Category
š¹
FunTranscript
00:00The universe is 13.8 billion years old.
00:03Modern humans have walked the Earth for only the last 300,000 years of that.
00:08There's still 13 and a half billion years that's wholly unaccounted for,
00:13along our personal timeline as a species.
00:16So what are the chances that we have never happened before?
00:20How likely is it that humanity is spread further out than we tend to believe?
00:26According to some interpretations of our story thus far,
00:31we might date back far, far further than even the age of the Earth itself.
00:38A headline-making study in June 2020 claimed that there could be dozens of alien civilizations
00:44living in our galaxy, the Milky Way. 36 was the most often-sighted figure, although the
00:49upper estimate went past 200. That's 200 individual alien societies reportedly living
00:55on our doorstepā¦ in cosmological terms. Now, let's be clear. There's so far
01:00zero actual proof that there are any alien civilizations out there. The general scientific
01:05consensus is that there must be, but we've so far found nothing by way of hard, irrefutable
01:10evidence. The Fermi Paradox continues to plague our search for extraterrestrial life.
01:15The 2020 study, though, was inspired by various projections and predictions,
01:19including the Drake Equation. Its claim of 36 neighbouring alien groups has since been debated
01:24and disputed. We ourselves released a video, and there's a link at the end of this episode.
01:29But, say there are other bands of living beingsā¦ and say they really are not so far away from usā¦
01:35then what are they doing there? Some theories, most notably the Zoo Hypothesis,
01:39argue that nearby, superior alien groups are busy watching and possibly experimenting on us.
01:45Others, like the Dark Forest Theory, suggest that any alien society trying to survive
01:50will wisely remain as quiet and undetectable as they possibly can.
01:54There are, though, some more unconventional theories to suggest that if there are aliens
01:58out there, they might not be all that different from us at all. One study, published in December
02:032020 by researchers at Caltech, aimed to map the potential for life in the Milky Way
02:08more precisely than ever before. Paying close attention to the probability that life will,
02:13and does eventually self-annihilate, as well as the likelihood of the emergence of life
02:18of abiogenesis in the first place, it delivered some interesting results. It found that life was
02:24most likely in the Milky Way around eight billion years after it formed, and around 13,000 light
02:29years from the galactic centre. Considering that we appeared more than 13.5 billion years after
02:34galaxy formation, and that we're now 25,000 light years from the galactic centre, this would
02:39suggest that humans are doing quite well for themselves. According to the study, we're here
02:44far too late, in completely the wrong place, and are therefore way past the peak of life in this
02:48galaxy. And yet, we're surviving. Well done, us! But what do these conclusions infer about the rest
02:55of life in the Milky Way? One takeaway is that, if the study rings true, there should be a band
03:00of space almost halfway between us and the heart of the galaxy, 13,000 light years from the centre,
03:05wherein life is much more likely to exist than anywhere else. But another is that most life in
03:10this galaxy should've emerged more than 5.5 billion years before we did. And, if that's true,
03:16then what happened to it? The short answer is, it killed itself off. The Caltech study highlights
03:22the key role self-annihilation likely plays in how far any civilization can reasonably spread.
03:28Away from the study, the general idea is that all life dies before it gets big enough to be noticed.
03:33The slightly frightening assumption, then, is that the same thing will happen to human beingsā¦
03:38that we'll only ever get so far before we destroy ourselves from within. But, still, if even just one
03:44such civilization did manage to survive, then they would certainly be considered ancient to our lowly
03:49minds. Recorded human history barely goes back five and a half thousand yearsā¦ but now we're
03:54imagining life that's five and a half billion years old. Not that such a hypothetical lifeform
04:00should ever automatically be billed as ancient humanā¦ even if we could prove that it exists.
