What if there are thousands of
alien empires in the Milky Way, each spanning a few to maybe tens
of star systems, chatting, trading, sometimes shooting or ignoring each other
politely? And if so, why is nobody visiting us? While the Milky Way is ancient and gigantic,
even travelling at 10% the speed of light, any civilization could take over the
whole galaxy within a million years. But we haven’t seen anybody yet. So it
seems we are alone in the Milky Way. But this idea is built on a lot of
assumptions. Usually when scientists speculate where all the alien civilizations
are, they assume technology will progress to a point where colonising all
of space becomes kind of easy. But what if we are thinking about
this the wrong way? What if the universe is full of life, but no matter
how technologically advanced you are, space is never easy? What if
aliens slowly crawl through space, expanding like humans did over the ocean? Let's
look at the only data point we have: ourselves. The Available Real Estate in the Galaxy Oceania is a region with tens of thousands of
islands scattered across millions of square kilometers, separated by an unforgiving,
deadly sea. Kind of like a galaxy. Some 5000 years ago the first people set
out to colonise Oceania. Especially the Polynesians achieved mind blowing feats.
Without any modern technology they set out into the vast nothingness hoping to find a
new island to claim or like die far from home. But most of the pacific islands are merely a
few wet rocks or corrals, maybe some palm trees and if you are lucky, birds making a pit stop.
Others with more vegetation are often hostile, lacking the resources to really sustain a lot
of people and remain uninhabited even today. And then there are the good islands. The Polyneisians colonised them, spreading
their culture and society to dozens of remote islands of all sizes. Some united in kingdoms
spanning many islands, others were independent, many home to competing and belligerent tribes. And
although thousands of kilometers apart, even the most remote islands were connected with at least
some trade and exchange. A microcosm of humanity. But it didn’t always work out. The
extremely isolated Pitcairn islands were settled for hundreds of years and relied
on trade with each other and bigger islands hundreds of kilometers away. And then
the local population vanished. We don’t know why – maybe because the islanders did the
human thing and ravaged the natural resources until they became unsustainable. Maybe the
decline on distant bigger islands severed important connections. We only know their
culture declined and they left or died out. What if space is an ocean to us? A
hostile place that’s hard to conquer? Would alien civilizations
spread like the Polynesians? The Universe is kind of a horrible place The Milky Way has around 200 billion star systems
and it seems that almost all of them have planets. Estimates vary, but there may be some 300 million
to tens of billions of rocky, earth-like planets, in the habitable zone around a star, where water
can be liquid. Amazing! Except that most of them are terrible. Hells of lava, dead frozen
worlds, bare rocks sterile from radiation, blanked by toxic atmospheres. It's easy to
forget, but Venus and Mars are “earth-like”, too. Mars is the next human frontier and fairly
exciting – but Mars dust is poison and deadly radiation and low gravity will make you sick.
Mars is the worst. Except Venus is even worse, crushing you to death, burning
and dissolving you in acid. If humanity was really motivated and had the
resources and energy, both could be terraformed within maybe a thousand years – we showed how in
other videos. But the thing is, we already have a planet that's pretty great, so currently
humanity's motivation is not very strong. Now let's think about this in
terms of galactic expansion. If the milky way is like a vast ocean full of
islands, most are planets like Mars and Venus., Barren rocks or corals, where nothing
grows and the elements kill you. Imagine boarding a generation ship to travel for
100 years or more, only to arrive at a new star and then you get a… Mars. Or worse, a Venus.
What a let down. Terraforming them is such an intense investment in terms of resources to
make it worth spending the time to travel to the stars for bad planets. Maybe the simple reason
we don’t see galaxy spanning civilizations is that the economics just don’t add up for
almost all of the star systems out there. But wait, you might say: It's actually easy!
