Speaker 1: Welcome to Stuff to Blow Your Mind from how Stuff
Speaker 1: Works dot com. Hey you welcome to Stuff to Blow
Speaker 1: your Mind. My name is Robert Lamb and I'm Joe McCormick.
Speaker 1: And today we're going to be looking at a question
Speaker 1: about the future a sort of today will be a
Speaker 1: speculative out ing. So the question that we want to
Speaker 1: start with today is the broad one, and then we'll
Speaker 1: break it down into specific, specific ways of looking at
Speaker 1: this question. The question is how long could a technological
Speaker 1: civilization last? And notice that I just used the word
Speaker 1: civilization and technological not necessarily human civilization, since time and
Speaker 1: space scales the kind we're talking about could really blur
Speaker 1: the lines of what it means for a civilization to
Speaker 1: be human or consistently any one biological species. So for now,
Speaker 1: I'd say, let's just define civilization as something like a
Speaker 1: continue this tradition of intelligent behavior. Uh, if you've got
Speaker 1: something like that, Assume a civilization like ours leaves Earth
Speaker 1: and spreads out to colonize other star systems and becomes
Speaker 1: a presence on the galactic stage. How long could a
Speaker 1: civilization like that actually survive into the future. You kind
Speaker 1: of have to think of of civilization as a virus
Speaker 1: spreading through this uh, this galactic and ultimately I as
Speaker 1: a universal host. How how far could it spread? How
Speaker 1: long could it maintain the infection? Um? And it's it
Speaker 1: is challenging at times just to think about it because
Speaker 1: we we can't help but extrapolate what we have now
Speaker 1: and what we know, and we have to do that
Speaker 1: in order to to sort of scale up the model
Speaker 1: of what a galactic civilization might look like. Um. And
Speaker 1: at the because I think back to Star Trek for instance.
Speaker 1: You know, Star Trek is essentially a show about clipper ships.
Speaker 1: It's about seafaring individuals. It's just extrapolated into space and
Speaker 1: then uh, you know, with a lot of cool science
Speaker 1: science and science fictional elements explored within it, exploring the
Speaker 1: planets of potted plants. Yeah. But but ultimately it is
Speaker 1: it is based on the model of the president in
Speaker 1: the past. Um. And then then there's also this this
Speaker 1: element too of just um you know, uh, grandiose pride
Speaker 1: and human accomplishment to to wonder where will we be
Speaker 1: uh in this distant age. It reminds me of of
Speaker 1: a quote from J. M. Coats. He's waiting for the barbarians,
Speaker 1: and which he writes, quote one thought alone preoccupies the
Speaker 1: submerged mind of empire, how not to end, how not
Speaker 1: to die, how to prolong its era. I think that's
Speaker 1: quite true, though, I mean the conception of empire that
Speaker 1: we have is so time limited. I mean people who
Speaker 1: are trying to prolong the empires that were used to
Speaker 1: thinking about, say Cotsy probably has in mind something like
Speaker 1: the British Empire um. That is an empire that, even
Speaker 1: though it existed for a long period of time, was
Speaker 1: on the scale of you know, people's recognizable descendants. You know,
Speaker 1: you would be saying, I want to hand on my
Speaker 1: empire to my child, or my grandchild or my great grandchild.
Speaker 1: Do you do you want to hand on your empire
Speaker 1: to something that is maybe not even recognizably the same
Speaker 1: species as you a million years down the road. Yeah.
Speaker 1: It kind of becomes the situation where one is, say
Speaker 1: passing on a typewriter or or some other piece of technology,
Speaker 1: where you're like, this has been in our family for years,
Speaker 1: and then you're like, well, thanks, but it's and it
Speaker 1: is now obsolete. It is it is kind of useless.
Speaker 1: It's it's actually of more value perhaps now as a
Speaker 1: mere museum piece or just as a metal to be recycled.
Speaker 1: That's true, I guess it. Also it sort of works
Speaker 1: out how you don't have to care about that thing
Speaker 1: that's a million years down the road, whether or not
Speaker 1: you think of that as your direct descendant or not,
Speaker 1: because you care about next generation, and that generation will
Speaker 1: always care about the next generation. It's just an echo
Speaker 1: through through time and space. Yeah. I think one of
Speaker 1: the important things to deep in mind and all of
Speaker 1: this is just to what extent to things UH scale up,
Speaker 1: you know, because we think about the empires and the
Speaker 1: technology we have today and UH, I think is what
Speaker 1: As we proceed through this discussion, it will be reminded
Speaker 1: time and time again that that that human life, human empires,
Speaker 1: they don't really scale up when you start applying them
Speaker 1: to even even at the interplanetary stage, things begin to
Speaker 1: get a little difficult. But certainly when you get beyond
Speaker 1: beyond that, when you talk about UH, an empire that
Speaker 1: spans solar systems or or or manages to spread throughout
Speaker 1: an entire galaxy and human life as well, there are challenges. Obviously,
Speaker 1: there are challenges when we think of of what we
Speaker 1: have now, and even if you achieve some sort of
Speaker 1: biological or digital immortality, um, it's it's difficult to put
Speaker 1: that in context. Yeah. Now, one of the first questions
Speaker 1: that you might ask is, well, how long would it take?
Speaker 1: How long is it gonna take for a galactic civilization
Speaker 1: to emerge? Okay, we gotta get there before we can
Speaker 1: ask how long it will exist or survive? Right, Yeah,
Speaker 1: And this is something that science fiction and authors often
Speaker 1: kind of hatch you out, depending on how into you
Speaker 1: know defining a timeline they are. Now. In his book Cosmos,
Speaker 1: Carl Sagan commented on the Drake equation. Right. So, the
Speaker 1: Drake equation we we've talked about on the show before,
Speaker 1: but if you'll recall, it's essentially an equation put together
Speaker 1: to come up with a rough estimate based on some
Speaker 1: some variables where you can plug in your assumptions for
Speaker 1: the answers UH to figure out how many technological civilizations
Speaker 1: you would expect to find in a galaxy. So basically,
Speaker 1: the short version is you take the number of planets
Speaker 1: that there could be life on and then multiply that
Speaker 1: by some probabilities like the fraction of planets where life emerges,
Speaker 1: the fraction of the is where intelligent life evolves, the
Speaker 1: fraction that's capable of interstellar communication, and the years a
Speaker 1: civilization tends to remain detectable before for whatever reason, uh
Speaker 1: disappearing right. And Sagan pointed out that civilizations might tend
Speaker 1: to destroy themselves soon after reaching the technological phase, but
Speaker 1: that at least some civilizations might learn to live with
Speaker 1: high technology. He figured that, using the Drake equation, if
Speaker 1: just one percent of all emergent technological civilization survived this
Speaker 1: technological adolescence, then there could be millions of civilizations out there. Now,
Speaker 1: there don't appear to be millions of civilizations out there
Speaker 1: well as far as we know, as far as we know.
Speaker 1: But but here's the thing. Sagan and William Newman calculated
Speaker 1: that if a mill that if a million years ago
Speaker 1: a space faring civilization emerged two hundred light years away
Speaker 1: from us and spread outward, survey ships would only just
Speaker 1: now be entering our solar system. And then what would
Speaker 1: that even look like? What would a million year old
Speaker 1: civilization uh, you know manifest as uh? I mean, our
Speaker 1: current and only model outside of sci fi dreams is
Speaker 1: our civilization. It's me. And it's a mere you know,
Speaker 1: tens of thousands of years old, and we've only been
Speaker 1: a technological civilization for a few centuries. So what would
Speaker 1: these presumed immortals even be interested in when it comes
Speaker 1: to exploring and colonizing new worlds? Would they have would
Speaker 1: would they be interested in that at all? Would they
Speaker 1: sort of would they perhaps give up on their colonization efforts,
Speaker 1: uh after they realize that they need to perhaps extend
Speaker 1: their their energy and other directions. It's a good question.
