Hey, Vsauce. Michael here. This is Earth as
seen from Saturn. That is us right there.
And if you look closely, ok, see this
little protuberance? That's the Moon.
This image was taken by the Cassini
spacecraft on July 19th, 2013 at 21:27
Coordinated Universal Time. The thing is,
NASA gave the public advanced warning
of when it would be taken, which means
that this image of Earth was the first
ever taken from space that some people on
Earth were actually posing for. Our planet
looks so small, insignificant, fragile.
I recently attended the premiere of Sky
1's upcoming "You, Me and the Apocalypse"
with some cool YouTubers and it got me
thinking. In the show, the characters find
out that they're only 34 days left before
a comet smashes into Earth that's likely
to end humanity. They all react in
different interesting ways, but what
would I do if I found out that there
were only 34 days
of human history left? Ok, my first priority
would be to get back to America to be
with my family.
But after that? I don't really have a
bucket list. Except that is exactly what
I would want to spend my last few weeks
doing. Making a list to put in a bucket
that I would then send far out into
space away from Earth's impending
vaporization. The list would contain
information about us, all Earthlings. So
that if libraries and monuments and
YouTube videos were all destroyed, a
record would still exist somewhere
of what and who we were. Like a stone
thrown into a lake, the ripples your life
causes last long after you vanish,
the tree you planted is climbed by future
generations, the books you donated inform
future readers. But what if it's not just
your stone that vanishes, but the entire pond?
Perhaps it's arrogance or vanity, but
getting cosmic messages in a bottle out
there, before the end, diversifies our
archive and gives a better chance for
future alien visitors, or whatever is
left of humanity, to find out that we
were once here,
to show what we learned. Maybe even to warn
future life forms of what we did or what
we didn't prepare for. We have already
sent some messages about humanity out
there, beyond Earth, and if Earth is
completely destroyed, those messages will
be all that's left of us. What are they?
Ok, first things first. How do you write
something for the future? I mean,
the distant future. The message might not be
found for millions of years or billions.
It might be discovered by an audience
that's completely different, not only in
language, but in senses? What if
they can't see or hear or feel or taste
or smell like we do, or at all.
What if their bodies destroy the very material
we write the message on? What language
do you even write it in? Well, in general, math
and physics, which are believed to be the
same everywhere in the universe,
have been what we write outer space bound
messages in.
Like the Arecibo message, written by
Frank Drake, Carl Sagan and others, which
was blasted towards the M13 star cluster
in 1974. It's composed of a semi prime
number of binary digits conveying some
info about us and it should reach the
center-ish of the M13 cluster in about
25,000 years, at which
point, if something intelligent lives
there and detects it, they can respond
and their response will return to us
another 25,000 years later. We won't be
around for that. But Earth has also been
broadcasting its radio and TV signals
into space. Currently it's about 200
light-years in diameter. Compared to the
Milky Way, it's about this big. Aliens within
that bubble could tune in and listen to
programs we sent out through our
airwaves, but these signals thin out as the
bubble expands. Across very large
distances they may be essentially
impossible to tune into.
Maybe a physical time capsule would be
more permanent, but it can't be buried on
Earth if Earth is about to be ravaged.
A time capsule in orbit might be smart,
like LAGEOS-1, a satellite put into orbit
in 1976 that allows for very precise
laser measurements of positions on Earth, 
but also contains a plaque designed by Carl Sagan, upon
which is written the numbers 1 to 10 in the binary, and the arrangement of the Earth's continents 250 million years ago,
today and their estimated arrangement
in 8.4 million years, which is how long we believe
the satellite's orbit will be stable. Drag caused by the thin atmosphere up where it orbits and
influences like solar activity
will eventually cause it to fall back down
to Earth, but its plaque will serve as a
time capsule - a message from us today to
whatever happens to be alive or
intelligent here on Earth
8 million years in the future.
To put that in perspective, the pyramids
were only built about 5,000 years ago.
8 million years ago, there weren't even
humans on the Earth. The latest common ancestor of
humans and chimpanzees was around though.
8 million years from today, when LAGEOS
returns, what will intelligent life on
Earth look like? If Earth's surface is
barren of life at that point, LAGEOS-1
will be alone. But what about
satellites in geostationary orbits? These
orbits are far enough out that they're
much safer from atmospheric drag and
could remain above Earth much much
longer than satellites like LAGEOS.
These satellites are our pyramids. They're
smaller than monuments built by past
civilizations, but impervious to anything
that might go wrong on the less stable
surface of our planet. If alien
archaeologists come by in a billion
years or so, these satellites may be what
their alien encyclopedias use as the
picture for the humans article. So far we
have erected about 450
of these geostationary monuments.
