• last year

Category

😹
Fun
Transcript
00:00 Of all the planets in the universe, potentially upwards of two trillion at last count,
00:05 we're all pretty lucky to have wound up on this one. Earth, it seems, has everything we need.
00:10 And yet, from some perspectives, cast as we are seemingly alone in this particular corner of the
00:15 cosmos, some bemoan how actually limited and isolated we are here. If only we had just a
00:22 little bit more of this world that works really rather well. This is Unveiled, and today we're
00:27 answering the extraordinary question; what if there were two Earths?
00:31 Life on Earth is pretty spectacular when you stop and think about it. It's predicted that there are
00:48 around 8.7 million species of plant and animal alive on this planet right now. Of those,
00:55 only around 1.2 million have been properly catalogued by us, human beings. Showing that
01:00 the true diversity of this place is pretty much beyond us even from the outset. But the numbers
01:06 get even more staggering when we consider Earth not just today, but over the entirety of its
01:11 history. Now, while the predictions do vary more widely, it's thought that there have been more
01:16 than four billion species alive at some point. That's a lot of life passing through. And remember,
01:22 those numbers are for whole species groups, where we'd account every single individual member of
01:28 every single species alive and extinct. Well, we'd literally be here for longer than the Earth is
01:34 old. One stark realisation, however, is that the very vast majority of species that have ever lived
01:40 have also died out. There may be almost nine million species alive today, but that's just a
01:46 tiny, tiny fraction of the total number that there's ever been. And clearly, in the modern
01:51 world, this business of species extinction has taken on all-new meaning as we, ourselves,
01:57 wrestle with various, seemingly existential threats. So, on the one hand, planet Earth is
02:02 pretty great. But on the other, we are busily trying to work out how to move off of it if the
02:07 need should arise. And we are increasingly aware of just how fragile the greatness of our world
02:13 really is. In an alternate reality, something that could really help is if we had another Earth to
02:19 fall back on. So, let's look at exactly how that would work… and also, if it ever could be possible
02:25 in this reality, as well. First off, although there are various alternate theories concerning
02:30 a so-called "Planet Five", "Planet Nine", or "Counter-Earth" in the solar system, we do know
02:36 with almost certainty that there is no "Second Earth" orbiting around our sun. True, the vast
02:41 majority of the solar system is still unknown and unreachable for us. Move beyond the orbit of Pluto
02:47 and out towards the Kuiper Belt, and much of what we think we know still amounts to educated
02:51 guesswork. But scientists and astronomers generally judge that if there were another
02:56 Earth-like world so close that we would've clocked it by now. Plus, we're almost 100% sure that
03:02 there's nothing else of note in our sun's habitable zone. So, any kind of Earth, too, would need to be
03:08 bucking all expectations on what a livable world should be and look like. All of which means that
03:13 our hypothetical Second Earth would most likely be outside the solar system. And so, immediately,
03:19 we're imagining a time when humankind is so much more advanced than it is right now. To even have
03:24 a Second Earth, we'd need to be an interstellar species… probably somewhere between levels two
03:30 and three on the Kardashev Scale, and generally upwards of ten thousand years more developed than
03:35 today. In the here and now, we're slowly beginning to chart potentially Earth-like worlds from afar,
03:41 ranking variously discovered exoplanets based on things like their probable surface temperature
03:46 and the likelihood of liquid water. In a future "two-Earth" time, though, we've progressed immensely
03:52 so that we've meticulously combed all of the nearest surrounding space, and visited a great
03:57 number of Earth-like worlds we've recorded, in order to have decided which was the best of all.
04:02 From there, we've mounted the largest and most complicated evacuation plan our species has ever
04:07 seen; to move people, plants, animals and general Earthliness - our Earthliness - to this brave new
04:14 world. Already, then, this clearly isn't something that's just going to happen tomorrow, in anyone's
04:20 lifetimes, or even for many, many generations to come. Nevertheless, what if you were alive when
04:26 it was happening? The prospect of a Second Earth is massively intriguing from a social point of
04:31 view. The questions come thick and fast. Who stays here and who gets moved there? Who are the first
04:37 to set foot on the new Earth? And who are the last to have a say in how Earth-2 is managed?
04:41 Would we even use Earth-2 for a living space, or just solely as a place to harvest resources?
04:47 In terms of who goes and who stays, perhaps there would be some kind of vote, or lottery,
04:52 in the run-up to the first few mass evacuations. Would that be a lottery that you'd want to win,
04:57 or wouldn't want to win? It all depends on context. Say this Earth was failing. Maybe it's become a
05:02 wholly dangerous and volatile place, thanks to environmental breakdown, or the onset of large-scale
05:08 war. Then clearly any serious route off of Earth would be something that many people would
05:13 desperately need. However, say this Earth was still stable, and the Second Earth was being
05:18 billed as only a place to redirect industry and energy efforts. Now, a lot of people would
05:23 probably rather stay put than get sent to a remote outpost without all of the comforts of home.
05:28 Of course, the influence of money could shape a lot of what the Second Earth becomes.
05:32 If it's found to be better than Earth as we know it, then it's easy to envisage a scenario where
05:38 only the rich ever get the opportunity to go there; where everyone else is immediately priced
05:43 out of getting on even the slowest ships to this new, promised land. That said, and again picturing
05:49 the wider situation for these hypothetical circumstances, if humanity really is an
05:54 interstellar species by this point, then money might not have a great deal to do with it after
05:59 all. Because, to make proper use of a whole new planet, this has to be a moment in time when we're
06:05 so advanced that we've overcome the kinds of structure and inequality that currently exists.
06:11 At the higher levels of the Kardashev Scale, and others like it, we almost always encounter plans
06:16 for a hive mind; effectively, a shared consciousness and knowledge. That might be the
06:22 level we'd need to have reached if discovering and colonising another Earth were to be possible.
06:27 And, at this point, humans would work less as individuals and more as a collective,
06:31 with no rich-poor divide to speak of. Finally, though, and perhaps more likely than anything
06:37 else, we have the rise of machines to contend with. Right now, in the twenty-first century,
06:43 we're much more open to sending probes and rovers to other planets in just the solar system,
06:48 rather than crude missions with real-life people. There are a number of reasons why,
06:53 not least how tricky it is from an engineering and propulsion point of view to get people off
06:58 the ground and into space. But, arguably, the biggest reason why we send probes first is
07:03 because it's infinitely safer. With only robots in tow, when a mission goes wrong it means that
07:09 no one needs to die. So, really, why would it be any different in the case of Earth-2?
07:14 It's not exactly romantic or exciting, but the first settlers of any other world will almost
07:20 certainly be machines. Advanced, artificial beings that can do one of two things; either
07:25 pave the way for humankind to visit in the future, or just make the place their own. In fact, in the
07:31 ongoing search for alien life, many believe that we are much more likely to find artificial life
07:36 than organic for exactly this reason. But what's your verdict? How would you choose to use Earth-2
07:43 if the decision were yours? Do you think that this is something that could ever happen? Or are
07:48 humans destined to live and die on this world only? Let us know in the comments. Because that's
07:54 what would happen if there were two Earths. What do you think? Is there anything we missed? Let
07:59 us know in the comments, check out these other clips from Unveiled, and make sure you subscribe
08:04 and ring the bell for our latest content.