Speaker 1: I mean, I think that it helps, um it helps
Speaker 1: when trying to imagine the future behavior of civilizations, whether
Speaker 1: alien or ours, to try to have as few assumptions
Speaker 1: baked in as possible. And so you can make assumptions
Speaker 1: maybe about what alien psychology might be, like, what their
Speaker 1: their directives are an exploration, but all of those are
Speaker 1: somewhat fallible. One of the things I think we can
Speaker 1: bank on as an assumption about future your civilizations is
Speaker 1: that they will need energy. That that's that's a that's
Speaker 1: a kind of ground level assumption that just you can
Speaker 1: count on that. But then how how might their goals change?
Speaker 1: Like they have energy, they could have all the energy,
Speaker 1: certainly in a world, in a solar system, in across
Speaker 1: multiple systems. But then what do they really want to
Speaker 1: do with it? And and indeed do they want to
Speaker 1: survive the long term challenges of life in our universe
Speaker 1: with their goals understanding? And even experience of time and
Speaker 1: space differ from what we humans value and experience today. Uh,
Speaker 1: it could be, but once you get into those scenarios,
Speaker 1: it's just hard to it's hard to predict anything with
Speaker 1: any confidence. Yeah, I mean so, yeah, this is where
Speaker 1: you get into the really the domain of science fiction. Um,
Speaker 1: I don't Oh, and there's plenty of great science fiction
Speaker 1: along these lines. Yeah. I'm reminded of the various advanced
Speaker 1: Elder civilizations in Ian Ebanks culture books. Um, because beyond
Speaker 1: the the high level involved civilizations that engage with other
Speaker 1: galactic civilizations in these books, there are what's known as
Speaker 1: the sublime. The sublime these are advanced civilizations that basically,
Speaker 1: at some point they just left all of their their
Speaker 1: works behind because they've left the known dimensions of space
Speaker 1: time behind to take up residents in several higher dimensions
Speaker 1: higher dimensions. Now, does this what assumes string theory or
Speaker 1: something like that, in which they're they're tiny higher dimensions
Speaker 1: where you can somehow bacond your consciousness into some kind
Speaker 1: of substrate that can transcend into those hidden dimensions. Well,
Speaker 1: that's where my mind goes to, especially since we've we've
Speaker 1: very recently spoken about dimensions and string theory. Uh. Now
Speaker 1: I haven't I haven't read some of at least one
Speaker 1: of the key books that deals with the sublime in
Speaker 1: the culture A series. But it's basically the idea that
Speaker 1: that suddenly that this particular group has reached a level
Speaker 1: of technological and cultural advancement where they're not even playing
Speaker 1: the same game as we are, that they are perhaps
Speaker 1: not even really experiencing the universe in the same way
Speaker 1: as we are, and they just kind of leave it behind.
Speaker 1: Uh indeed, like a like like like something emerging from
Speaker 1: a chrysalis and uh in taking off into a new
Speaker 1: realm of being. And but in doing this, at the
Speaker 1: same time, it's possible that sublimation uh might actually protect
Speaker 1: them from the truly long term environmental risks of living
Speaker 1: in our universe. So maybe it accomplishes the same go
Speaker 1: But of course that is that is the benefit afforded
Speaker 1: by playing in the realm of imagination. We don't know
Speaker 1: if anything like that is possible or not. So let's
Speaker 1: get into some of the long term environmental challenges of
Speaker 1: of life in a hostile universe. Well, I guess first
Speaker 1: we should look just the planetary level. Yeah, let's start
Speaker 1: with with Earth itself, right, So there are a number
Speaker 1: of factors to consider here, the most obvious being threats
Speaker 1: from within and threats from beyond. So we certainly have
Speaker 1: the ability to drastically damage the life sustaining properties of
Speaker 1: planet Earth. In fact, we are we are currently doing that. Yes, yes,
Speaker 1: with with say greenhouse gas emissions leading to global climate change,
Speaker 1: we are verely hampering the Earth's ability to sustain a
Speaker 1: civilization like ours far into the future. Yeah, the results
Speaker 1: can be catastrophic. Now, could we actually wipe out all
Speaker 1: life on the planet if such an evil aim possessed us?
Speaker 1: I think we would probably have a hard time doing that.
Speaker 1: I mean, life is pretty resilient, but we could come
Speaker 1: frighteningly close. I've seen some estimates for how a large
Speaker 1: enough nuclear war uh could could severely damage and wipe out,
Speaker 1: you know, a significant number of of life forms on
Speaker 1: our planet. I also read get this, um how even
Speaker 1: even an extremely powerful detonation in the Mariana Trench could
Speaker 1: collapse the food chain and wipe out most plant and
Speaker 1: animal life specifically. And this is according to uh x
Speaker 1: k c D s Randall Monroe uh x k c
Speaker 1: d as a science blog and comic series online. Uh He,
Speaker 1: according to his calculations, a fifty three million in megatun
Speaker 1: explosion down in the trench might just do the trick.
Speaker 1: This would be equal to the chicks Aloop impact that
Speaker 1: occurred roughly sixty six million years ago, which led to
Speaker 1: the Cretaceous Paleogene extinction event, and that killed sev of
Speaker 1: all animal and plant species. That was the size of
Speaker 1: a city, and it had the power of a billion
Speaker 1: nuclear bombs. And this brings us to the extinction events
Speaker 1: that can occur due to unchecked space collisions. Yeah, now
Speaker 1: there's there's actually been some evidence to support the idea
Speaker 1: that there's a a twenty six million year cycle linking
Speaker 1: comet showers and global die offs. Yeah, there are people
Speaker 1: who pause it all kinds of like like periods of
Speaker 1: space impacts and what the causes of those might be.
Speaker 1: But one thing we can say is that space impacts
Speaker 1: are just a statistics game. I mean, you're it's just
Speaker 1: a waiting game. Like you know, every so many years,
Speaker 1: you're you're pretty much statistically guaranteed to get X number
Speaker 1: of powerful storms that hit a certain part of the world.
Speaker 1: Space impacts are the same way. There are a bunch
Speaker 1: of objects out there, they're flying around, and you can
Speaker 1: just calculate it out over certain periods of time, statistically
Speaker 1: you're going to be hit by X number of objects
Speaker 1: above a certain mass. So when you're we're talking about
Speaker 1: a human civilization, uh, surviving however many you know, thousands
Speaker 1: upon thousands upon thousands of years, certainly reaching like the
Speaker 1: million or two million. Your point. If you want life
Speaker 1: to continue on Earth, then you have to do something
Speaker 1: about the potential impacts. Because defense, Yeah, you gotta have
Speaker 1: planetary defense, which is something that uh that people are
Speaker 1: working on. Uh we've discussed it on the show before.
Speaker 1: It's still not as much of a priority as it
Speaker 1: should be. You have all of these uh, these politicians
Speaker 1: out there, you know, making campaign promises and talking about
Speaker 1: what they're gonna do for for for to improve everyone's life,
Speaker 1: and it always floors me that this is not something
Speaker 1: that people take up because this is one of the
Speaker 1: This is perhaps the only, or at least one of
Speaker 1: the very few causes where we can say this is
Speaker 1: something we can do to save the world. This is
Speaker 1: something we can do to protect the planet. Yeah, what
Speaker 1: what if there? That was like a what if that
Speaker 1: was a campaign platform? It was basically civilization level defense.
