Life is fundamentally different
from dead stuff—or is it?

Physicist Erwin Schrödinger
defined life this way:

Living things avoid decay into
disorder and equilibrium.

What does this mean?

Let’s pretend that your download
folder is the universe.

It started orderly and got more
and more chaotic over time.

By investing energy, you can create
order and clean it up.

This is what living things do.

But what <i>is</i> life?

Every living thing on this
planet is made of cells.

Basically, a cell is a protein-based robot
too small to feel or experience anything.

It has the properties we just
assign to life:

it has a wall that separates it from the
surroundings, creating order;

it regulates itself and maintains
a constant state;

it eats stuff to stay alive;

it grows and develops;

it reacts to the environment;

and it’s subject to evolution;

and it makes more of itself.

But of all the stuff that makes up
a cell, no part is alive.

Stuff reacts chemically with other stuff,
forming reactions

that start other reactions which
start other reactions.

In a single cell, every second several
million chemical reactions take place,

forming a complex orchestra.

A cell can build several thousand
types of protein:

some very simple, some complex
micromachines.

Imagine driving a car at 100 km/h while
constantly rebuilding every single

part of it with stuff you collect
from the street.

That is what cells do.

But no part of the cell is alive;
everything is dead matter

moved by the laws of the universe.

So is life the aggregate of all these
reaction processes that are taking place?

Eventually, every living thing will die.

The goal of the whole process is to
prevent this by producing new entities;

and by this, we mean DNA.

Life is, in a way, just a lot of stuff
that carries genetic information around.

Every living thing is subject to
evolution,

and the DNA that develops the best living
thing around it will stay in the game.

So, is DNA life, then?

If you take DNA out of its hull,
it certainly is a very complex molecule,

but it can’t do anything by itself.

This is where viruses make everything
more complicated.

They are basically strings of RNA
or DNA in a small hull

and need cells to do something.

We’re not sure if they count as
living or dead.

And still, there are 225,000,000 m³
of viruses on Earth.

They don’t seem to care what
we think of them.

There are even viruses that invade
dead cells and reanimate them

so they can be a host for them, which
blurs the line even more.

Or mitochondria.

They are the power plants of
most complex cells and

were previously free living bacteria that
entered a partnership with bigger cells.

They still have their own DNA and can
multiply on their own, but

they are not alive anymore; they are dead.

So they traded their own life for the
survival of their DNA,

which means living things can evolve into
dead things as long as it’s beneficial

to their genetic code.

So, maybe life is information that manages
to ensure its continued existence.

But what about AI
(artificial intelligence)?

By our most common definitions, we are
very close to creating artificial life

in computers.

It’s just a question of time before the
technology we build gets there.

And this is not science fiction, either;

there are a lot of smart people
actively working on this.

You could already argue that computer
viruses are alive.

Hm, okay. So what is life, then?

Things, processes, DNA, information?

This got confusing very fast.

One thing is for sure:

the idea that life is fundamentally
different from non-living things

because they contain some
non-physical element

or are governed by different principles
than inanimate objects

turned out to be wrong.

Before Charles Darwin, humans drew a line
between themselves and the rest

of living things; there was something
magical about us that made us special.

Once we had to accept we are like every
living being, a product of evolution,

we drew a different line.

But the more we learn about what
computers can do and how life works,

the closer we get to creating the first
machine that fits our desciption of life,

the more our image of ourselves
is in danger again.

And this will happen sooner or later.

And here’s another question for you:

if everything in the universe is made
of the same stuff,

does this mean everything
in the universe is dead

or that everything in the universe
is alive?

That it’s just a question of complexity?

Does this mean we can never die

because we were never alive
in the first place?

Is life and death an irrelevant question
and we haven’t noticed it yet?

Is it possible we are much more part of
the universe around us than we thought?

Don’t look at us; we don’t have any
answers for you.

Just questions for you to think about.

After all, it’s thinking about questions
like this that makes us feel alive

and gives us some comfort.