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Are you alone in the universe?

Or are you connected to anything?

First of all, you’re part of a group of mammals that’s still very young,

but we can make YouTube videos already,

and build Large Hadron Colliders!

We’ve also split the atom and invented Pokémon.

We stem from an ancient lifeform

that began living about three and a half billion years ago.

We feel like we’re in control of this planet, but we aren’t really.

One little asteroid or one creative virus is really all it would take

to kill us off for good!

Humanity credits itself with being able to destroy the planet,

but even with all our nuclear toys,

we would probably just cause a huge mass extinction, at best.

Maybe we could kill 90% of everything living on this planet.

Big deal!

A few million years later, life would be back everywhere.

Most microscopic life and life below the surface

wouldn’t even be disturbed that much, probably.

On a geological timescale, our impact on Earth

is kind of laughable.

We’re actually not that powerful.

We live on this tiny wet rock that speeds through space

following a massive ball of burning plasma.

One day, this ball of plasma will stop burning

and most likely kill us in the process.

If we survive the death of the Sun and colonize the galaxy,

theoretically, we could survive until

the last star in the universe goes out.

After that, life becomes pretty impossible.

Okay, so everything has an end.

Where does this leave you as an individual?

At one point in your life, for about half an hour,

you were only one single cell inside your mother’s womb.

A creature just 0.1 mm in diameter.

Today, you consist of about 50 trillion cells.

50 trillion incredibly complex little biological machines

that are much bigger and more complex than the average bacteria!

They operate by the laws of physics and chemistry

and use micromachines to build proteins, make energy usable, devour food,

transport resources, transmit information, or reproduce.

They communicate, duplicate, commit suicide, fight off intruders, and fulfil

super-specialized duties for the greater good of keeping you alive

so you can have babies.

But where is the “you” part in this, if you’re made of trillions of little things?

The basic information for “you” is stored in the DNA,

a molecule that encodes the genetic instructions

used in the development and functioning of all known living things.

If you were to unravel it, it would be two meters long!

If you combined all the little DNA strings in all your cells,

you’d get a string so long that it would stretch to Pluto and back to Earth.

That’s pretty long!

And your DNA is a direct connection to your very first ancestor.

Take a second to think about this:

in every cell of your body, there’s a little string of stuff

that’s been there in various forms for 3.4 billion years.

It evolved, it mutated, it duplicated trillions of times,

but it directly connects you to the first living being on this planet.

We could say you “touched” every living being that came before you

with your DNA.

But you are more than your DNA.

Your body is made of seven octillion atoms.

That’s seven billion billion billions.

Roughly 93% of the mass the human body is made up of just three elements:

oxygen, carbon, and hydrogen.

Oxygen and hydrogen are predominantly found in water,

which makes up about 60% of the body by weight.

Carbon is, maybe, the most important element for life.

It can easily bond with other atoms, which allows for the building of long

complex chains of molecules, which make up the solid part of you.

The remaining 7% is a tour of the periodic table of elements:

nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium,

iron, fluorine, zinc, copper, iodine, selenium, chromium, manganese,

molybdenum, cobalt, lithium, strontium, aluminum, silicon, lead, vanadium,

arsenic, and bromine… phew!

By the way, this also means you’re about 0.5% metal,

no matter what your favorite music is.

Anyway, these elements perform various functions like

enabling oxygen transport, building of bones and cell structures,

carrying signals, driving chemical reactions, and a lot more.

Your body is in a constant state of transition.

Every 16 days, 75% of “you” has been replaced,

because a healthy human exchanges about 100% of their water in that time period.

Each year, about 98% of your atoms are replaced by new ones,

and every 5 years, close to all of the atoms that make up your body

weren’t there five years ago.

So, you could call yourself a temporary collection of atoms.

But where did these atoms come from?

In the beginning of the universe, there were mostly hydrogen and helium atoms.

Enormous gas clouds formed over millenia and grew denser and denser,

until they collapsed under their own gravity, giving birth to the first stars.

In the cores of these stars,

hydrogen was converted into helium under extreme conditions.

After millions of years, the hydrogen became exhausted,

and the stars began dying.

Under super-extreme conditions, all elements we know today

were created a fraction of a second before they died and exploded in supernovas.

They shot most of their contents into space,

while the cores collapsed and became black holes.

All these elements traveled through space for who knows how long.

Until they arrived at a different cloud that was slowly forming a new star—

our Sun.

These elements, that once were the insides of a star,

formed planets and found their way onto Earth,

where they enabled life to begin.

So we are directly connected to the first stars ever born in the universe.

We are part of the universe.

The idea of being a deeply connected minuscule part of an enormous structure

is really mindblowing.

We don’t know what all this means, or if it means anything at all.

We know that we are made of little parts that connect us

to everything in the universe, to the beginning of everything.

Then this is kind of a nice thought:

you are not alone; you never were; you never will be.

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