Speaker 1: So your your campaign platform is fight climate change, protect
Speaker 1: the planet from space object impacts, and let's say the
Speaker 1: other big one would be prepared for the next superflu
Speaker 1: It makes sense to me, I mean, I guess the
Speaker 1: the the the counter argument here is that most these
Speaker 1: are these are generally longer term threats. Uh, so people
Speaker 1: are going to be less inclined to let it impact
Speaker 1: their voting behavior. It's frustrating. But anyway, uh some other
Speaker 1: problems that, of course so be as we've discussed before.
Speaker 1: Venus offers an example of this of a sort of
Speaker 1: worst case runaway greenhouse effect that could leave a planet,
Speaker 1: even a planet like Earth, uninhabitable, And there are also
Speaker 1: various long term scenarios involving the world's oceans, the magnetosphere,
Speaker 1: which if you listen to the show, you know that
Speaker 1: the magnetosphere plays a vital role in protecting our planet
Speaker 1: from silver and cosmic radiation, and if something were to
Speaker 1: happen to that, then we're unprotected. There are also biological
Speaker 1: threats from within Earth's biosphere. That's right. You have to
Speaker 1: consider the likes of Peter Ward's media hYP hypothesis. I
Speaker 1: was actually not familiar with this. This is a kind
Speaker 1: of an opposite of the Gaia hypothesis and uh, the
Speaker 1: Medeia hypothesis is that multicellular life is a suicidal superorganism
Speaker 1: leading to microbial triggered mass extinctions. I mean, whether you
Speaker 1: buy the framing is a suicidal superorganism, it is clear
Speaker 1: that there have been times in the past where life
Speaker 1: on Earth caused massive extinctions of other types of life
Speaker 1: on Earth. I mean, we think about the oxygenation of
Speaker 1: our atmosphere that we are now adapted to was initially
Speaker 1: tragedy that killed killed off tons of life, and then
Speaker 1: of course we've seen this this particular primate species rise
Speaker 1: up and uh and and alter the atmosphere from a
Speaker 1: very early time. And then of course there are the
Speaker 1: outside context problems to consider, which, of course is a
Speaker 1: term that was coined by Ian M. Banks but has
Speaker 1: been used since then by various other authors and even scientists.
Speaker 1: You call them outside context problems to consider, but sort
Speaker 1: of the nature of them means that what you can't
Speaker 1: consider the right right. Yeah. Banks said that an outside
Speaker 1: context problem is the sort of thing most civilizations encounter
Speaker 1: just once, in which they tend to encounter rather in
Speaker 1: the same way as sentence encounters a full stop. Um.
Speaker 1: So yeah, if we could. The classic example, of course
Speaker 1: is um, if you have a primitive terrestrial society and
Speaker 1: then uh, a colonial force shows up with advanced technology,
Speaker 1: you know, and then to extrapolate that into space, an
Speaker 1: alien civilization shows up with it with advanced head ology.
Speaker 1: But of course, when the thing about the the alien
Speaker 1: consideration is that a lot of very intelligent folks have
Speaker 1: thought about this problem. There are even some rudimentary plans
Speaker 1: in place to deal with it when it occurs, you know,
Speaker 1: people who think about first contact. So it's not really
Speaker 1: a completely outside contact problem. Yeah. You could look at
Speaker 1: a lot of science fiction as us doing our very
Speaker 1: best to use our imaginations to prepare for this potential conflict. Right.
Speaker 1: But one of the big hard limits for life on
Speaker 1: Earth uh and in our solar system itself, concerns the
Speaker 1: life cycle of our son. Now maybe we should take
Speaker 1: a quick break and then come back to UH to
Speaker 1: discuss and weep in anguish over the death of the Sun.
Speaker 1: Than alright, we're back. So we we've talked about the
Speaker 1: life cycle of the Sun before on this show, but
Speaker 1: just to refresh, this is basically how it it works.
Speaker 1: So our son has been going strong for four point
Speaker 1: five billion years and it has another five billion years
Speaker 1: left in the town. When the courts roughly speaking, roughly speaking, now,
Speaker 1: when the core runs out of hydrogen fuel, it's going
Speaker 1: to contract under the weight of gravity. Some hydrogen fusion
Speaker 1: will occur in the upper layers at this point. But
Speaker 1: as a depleted core contracts, it heats up, and this
Speaker 1: heats the upper layers of the Sun, causing them to expand.
Speaker 1: And as the outer layers expand, the radius of the
Speaker 1: Sun will increase and it will become a red giant.
Speaker 1: And the radius of the of a red giant son,
Speaker 1: our red giant son would be a hundred times what
Speaker 1: it is now. It's not good. Now, that's that's not
Speaker 1: good for anybody, because this would this would put the
Speaker 1: put the the the the outside of the Sun just
Speaker 1: beyond the Earth's orbit, and some scientists have estimated that
Speaker 1: this would just vaporize our planet, but there's also a
Speaker 1: good chance it would push Earth and its moon outward
Speaker 1: after consuming mercury and venus. In any case, whatever it does,
Speaker 1: it does not sound like a survivable event for the
Speaker 1: inhabitants of Earth. That's right, It's just it's it's bad news.
Speaker 1: And long before this happens, say in a mirror one
Speaker 1: to two billion years, the Earth is gonna go hot
Speaker 1: enough to to boil away its oceans as well. And
Speaker 1: if we're looking really long term, um, here's how it'll
Speaker 1: it'll all play out. According to Ethan Seagull, who wrote
Speaker 1: how our Solar System will end in the Far Future
Speaker 1: for Forbes. Uh. He says that in nine point five
Speaker 1: billion years, the sunile collapse into a white dwarf, and
Speaker 1: the remaining dead worlds will continue to orbit it, and
Speaker 1: eventually the white dwarf will go dark in the inevitable
Speaker 1: collision between it and another black dwarf will blast apart
Speaker 1: the remnants of our solar system. So all that and
Speaker 1: the Sun doesn't even get to turn into a black hole.
Speaker 1: That's right, the Sun will never get to turn into
Speaker 1: a black it's not massive enough. Uh, and yet it
Speaker 1: will wreak havoc. Nonetheless, So what's our fight or flight
Speaker 1: response here? Well, it obviously means if our civilization is
Speaker 1: going to survive into the realm of say billions of years,
Speaker 1: if you're on the billions order of magnitude for the future,
Speaker 1: we can't stay here, that's right. We've got to build ships,
Speaker 1: We've got to build colonies. We've got to estab colonies
Speaker 1: on other worlds and other systems as well. Or perhaps
Speaker 1: we do something to just move the Earth itself, because
Speaker 1: as we ascend the Kardashian scale, such things do theoretically
Speaker 1: become possible. Sure, at least in theory. For instance, we
Speaker 1: can harness comments and asteroids so they gravitationally slingshot past
Speaker 1: Earth and move us into a wider orbit away from
Speaker 1: the Sun. We could build planetary sunshades that have the
Speaker 1: same effect, or or very or even just sort of
Speaker 1: turn the Earth into a spaceship of sorts, you know,
Speaker 1: just take it with us. Well, there are versions, like,
Speaker 1: for example, there is one idea that's not for moving
Speaker 1: planets so much as it is for moving stars. But
Speaker 1: I wonder if similar principles could be applied to planets,
Speaker 1: where it's known as the Scatoff thruster if you're read
Speaker 1: about the Yeah, so this is for stars. But what
Speaker 1: it would do would be would be sort of a
Speaker 1: large reflective encasement for part of a star that would
Speaker 1: cause a positive radi asian pressure in one direction back
Speaker 1: against the star. And by reflecting all of this radiation
Speaker 1: back in the direction of the star, you could actually
Speaker 1: steer the movement of a star. One wonders if you
Speaker 1: could create some kind of similar solar sale like thing
Speaker 1: for a planet. Then again, the planet is not emitting
Speaker 1: radiation the way a star is, So I don't know,
Speaker 1: maybe maybe possible, maybe not, Yeah, or ultimately we could
Speaker 1: just leave it behind, move on to better worlds, make
Speaker 1: better worlds. Exodus from an uninhabitable Earth has been a
Speaker 1: sci fi staple for decades, going back at least to
Speaker 1: the nineteen thirties. That's when British sci fi author Olaf
Speaker 1: Stapleton wrote about it and uh during the events of
Speaker 1: Frank Herbert's Dune, Old Earth is said to be an
Speaker 1: uninhabited waste. Oh yeah, do they ever go there? I
Speaker 1: don't not. In the the original books that they might
Speaker 1: have something that takes place in the more recent Dune
Speaker 1: franchise books, but I have not read them, so I
Speaker 1: would love to hear from from hardcore Dune readers on that. Now.
