0:00:00.000,0:00:05.460
There are probably 10,000 stars for every grain of sand on Earth, in the observable universe.

0:00:05.680,0:00:08.200
We know that there are maybe trillions of planets.

0:00:08.221,0:00:10.201
So where are all the aliens?

0:00:10.210,0:00:12.390
This is the Fermi Paradox

0:00:12.420,0:00:15.280
If you want to know more about it, watch part one.

0:00:15.334,0:00:19.234
Here we look to the possible solutions to the Fermi Paradox.

0:00:19.298,0:00:23.298
So will we be destroyed or does a glorious future await us?

0:00:29.787,0:00:35.667
Space travel is hard. Although possible, it's an enormous challenge to travel to other stars.

0:00:35.722,0:00:39.910
Massive amounts of materials have to be put into orbit and assembled.

0:00:39.960,0:00:46.170
A journey of maybe thousands of years needs to be survived by population big enough to start from a scratch.

0:00:46.209,0:00:50.429
And the planet might be not as hospitable as it seems from afar.

0:00:50.478,0:00:54.478
It was already extremely hard to set up a spaceship that could survive the trip.

0:00:54.506,0:00:58.506
And interstellar invasion might be impossible to pull off.

0:00:58.536,0:01:02.586
Also consider time, the universe is very old.

0:01:02.639,0:01:06.639
On Earth there's been life for at least 3.6 billion years.

0:01:06.685,0:01:10.685
Intelligent human life for about 250,000 years.

0:01:10.747,0:01:15.667
But only for about a century have we had the technology to communicate over great distances.

0:01:15.684,0:01:23.504
There might have been grand alien empires that stretched across thousands of systems and existed for millions of years,

0:01:23.537,0:01:25.377
and we might just have missed them.

0:01:25.400,0:01:29.270
There might be grandiose ruins washing away on distant worlds.

0:01:29.288,0:01:33.618
99% of all species on Earth have died out.

0:01:33.631,0:01:37.371
It's easy to argue that this will be our fate sooner or later.

0:01:37.407,0:01:44.337
Intelligent life may develop, spread over a few systems and die off over and over again.

0:01:44.337,0:01:47.717
But galactic civilizations might never meet.

0:01:47.733,0:01:53.993
So maybe it's a unifying experience for life in the universe to look at the stars and wonder "Where is everyone?"

0:01:54.033,0:01:57.803
But there is no reason to assume aliens are like us

0:01:57.830,0:02:00.470
or that our logic applies to them

0:02:00.509,0:02:06.039
It might just be that our means of communications are extremely primitive and outdated.

0:02:06.079,0:02:12.069
Imagine sitting in a house with a Morse code transmitter, you keep sending messages but no people answer

0:02:12.097,0:02:17.137
and you would feel pretty lonely, maybe we're still undetectable for intelligent species

0:02:17.165,0:02:21.715
and we'll remain so until we learn to communicate properly.

0:02:21.738,0:02:28.048
And even if we met aliens we might be too different to be able to communicate with them in a meaningful way.

0:02:28.113,0:02:30.433
Imagine the smartest squirrel you can,

0:02:30.466,0:02:35.233
no matter how hard you try, you won't be able to explain our society to it

0:02:35.253,0:02:42.843
After all from the squirrel's perspective a tree is all that sophisticated intelligence like itself needs to survive.

0:02:42.895,0:02:50.005
So she learns cutting down whole forest is madness but we don't destroy forest because we hate squirrels.

0:02:50.078,0:02:51.828
We just want the resources

0:02:51.879,0:02:55.749
The squirrel's wishes and the squirrel's survival are no concern to us.

0:02:55.763,0:03:00.903
A type three civilization in need of resources might threat us in a similar way.

0:03:00.903,0:03:05.183
They might just evaporate our oceans to make collecting whatever they need easier.

0:03:05.192,0:03:12.792
One of the aliens might think for second "Ughh tiny little aches, they built really cute concrete structures, oh well now they're dead."

