The history of our world in 18 minutes David Christian

first a video yes it is a scrambled egg

but as you look at it I hope you’ll

begin to feel just slightly uneasy

because you may notice that what’s

actually happening is that the egg is on

scrambling itself and you will now see

the yolk and the white have separated

and now they’re going to be poured back

into the egg and we all know in our

heart of hearts that this is not the way

the universe works a scrambled egg is

mush tasty mush but it’s mush an egg is

a beautiful sophisticated thing that can

create even more sophisticated things

such as chickens and we know in our

heart of hearts that the universe does

not travel from mush to complexity in

fact this gut instinct is reflected in

one of the most fundamental laws of

physics the second law of thermodynamics

or the law of entropy what that says

basically is that the general tendency

of the universe is to move from order

and structure to lack of order lack of

structure in fact to mush and that’s why

that video feels a bit strange and yet

look around us what we see around us is

staggering complexity Eric pine hotter

estimates that in New York City alone

there are some 10 billion skews or

distinct commodities being traded that’s

hundreds of times as many species as

there are on earth and they’re being

traded by a species of almost 7 billion

individuals who are linked by trade

travel and the internet into a global

system of stupendous complexity so

here’s a great puzzle in a universe

ruled by the second law of

thermodynamics how is it possible to

generate the sort of complexity I’ve

described the sort of complexity

represented by you

and me and the convention center well

the answer seems to be the universe can

create complexity but with great

difficulty in pockets there appear what

my colleague Fred’s vehicle’s Goldilocks

conditions not too hot not too cold just

right for the creation of complexity and

slightly more complex things appear and

where you have slightly more complex

things you can get slightly more complex

things and in this way complexity builds

stage by stage each stage is magical

because it creates the impression of

something utterly new appearing almost

out of nowhere in the universe we refer

in big history to these moments as

threshold moments and at each threshold

the going gets tougher the complex

things get more fragile more vulnerable

the Goldilocks conditions get more

stringent and it’s more difficult to

create complexity now we as extremely

complex creatures desperately need to

know this story of how the universe

creates complexity despite the second

law and why complexity means

vulnerability and fragility and that’s

the story that we tell in big history

but to do it you have to do something

that may at first sight seemed

completely impossible

you have to survey the whole history of

the universe so let’s do it

let’s begin by winding the timeline back

13.7 billion years to the beginning of

time

around us there’s nothing there’s not

even time or space imagine the darkest

emptiest thing you can and cube it a

gazillion times and that’s where we are

and then suddenly BAM

a universe appears and the entire

universe and we’ve crossed our first

threshold the universe is tiny it’s

smaller than an atom it’s incredibly hot

it contains everything that’s in today’s

universe so we can imagine it’s busting

and it’s expanding at incredible speed

and at first it’s just a blur but very

quickly distinct things begin to appear

in that blur within the first second

energy itself shatters into distinct

forces including electromagnetism and

gravity and energy does something else

quite magical it congeals to form matter

quarks that will create protons and

leptons that include electrons and all

of that happens in the first second now

we move forward 380,000 years that’s

twice as long as humans have been on

this planet and now simple atoms appear

of hydrogen and helium now I want to

pause for a moment 380,000 years after

the origins of the universe because we

actually know quite a lot about the

universe at this stage we know above all

that it was extremely simple

it consisted of huge clouds of hydrogen

and helium atoms and they have no

structure they’re really a sort of

cosmic mush but that’s not completely

true recent studies by satellites such

as the W map satellite have shown that

in fact there are just tiny differences

in that background what you see here the

blue areas are about a thousandth of a

degree cooler than the red areas these

are tiny differences but it was enough

for the universe to move on to the next

stage of building complexity and this is

how it works

gravity is more powerful where there’s

more stuff so where you get slightly

denser areas gravity starts compacting

clouds of hydrogen and helium atoms so

we can imagine the early universe

breaking up into a billion

and each cloud is compacted gravity gets

more powerful as density increases the

temperature begins to rise at the center

of each cloud and then at the center of

each cloud the temperature crosses the

threshold temperature of 10 million

degrees protons start to fuse there’s a

huge release of energy and bam we have

our first stars from about 200 million

years after the Big Bang stars begin to

appear all through the universe billions

of them and the universe is now

significantly more interesting and more

complex stars will create the Goldilocks

conditions for crossing to new

thresholds when very large stars die

they create temperatures so high that

protons begin to fuse in all sorts of

exotic combinations to form all the

elements of the periodic table if like

me you’re wearing a gold ring it was

forged in a supernova explosion so now

the universe is chemically more complex

and in the chemically more complex

universe it’s possible to make more

things and that starts happening is that

around young sons young stars all these

elements combine they swirl around the

energy of the star stirs them around

they form the particles they form

snowflakes they form little dust motes

they form rocks they form asteroids and

eventually they form planets and moons

and that is how our solar system was

formed four and a half billion years ago

rocky planets like our earth are

significantly more complex than stars

because they contain a much greater

diversity of materials so we’ve crossed

a fourth threshold of complexity now the

going gets tougher the next stage

introduces entities that are

significantly more fragile significantly

more vulnerable but they’re also much

more creative and much more capable of

generating further complexity I’m

talking of course about living organisms

living organisms are created by

chemistry we are huge

Edge’s of chemicals so chemistry is

dominated by the electromagnetic force

that operates over smaller scales and

gravity which explains why you and I are

smaller than stars or planets now what

are the ideal conditions for chemistry

what are the Goldilocks conditions well

