How’s it going everyone?
I’m Nick and you are listening to the Fresh
Perspective Podcast.
Did you get a chance to listen to our last
episode about our journey back through 4 Billion
years of earth’s history?
If not, pause this episode and go check it
out.
I’ll be sure to leave a link below.
This episode is the second part in a series
where we will be looking back through the
past, a few billion years at a time.
If you invented a time machine and began to
travel backwards, what would you see?
How far back could you go?
In this episode, we will try to wrap our minds
around some planetary science, astrophysics,
and cosmology, as we rewind time at one billion
years per minute, with the help of a little
imagination.
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(Crunching Noises)
Mmmhmm, now that was a good lunch!
I noticed you were looking out the window.
Are you hoping to see something swimming out
there?
It’s unlikely, we have already traveled
over 4 billion years into the past.
As far as we know, our planet is now completely
barren.
True, there are organic molecules all over
the earth, but they’re not quite yet alive.
Did you hear that?
It could be an earthquake or volcano.
Most likely, the earth has been hit.
You see, this far back in time, the space
between the planets of the solar system wasn’t
quite as empty like it is in our time.
There is an awful lot of space junk up there
being collected by gravity into anything big
close by, like us.
Our time machine is about to surface, and
then we can continue our trip back to the
beginning of time.
To tell you the truth, we aren’t even half
way there!
Are you ready?
Alright, I’ll re-set our speed to travel
at about one billion years per minute, or
at about 16 million years per second.
Our computer will also let us know when we
reach each billion-year milestone.
Go ahead and pull that lever back!
Our vehicle glows and twists space-time, hurdling
us back into the past.
We are in the Hadean Eon, looking down, as
much of our oceans boil and rumble into clouds
of steam.
The clouds are reabsorbed into balls of rocky
ice, comets, which fly off in all directions,
leaving massive craters in the hellish landscape
of our infant planet.
We pass through the late heavy bombardment
in which the Earth and moon is pelted, non-stop,
by asteroids, meteorites, and all kinds of
space debris.
The moon flies past us, dangerously close
to the surface of the earth, spiraling in
until it dissolves into countless rocks and
globs of earth.
For a few seconds, our lava planet has no
moon, but has at least a partial set of rings.
At 30 seconds into our journey, the planet
shakes and is almost broken in half!
Its rings and vaporized-rock atmosphere re-form
into its surface and a proto-planet, about
the size of mars, which struck the earth!
This proto-planet, named “Theia,” flies
back into space, re-assuming its doomed spiral
toward us.
More evaporated water is pulled back onto
the infant world, a red-hot ember of molten
rock and radioactive elements.
From here, you can almost see the light rocky
elements of the crust falling and the heavy
metal elements rising, mixing the world up
into a liquefied mess as rocks from space
continued to bombard it.
We pull back to keep our distance in just
enough time to see our world spin faster and
faster, flinging its rock, metal, and water
out into space.
In no time at all, it’s gone.
The earth is nothing but a massive cloud of
light elements, a dust pile around a new star.
I was so focused on our planet that I missed
the formation of Mercury, Venus, Mars, or
Jupiter.
All the planets, moons, and objects in our
solar system have now dissolved into a scattered
and dusty gas cloud.
Once we pass 40 seconds back, the light goes
out.
99% of the mass of our solar system is no
longer condensed by gravity enough for nuclear
fusion.
The matter around us is no longer compact
enough to form a star.
In a few more seconds, we drift in the darkness
of space, unable to tell that we were once
in a system of majestic planets.
If you look down there, you can see the constellation
Libra.
Below that you can see the stars of the Southern
Cross.
Between those two is the Centaurus constellation.
Do you see the brightest star in the centaur?
That is where you can find the Alpha Centauri
system of three stars and a planet.
Proxima Centauri is the closest star to us,
but at about 50 seconds we see it fly further
away from us, and then shrink back into its
own stellar nursery of gas clouds.
Surrounded mostly by invisible hydrogen and
helium in a molecular cloud, we see the stellar
siblings of our sun grow closer to us, only
to also be snuffed out in the rewinding of
time.
5 Billion Years Ago
At this speed you can see some of the constellations
slowly contort and become unrecognizable.
Some stars in other constellations go out
while other remain unchanged.
The expansion of the universe is stretching
the space between the galaxies, but we are
seeing this in reverse.
In fact, distant stars and galaxies seem to
be rushing closer.
Don’t worry, we have plenty of time before
they collide with us.
They appear to be moving quickly now because
we are in the Dark Energy Dominated Era.
Pretty soon, the mysterious dark energy that
accelerated this expansion will, for some
reason, have a weaker effect.
6 Billion Years Ago
From here, you can see the bright center of
our galaxy.
There is an ancient black hole there, and
it usually takes our sun about 225 million
years to circle it.
At our speed of one-billion-years per minute,
we will rotate around the center of the galaxy
about every 14 seconds.
Our Milky Way has about 100 billion stars,
and there are about 125 billion galaxies in
the universe, but that number is slowly dropping
as we fly through history.
As far as we know, we are the only living
things that can see this view out the window.
