't exactly like particle

44:21

collisions inside the Large Hadron Collider,

44:23

and exactness is kind of important when

44:25

you're trying to show the world that your machine

44:28

won't bring about the end of the universe. Cosmic

44:31

rays travel at high speeds, yes, but

44:34

the particles that the cosmic rays smash

44:36

into, say particles in the Earth's

44:38

atmosphere, are just kind of

44:40

hanging out there. They're relatively stationary,

44:44

which means that the collisions are

44:46

a lot like rear end collision and

44:48

most importantly, in a rear end collision,

44:51

the momentum of the faster vehicle or

44:54

particle carries it and the

44:56

other vehicle or particle careening

44:58

off in some direction away from

45:00

the site of the crash. This

45:03

is important because it means that

45:05

if cosmic rays do produce microscopic

45:07

black holes, the momentum of the crash

45:10

would carry the microscopic black holes away

45:12

from the collision to most

45:14

likely they'd pass harmlessly through

45:16

Earth and right out into outer space.

45:19

The problem is in a particle collider,

45:22

the collisions are different. They're less

45:24

like rear end collisions and more like

45:27

head on collisions, and

45:29

then a head on collision, the two particles

45:31

cancel one another's momentum out when

45:34

they collide, they don't go anywhere.

45:37

The upshot of all of this is that a

45:39

microscopic black hole produced

45:41

by the collision wouldn't go careening

45:43

off away from the impact and into outer

45:45

space. It would be stationary.