Speaker 1: When it comes to moving the planet, though, we also
Speaker 1: see some work there in science fiction. Sci fi writer
Speaker 1: Stanley Schmidt explored it in nineteen and Ian M. Banks
Speaker 1: also wrote about it. So we're kind of climbing a
Speaker 1: Kardashian scale of destruction here. So planetary power and the
Speaker 1: ability to save one's planet in some sense, then solar
Speaker 1: system power and the ability to save oneself or roll
Speaker 1: with the changes to a single star system. But what
Speaker 1: about beyond that? What about the fate of galaxies in
Speaker 1: the universe itself. Yeah, yeah, that's a good question. I
Speaker 1: guess that's where we have to go next. Now, before
Speaker 1: we do that, we should pause for the reality check
Speaker 1: and and not ignore the much much nearer, more salient
Speaker 1: threats facing our species right now. We mentioned some of
Speaker 1: those earlier, primarily things like climate change in all of
Speaker 1: its myriad downstream effects, killer pandemics like the next super flu,
Speaker 1: the threat of space impacts, nuclear war. Maybe some people
Speaker 1: would throw artificial intelligence in there. I don't know. That's
Speaker 1: that seems like a much bigger question mark to me.
Speaker 1: But I think the big ones we really know to
Speaker 1: be concerned about, based on the most solid science, would
Speaker 1: be things like climate change in pandemics. We know those
Speaker 1: are real threats right now. We have to be fighting
Speaker 1: and preparing today if we want to thrive in the future. Uh.
Speaker 1: And of course we've discussed those in the past and
Speaker 1: we will revisit them in the future. But to continue
Speaker 1: today's thought experiment, let's let's go that next step. So
Speaker 1: we imagine our technological behaviors can be changed, and we
Speaker 1: beat back global climate change, we survive all these other
Speaker 1: threats in the near term, We expand our space exploration
Speaker 1: and colonization ability. We spread out our civilization so that
Speaker 1: no one local event in any individual solar system can
Speaker 1: bring it to an end. When do much bigger concerns
Speaker 1: like the space, time, and energy dynamics of the larger
Speaker 1: universe start to actually become a threat to our survival, Well,
Speaker 1: not anytime soon, right, but but as far as we know,
Speaker 1: as far as we know, but there are predictions for
Speaker 1: how it might go down. The sort of universal apocalypse.
Speaker 1: In fact, they're there at least four main models here.
Speaker 1: We're gonna start with the two older models. One is
Speaker 1: the Big Freeze. Uh. And this has to do with
Speaker 1: just an eternally expanding universe. Uh. And we know the
Speaker 1: universe is expanding. Uh. So the idea here is that
Speaker 1: everything expands to the point where there's just heat death
Speaker 1: across the universe, the triumph of entropy in your life
Speaker 1: with just a cold, dead universe. According to some of
Speaker 1: the models. One thing that can often be misleading about
Speaker 1: the idea of the heat death of the universe is
Speaker 1: that if you if you're not familiar with this term,
Speaker 1: it sounds like that might be hot. It's not hot.
Speaker 1: It's the opposite. It means it means usable energy gets
Speaker 1: converted into heat, which is entropy energy you can't use,
Speaker 1: and everything is just this cold bath of slightly above
Speaker 1: absolute zero radiation. Now, the the other side of that,
Speaker 1: of course, is the idea that what if things expand
Speaker 1: to the point and then they retract uh in a
Speaker 1: collapsing mechanism. This was this would lead to what is
Speaker 1: considered the big crunch. So the universe stops expanding, crunches
Speaker 1: back down over time into the reverse of the Big Bang.
Speaker 1: That doesn't sound good for you know, but yeah, but
Speaker 1: this would be this would be a hot death as
Speaker 1: a cold as opposed to a cold death. Now, back
Speaker 1: in nineteen seventy nine, physicist Freeman Dyson. Dyson is still
Speaker 1: with us as of this recording. He was born in
Speaker 1: But he pondered just how these two possibilities would impact
Speaker 1: humanity or whatever humanity becomes over the course of time,
Speaker 1: and he was he was pretty optimistic. Yeah, we should
Speaker 1: know that this paper we're gonna be talking about is
Speaker 1: fantastically readable. But Dyson was working with the knowledge available
Speaker 1: to him at the time in nineteen seventy nine. So,
Speaker 1: for example, this predates the discoveries that seemed to indicate
Speaker 1: that the expansion of the universe is accelerating. Dyson didn't
Speaker 1: know that at the time. At the time, he vote, quote,
Speaker 1: the prevailing view holds the future of open and closed
Speaker 1: universe versus this being the idea that to a closed
Speaker 1: universe is one that will eventually collapse into the Big crunch,
Speaker 1: and an open universe is one that will just continue
Speaker 1: to expand towards this big freeze. He said, uh uh,
Speaker 1: quote the future of open and closed universe is to
Speaker 1: be equally dismal. According to this view, we have only
Speaker 1: the choice of being fried in a closed universe or
Speaker 1: frozen in an open one. And he can He goes
Speaker 1: on regrettably, I have to concur with es verdict that
Speaker 1: in the case, in this case, we have no escape
Speaker 1: from frying. No matter how deep we burrow into the
Speaker 1: earth to shield ourselves from the ever increasing fury of
Speaker 1: the blue shifted background radiation, we can only postpone by
Speaker 1: a few million years. Are miserable? End? Oh wow, I
Speaker 1: was just thinking. So the blue shifting of radiation means
Speaker 1: that if radiation sources are accelerating towards you, the radiation
Speaker 1: they emit gets uped in frequency, gets blue shifted up higher.
Speaker 1: So does that mean like radio waves, the cosmic microwave
Speaker 1: background radiation and all that as it closes in towards
Speaker 1: you gets blue shifted up and turned into gamma rays.
Speaker 1: I get something like that. That's that's That's what I'm
Speaker 1: getting from this. But this is with the closed universe model, right,
Speaker 1: and and he he largely avoids the quote unquote claustrophobic
Speaker 1: nature of the closed universe in this paper, but he
Speaker 1: does offer this. Uh, this idea, he says, supposing that
Speaker 1: we discover the universe to be naturally closed and doomed
Speaker 1: to collapse, is it conceivable that by intelligent intervention converting
Speaker 1: matter into radiation and causing energy to flow purposefully on
Speaker 1: a cosmic scale, we could break open a closed universe
Speaker 1: and change the topology of space time so that only
Speaker 1: a part of it would collapse, in another part of
Speaker 1: it would expand forever. Uh. Yeah, I would call that optimistic. Yeah,
Speaker 1: but I mean he's he's basically throwing it out here
Speaker 1: and saying, look, I'm not sure how this would work exactly,
Speaker 1: but if we're talking about a significantly advanced civilization, this
Speaker 1: sounds like the kind of thing such a civilization would
Speaker 1: be into doing and maybe maybe have the ability to
Speaker 1: do it. Yeah. Uh. One thing I like about Dyson's
Speaker 1: attitude here is that he he's essentially saying, you know, physicists,
Speaker 1: you should explore extreme implications. Uh. He starts off his
Speaker 1: paper by talking about Stephen Weinberg, the Stephen Weinberg quote
Speaker 1: that the problem with physicists is not that they take
Speaker 1: their theories too seriously, but that they don't take them
Speaker 1: seriously enough. You know that they scoff at some of
Speaker 1: the discussing some of the more outlandish implications of theories
Speaker 1: that we know to be good theories and are confirmed
Speaker 1: by evidence. Uh, and Dyson's like, no, let's get into
Speaker 1: the weirdness. Okay, we've got a theory. We think it's
Speaker 1: a good theory because it predicts all the stuff we see.
