Big history

We know from experience that a scrambled egg,

cannot reorganise itself, to form a full egg.

This is reflected in one of the most fundamental laws of physics.

The second law of thermodynamics, or the law of entropy, 

states that the universe tends to move from order and structure,

to lack of order and complexity.

The world we see today is indeed very complex.

The universe can create complexity, under certain conditions.

These conditions can be called as Goldilocks conditions.

The conditions need to be just right, for the creation of complexity.

When we have a slight more complex things, 

it can create even more complex things.

In this way complexity builds stage by stage.

Each stage appears magical, because it creates the impression, 

of something utterly new.

In big history we refer to such moments as thresholds.

At each threshold going gets tougher.

The complex things gets more fragile, and more vulnerable.

The goldilocks condition gets more stringent.

It becomes more difficult to create complexity.

We need to know the story, how the universe creates more complexity,

despite the second law, and why complexity needs vulnerability and fragility.

To understand this we need to survey the entire history, of the universe.

Let us wind back time by 13.7 billion years, to the beginning of time.

Initially there is no time or space.

Then there is a big bang.

And suddenly an universe appears.

We have crossed the first threshold.

The universe is tiny, and smaller than an atom.

It contains everything that's there in today's universe.

Initially it was just a blurb.

But very soon distinct things began to appear.

With in the first second, energy itself shatters into distinct forces,

including electromagnetism and gravity.

And energy does something even more magical.

It congeals to form matter.

The quarks that create protons, and leptons that include electrons, etc,.

are created in the first second.

Now we move forward 380,000 years.

Now simple atoms of hydrogen and helium appear.

We know quite a lot about this stage of the universe.

We know that it was extremely simple.

It consisted of huge clouds of hydrogen and helium atoms.

They had no structure.

It was some kind of cosmic mush.

That is not completely true.

Recent satellite studies have shown that there are just tiny differences in the background.

There are some areas, which are a thousandth of a degree cooler, than the adjacent areas.

But this was enough for the universe to move on to the next stage, of building complexity.

This is how it works.

Gravity is more powerful when there is more stuff.

In areas which are denser gravity starts compacting clouds of hydrogen and helium atoms.

Universe is breaking up into billions of clouds.

Each cloud is compacted.

Gravity gets more powerful as density increases.

The temperature begins to increase, at the centre of each cloud.

The temperature crosses the threshold of ten million degrees.

Protons start to fuse.

There is a huge release of energy.

We have our first stars.

For about 200 million years after the big bang, 

billions of stars were born throughout the universe.

The universe is now more interesting and more complex.

Stars will create the Goldilocks conditions for crossing two new thresholds.

When very large stars die, they create temperatures so high,

the protons began to fuse in all sorts of exotic combinations.

All the elements of the periodic table was formed this way.

If we are wearing a gold ring, it was forged in a supernova explosion.

Now the universe is chemically more complex.

In a chemically more complex universe, it is possible to make more things.

Young stars are young suns.

Materials around the sun, start to form rocks, meteorites and planets.

This is how our solar system was formed, 4.5 billion years ago.

Rocky planets like our Earth are significantly more complex than stars.

They have a much greater diversity of materials.

We have crossed the fourth threshold of complexity.

Now the going gets tougher.

The next stage introduces entities, that are significantly more fragile,

and significantly more vulnerable.

But they are also much more creative.

We are now talking about living organisms.

Living organisms are created by chemistry.

We are a package of chemicals.

Chemistry is dominated by the electromagnetic force.

They operate over smaller scales than gravity.

This explains why living organisms are smaller than stars or planets.

For living organisms to come about requires some critical Goldilocks conditions.

We need the right amount of energy.

There should not  be too much of energy.

In the centre of stars, there is so much energy, that any atoms that combine,

will get busted apart.

There should not be too little energy.

In intergalactic space, there is so little energy, that atoms cannot combine.

Planets are good candidates for this condition.

They are close to stars, but not too close.