45:48

It would stay put, which

45:50

means that it would stay put here on

45:52

Earth. That is a problem

45:55

because if we've already thrown out the idea

45:57

of hawking radiation, and along with

46:00

it, the concept that a microscopic black

46:02

hole would simply wink right out of existence

46:04

if it was created, then that means

46:06

that if we do create a microscopic black

46:09

hole in a particle collider, it

46:11

would hang around here on Earth, which

46:13

means that it could possibly grow, which

46:16

means that it actually might pose an existential

46:19

threat to us. As

46:22

far as safety arguments go, this is decidedly

46:24

not reassuring, especially

46:26

considering the idea of the two thousand one

46:28

paper by Stephen Gettings that

46:31

said that the LHC is a black hole

46:33

factory. If that paper

46:35

was correct, then a new, stable,

46:37

earthbound microscopic black hole is

46:40

created inside the collider every

46:42

second it's proton beams are crossed. So

46:46

certain looked again for a new way

46:48

to show that LHC was existentially

46:50

safe. What

46:53

they needed was something out there in the cosmos

46:55

that was dense enough to have a gravitational

46:58

pull that could hang to do a microscopic

47:01

black hole. Something that could do

47:03

that would show again simply

47:05

by existing, that microscopic

47:07

black holes really are harmless. It

47:10

would show that even if the Large Hadron

47:12

Collider produced a microscopic black

47:14

hole and the Earth hung onto it,

47:16

there's still no cause for concern. It

47:19

was basically cosmic ray argument two

47:22

point out, and CERN

47:24

finally found what they were looking for in

47:26

white dwarf stars. A

47:31

white dwarf is a star that's run

47:33

out of fuel and has partially collapsed,

47:36

so it becomes far denser and

47:39

exerts a much stronger gravity on things

47:41

around it, definitely more

47:43

than Earth's gravity. So any

47:45

microscopic black holes that a rear

47:47

end cosmic ray collision could produce would

47:50

still be stuck in the star that wouldn't

47:52

careen off into outer space. And

47:55

since white dwarfs are bombarded with those

47:57

cosmic rays, and since they enough

48:00

gravity that they could trap a microscopic

48:02

black hole, then the fact that

48:04

they continue to exist strongly

48:06

suggests that microscopic black holes

48:09

are not a danger. That is to say,

48:11

again, if microscopic black holes

48:13

even exist. Based

48:16

on astronomical measurements of white dwarfs,

48:18

CERN found eight of them that, in

48:20

their opinion, were dense enough and old

48:23

enough to sufficiently demonstrate the

48:25

safety of the large Hadron collider

48:28

certain issue of paper, and it was followed

48:30

by another paper that concluded the first

48:32

paper was sound, and

48:35

they circulated both papers to the physics

48:37

community, which in turn provided

48:39

CERN with quotes about just how

48:41

sound the conclusions of the papers are and

48:43

just how utterly safe they show the LHC

48:46

to be. Certain included these

48:48

quotes on their website, and

48:50

that's where things stand today. Classical

48:53

physics, which represents our current understanding

48:55

of physics, doesn't allow for microscopic

48:58

black holes to form in the place. But

49:01

even if those microscopic black holes could

49:03

form, so long as those eight

49:06

white dwarfs exist in the sky, Certain

49:08

is willing to bet the whole farm on the

49:10

safety of the LHC. But

49:14

with physics, our understanding

49:16

has a way of changing. The whole

49:18

idea of particle physics is to

49:21

discover new things. Particle physics

49:23

works at the leading edge of human

49:25

knowledge, at the leading edge of theory. That's the

49:27

whole point of it is to be out

49:29

there trying to figure out something new. So

49:32

it does evolve all the time.

49:35

And I think it would be naive to

49:37

say that right

49:39

now this year, we've arrived

49:42

at a point where the theory is not going

49:44

to change, or the assumptions are not going to

49:46

change, so that we can feel satisfied

49:49

that whatever conclusion particle

49:51

physicists have today about

49:53

the safety of a particle

49:55

accelerator that that's not going to change

50:00

m M. By

50:11

now, you might be asking yourself exactly

50:14

how might a black hole be created inside

50:16

the large Hadron collider? Well,

50:18

that is an excellent question. When

50:21

you take a little tiny particle like a proton,

50:24

and accelerated to almost the speed

50:26

of light, something very peculiar happens

50:28

to it. The little amount of mass

50:31

that it has starts to grow, and

50:33

as its mass grows, the stronger the

50:35

gravity acting on it grows too. A

50:39

very fast particle accelerated

50:41

in the Large Hadron Collider begins

50:43

to grow enough mass that it warps

50:45

the fabric of spacetime around it.

50:48

This warping has the effect of concentrating

50:51

gravity, and in the minute

50:53

fraction of a moment before two extremely

50:56

fast moving particles collide, they're

50:58

bent gravity's over lap and

51:01

concentrate gravity even further. The

51:04

sum of all these parts amounts

51:06

to an unusual amount of mass

51:08

and extremely high gravity concentrated

51:11

within a very very tiny

51:13

area. All of this together

51:15

could produce a microscopic black

51:17

hole. Because

51:23

it would lack the kind of escape velocity

51:25

that a cosmic ray might give it. The microscopic

51:27

black hole would be held fast by the gravity

51:30

exerted by the Earth's mass. About

51:32

every half hour, the microscopic

51:35

black hole would oscillate between

51:37

the LHC and a point on the

51:39

opposite side of the world, somewhere

51:41

off the coast of New Zealand, and back inside

51:44

the Earth. The black hole would grow over

51:47

time, but exactly how

51:49

long that process would take depends, as

51:51

does everything, it seems like, on

51:53

the correctness of one of the unifying

51:56

theories that combine relativity

51:58

with the standard model. One

52:01

of the things that's so unsettling

52:03

about the idea of Hawking radiation, the

52:06

theory that a microscopic black hole will wink

52:08

right out of existence just as fast as it's created,

52:11

is that whether Stephen Hawking was right or

52:13

wrong, microscopic black

52:16

holes still pose an existential risk. If

52:19

Hawking was wrong and there is no such

52:21

thing as Hawking radiation, then

52:23

a microscopic black hole could stick

52:25

around and slowly eat the world.

52:29

What would a black hole eating the Earth from the inside

52:31

out look like, Well, it's hard

52:33

not to imagine a microscopic black hole growing

52:35

in the Earth's core until it emerged

52:38

on the planet's surface, kind of popping out

52:40

as a gaping bottomless pit that

52:43

some hapless person wandering through the

52:45

woods might accidentally stumble into.

52:48

But this isn't what it would look like at all. Remember,

52:51

if the Earth itself could be compressed

52:53

into a black hole, it would have an event horizon

52:56

just about a centimeter in diameter, So

52:58

any microscopic black hole that consumed

53:01

all of the Earth's mass would have an

53:03

event horizon about the same size.