0:03:12.792,0:03:14.842
before activating warp speed.

0:03:14.842,0:03:18.992
But if there is a civilization out there that wants to eliminate other species,

0:03:18.992,0:03:22.992
it far more likely that it will be motivated by culture rather than by economics.

0:03:22.992,0:03:28.902
And anyway it will be more effective to automate the process by constructing the perfect weapon,

0:03:28.902,0:03:32.902
a self replicating space probes made from nano-machines.

0:03:32.902,0:03:36.902
They operate on molecular level incredibly fast and deadly,

0:03:36.902,0:03:40.332
with the power to attack and dismantle anything in an instant.

0:03:40.332,0:03:43.662
You only need to give them four instructions.

0:03:43.662,0:03:45.672
One, find planet with life.

0:03:45.672,0:03:49.482
Two, disassemble everything on this planet into its component parts.

0:03:49.482,0:03:52.832
Three, use the resources to build new space probes.

0:03:52.832,0:03:54.042
Four, repeat.

0:03:54.042,0:03:59.152
A doomsday machine like this could render a galaxy sterile in a few million years,

0:03:59.152,0:04:03.152
but why would you flight light years to get the resources or commit genocide.

0:04:03.152,0:04:05.892
The speed of light is actually not very fast.

0:04:05.892,0:04:11.382
If someone could travel at the speed of light, it will still take 100,000 years to cross the milky way once

0:04:11.382,0:04:13.665
and you'll probably travel way slower.

0:04:13.665,0:04:19.275
There might be way more enjoyable things than destroying civilizations and building empires.

0:04:19.275,0:04:22.064
An interesting concept is the Matrioshka Brain.

0:04:22.064,0:04:24.370
A mega-structure surrounding a star,

0:04:24.370,0:04:32.686
a computer of such computing power that an entire species could upload their consciousness and exist in a simulated universe.

0:04:32.686,0:04:39.836
Potentially, one could experience an eternity of pure ecstasies without ever being bored or sad, a perfect life.

0:04:39.846,0:04:45.136
If built around the red dwarfs, this computer could be powered for about ten trillions years.

0:04:45.141,0:04:50.201
Who would want to conquer the galaxy or make contact with other life forms if this were an option.

0:04:50.201,0:04:53.684
All these solutions to the Fermi Paradox have one problem.

0:04:53.684,0:04:56.784
We don't know where the borders of technology are.

0:04:56.805,0:04:59.845
We could be close to the limit or nowhere near it.

0:04:59.845,0:05:02.348
And super technology awaits us,

0:05:02.348,0:05:07.879
granting us immortality, transporting us to other galaxies, elevating us to the level of gods.

0:05:07.879,0:05:12.719
One thing we do have to acknowledge is that we really don't know anything.

0:05:12.732,0:05:17.382
Humans have spent more than ninety percent of their existence as hunters-gatherers.

0:05:17.392,0:05:20.343
500 years ago we thought we were the center of the universe.

0:05:20.343,0:05:24.653
200 years ago we stopped using human labors as the main source of the energy.

0:05:24.664,0:05:29.864
30 years ago we had apocalyptic weapons pointed at each other because of political disagreement.

0:05:29.867,0:05:32.497
In the galactic time scale we are embryos,

0:05:32.497,0:05:35.598
we've come far but still have a long way to go.

0:05:35.598,0:05:40.388
The mindset that we really are the center of the universe is still strong in humans,

0:05:40.388,0:05:44.548
so it's easy to make arrogant assumptions about life in the universe.

0:05:44.548,0:05:49.818
But in the end, there's only one way to find out right?

0:05:51.768,0:05:55.209
Hey everybody, we finally have our own subreddit.

0:05:55.325,0:06:00.932
Come by for surveys, discussions about future videos, FAQs and stuff like that.

0:06:01.756,0:06:05.599
This video was made possible by your support on Patreon.

0:06:05.825,0:06:12.109
If you want us to make more videos, and maybe get your own bird avatar in return, check it out.