Cosmological Time Scale 1

What I've done here is
I've copied and pasted

a bunch of pictures
that signify events

in our history, when
you think about history

on a grander scale, that most
of us have some relation to

or we kind of have heard it
talked about a little bit.

And the whole point
of this is to try

to understand, or try
to begin to understand,

how long 13.7 billion years is.

So just to start off,
I have here-- this

is the best depiction
I could find

where it didn't have copyrights.

This is from NASA--
of the Big Bang.

And I've talked about
it several times.

The Big Bang occurred
13.7 billion years ago.

And then if we go a
little bit forward,

actually a lot forward,
we get to the formation

of our actual solar
system and the Earth.

This is kind of the
protoplanetary disk

or a depiction of a
protoplanetary disk forming

around our young Sun.

And so this right here
is 4.5 billion years ago.

Now this over here-- once again,
these aren't pictures of them.

These are just depictions
because no one was there

with a camera.

This is what we think
the asteroid that

killed the dinosaurs looked like
when it was impacting Earth.

And it killed the dinosaurs
65 million years ago.

So until then, we
had land dinosaurs.

And then this, as far as
the current theories go,

got rid of them.

Now, we'll fast forward
a little bit more.

At about 3 million years ago--
let me do this in a color

that you can see--
about 3 million,

so three million years ago,
our ancestors look like this.

This is Australopithecus
afarensis.

This is I think a depiction
of-- this is Lucy.

I believe the theory is that all
of us have some DNA from her.

But this was 3
million years ago.

And you fast forward some
more and you actually

have the first modern humans
appearing on the planet, people

that looked and thought
like you and me.

This is 200,000 years ago.

That's right over here.

Obviously, this drawing
was done much later.

But this is a depiction of
a modern human, so 200,000

years ago.

And then you fast
forward even more.

And I don't want to
keep picking on Jesus.

I did that with him
getting on the jet liner.

And I genuinely don't mean
any offense to anyone.

I just keep picking Jesus
because frankly our calendar is

kind of-- he's a good person
that most people know about,

2,000 years ago.

And so when we
associate kind of a lot

of modern history
occurring after his birth.

So this right here is
obviously a painting

of the birth of Jesus.

And this is 2,000 years ago.

And then this might be a
little bit American-centric.

But the Declaration
of Independence, it

was a major event.

Actually even on
a worldwide basis,

it was the first
secular democracy

based on a kind of a
constitutional democracy that

showed up on the planet.

They said we don't want the
king of England anymore.

And this was about
234 years ago.

And I always remembered
because I was born almost

on the 200th anniversary.

So you just have to
add my age to 200.

So this is 234 years ago.

So these are all events
or periods of time

that we've heard about
and we've talked about.

And people throw around
these type of years.

But what I want to
do in this video

is relate it to time scales
that we can comprehend.

So instead of the Big Bang
occurring 13.7 billion years

ago, let's pretend like
it occurred 10 years ago.

Because most of us, especially
if you're over the age of 10,

can kind of understand
what 10 years is.

It's a very, very
long period of time.

But something that's well
within our lifetimes,

well within our experience.

So let's say the 13.7 billion--
instead of saying the Big

Bang occurred 13.7
billion years ago, let's

pretend like it
occurred 10 years ago.

And if we pretend that
it occurred 10 years ago,

let's think about how many
years, or minutes, or hours

ago each of these events
would have occurred.

So if Big Bang, which is
really 13.7 billion years,

if it really had
occurred 10 years ago,

and we scaled everything down,
if we had scaled everything

down, then the Earth
would have been

created about 3.3 years ago.

So this would have
been 3.3 years ago.

So there's nothing kind
of amazing about this.

This is a significant fraction
of the age of the universe.

So not that mind
blowing just yet.

But if we go all the way to
when the dinosaurs were extinct,

the last land dinosaurs, now
the 65 million years-- and this

will give you an appreciation of
the difference between million

and billion-- if the universe
was only 10 years old,

then the dinosaurs would have
been extinct 17 days ago.

Not even a month
ago, the dinosaurs

would have been extinct.

So if the universe was created
when I was just graduated--

well, I'm in my '30s
now, so when I was 24--

just last month, the dinosaurs
would have gone extinct.

And it gets even crazier.

17 days ago, the dinosaurs
would have extinct.

Australopithecus
afarensis would have

walked on the Earth 19
hours ago, yesterday.

19 hours ago, she would
have been walking around

on the planet.

And modern humans wouldn't have
shown up until 80 minutes ago,

80 minutes, a
little over an hour.

There wasn't even
a modern human.

Then the universe
was 10 years, it

didn't take until
just very recently,

the last hour, for us to see
someone that looks something

like us, looks and
thinks something like us.

Fast forward even more,
the birth of Jesus,

if the universe was 10 years
old instead of 13.7 billion--

and we scaled everything
down-- then the birth of Jesus

would have been 46 seconds ago.

And then if we fast
forward all the way

to the Declaration
of Independence,

this would have occurred
five seconds ago.

So this isn't quite
as mind blowing

as the scale of the universe.

But in my mind, this is
still pretty amazing.

I mean all that's happened
since 1776 on a global basis

could have been
encapsulated in five seconds

if the age of the
universe was 10 years.

So hopefully, that gives you
a little bit of a perspective.

In the next video, instead
of condensing things in time,

I'm going to compare this scale
to kind of a distance scale.

So we can kind of say,
hey, if the universe was

the number of
pixels on my screen,

how big would each
of these things be?