For life, you also need a great diversity of chemical elements,

and need liquids such as water.

In gases atoms move past each other so fast, that they cannot combine.

In solids atoms are struck together, they cannot move.

In liquids they can move and link up to form molecules.

Our planet Earth was just perfect for life to be born.

It is at the right distance from the sun.

It has huge oceans of liquid water.

Beneath these oceans, there are cracks through which heats seeps out.

There was a great diversity of elements.

In these deep oceanic vents , amazing chemistry began to happen.

Atoms combine in all sorts of exotic combinations.

Life is more than just exotic chemistry.

How do you stabilise those huge molecules, that seems to be viable?

This is where life introduces an entirely new trick.

You do not stabilise the individual,  you stabilise the thing that carries information.

You allow the template to copy itself.

DNA is that beautiful molecule, that contains that information.

DNA is a double helix molecule.

Each rung contains information.

The DNA molecule has the information on how to make living organisms.

DNA also copies itself.

It scatters the templates throughout the ocean.

The information spreads.

Information has now become part of the story.

The real beauty of DNA is its imperfections.

As it copies itself, once in every billion rungs, there tends to be an error.

What that means is, DNA in effect is learning.

It is accumulating new ways of making living organisms,

because some of these errors work.

DNA is building greater diversity, and greater complexity.

We can see this happening in the last four billion years.

For most of that time, life on Earth was relatively simple single cells.

But they had great diversity.

And about 600 million years ago, multicellular organisms appear.

We get fungi, fish, plants, amphibia, reptile, and dinosaurs.

Occasionally there are disaster.

65 million years ago, an asteroid landed on earth.

It created conditions when many forms of life including the dinosaurs were wiped-out.

Terrible news for the dinosaurs, a great news for our mammalian ancestors who flourished,

in the niches left by the dinosaurs.

We human beings are part of that creative evolutionary pulse, that happened 65 million years ago. 

Humans appeared about 200 thousand years ago.

We can consider ourselves as a threshold, in big history.

We have seen that DNA learns, in a sense.

It accumulates information.

DNA generated a faster way of learning.

It produced organisms with brains.

These organisms can learn in real time.

The sad thing is, when they die, the information dies with them.

What makes human different, is human language.

We have developed a system of language, so powerful and so precise.

that we can share what we learn, and it can accumulate in the collective memory.

This means it can outlast the individuals who learnt that information.

It can accumulate from generation to generation.

That is why as a species, we are so creative and so powerful.

That is why we have a history.

We seem to be the only species in 4 billion years to have this gift.

We can call this the ability for collective learning.

It is what makes us different.

We can see it at work at the earliest stages of human history.

We evolved in the savannah in Africa.

We then migrated to new environments, into desert lands, jungles, and the ice age tundra of Siberia,

into the America's, into Australasia.

Each migration involved learning new ways of exploiting the environment.

Then 10000 years ago, exploiting a sudden change in global climate, with the end of last ice age,

humans learnt to farm.

Farming was a energy bonanza.

Exploiting that energy, human populations multiplied.

Human societies got larger, denser and more inter connected.

And then from about 500 years ago, humans began to link up globally,

through trains, through shipping, through telephone, through the internet, 

and now we seem to form a single global brain, of about seven billion persons.

And that brain is learning at warp speed.

In the last 200 years, something else happened.

We stumbled on another energy bonanza, in fossil fuels.

Fossil fuels and collective learning together, explains the staggering.

Big history is a powerful story, and recently humans have played a leading role.

It also contains warnings.

Collective learning is a very very powerful force.

It is not clear that we humans are in charge of it.

We need to avoid massive self destructions with advanced weapons.

We are burning fossil fuel at such a rate, that we seem to be undermining the Goldilocks conditions.,

that made human civilisation possible for the last 10000 years.

What big history can do is show us the nature of complexity and our fragility.

It can show us the danger and also the power of our collective learning.

We need to understand Big history, to understand the challenges and the opportunities that face us,

at this threshold moment, in the history of our beautiful planet.