53:06

A microscopic black hole then would never

53:08

pop up on Earth's surface. It

53:11

would still be unnoticeably tiny as

53:13

it tore the planet apart. Plus,

53:16

let's not forget we couldn't see it anyway,

53:19

being a black hole, like couldn't escape it,

53:21

so it couldn't reflect off the black hole's surface,

53:24

which would make the microscopic black hole both

53:26

tiny and invisible. But

53:30

we would be able to clearly see the effects

53:32

it had as it tore our planet apart.

53:35

One of the defining traits of a black hole is,

53:38

of course, the intense gravitational

53:40

pull that it exerts on matter around

53:42

it. Black Holes are capable of pulling

53:45

matter literally apart, and

53:47

as it does, it releases enormous amounts

53:49

of energy. That violence

53:51

produces extremely high temperatures

53:54

and all of that hot torn apart

53:56

matter becomes trapped in

53:58

an orbit around the black hole. Eventually

54:01

that matter falls past the event horizon,

54:04

unable to escape. Particles

54:07

that the microscopic black hole encounters

54:09

in the quantum world would be among its

54:11

first victims. But as

54:13

it grows over time, the black hole

54:15

would eventually get big enough to devour

54:17

whole atoms. And as

54:19

the black hole grows, so too

54:22

will its strength. The

54:24

more it increases in mass, the more

54:26

of the Earth it will draw into it, pulling

54:29

Earth apart and into that gaseous

54:31

stew of hot matter that circles

54:33

around it. Over time, the

54:35

magma, the bedrock, the soil,

54:38

the lakes, the very planet itself

54:40

would be pulled apart. There would

54:42

be no place left for life to live on Earth,

54:45

which would be a moot point anyway, since

54:48

every bit of life on Earth would be pulled

54:50

apart as irresistibly as the planet

54:53

itself, drawn into

54:55

that roiling circle of plasma

54:57

around the black hole, which would

54:59

slowly feed on our planet for

55:01

a very long time. Under

55:15

classical physics, the time it would take for a

55:17

tiny black hole produced in the LHC to

55:20

gain enough mass to become a threat

55:22

to life on Earth is longer

55:24

than the current age of the universe, more than

55:26

thirteen billion years, but

55:29

that time shortens dramatically when

55:31

new dimensions are added. The

55:34

additional dimensions allow for stronger

55:36

gravity on those quantum scales, which

55:38

would allow a microscopic black hole to

55:41

attract and consumed particles early

55:43

in its life much more quickly.

55:46

Such a black hole could destroy the Earth

55:48

in as little as three hundred thousand years,

55:51

which is a bit alarming considering

55:53

the possibility the LHC has been

55:55

creating a microscopic black hole every

55:57

second it's been colliding protons to

56:00

as it came online back in two thousand nine.

56:03

Humanity might still very much place a high

56:05

value on our home planet a few hundred thousand

56:07

years from now, and prefer that it continued

56:10

to exist. It's probably

56:12

a good bet that our descendants would

56:14

not want the planet ruined by haphazard

56:17

physics experiments conducted by their ancestors.

56:20

I imagine the rest of life on Earth would

56:22

have similar feelings on the matter too. But

56:29

what if Hawking was right and microscopic

56:31

black holes do evaporate, It

56:33

could still pose an existential threat

56:36

because in evaporating microscopic black

56:38

hole could give a low energy vacuum

56:40

bubble from the Higgs field just the boost

56:43

it needs to grow and ruin

56:45

the universe. If

56:47

we can rewind back to the moment in the LHC

56:49

when those two particles collided head to head

56:51

at amazing speeds and they're concentrated

56:54

gravity overlapped, Let's

56:56

say that the microscopic black hole they produced

56:58

didn't grow up to tear Earth apart, but

57:00

instead it evaporated, just as

57:03

Stephen Hawking predicted. As

57:05

it evaporated, it could become the

57:07

nucleus for a low energy vacuum

57:10

bubble to grow, in a very

57:12

similar way to how tiny impurities

57:14

in a metal pot become the places where

57:16

water can undergo a phase transition

57:19

from liquid to gas within

57:21

itself. This is what we call forming

57:23

a bubble. An evaporating black

57:25

hole could serve as a nucleation site

57:27

for the Higgs field to undergo a transition

57:30

from its current state to the

57:32

lower energy version of itself, which

57:35

again would bring about vacuum

57:37

decay, the ultimate ecological

57:40

catastrophe, which, again, at

57:42

the risk of restating the obvious, would

57:44

be very bad for the current arrangement

57:46

of our energetic vibrations. This

57:49

would not take a few hundred thousand years

57:51

to notice. It would happen so fast

57:54

that we likely wouldn't notice we

57:56

just suddenly be gone.