Speaker 1: What does it imply? What are the weirdest things that implies? Again,
Speaker 1: this paper is uh is really readable, very accessible, especially
Speaker 1: for a paper that has so many equations in it.
Speaker 1: But but he also has some some very helpful timetable
Speaker 1: scale els. For instance, he has his table one summary
Speaker 1: of time scales, and he he holds it in a
Speaker 1: closed universe, you'd have a total duration for the universe
Speaker 1: of ten to the eleventh power years or a hundred
Speaker 1: billion years. And and then when he looks at the
Speaker 1: open universe, he basically takes it by by order of magnitude.
Speaker 1: So he taught this is what he says, quote, it
Speaker 1: takes about ten to the six or one million years
Speaker 1: to evolve a new species tend to the seventh power,
Speaker 1: or ten million years to evolve a genus tend to
Speaker 1: the eighth power or a hundred million years to evolve
Speaker 1: a class ten to the ninth power, or one billion
Speaker 1: years to evolve a phylum in less than ten to
Speaker 1: the tenth power years, or ten billion years to evolve
Speaker 1: all the way from the primeval slime to Homo sapience.
Speaker 1: I'm not sure if his taxonomic organization of of time
Speaker 1: scales of evolution is exactly right, but I mean he's
Speaker 1: working essentially with orders of magnetzya. He's definitely rounding up.
Speaker 1: He's so, for example, he says, you know, less than
Speaker 1: ten billion years, I guess that's actually that's a fair
Speaker 1: number to work with if you're just trying to estimate
Speaker 1: galactic evolution, right, because you're ultimately trying You're you're dealing
Speaker 1: with with life and life on Earth, which is just
Speaker 1: a pin drop in the in in terms of cosmic history.
Speaker 1: But you're you're, so you have to work with these
Speaker 1: exceedingly large orders of magnitude, right, But but playing with
Speaker 1: rough orders of magnitude gives you more, essentially more room
Speaker 1: to play around. So life on Earth has not been
Speaker 1: around for ten billion years, but it's been around for
Speaker 1: more than one billion years, So you can essentially just
Speaker 1: round up or down to the nearest order of magnitude.
Speaker 1: Now ultimately for an open universe scenario. He does say
Speaker 1: that he does think it's pretty hopeful. He says, quote,
Speaker 1: so far as we can imagine into the future, things
Speaker 1: continue to happen in the open cosmology, history has no
Speaker 1: heir and his in this paper. His basic breakdown in
Speaker 1: this paper is that consciousness is not bound to biology
Speaker 1: of it is structural. Then we can move beyond the body.
Speaker 1: We can become digital machines, we can become uh, you know,
Speaker 1: black clouds of particles. That intelligence doesn't necessarily have to
Speaker 1: be confined to flesh beings anymore. And he had There's
Speaker 1: also an interesting point in this where he talks about
Speaker 1: immortal computing, which I hadn't really thought about. He says, quote,
Speaker 1: a society with finite material resources can never build a
Speaker 1: digital memory beyond a certain finite capacity. Therefore, digital memory
Speaker 1: cannot be adequate to the needs of a life form
Speaker 1: planning to survive indefinitely. Fortunately, there is no limited principle
Speaker 1: to the capacity of an analog memory built out of
Speaker 1: a fixed number of components in an expanding universe. For example,
Speaker 1: a physical quantity such as the angle between two stars
Speaker 1: and the sky can be used as an analog memory unit.
Speaker 1: The capacity of this memory unit is equal to the
Speaker 1: number of significant binary digits to which the angle can
Speaker 1: be measured. As the universe expands and the stars recede,
Speaker 1: the number of significant digits in this angle will increase
Speaker 1: logarithmically with time. Measurements of atomic frequencies and energy levels
Speaker 1: can also, in principle be measured with a number of
Speaker 1: significant figures proportional too, and then he refers to an
Speaker 1: equation log T. Therefore, an immortal civilization should ultimately find
Speaker 1: ways to code its archives in an analog memory with
Speaker 1: capacity growing like log T. Such a memory will put
Speaker 1: severe constraints on the rate of acquisition of permanent new knowledge,
Speaker 1: but at least it is not forbid it altogether. WHOA,
Speaker 1: So I love that because he's he's really thinking big
Speaker 1: about about how even you know, memory and recorded history
Speaker 1: would work with a civilization that is this far advanced
Speaker 1: beyond what we have now. Again, what we have now
Speaker 1: does not scale up well, So ultimately Dyson is taking
Speaker 1: a very optimistic view of the ways that intelligence civilization
Speaker 1: could adapt to the changing physical environment of the universe.
Speaker 1: At large, right, but again this was this was We've
Speaker 1: had some some some changes since then. And in fact
Speaker 1: BBC writer Adam Becker reached out to Dyson in um
Speaker 1: on the matter of of of the expansion in our
Speaker 1: universe seeming to accelerate, which which puts a new spin
Speaker 1: on everything that we've discussed thus far. And uh, and
Speaker 1: so he reached out to Dyson, and Dyson said that
Speaker 1: he's he's far less optimistic, and that the most optimistic
Speaker 1: view is that perhaps the acceleration will slow down on
Speaker 1: its own, because he points out, we we don't know
Speaker 1: what's accelerating it, so it's still possible that it could
Speaker 1: stop um or slow down. Otherwise, Uh, he says, our
Speaker 1: descendants will lose touch with most galaxies, drastically limiting the
Speaker 1: available energy that he's discussing in these models. And that
Speaker 1: sets us up in a pretty key way to talk
Speaker 1: about one of the papers we wanted to discuss today,
Speaker 1: a new paper from the physicist Dan Hooper. But first, Robert,
Speaker 1: did you want to mention a couple of other hypothesized
Speaker 1: ways that the universe could end? Yeah, yeah, they we'll
Speaker 1: throw these out here. The first one is the big change.
Speaker 1: This is in this a bubble of new lower temperature
Speaker 1: vacuum emerges in our own universe and expands at the
Speaker 1: speed of light, converting everything in our universe. As Adam
Speaker 1: Becker wrote in that BBCO in his BBC article how
Speaker 1: will the universe end? And could anything survive? Um quote,
Speaker 1: the properties of fundamental particles like electrons and quarks could
Speaker 1: be entirely different inside the bubble, radically rewriting the rules
Speaker 1: of chemistry and perhaps preventing atoms from forming. Plus a
Speaker 1: dark energy inside the bubble might behave in a different matter,
Speaker 1: perhaps causing collapse rather than expansion. So um this this
Speaker 1: sounds like a very problematic scenario if it where to
Speaker 1: come to pass. It almost is love craft Ian and
Speaker 1: it's uh and it's a scope right, the idea that
Speaker 1: suddenly here is an emergence of a part of our
Speaker 1: space that is not bound by the same rules. Yeah.