What is so special about the stars and galaxies
out there?
To be fair, it still looks a lot like something
you’d see from the Hubble telescope.
Well, we’ve made it half way.
We have traveled through half of the age of
the universe.
In other words, we are half way to the Big
Bang!
7 Billion Years Ago
After seven minutes of travel, our milky way
is starting to change its size and shape.
Many of its stars, including our sun, have
gone out, but long dead stars have reignited.
Smaller galaxies slowly pull away from it
and the Milky Way has begun to shrink.
Some parts of our home galaxy house some of
the oldest stars in the universe, so we shouldn’t
expect it to vanish any time soon.
8 Billion Years Ago
Superclusters begin to break apart into clusters,
clusters into groups, and groups into lone
galaxies.
Neighboring galaxies in our local group are
spinning and dissolving into smaller clusters
of stars.
For the next 6 minutes, you are going to see
a lot of that.
The universe is expanding in reverse for us,
so as it slowly closes in, it is getting easier
to spot other galaxies shrinking, splitting
apart, and growing dimmer as fewer stars set
them apart from the inky black cosmos.
9 Billion Years Ago
The universe is only 4.8 billion years old
now, and many of the elemental clouds that
would give birth to future stars are collapsing
into supernovae, blinding explosions that
flash for the briefest instant, only to swell
back into super massive stars where most of
the heavy elements of the cosmos are cooked.
10 Billion Years Ago
The edges of the universe have again begun
to speed up toward us.
The universe is only 3.8 billion years old
now, and it is getting warmer.
Gravity hasn’t had much time to clump all
of the galaxies together, so the stars we
see are far more spread out compared to what
we are used to seeing.
To us, our own Milky Way has become unrecognizable,
but I am sure there are some experts that
could point out some notable features even
this far back.
11 Billion Years Ago
Wait, have you been touching any of the controls
to the time machine?
I haven’t.
It seems like we are getting faster.
Does time itself warp more dramatically, the
closer we get to the big bang?
I don’t know, but it is a fascinating thing
to consider.
12 Billion Years Ago
It is really dark out there!
There are a few stars near us, and there must
be countless other stars, but most of them
are just too far away for us to see.
It was nice when there were bright galaxies,
but I can’t even see any of them anymore.
There are plenty of black holes out there.
The truth is we could fall into one of the
smaller ones at any moment, and we would never
see it coming.
Look!
Even the oldest stars, quasars, and dwarf
galaxies are going out!
In a few seconds, we won’t see a thing…
I don’t think I have ever seen anything
so dark.
13 Billion Years Ago
Our sensors are picking up a great deal of
ultraviolet light.
The space around us is quickly heating up
into a kind of plasma.
Blasts of light come from blinding hyper novae,
the death of the very first stars.
They were super massive Hydrogen giants.
Now that they have reformed we have crossed
into a universe ruled by energy, not matter.
The Hydrogen giants weren’t formed by gravity
collecting hydrogen gas alone.
No, most of the stuff out our window is dark
matter, as has always been the case, accelerating
the collection of molecules together.
At 13 minutes and 50 seconds into our voyage,
even the first black holes are evaporating
back into their stellar forms.
Matter is spread fairly evenly across the
cosmos.
We are plunged in darkness yet again.
This is fitting, because we have crossed into
the Cosmic Dark Age.
At our current speed, it’s not going to
stay dark for long.
White light floods our windows, like a searchlight,
right into our eyes!
No, that isn’t some explosion or star.
That is a wave of photons released from the
Recombination & Decoupling stage of our universe.
The first neutral atoms had just formed, allowing
tremendous amounts of energy to fly free in
the now transparent cosmos.
We can even see this energy back in our own
time, as the cosmic microwave background radiation!
Just as suddenly as the light arrived, it
vanishes.
This is the end of the line for us.
I know we wanted to go further, but I have
to insist.
The universe is only 47,000 years old, but
this is as far as we can go.
It is getting so hot outside our time machine
that atoms are no longer able to hold onto
their electrons.
In other words, our time machine will soon
dissolve into a plasma itself!
The universe is now dark and opaque, a dense
foggy soup of plasma, like the inside of a
star.
If we travel much further, we will be ripped
apart by antimatter and crushed by the pressure
of the universe closing in around us.
There is no time for a debate!
Our craft can’t take this heat!
Push that button to reverse our course – hurry!
…
Now that was an adventure.
Now that we are safe back home, I really can’t
wait to get my feet back on the ground.
I hope you aren’t too disappointed that
we couldn’t see the big bang.
I suppose that no time-machine, probe, robot,
or space craft can really go much further
back in time than we did.
However, if you would like to perform a thought
experiment to see if we can go back to the
big bang, and even before it, I do have an
episode of this podcast called, “What Happened
before the Big Bang?”
Why don’t you give it a listen?
I bet you’d get a kick out of it.
That is all I have for you today, but the
conversation continues across social media
and in the comment sections below.
Do you agree with today’s message?
Am I mistaken about some detail?
How can I better elaborate on this topic in
the future?
Feel free to share your perspective!