58:02

So we have then at least two

58:04

possible catastrophic outcomes from

58:06

the creation of man made microscopic

58:09

black holes here on Earth. And

58:11

what's unsettling about them is

58:13

that there's a catastrophe for each

58:15

possibility. Where Stephen Hawking

58:17

was either right about evaporating black

58:20

holes or where he was wrong. Take

58:22

your pick. One

58:33

day in two thousand and eight, a bird that

58:35

lived in the countryside along the border between

58:37

Switzerland and France found itself

58:40

a bit of crusty bread. Around

58:43

that same time, one of the electrical

58:45

supply stations that cools the Large

58:47

Hadron collider's magnets with liquid helium

58:50

suddenly went offline. When

58:52

workers went to investigate, they

58:54

found a bit of crusty bread and some

58:56

feathers. The press

58:59

reported on it, took liberties with

59:01

it, and that story grew to enormous

59:03

proportions. Words

59:05

spread that a single bird with some

59:08

baguette had knocked out the Large

59:10

Hadron Collider, the fastest

59:12

and largest particle collider on Earth.

59:15

A pair of theoretical physicists named

59:18

Hulger Nielsen and Massao Ninomia

59:21

had been taking note of the accidents

59:23

in weird setbacks like this that plague

59:25

the LHC as it was being built. They

59:28

had come to believe that something, possibly

59:31

God, was reaching back from

59:33

the future two sabotage

59:35

the Large Hadron Collider and prevent

59:38

it from ever reaching full power. It

59:41

might mean that the LHC would create

59:43

something, the physicists said, that

59:46

could destroy the universe. They

59:48

took the bird in the baguette as further

59:51

evidence for their hypothesis. Nielsen

59:54

and Ninomia proposed issuing a challenge

59:57

to the future to determine if we should

59:59

shut down the Large Hadron Collider and abandon

1:00:01

it forever. We could

1:00:04

present the LHC with some luck of

1:00:06

the draw, maybe something

1:00:08

like ten million cards, all

1:00:10

of them hearts, except one, just

1:00:12

a single spade. And if we

1:00:15

asked the Large Hadron Collider to pick a card,

1:00:17

and the Large Hadron Collider picked that one single

1:00:20

spade, an extraordinarily unlikely

1:00:22

event, then the particle physics

1:00:24

community should take it as a sign that

1:00:27

the future was communicating a warning

1:00:29

to us. Sir, never

1:00:32

took the physicists up on their card draw proposal.

1:00:35

Nielsen and Ninomia suspected

1:00:37

that the future was trying to prevent the

1:00:39

Large Hadron Collider from creating

1:00:41

a Higgs boson, that particle that

1:00:44

gives everything that has mass mass. It

1:00:47

was widely hoped. In fact, it

1:00:49

was largely the reason it was built that

1:00:51

the LHC would produce the Higgs

1:00:53

boson, which again was the last

1:00:55

undiscovered particle predicted by the standard

1:00:58

model. And in two thousand

1:01:00

and twelve, the Large Hadron's computers

1:01:02

found something that had been created for

1:01:04

a fraction of a fraction of a second

1:01:06

inside the collider that fit the

1:01:08

parameters for the Higgs boson. There

1:01:11

was no catastrophe, The world

1:01:13

didn't end, and to an extent,

1:01:15

the discovery of the Higgs frustrated physicists

1:01:18

even more since it further supported

1:01:20

the stubbornly accurate Standard model

1:01:22

they've been hoping to break. But

1:01:25

finding reassurance in the survival of

1:01:27

the universe after the successful creation

1:01:29

of the Higgs boson in the LHC is

1:01:32

actually a logical fallacy.

1:01:35

Specifically, it produces what's called the normalcy

1:01:37

bias. We tend to assume

1:01:39

that because no catastrophe has befallen

1:01:42

us, yet none will. It's

1:01:44

the same false belief that drives investors

1:01:47

to buy stock based on past performance.

