Good Morning, John. You'll remember a couple months ago when I made a video specifically to blow your mind, it was about the Hubble Ultra Deep Field Experiment.

Well, this video is gonna be a continuation of that video, so if you haven't seen that video, go and watch it now. So there are between one hundred billion and four hundred billion stars in our galaxy. So a while back, a very well-respected scientist named Enrico Fermi was talking with some of his very-well-respected-scientist buddies, and they were talking about humanity and civilization and the giant-ness of the universe and Enrico Fermi called out, "WHERE ARE THEY?" Cuz that's kinda the question. If there are four hundred billion stars in our galaxy, chances are a lot of them have planets. And a lot of those planets could support life. And a lot of those planets that can support life have life. And a lot of that life that has been supported has evolved into an advanced civilization.

And if that's the case, based on the way that humanity has done things - and if interstellar travel is possible - then one would assume that we would continue growing exponentially until we had colonized the entire galaxy. And so, if that is the case, where are they?

And even if they don't expand like our civilization has, and even if interstellar travel isn't possible - we should at least be able to hear them. We should at least have some evidence that they exist. Our civilization has been broadcasting ultra-high-frequency broadband signals into the galaxy that can be detected tens of thousands of light years away. So we assume that other civilizations have, likewise, also been doing it - and if they have been, then we should be able to detect that as a distinctly artificial, non-natural phenomenon, that we could then say, "Hey look, aliens have television, too, and they watch it all the time, and they're out there!"

But we haven't been able to do that. As far as we can tell, aliens either aren't out there, or they're not watching TV. That was a simplification. Examining this, it's called the Fermi Paradox, why we don't hear them if there should be so many of them.

Helps me think a lot more about h-humanity and our civilization than it helps me think about alien civilizations. It is possible, and this constantly worries me, that advanced civilization tends to destroy itself. And this could of course happen in any way. Cuz it could happen in the familiar ways, where we think about Atomic Winter and all of us dying - or it could happen in more peculiar ways, like big natural events, advanced civilizations for some reason losing interest in procreation, which I kind of understand. Or maybe the civilizations change into something that we can't quite understand, maybe they'd download their consciousnesses into giant, planet-wide computers that need no materials, only the power provided by the sun. And they sit there, looking like a ball of rock, transmitting no signal for us to decipher.

BUT there are other options, too. Maybe ... they're hiding. ALL you people who love Star Trek the way that I do, you know about the Prime Directive! The Prime Directive, it say, "Don't mess with non-spacefaring civilizations, you could totally screw them up!" ...Or maybe the aliens ... have us locked in a little zoo. And they're watching us and doing little scientific experiments and chuckling when we try and kill each other over whose religion is more accurate.

Or maybe, you know, we aren't as advanced as we think we are. For barely a hundred years we've been broadcasting radio.

That might seem like a long time, but friends, it is not! If the nearest civilization that could detect our signals is fifty thousand light years away, then our radio signals won't be getting there for another fourty-nine thousand nine hundred years! The first civilization to hear our radio signals spilling out into space might not even exist yet. And by the time they hear those signals, we might ... not exist anymore.

But we do know of one advanced civilization at least. It might unique, or it might be one of millions. But there's only one that we can even observe, and so we have to observe it carefully. And, most importantly, protect it as much as we can from its greatest enemy, which is, of course, itself.

Question to you, Nerdfighteria, is - Do you think there's life out there, somewhere in the galaxy, and do you think we'll ever see anything of it? And if we do, will they kill us - or will they be friendly?

John, I'll see you on Friday.