Speaker 1: Nice laws of physics you've got. There be a shame
Speaker 1: if something happened to them. Now. Another another apocalyptic scenario
Speaker 1: for the universe is the Big Rip and this one
Speaker 1: was presented by Robert Caldwell of Dartmouth College in two
Speaker 1: thousand three based on the idea of phantom dark energy,
Speaker 1: in which the intensity of dark energy increases as the
Speaker 1: universe expands. So it's the density of of dark energy
Speaker 1: right now, as we understand it is pretty low, but
Speaker 1: if it builds up, it would rip the universe to shreds.
Speaker 1: So maybe overcoming the other forces, Like right now we
Speaker 1: see dark energy increasing the distance between the galaxies out there.
Speaker 1: But things that are gravitationally bound to each other, or
Speaker 1: say bound by the nuclear force that holds atoms together, Uh,
Speaker 1: that stuff is pretty safe from dark energy. If dark
Speaker 1: energy said no, I'm going to overcome your gravity, overcome
Speaker 1: your nuclear force, that would be a problem. Yeah, this
Speaker 1: is This is how Caldwell described it in his in
Speaker 1: his presentation quote, the positive phantom energy density becomes infinite
Speaker 1: in finite time, overcoming all other forms of matters, such
Speaker 1: as that of gravitational repulsion, rapidly bringing our brief epoch
Speaker 1: of cosmic structure to a close. The phantom energy rips
Speaker 1: apart the Milky Way solar system, Earth, and ultimately the molecules, adams,
Speaker 1: nuclei and nucleons of which we are composed before the
Speaker 1: death of the universe in a big rip. Who gives
Speaker 1: a rip. So so that sounds that sounds terrifying as well.
Speaker 1: And on that note, let's take one more quick break
Speaker 1: and then we'll return to the discussion. Thank you, all right,
Speaker 1: we're back. Okay. So what spurred this whole conversation was
Speaker 1: that we wanted to talk about a highly speculative but
Speaker 1: very fun paper that just was just published online by
Speaker 1: the physicist Dan Hooper, in which Hooper tries to imagine
Speaker 1: and scientifically characterize a survival strategy for a galactic civilization
Speaker 1: that sees the writing on the wall about the long
Speaker 1: term fate of the universe and decides it wants to
Speaker 1: survive as long as possible, because it turns out, if
Speaker 1: you are a galactic civilization, you don't need to wait
Speaker 1: until the cold death of the entire universe to have
Speaker 1: a problem. You just have to discover that usable energy
Speaker 1: is becoming scarce where you live. Hooper's paper is called
Speaker 1: Life versus Dark Energy, How an advanced civilization could resist
Speaker 1: the accelerating expansion of the Universe. Uh. And we should
Speaker 1: point out that this has not been published in a
Speaker 1: peer of view journal yet or anything. This is just
Speaker 1: something he put out on the internet ahead of publications
Speaker 1: so people could comment on it and talk about it.
Speaker 1: I think it may eventually come out in the Journal
Speaker 1: of Cosmology and Astroparticle Physics, but we'll pay attention there.
Speaker 1: But as always with anything that hasn't been uh been
Speaker 1: put through peer of view yet, grain assault. So who
Speaker 1: is Dan Hooper? He is an associate professor of astronomy
Speaker 1: and astrophysics at the University of Chicago, and he's a
Speaker 1: senior scientist and the head of the Theoretical Astrophysics Group
Speaker 1: at Fermi National Accelerator Laboratory. And a lot of his
Speaker 1: work focuses on the intersection between particle physics and the
Speaker 1: evolution of the universe at large. So he's interested on
Speaker 1: where the biggest stuff we know about in the smallest
Speaker 1: stuff we know about effect one another. So what's what's
Speaker 1: Hooper's argument about the future survival of a galactic civilization. Well,
Speaker 1: he turns his attention to dark energy what we've just
Speaker 1: been talking about, So on the scale of the universe
Speaker 1: at large, not necessarily in our own local neighborhood, but
Speaker 1: averaged across the entire observable sky, we've discovered that the
Speaker 1: energy that dominates the vacuum of space is not gravity,
Speaker 1: not electromagnetism, not any of the normal forces that govern
Speaker 1: our lives and our solar system, but a poorly understood
Speaker 1: form of energy that we call dark energy, which drives
Speaker 1: expansion of the universe. So mass and gravitation attract objects
Speaker 1: to one another, dark energy drives them apart. It's the
Speaker 1: energy that causes the space between galaxies to spread, meaning
Speaker 1: that the whole universe is growing larger and all the
Speaker 1: stuff within it is growing farther apart, and the galaxy
Speaker 1: is farthest away from us are receding from us the fastest.
Speaker 1: So as far as we know right now, dark energy
Speaker 1: might not have any practical applications for life bound to
Speaker 1: Planet Earth outside of scientific research, that is. But then again,
Speaker 1: we should know better than to dismiss the usefulness of
Speaker 1: any scientific discovery ahead of time. I'm always reminded of
Speaker 1: the English physicists who is credited as one of the
Speaker 1: discoveries of the electron, J. J. Thompson, who originally thought
Speaker 1: that the electron, which he was calling it the corpuscles uh.
Speaker 1: He thought this particle he had discovered would not be
Speaker 1: very useful outside of the lab, had no idea had
Speaker 1: anything to do with electricity. But Hooper points out how
Speaker 1: once a civilization expands to a S and scale and
Speaker 1: its energy needs scale with that expansion, dark energy becomes
Speaker 1: a pressing concern for the future of that civilization. And
Speaker 1: this is because dark energy presents us the future of
Speaker 1: an encroaching cosmic horizon. So we are unable to interact
Speaker 1: with anything beyond what's known as our cosmic horizon. This
Speaker 1: is the distance beyond which it is impossible to see
Speaker 1: because light from beyond this distance will never have time
Speaker 1: to reach us. Beyond that distance, everything is causally cut
Speaker 1: off from us. We can't see it, we can't talk
Speaker 1: to it or travel to it. Uh. You can think
Speaker 1: about it this way with an analogy. Imagine that the
Speaker 1: city or the neighborhood you live in is expanding. Are
Speaker 1: you there, Robert, Yeah, I'm there. It seems to be
Speaker 1: the case. Actually no, no, no no, no. What you're thinking
Speaker 1: of is the increasing density of the city you live in.
Speaker 1: More stuff is filling it. But instead you actually need
Speaker 1: to think of exactly the opposite. The distance between your
Speaker 1: house and other buildings is steadily increasing at an accelerating rate,
Speaker 1: so at normal walking speed. You say, used to be
Speaker 1: able to walk to the post office or the grocery
Speaker 1: store and then back to your house in what half
Speaker 1: an hour something like that, But as the distance between
Speaker 1: your house and these locations expands, the trip starts to
Speaker 1: take forty five minutes than an hour, then longer and
Speaker 1: longer at normal walking speed. Now you could try to
Speaker 1: walk faster, you could run, ride a bike, drive a car,
Speaker 1: and this would help. But eventually, as the space between
Speaker 1: the locations keeps expanding faster and faster, even these more
Speaker 1: powerful vehicles and methods of travel will take longer and
Speaker 1: longer to get you between locations, until eventually you reach
Speaker 1: a point where no vehicle you can get can make
Speaker 1: the trip because the distance between the two points expands
Speaker 1: faster than you can travel. You could travel toward the
Speaker 1: grocery store at maximum speed for the rest of your
Speaker 1: life and never get there, and this would mean that
Speaker 1: the grocery store has crossed beyond your cosmic horizon from
Speaker 1: your house. Uh So, now, beyond the cosmic horizon of
Speaker 1: the real universe, there might be lots of other stuff
Speaker 1: we can only see to our cosmic horizon, and beyond
Speaker 1: that it's possible there are other galaxies, stars, planets, but
Speaker 1: because the interaction, our ability to interact with all that
Speaker 1: stuff is cut off by the speed of light, we
Speaker 1: will never be able to touch it. We can't land
Speaker 1: on those planets, we can't send messages to those civilizations
Speaker 1: or get messages from them. We're just cut off by
Speaker 1: the universal speed limit of the speed of light and
Speaker 1: a vacuum. So, for instance, if you had this vast
Speaker 1: galaxy spanning uh Empire where everything everything is kind of compartmentalized.