the first you need energy but not too

much in the center of the star there’s

so much energy that any atoms that

combine will just get busted apart again

but not too little in intergalactic

space there’s so little energy that

atoms can’t combine what you want is

just the right amount and planets it

turns out are just right because they’re

close to stars but not too close you

also need a great diversity of chemical

elements and you need liquids such as

water why well in gases atoms move past

each other so fast that they can’t hitch

up in solids atoms stuck together they

can’t move in liquids they can cruise

and cuddle and link up to form molecules

now where do you find such Goldilocks

conditions

well planets are great and our early

Earth was almost perfect it was just the

right distance from its star to contain

huge oceans of liquid water and deep

beneath those oceans that cracks in the

earth crust you got heat seeping up from

inside the earth and you’ve got a great

diversity of elements so at those deep

oceanic vents fantastic chemistry began

to happen and atoms combined in all

sorts of exotic combinations but of

course life is more than just exotic

chemistry how do you stabilize those

huge molecules that seem to be viable

well it’s here that life introduces an

entirely new trick you don’t stabilize

the individual you stabilize the

template the thing that carries

information and you allow the template

to copy itself and DNA of course is the

beautiful molecule that contains that

information you’ll be familiar with the

double helix of DNA each rung contains

information

so DNA contains information about how to

make living organisms and DNA also

copies itself so it copies itself and

scatters the templates through the ocean

so the information spreads notice that

information has become part of our story

the real beauty of DNA though is in its

imperfections as it copies itself once

in every billion runs there tends to be

an error and what that means is that DNA

is in effect learning it’s accumulating

new ways of making living organisms

because some of those errors work so DNA

is learning and it’s building greater

diversity and greater complexity and we

can see this happening over the last

four billion years for most of that time

of life on earth living organisms have

been relatively simple single cells but

they had great diversity and inside

great complexity then from about 600 to

800 million years ago multi-celled

organisms appear you get fungi you get

fish you get plants you get and figure

you get reptiles and then of course you

get the dinosaurs and occasionally there

are disasters 65 million years ago an

asteroid landed on earth near the

Yucatan Peninsula creating conditions

equivalent to those of a nuclear war and

the dinosaurs were wiped out terrible

news for the dinosaurs but great news

for our mammalian ancestors who

flourished in lanisha’s left empty by

the dinosaurs and we human beings are

part of that creative evolutionary pulse

that began 65 million years ago with the

landing of an asteroid humans appeared

about 200,000 years ago and I believe we

count as a threshold in this great story

let me explain why we’ve seen that DNA

learns in a sense it accumulates

information but it is so slow

DNA accumulates information through

random errors that just some of which

just happened to work but DNA had

actually generated a faster way of

learning it had produced organisms with

brains

and those organisms can learn in real

time they accumulate information they

learn the sad thing is when they die the

information dies with them now what

makes humans different is human language

we are blessed with a language a system

of communication so powerful and so

precise that we can share what we’ve

learned with such precision that it can

accumulate in the collective memory and

that means it can outlast the

individuals who learnt that information

and it can accumulate from generation to

generation and that’s why as a species

we are so creative and so powerful and

that’s why we have a history we seem to

be the only species in four billion

years to have this gift I call this

ability collective learning it’s what

makes us different we can see that work

in the earliest stages of human history

we evolved as a species in the savanna

lands of Africa but then you see humans

migrating into new environments into

desert lands into jungles into the Ice

Age tundra of Siberia tough tough

environment into the Americas into

Australasia each migration involved

learning learning new ways of exploiting

the environment new ways of dealing with

their surroundings then 10,000 years ago

exploiting a sudden change in global

climates with the end of the last ice

age humans learnt to farm

farming was an energy bonanza and

exploiting that energy human populations

multiplied human societies got larger

denser more interconnected and then from

about 500 years ago humans began to link

up globally through shipping through

trains through Telegraph through the

Internet until now we seem to form a

single global brain of almost 7 billion

individuals and that brain is learning

at warp speed and then the last 200

years something else has happened we’ve

stumbled on another energy bonanza in

fossil fuels so fossil fuels and

collective learning together explain the

staggering complexity we see around us

so here we are back at the convention

center we’ve been on a journey a return

journey 13.7 billion years I hope you

agree this is a powerful story and it’s

a story in which humans play an

astonishing and creative role but it

also contains warnings collective

learning is a very very powerful force

and it’s not clear that we humans are in

charge of it I remember very vividly as

a child growing up in England living

through the Cuban Missile Crisis for a

few days the entire biosphere seemed to

be on the verge of destruction and the

same weapons are still here and they’re

still armed if we avoid that trap others

are waiting for us we’re burning fossil

fuels at such a rate that we seemed to

be undermining the Goldilocks conditions

that made it possible for human

civilizations to flourish over the last

10,000 years

so what big history can do is show us

the nature of our complexity and

fragility and the dangers that face us

but it can also show us our power with

collective learning and now finally this

is what I want I want my grandson Daniel

and his friends and his generation

throughout the world to know the story

of big history and to know it so well

that they understand both the challenges

that face us and the opportunities that

face us and that’s why a group of us are

building a free online syllabus in big

history for high school students

throughout the world we believe that big

history will be a vital intellectual

tool for them as Daniel and his

generation face the huge challenges and

also the huge opportunities ahead of

them at this threshold moment in the

history of our beautiful planet

I thank you for your attention