04:05The chances of anything else separately evolving to be even slightly recognisably similar to us are
04:10extremely low. The aliens we see in movies and read about in books are all too often humanoid
04:16in nature, with eyes and hands and heads and some kind of audio languageā¦ but, in reality,
04:22they'd probably look nothing like us, and according to some theories, might not even be
04:26carbon-based. The picture gets a little stranger, though, when ideas on panspermia get thrown into
04:32the mix. Subscribers to various ancient alien theories argue that biological material could
04:37have been distributed all across the universe in the time since its inceptionā¦ that we think we're
04:42rare on Earth, but that actually we're just one of countless locations that life has reached.
04:47And this is what panspermia amounts to. The spreading of life throughout the cosmos,
04:51usually via space dust, asteroids and colliding planets. Directed panspermia, though, brings a
04:57degree of agency to the tableā¦ the idea now being that life is deliberately spread to other worlds
05:03by advanced, travelling alien species. Again, there's little by way of credible, mainstream
05:08science to suggest that this is what actually happened here on Earth. But, with such a long
05:13time gap to fill between the start of this planet and the start of humankind on this planet,
05:17fringe theories abound that ancient humans either seeded here or arrived and settled here
05:22millions or billions of years ago. In this version of life, the universe and everything,
05:27it's as though we're a colony established in the distant past by an older, more advanced version of
05:32ourselves. Through the lens of the Caltech study, we might imagine that those older, superior humans
05:38had emerged long ago, out of the optimum region for life in the Milky Way, 13,000 light-years away
05:43from the galactic centre, and 12,000 light-years away from us. They then brought their human
05:48civilisation here before carrying on their merry way into the rest of the galaxy. But one final
05:54consideration for today's question is, what if we aren't the product of panspermia, but were
05:59actually the ones facilitating it? Another popular fringe theory is that life did originate on Earth,
06:04but the history of human evolution isn't what we generally think of it as. Instead of the earliest
06:10hominins emerging around nine million years ago, and modern humans about 300,000 years ago,
06:15some claim that there were humans before this, and that they became advanced enough to leave Earth
06:20forever. Importantly, there is, again, precious little scientific or historical evidence that
06:26this really is the case. It's an idea, an unsubstantiated theory, but one that's captured
06:31the imagination of many a science fiction writer before now. Again, it allows us to imagine that
06:36the Milky Way is actually full of life, perhaps boasting far more than just the thirty-six
06:41civilisations suggested by the June 2020 study. Only, in this version of events, many of those
06:46could be our ancestors. It's just that they started on Earth and then set off to the stars,
06:51just as we're trying to do today. The biggest argument against this line of thinking, however,
06:56is that it assumes that Earth is basically the centre of everything. That's despite the
07:01overwhelming statistical likelihood that it isn't. If either Panspermia theory is true,
07:06that we were spread by others, or that we started on Earth and are now spreading elsewhere,
07:10it's much more likely the first one. To bring in the Caltech study one final time,
07:15even had humans somehow instantly appeared on this planet at the moment that Earth was born,
07:20an obvious impossibility, then they'd still be only 4.5 billion years oldā¦ which would still
07:25place us as arriving later than the optimum time for life in the Milky Way, eight billion years
07:30after it formed. The idea becomes marginally more palatable if we imagine that humans didn't
07:35start on Earth, but were seeded here instead by other humans. Then, theoretically, we'd have so
07:41much more time to play with across the history of the universe. Our story could be pushed further
07:47back, to a time before Earth and a time within Caltech's optimum parameters. And it can be
07:52pushed further forward, because we're no longer confined to just one world. Earth becomes just one
07:58of many that we might have visited in the past, or in the future. And, suddenly, the rest of the
08:02Milky Way is our playground. But, ultimately, all of those stipulations require us to make
08:08some gigantic leaps in our understanding of why we're here, what it takes for us to survive,
08:13and how significant we really are in the universe. More and more scientists are growing to accept
08:18that alien life must exist somewhere in spaceā¦ but human life? Perhaps we'll only believe that
08:24when we see it. What do you think? Is there anything we missed? Let us know in the comments,
08:29check out these other clips from Unveiled, and make sure you subscribe and ring the bell for
08:33our latest content.