When such a satellite wears down and
ceases to be operational, it takes a lot
of energy to slow it down so it can move
out of the way and fall to Earth to burn up in
the atmosphere. So instead, they're
usually pushed into what's known as a
graveyard orbit.
A shell around the planet where they can
be part without interfering with
important operational satellites.
It's fitting that we call these graveyard
orbits because tombs are often the most
stunning things we have from previous
civilizations. These graveyard orbits are
tombs in a way. Not for kings, but for
machines. Junkyards that will out-exist the
very societies and people they so
largely define. Luckily, a few contain
more than just our craftsmanship. They
also contain a record, like EchoStar XVI,
a communications satellite launched into
geostationary orbit in 2012. Aboard it is a
silicon disc created by artist Trevor
Paglen, containing 100 images of
Earth and Earthlings. Now, unlike LAGEOS,
EchoStar XVI will likely remain in orbit
for billions of years,
safe from discord and change down here.
But here's the thing. What if our entire
solar system is lost? Or what if life out
there doesn't decide to ever visit our
system? Well, in that case, we have sent
interstellar messages. At this moment, so
far, there are 11 distinct human made
things on trajectories out of the
solar system into interstellar space.
They're all related to five probes.
Pioneer 10, Pioneer 11, Voyager 1 and
Voyager 2 and New Horizons, the thing
that recently made a Pluto flyby.
These objects are our most distant hellos.
Over the next ten thousand, million,
billion years, they'll pass close enough
to other star systems, maybe even planets,
to possibly be discovered by other
intelligent life forms. We had the
foresight to include special messages on
these probes. The Pioneer plaques are
attached to Pioneer 10 and 11, which
launched in the early 1970's,
were the first human-made objects to
ever be sent on a trajectory to not just
leave Earth, but to leave the solar
system entirely. If discovered by other
life out there, these plaques, designed by
Frank Drake and Carl Sagan,
could be our first chance to say "hello,
we exist," or, depending on how long
humanity lasts, our only chance to say
"Hello,
we existed. This is what we were." But will
the plaques makes sense to aliens? Many
humans scientists have had trouble
deciphering their meaning, but here's
what they say. At the bottom is a map of
our solar system with a path showing the
Pioneer probe itself and where it came
from. This element has been particularly
criticized for being human centric.
I mean, an arrow? Who's to say aliens will know
that this depicts a path and not some
structure in our solar system? Also, it's
an arrow. Arrows might convey this way
only two civilizations that hunted or
developed pointy projectiles. Anyway. 
Up here, we define units. You can't tell
aliens about humans or Earth by using
seconds, kilometres or light years,
because we made those measurements up.
Instead, the plaque uses hyperfine
transitions to communicate distances and time.
The hope is that curious
intelligent life forms who find this
will understand that this is a hydrogen
atom - one proton, one electron. Hydrogen is
the most abundant element in the
universe, so hopefully its properties
will be a common point of understanding.
Now sometimes, if you've got enough
hydrogen around, you can catch atoms in
the heap transitioning between particles
with parallel spins and antiparallel
spins. Now, whenever this transition
happens, electromagnetic radiation is
released with a period of about 2.7
nanoseconds and a wavelength of about
21 centimetres. It's hoped that
aliens equate this tick mark with these
two units of measurement. For example,
the woman is said to be, in binary, eight of
these units tall. 21 centimetres times
eight is a 168 centimetres.
You would think that putting
the probe itself behind them for scale
would be enough to show our size,
but having both might help solidify the
connection. This diagram is meant to show
where we live. We are in the middle.
The direction and proportional length of
the lines show where distant pulsars are.
A tick-mark near the ends of each line
shows the third direction, behind or in
front of the plaque, that the line should
go in. In binary, next to each line is the
period of each pulsar. Again, in the
time units described above. If aliens
make this connection they could possibly
match the periods with the correct
pulsars in real life,
triangulate our position and come say hello.
Also, since the period of a pulsar
changes over time, they could use our
observed periods to date back how long
ago this plaque was made. So that's how
the plaque works. It kind of feels like
we're just sending out a bunch of
science homework to space, but how else
can you find common ground with
something that might not resemble you in
any way you could even imagine? Despite
heading out first,
the Pioneer plaques are not the first
physical messages made by us to go
interstellar.
That title belongs to Voyager 1.
Currently moving at 17 km/s, it is
the most far-out thing humans have ever made.
Literally. In about 40,000 years,
both Voyagers will pass within less than
two light years of other stars.