1:01:50

But any financial advisor worth their salt

1:01:52

will tell you there is no certainty about the

1:01:54

future to be found in the past, and

1:01:57

so too will a particle physicist

1:02:00

tell you that. One of the

1:02:02

tenets of quantum physics is that

1:02:04

there is no such thing as

1:02:06

certainty. We are incapable

1:02:09

of certainty. Instead,

1:02:11

particle physicists deal improbability.

1:02:15

As one certain physicist explained it to me,

1:02:17

you can, for example, take the number

1:02:19

of times that a car's engine has ever been

1:02:22

started and calculate the probability

1:02:24

that the next time you start your car it

1:02:27

won't create a chain reaction that ignites

1:02:29

Earth's atmosphere. What you have,

1:02:31

then is what's called the lower bound probability

1:02:33

that it would happen in

1:02:36

an odd, roundabout way. When

1:02:38

cars were first invented, they actually

1:02:40

had a higher probability of igniting the

1:02:42

atmosphere compared to cars today,

1:02:45

simply because fewer cars had ever

1:02:47

been turned over back then. The

1:02:49

large Hadron collider is in a similar position

1:02:52

with the LHC. We simply have

1:02:54

a smaller data set from the fewer

1:02:57

times that it's been turned on. This

1:02:59

is in a perfect analogy, though there

1:03:02

aren't any quantum theories that suggest

1:03:04

a car could ignite the atmosphere, like

1:03:06

there are that suggests the LHC might

1:03:09

be capable of creating a black hole or

1:03:11

a strange lit But ironically,

1:03:14

the more times we press our luck and

1:03:16

run the LHC, the lower

1:03:18

the probability that something terrible will happen.

1:03:21

Get the thing

1:03:23

is, no matter how many times we run

1:03:25

the Large Hadron Collider, we will never

1:03:27

be certain that something terrible

1:03:30

won't happen. This is the

1:03:32

curse of the universe that quantum physics

1:03:34

carries with it. We are doomed to uncertainty.

1:03:40

Eight white dwarfs still hang in the sky,

1:03:43

but we still can't be certain that one of them

1:03:45

won't begin to come apart tomorrow from

1:03:47

the microscopic black hole growing within it.

1:03:50

It's a matter of faith, faith,

1:03:53

and probabilities when

1:03:58

it comes to the existential safety of physics.

1:04:01

Uncertainty curses. All of us physicists

1:04:05

face a dilemma when they talk about

1:04:07

the safety of their work to people like you

1:04:09

and me. The general public. If

1:04:11

they speak openly about it, they may

1:04:13

cause a panic and possibly even undermine

1:04:16

their own field of research. If

1:04:18

they don't, they appear like they're

1:04:20

hiding something. Here's physicist

1:04:22

Daniel Whiteson again. And I think the

1:04:25

reason is that they don't believe

1:04:27

that there's a lot of and that

1:04:29

there's a lot of numerous e in

1:04:32

the public and in journalism,

1:04:34

and that a nuanced position where

1:04:37

you're saying, um, there's

1:04:39

no none of the threats we understand

1:04:42

are significant. However, there's a possibility

1:04:45

of a thing we don't know that we hadn't considered

1:04:47

that could of course destroy the world,

1:04:49

but you know that's unlikely and

1:04:52

unknowable and so not something

1:04:54

to consider. That kind of nuanced position,

1:04:56

I think it is very difficult to convey.

1:04:59

So physicis systs may decide that the general

1:05:01

public can't really understand probabilities,

1:05:04

and we'll stop hedging when they speak about

1:05:06

the safety of their work, erasing

1:05:08

those remote possibilities of catastrophe

1:05:11

and presenting a full certainty

1:05:13

that particle physics is perfectly safe,

1:05:15

that there is no risk. This

1:05:18

is a dangerous position when

1:05:20

it inevitably comes out that there is in

1:05:22

fact a risk and that scientists

1:05:24

are well aware of it. Trust is lost

1:05:27

in the very people who carry out existentially

1:05:30

risky experiments, and the

1:05:32

most sensational and unfounded

1:05:34

stories start to gain traction among

1:05:36

the general public. And

1:05:38

it's also directly a dangerous position

1:05:41

as far as existential risks go, because

1:05:44

existential risks are by definition remote.

