The beginning of the universe, for beginners - Tom Whyntie

The universe,

rather beautiful, isn't it?

It's quite literally got everything,

from the very big

to the very small.

Sure, there are some less than savory elements in there,

but on the whole, scholars agree that its existence

is probably a good thing.

Such a good thing, that an entire field

of scientific endeavor is devoted to its study.

This is known as cosmology.

Cosmologists look at what's out there in space

and piece together the tale of how our universe evolved:

what it's doing now,

what it's going to be doing,

and how it all began in the first place.

It was Edwin Hubble who first noticed

that our universe is expanding

by noting that galaxies seem to be flying

further and further apart.

This implied that everything should have started

with the monumental explosion

of an infinitely hot,

infinitely small point.

This idea was jokingly referred to at the time

as the "Big Bang,"

but as the evidence piled up,

the notion

and the name

actually stuck.

We know that after the Big Bang,

the universe cooled down

to form the stars and galaxies that we see today.

Cosmologist have plenty of ideas

about how this happened.

But we can also probe the origins of the universe

by recreating the hot, dense conditions that existed

at the beginning of time in the laboratory.

This is done by particle physicists.

Over the past century,

particle physicists have been studying

matter and forces at higher and higher energies.

Firstly with cosmic rays,

and then with particle accelerators,

machines that smash together

subatomic particles at great energies.

The greater the energy of accelerator,

the further back in time they can effectively peek.

Today, things are largely made up of atoms,

but a hundreds of seconds after the Big Bang,

it was too hot for electrons to join

atomic nuclei to make atoms.

Instead, the universe consisted of

a swirling sea of subatomic matter.

A few seconds after the Big Bang,

it was hotter still,

hot enough to overpower the forces

that usually hold protons and neutrons together

in atomic nuclei.

Further back, microseconds after the Big Bang,

and the protons and neutrons were only just beginning

to form from quarks,

one of the fundamental building blocks

of the standard model of particle physics.

Further back still,

and the energy was too great even

for the quarks to stick together.

Physicists hope that by going to even greater energies,

they can see back to a time

when all the forces were one in the same,

which would make understanding

the origins of the universe a lot easier.

To do that, they'll not only need to build bigger colliders,

but also work hard to combine our knowledge

of the very, very big

with the very, very small

and share these fascinating insights

with each other and with,

well, you.

And that's how it should be!

Because, after all,

when it comes to our universe,

we're all in this one together.