Speaker 1: You have all these different divisions of the empire, and
Speaker 1: maybe they're they're not even in direct communication anymore. They
Speaker 1: just kind of have periodic updates about what culture and
Speaker 1: life is like in these distant places. But eventually you
Speaker 1: reach the point where they're just too far from each
Speaker 1: other for there to ever be contact again. Well, it
Speaker 1: would depend on how far away from each other they are,
Speaker 1: because if they're within a galaxy or even within nearby galaxies,
Speaker 1: within what's known as the local group. The local group
Speaker 1: is a cluster of roughly fifty something nearby galaxies, they
Speaker 1: will probably one day merge into the same big old clump.
Speaker 1: The local group is gravitationally bound, so we're going to
Speaker 1: pretty much stick together with the other stuff in the
Speaker 1: local group. So it's the galaxies far far away we
Speaker 1: have to worry about. Right. So if if, for instance,
Speaker 1: if Star Wars films were actually made in a galaxy
Speaker 1: far far away beyond the local group, and they have
Speaker 1: to be shipped back to us, there would reach a
Speaker 1: point where we could receive no more new Star Wars films.
Speaker 1: It would be a tragedy, wouldn't it. That's why we're
Speaker 1: stockpiling them now. We're getting as many per year as possible,
Speaker 1: because eventually it's going to pass beyond the cosmic horizon.
Speaker 1: Oh no, wait, I don't want to be misinterpreted, because
Speaker 1: I know there are actually people who like hate the
Speaker 1: last Jedi. I am not one of those. I liked
Speaker 1: it too. Um, but yeah, I've seen this all over
Speaker 1: the internet. People are like, people are like pulling their
Speaker 1: hair out about how much they hated. I don't understand. Yeah,
Speaker 1: I mean they're talking about making a Boba Fett movie, Like,
Speaker 1: do not disappoint like five year old Robert lamb and
Speaker 1: and and and ruin the possibility of a boa Fett
Speaker 1: movie for because I know that that he really wants
Speaker 1: to see it now. We'll come back to the cosmic
Speaker 1: horizon and the universal speed limit in just a minute,
Speaker 1: but uh to to shift our attention to another issue.
Speaker 1: It's often supposed that far far future civilization can keep
Speaker 1: itself alive and create usable energy by harvesting the energy
Speaker 1: from stars, and this is a good strategy. We we
Speaker 1: often think about future energy sources. We think about what like, oh,
Speaker 1: cold fusion or something like that, but these are paltry
Speaker 1: energy sources. Any kind of like human made reactor that
Speaker 1: we can can feasibly think of right now would be
Speaker 1: a very paltry energy source compared to what's already out there,
Speaker 1: which is the Sun right that. I mean, that is
Speaker 1: the energy source for everything that we hold dear. I mean,
Speaker 1: there's there's a reason that we we have worshiped it
Speaker 1: as a god in in previous ages because it it
Speaker 1: essentially is the almighty in our solar system. It is
Speaker 1: our creator. It is everything you know. I mean, it
Speaker 1: is a thing I used to say that I haven't
Speaker 1: thought of in a while, but I still stand by.
Speaker 1: Is that when you think about energy sources, really it's
Speaker 1: with a few caveats, it's all solar Yeah, Like if
Speaker 1: you're eating a steak or or a Caesar salad, what
Speaker 1: have you, you were eating uh, converted sunlight, Like this
Speaker 1: is sunlight you were eating. That's where the energy came from.
Speaker 1: It's just you're getting it downstream coal or oil or
Speaker 1: something like that that you would burn. Fossil fuels that
Speaker 1: you burn have chemical energy baked into them that was
Speaker 1: created when ancient organisms photosynthesized with the with the energy
Speaker 1: of sunlight. They took carbon out of the air, used
Speaker 1: the energy from sunlight to make that into sugar that
Speaker 1: turned into chemicals later down the road that you're now
Speaker 1: burning to power your car. And this is why Kardaschef
Speaker 1: Scale level two is to simply master a sign to
Speaker 1: say all this energy that is uh, it's maintaining the
Speaker 1: solar system. This is now all mine, right uh, And
Speaker 1: so how would you do that? I mean to come
Speaker 1: back to Freeman Dyson. We've discussed on the show before
Speaker 1: the idea of the Dyson's Fear. The Dyson's Fear comes
Speaker 1: to us from Freeman Dyson, and he basically says, you know,
Speaker 1: a civilization in the future that has a lot of
Speaker 1: technological power and wants to get the most bang for
Speaker 1: its buck will just completely surround its star with the
Speaker 1: equivalent of solar panels, right. And this brings me back
Speaker 1: to Star Trek, because I earlier was talking about Star
Speaker 1: Trek and you know, scaling up of our current models
Speaker 1: of life and all I do have to point out
Speaker 1: that Star Trek the next Generation is the first place
Speaker 1: I saw any mention or depiction of a Dycen sphere.
Speaker 1: And it blew me away then, and it still blows
Speaker 1: me away now. Yeah. I mean, it's fantastic to think about. Uh.
Speaker 1: And one of the ways that it's actually relevant to us.
Speaker 1: I mean, obviously it could be relevant in the far
Speaker 1: future if we wanted to try to build something like this.
Speaker 1: It's not technologically relevant to us today, except in the
Speaker 1: sense that if we're doing say CT and we want
Speaker 1: to look for ways of detecting alien civilizations out there
Speaker 1: that maybe aren't beaming us radio signals on purpose or
Speaker 1: anything like that. One thing that Dyson proposed is, hey,
Speaker 1: you know, we could look for Dyson's fears out there.
Speaker 1: I don't think he called them dycens fears, but I
Speaker 1: don't know Dycen spears Dyson clouds, but I don't know,
Speaker 1: I'm not true to what extent he referred to them
Speaker 1: with his own name somehow I doubt it. I don't remember,
Speaker 1: but uh, if he did, that kind of be awesome anyway. No,
Speaker 1: but I mean he was like, you know, you could
Speaker 1: look for this kind of thing, and so people people
Speaker 1: have looked for this kind of thing. It would have
Speaker 1: a certain kind of signature. One of the things that
Speaker 1: we could observe about a Dicen sphere is that if
Speaker 1: it completely surrounded a star and turned all of the
Speaker 1: stars solar radiation into usable in gy that could be
Speaker 1: used by the civilization somehow to survive after all, that,
Speaker 1: it would have to have a waste product, which would
Speaker 1: be heat, which we would be able to see as
Speaker 1: infrared radiation, like submillimeter infrared radiation. And so if you
Speaker 1: see like darkened stars out there that are not producing
Speaker 1: any kind of light you can see, but are producing
Speaker 1: infrared radiation and the certain kind of with a certain
Speaker 1: kind of band, you've gotta wondering, is this just a
Speaker 1: giant hot ball that's taken everything a son's got, using
Speaker 1: it and then spitting some heat into space. Now, because
Speaker 1: sons and stars are already plentiful and they're already a
Speaker 1: great source of energy. I think it is a fairly
Speaker 1: safe assumption to think that if there is a galactic
Speaker 1: civilization anywhere, will try to make use of something like
Speaker 1: a dicensephere, maybe not exactly the original design, but he
Speaker 1: will try to use stars as an energy source to
Speaker 1: sustain the civilization and feed its people and power its
Speaker 1: machines and do all that kind of stuff. And they're
Speaker 1: gonna need more than one. Yeah, and as the civilization
Speaker 1: scales up, it will need more and more energy needs
Speaker 1: scale up with population increasing. So what if your galaxy
Speaker 1: runs short on stars? You've got them all sphered up,
Speaker 1: all the usable ones, and you're getting all the energy
Speaker 1: you need from them, but your population is still growing.