1:05:46

They are the risks that get erased when

1:05:49

physicists speak with certainty about

1:05:51

the safety of their work. But

1:05:54

as you know by now, those same existential

1:05:56

risks are the ones that can erase humanity

1:05:59

should the ability surrounding an experiment

1:06:02

suddenly skew towards the remote Unexpectedly.

1:06:06

Pretending those risks are not there is

1:06:08

the most dangerous route we can take. But

1:06:14

scientists who do have the integrity to

1:06:16

admit that they can't be certain their field

1:06:18

doesn't pose existential risks frequently

1:06:21

find that they're misquoted or misrepresented

1:06:23

in the media, which can lead to them

1:06:25

being ostracized by their colleagues

1:06:28

for stirring up problems for the field. So

1:06:30

they may become defensive, which

1:06:33

is never good for keeping lines of communication

1:06:35

open. But I think the experience

1:06:37

of a lot of scientists is that they

1:06:39

say Oh, that's very unlikely,

1:06:42

but of course possible. And then they read

1:06:44

an article where they say certain scientists

1:06:46

says end of the world possible, you

1:06:48

know, and so it's it's um, I think

1:06:51

you're right that they're defensive, but I think that comes

1:06:53

from some experience and some caution

1:06:55

about the level of the discourse

1:06:58

in the public arena. It is with this

1:07:00

in mind that CERTAIN is to be commended for

1:07:02

working to show that the large Hadron

1:07:04

collider is a safe machine, even

1:07:06

considering that it was a reactive procedure

1:07:09

rather than a proactive one. CERTAIN is

1:07:11

a great institution, and one

1:07:13

thing that I admire so much about them is how open

1:07:16

they are. And much of what I

1:07:18

was able to do in my research is thanks

1:07:20

to them being very open. They're very

1:07:23

very open in terms of sharing their data,

1:07:25

sharing their papers, being accessible

1:07:27

in terms of talking to them. That's part of what

1:07:30

makes me admire them so much as an academic

1:07:33

myself. I just think that that's

1:07:35

a great model for building

1:07:37

and sharing knowledge, and

1:07:40

it's to their credit that they have looked

1:07:42

at these issues with a great deal of

1:07:44

transparency. It is extremely

1:07:46

important that the physics community follows

1:07:49

CERN's lead and its willingness to investigate

1:07:51

the safety of its work has their experiments

1:07:54

grow more and more powerful in the future.

1:07:58

There's a different interpretation to the

1:08:00

cosmic ray argument, a more nihilistic

1:08:02

one. It says that the

1:08:04

presence of cosmic rays doesn't

1:08:06

prove that particle colliders are safe.

1:08:09

It just shows that our particle colliders can't

1:08:11

make anything more precarious than they already

1:08:13

are. Turning on a particle collider

1:08:16

is safe because we can't turn

1:08:18

cosmic rays off, so we're

1:08:20

not going to be causing any new danger by turning them

1:08:22

on. But what about some decades

1:08:24

or a century from now, when our experiments

1:08:27

begin to reach levels that exceed cosmic

1:08:29

rays. If the Large

1:08:31

Hadron Collider is an early incarnation

1:08:34

of a long line of particle colliders

1:08:36

to come, as physicists hope, there

1:08:39

will likely be a point where the energies

1:08:41

of future colliders rub up against

1:08:43

and then eventually exceed, the energies

1:08:45

of cosmic rays, the very

1:08:47

same cosmic rays that we use today

1:08:50

as some sort of proof that our colliders are safe.