If aliens find them, or if future
humans find them, a golden record is attached to
both that contains information about
humanity. The record is made of gold
plated copper with an aluminum cover,
containing some uranium 238. Given its
half-life, smart aliens could analyze it
to determine how long ago the record was
made. On the record is the inscription to
the makers of music All Worlds All Times.
The record contains 116 images, as well
as audio and video recordings of humans,
animals, songs and greetings in fifty
five languages. Printed on the record are
instructions for playback and info about
us. The hydrogen hyperfine transition
unit definition and the Pulsar map,
included on the Pioneer plaques, but the
record also comes with a stylus and
platter to play it. Instructions for using
the stylus are on the record. This is a
picture of the stylus being used
correctly and then in binary using the
transition units, the record tells the
aliens that the stylus should go around
the record once every 3.6 seconds
to play back correctly and in
total should take about one hour to do so.
For the video portion, instructions
are given in a circle. The first video
image is displayed, so they know they did
it right.
Also included on the record is a message
from then-president of the United States,
Jimmy Carter. There's something
vulnerable about the message. It's
delivered to an unknown recipient,
like when someone in a horror movie asks
into the darkness "Is anyone there?
Hello?" This is what it says. "We cast this message
into the cosmos. It is likely to survive
a billion years into the future, when our
civilization is profoundly altered and
the surface of the Earth
may be vastly changed. Of the two hundred
billion stars in the Milky Way galaxy,
some, perhaps many, may have inhabited
planets and space faring civilizations.
If one such civilization intercepts
Voyager and can understand these
recorded contents, here is our message.
This is a present from a small, distant
world. A token of our sounds, our science,
our images, our music, our thoughts and
our feelings. We are attempting to
survive our time, so we may live into
yours. We hope someday, having solved the
problems we face, to join a community of
galactic civilizations. This record
represents our hope and our
determination and our goodwill in a vast
and awesome universe." Are these messages
enough?
Should we send more? Well, why not send
everything? We could, if we sent the
Library of Babel.
It's a website built by Jonathan Basile
that currently offers everything that
has been or could be written.
Seriously. Divided into pages, it is built
to produce and locate on demand any 3200
character combination of English letters
and the comma, space and period. Basile
has organized it all into hexagon-shaped
rooms, each with four walls of books
containing five shelves with 32 volumes
of four hundred and ten pages each.
Everything's arranged in a pseudo-random
fashion, so browsing the online library
feels like a treasure hunt.
Here's how it works.
Each page is given a unique sequential
page number in base 10. The text on each
page is encased inside this number.
An algorithm Basile created uses the
page number as a seed to generate a
unique big number. That output is then
converted into base 29 so that it can be
represented using every letter in the
English alphabet as well as the comma,
the space and the period. This is what
you see on the page. Basile has made
sure that the algorithm will produce
every possible combination and the same
page number will create the same output
every time.
Which means that what is on each page is
already predetermined. So, in a way, every
page already exists.
It only needs to be looked up.
And here is the really mind blowing
thing. The contents of a page can be
converted to base 10, sent through the
inverted algorithm and turned into the
exact page number they're found on. It's a
truly eerie experience, because you can
find the permanent location for any 3200
character text. You can find in this
library the description of your birth,
every possible description of your death,
every poem, every joke, every lie,
anything that could be said
can be found on this site.
This thing blurs the line between invention
and discovery. Did you really discover or invent
that thing if its description already existed?
10 to the 5,000 different
pages
are offered by the Library of Babel.
In comparison, there are only 10 to the 80 atoms
in the observable universe.
I searched for what I've just said and
sure enough in this hexagon, on this wall,
this shelf and this volume on this page it's
there.
Hello.
But deep down, we feel like there's a
difference between this program
permuting something unknowingly and
a person actually meaning it, intending it,
saying it because they wanted to with
agency. We use a finite number of symbols
to say things. For that reason, a library of
every finite combination of those
symbols can be made,
but just because it can be made
doesn't need it has been said. That is
the power we have. Perhaps you and I were
born too late to explore the world and
too early in history to explore the
stars, but we were born at just the right
time, which is pretty much all times ever
to explore language. To explore what can be
said. What should be said.
What should we send out to space. What that
can't be said will you be the first to say?
And as always,
thanks for watching.
To watch the trailer of You, Me and the Apocalypse
click right up there and
to see some other cool things YouTubers
have done inspired by the series. Well,
you can also click right over there.
Colin Furze is building a giant
apocalyptic bunker in his backyard, like
for real. It's huge. Also, The Dictionary of
Obscure Sorrows has weight in. Check those
out and thanks for watching.