A high tech race with unlimited resources could automate this process, sending thinking
machines that report back every few thousand years with new planets ready for fresh settlers,
or automated ships with embryos. But if it were that easy someone would have done it by now. So
either we are really alone – or it's not easy. Thinking about alien civilizations you
need to make loads of assumptions – and for this video we are assuming that space is hard, even for high tech civilizations that have
broken free from the limitations we have today. Now things are getting exciting. So what if alien civilizations actually
ignore the bad islands and just pick the very best? Stringing together
island empires like the Polynesians? Thousands of Galactic Empires Every star moves in its own orbit through
the galaxy and most stellar neighbourhoods are only temporary. At any given time, in
some regions there will be more good islands than in others. While simply because of bad
luck, other regions will be pretty isolated. Earth might currently be in one of these
backwaters, surrounded by really bad islands for dozens of light years in all
directions. We may be Pitcairn island, so isolated that nobody knows we are here,
or cares to establish a colony so remote. But elsewhere in the Milky Way good islands may
be more common! There it would be relatively easy for a high tech civilization to jump from one
good star system to the next, creating connected empires. Strings of worlds, with all the adventure
and challenges of expansion even to really good planets. Do they need to animate dead worlds with
oceans? How do they cope with alien microorganisms or strange ecosystems? Do they need to burn it
all down and create a mirror of their home world, or do they adapt? How many centuries do
they need to make a planet truly their home? Empires expanding in regions full of good islands
would probably meet each other. Maybe they trade, maybe they fight. Maybe they have coffee
and chat about the meaning of it all. And just like some of the Polynesian islands,
it is likely that many of these planets would be abandoned or for the empires to
break apart for a number of reasons: First of all, most great neighbourhoods
would dissolve over time and connected islands would become remote. Then it just
may be the nature of civilization to become unsustainable or self destructive – humanity
is extremely young and we’ve already flirted with extinction. There are numerous existential
risks, cultural, technological and environmental that any civilization has to deal with. And
smaller colonies on new planets would likely be less resilient than their homeworlds and
in bigger danger of dying out. Whenever this happens this would leave a good island free
again for others to rediscover and colonise. Also space is just a different ballpark.
The enormous distances between stars make it hard to maintain a consistent civilization
– just think about how many cultures we have on Earth alone. Imagine if sending a message
between continents took decades to arrive. Would colonies care what the home world wants
from them, if it can neither help nor really enforce its will on them? This also would make
interstellar war, except the genocidal kind, completely uneconomic. Would you go to war with
someone because their great grandfather killed yours? At these distances, it's not like anyone
could easily sneak up on each other anyway. And on a much more fundamental level, if
island empires don’t exchange relevant amounts of genetic information – if there
are no hook ups between worlds –, sooner or later these populations will develop in
different directions and eventually become different species. Making it less likely
that they’ll want to be under common rule. So the idea of enormously big, connected
empires may just not be feasible if the galaxy is an ocean where good islands are few
and far between. But this also means that new civilizations may pop up constantly, spread and
partially or completely die out, even if just by splitting into different factions. Islands
may be recolonized and abandoned over and over. What would this mean for us? We might think we are alone only because
we are on an isolated island right now. But there could be thousands of worlds full of
diverse civilizations elsewhere, that we would eventually drift closer to - does this make
the milky way more scary or less scary? Is it a good thing that we'd have time to get our act
together before we face anyone else? Or is it a great tragedy that we might not have the chance to
meet our neighbours beyond for a long, long time? Well we don’t know, but it is something for you to
ponder tonight when you look up at the sky again. Hopefully humanity is still at the beginning
and we’re learning a tiny bit more about the universe every day – one day, we might spot a good
island. And if we are lucky, many more close by. One huge problem we face as a species is that we
can’t agree on what's going on. There are loads of news media but most of them tend to frame
reality through their point of view. And worse they are trying to get your attention with the
most alarmist take, distorting reality further. Ground News, the sponsor of this video,
helps you navigate our biased media landscape by letting you directly compare
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boredom, every day – it was simply shocking and revealing how much framing was going on,
especially in headlines. One would be framing an event as mildly noteworthy another as a huge
scandal – or one side would completely ignore events. If it seems to you that people who you
disagree with live in a parallel world, this is a huge reason why. But all of us really should
have a complete picture of what's going on. And this is why Ground News is a genuine,
personal recommendation. If you consume news, do it with a bird's eye perspective,
above the framing. So check them out at ground.news/nutshell to make
sure you’re seeing the full picture. Welcome to the kurzgesagt lab. Let’s
conduct a few stellar experiments! We’ll first add some more mass to this protostar.
More.. a bit more.. Wow! We’ve just created a blue giant, a star with 10 times the mass of our sun.
Let’s now add a couple of million years and see what happens. A supernova! Breathtaking. And look! It
leaves behind a black hole. Fascinating stuff. Now we record our findings. Be
careful to preserve the sparkle! It’s now time for Duck’s final inspection.
This one is always a nailbiter. He has incredibly high standards.
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