1:08:53

And over time, as physicists develop

1:08:56

a greater mastery over the rules of our universe,

1:08:59

particle colliders may transition into

1:09:01

laboratories that physicists use to

1:09:03

bend the laws of physics to their will. Those

1:09:07

nearly blind pokes and prods

1:09:09

into the darkness of our understanding that

1:09:11

physicists today carry out are

1:09:13

providing the body of knowledge that

1:09:16

physicists to come in the future will

1:09:18

build upon. And if humanity

1:09:20

can survive our infro to physics, a

1:09:22

tremendous amount of promise lies in store

1:09:24

for us from it. An

1:09:27

odd thing about the universe has been

1:09:29

bothering physicists for a while now,

1:09:31

and it's something that the discovery of the Higgs

1:09:33

didn't help. It seems

1:09:36

more and more that our universe appears

1:09:38

to be finely tuned to allow

1:09:40

for life to exist. The

1:09:42

Higgs field, gravity, all

1:09:45

of it is right within the narrow bounds

1:09:47

that allow for atoms, chemistry, and

1:09:49

life. When the Higgs

1:09:51

boson was finally founded two thousand twelve,

1:09:54

it appeared right in the very middle of

1:09:56

where it was predicted, as perfectly

1:09:59

finely tuned as the rest of the fundamental

1:10:01

particles. One answer

1:10:03

to the strange situation is that our

1:10:06

universes finally tuned for life simply

1:10:08

because of random chance. There's

1:10:11

a remarkable implication of string theory,

1:10:13

one of those theories that seeks to unify

1:10:15

gravity with the quantum forces. String

1:10:18

theory says that if you take all of the

1:10:20

particles and forces and dimensions

1:10:23

that the theory predicts, you can come up

1:10:25

with ten to the five power

1:10:28

different possible combinations among

1:10:30

them. If you consider each

1:10:32

of those combinations as a set of rules

1:10:34

for a potential universe, including

1:10:37

the combination that governs our own universe,

1:10:40

then you have as many possible universes

1:10:42

as ten to the five power.

1:10:45

Our universe just so happens to be one

1:10:47

with the combination of those dimensions and particles

1:10:50

and forces that allow for life.

1:10:53

That's the basis of what's called the anthropic

1:10:55

principle. The kind of universe

1:10:58

where life could evolved is the only

1:11:00

type where we would find ourselves wondering

1:11:02

about why things seem so finely

1:11:04

too fine tuning may

1:11:06

really not mean anything at all. By

1:11:09

learning about the reality of our universe,

1:11:12

physicists will answer questions like this,

1:11:15

and when they do, they will be able

1:11:17

to do amazing things like predict

1:11:20

anything that could possibly happen with

1:11:22

absolute accuracy, and

1:11:24

perhaps future physicists will learn

1:11:27

to construct new universes within their

1:11:29

particle colliders grow them from

1:11:31

seat. Exactly how

1:11:33

we may someday be able to do this has

1:11:35

already been roughly sketched out, and

1:11:37

now the data must catch up to the theories.

1:11:44

To some people physicists

1:11:46

creating new universes where life might

1:11:48

arise organically, it's actually a dreary

1:11:51

sad idea. Any universe

1:11:54

we might create in the lab would almost certainly

1:11:56

have its own space time, and so

1:11:58

it would be totally detached from our own

1:12:00

universe, And so those

1:12:02

physicists who created that universe

1:12:05

would have no way to alleviate

1:12:07

the profound suffering that life

1:12:09

in that other universe might experience. To

1:12:13

people who believe that the purpose of life

1:12:15

is to reduce suffering, creating

1:12:17

a universe like this would be a

1:12:19

profoundly irresponsible act by

1:12:22

a creator God with no power

1:12:24

to interview. But

1:12:29

there is also a tremendous amount of promise

1:12:32

in the idea of lap grown universes.

1:12:35

Perhaps we will be the life that populates

1:12:37

them. Perhaps future humans

1:12:40

will be able to grow new universes to

1:12:42

move into when our universe begins

1:12:44

to expire. Perhaps,

1:12:47

unbeknownst to us, those physicists

1:12:49

of the future will be carrying out the same

1:12:51

kind of experiments that produced our

1:12:54

universe, or perhaps

1:12:56

they will be creating our universe.

1:12:59

For phaps, that is how we will make our escape

1:13:02

back to the beginning. Perhaps

1:13:04

that's what we've always done. On

1:13:12

the next episode of the End of the World with Josh

1:13:15

Clark, the future

1:13:17

is what's called a transgenerational global

1:13:19

commons. We share it not just with

1:13:21

everyone alive today, but everyone

1:13:23

to come as well. And for the

1:13:25

first time in human history, it is in

1:13:28

the power of those of us alive to save

1:13:30

it or destroy it permanently.

1:13:33

And now, if you think about what the existential risk

1:13:35

mitigation is, not all that is it the

1:13:37

global public good existential

1:13:40

risk mitigation, but it's also of transgenerational

1:13:42

public good. But to take on the existential

1:13:45

risks we face, we will have to overcome

1:13:47

our own worst impulses.