Speaker 1: What do you do then? Yeah? I mean you're essentially
Speaker 1: using all of your farmland here to produce the crops
Speaker 1: that are necessary for life, or that the model of
Speaker 1: life that you've built. And uh, yeah, what what do
Speaker 1: you do when you maxed out? And then what do
Speaker 1: you do when say one of the stars blinks out
Speaker 1: on you? Uh, You're gonna have to scale back on
Speaker 1: what you can do as an empire. Stars also have
Speaker 1: finite lifespans. You eventually are going to need new stars
Speaker 1: to replace the old ones that are that are running
Speaker 1: down their fuel. Now, one thing you could do is
Speaker 1: just continually keep expanding, right, You could expand other galaxies.
Speaker 1: I mean, this is this is very crazy and very
Speaker 1: far future, because we don't have anything like the ability
Speaker 1: to travel to another gal see today. But if you
Speaker 1: imagine one of these Cardashev three type civilizations that has
Speaker 1: mastered in an entire galaxy, it could spread to other galaxies.
Speaker 1: It could keep on expanding. But we're limited to our
Speaker 1: local group right now. Because if you imagine just trying
Speaker 1: to continue expanding to other galaxies beyond into the far future,
Speaker 1: you would eventually come up against the problem we were
Speaker 1: mentioning earlier, the cosmological horizon problem. That's right, because even
Speaker 1: if you imagine and that releast is what I'm imagining,
Speaker 1: is that you know, just cosmic marauders. And this is
Speaker 1: something that is Hawking has has touched on himself. Uh,
Speaker 1: and to a certain extent I think was touched on
Speaker 1: and that uh in the film Chronicles of Riddic and
Speaker 1: that it's kind of what the necromongers were doing, right.
Speaker 1: I don't think they're doing it with stars. But you know,
Speaker 1: they had the whole kind of like life sucking undead um,
Speaker 1: you know, ravager kind of thing going on. I mean
Speaker 1: I never saw Chronicles. Well, yeah, you've got to see it.
Speaker 1: I've seen Pitch Black at your recommendation. Well, that's the
Speaker 1: necessary precursor to Chronicles of Riddic. You should see it.
Speaker 1: Is Keith David in it? Yes, okay, yeah, it's it's
Speaker 1: it's fun. It's fun. But yeah, I'm picturing a marauding
Speaker 1: um interstellar civilization. It just goes from one system to
Speaker 1: the next, using up sons and then spitting them out again.
Speaker 1: But eventually they're going to reach that point where there
Speaker 1: are no new sons to conquer. And Alexander wept where
Speaker 1: there were no worlds to conquer. Yeah, and then you're
Speaker 1: just left to uh just stew in the in the
Speaker 1: cosmic darkness. Uh So, if we're gonna keep expanding, we
Speaker 1: need stars, and if we run out of local stars,
Speaker 1: we're gonna have to get him from somewhere else. And
Speaker 1: Hooper writes, quote over the next approximately one billion years,
Speaker 1: so basically times the age of the Earth. He writes,
Speaker 1: all stars residing beyond the local group will fall beyond
Speaker 1: the cosmic horizon and become not only unobservable but entirely inaccessible.
Speaker 1: So he's saying, like, we're going to run out of
Speaker 1: time if if you know, a civilization doesn't do something
Speaker 1: early on, it's going to run out of time to
Speaker 1: get at all those extra stars to give them, to
Speaker 1: give them more energy. So you've got stars speeding away,
Speaker 1: how do you make use of them for the future.
Speaker 1: Hooper has an idea. What if you go out to
Speaker 1: those stars, you go snag them, and then you use
Speaker 1: the Dyson's fears that you build around them as a drive.
Speaker 1: We talked earlier about the idea of scattow thrusters and
Speaker 1: things like that. What if you used a Dyson sphere
Speaker 1: to steer and drive a star back home to where
Speaker 1: your civilization is, so that you can hoard stars from
Speaker 1: the entire universe at large and keep them nearby to
Speaker 1: use them for the future before they go beyond your
Speaker 1: cosmic reach. I think we should call this star jacking.
Speaker 1: That's what it sounds like to me. It's star hoarding.
Speaker 1: And so the the emitted radiation from a star could
Speaker 1: provide some thrust which could be used at least in theory,
Speaker 1: to steer a star are and it s Dyson's fear
Speaker 1: in a particular direction, meaning that you know, this civilization
Speaker 1: could gather stars close together and keep them from expanding
Speaker 1: out of reach and great leaks in the lifespan of
Speaker 1: their civilization. But there are limits on this, and a
Speaker 1: lot of Hooper's paper is used to calculate types of
Speaker 1: stars that would be fruitful for this. Only certain types
Speaker 1: of stars would work, mainly stars somewhat within the range
Speaker 1: of the mass of our Sun, because stars that are
Speaker 1: much bigger tend to be older or tend to not
Speaker 1: have as much life left in them. Yeah, you don't
Speaker 1: want to go to the trouble of Jack and those
Speaker 1: stars if they're just going to burn out or collapse
Speaker 1: before you can make use of them exactly. So this
Speaker 1: is a problem. The bigger stars would not have enough
Speaker 1: life left in them to survive the journey back to
Speaker 1: the home base, and so they're not really worth hoarding.
Speaker 1: On the other hand, stars much smaller than our Sun
Speaker 1: would not provide enough energy to drive the star to
Speaker 1: its central star Hoarde fast enough before it passed beyond
Speaker 1: the cosmic horizon, and so there is kind of a
Speaker 1: Goldilocks star. You know, a Goldilocks star that you want
Speaker 1: that that is big enough to give you enough energy,
Speaker 1: that's small enough that it's still going to have plenty
Speaker 1: of life left in it by the time you get
Speaker 1: at home, And that's the kind you want to bring home. Interestingly,
Speaker 1: Hooper points out that if alien civilizations anywhere out there
Speaker 1: are doing this quote, this would not be a subtle activity,
Speaker 1: so we should be able to detect it. Kind of
Speaker 1: like the original idea of the Dicen sphere. If anybody
Speaker 1: out there is doing anything like this, you've got a
Speaker 1: galactic civilization in one of those galaxies far out there,
Speaker 1: and it's making these kinds of preparations for the future.
Speaker 1: This could give us a new path to setty observation.
Speaker 1: Can we look out at galaxies out there and detect
Speaker 1: the removal, transport, and hoarding of certain kinds of stars? Yeah,
Speaker 1: I mean it makes it makes sense. Like you said,
Speaker 1: this would not be a subtle act. This would be
Speaker 1: the kind of thing that we would conceive will be
Speaker 1: able to observe. Yeah, and so Hooper writes, quote, such
Speaker 1: a civilization could pier as a region up to tens
Speaker 1: of mega par sex and radius in which most or
Speaker 1: all of the stars lighter than about two solar masses
Speaker 1: are surrounded by Dyson's fears. Now that's a cool image. Yes,
Speaker 1: the star hoarde, the star hoard Yeah, there the empire
Speaker 1: of the star hoarders or star jackers, which whichever one,
Speaker 1: whichever one you want to use. Star jacking is the verb,
Speaker 1: the star hoarde is the Now the star jackers work
Speaker 1: for the star hoarders. Yeah, and then our only hope
Speaker 1: is to just, I guess, somehow present a case that
Speaker 1: we're we're worth keeping around, like we're culturally interesting enough,
Speaker 1: or maybe they have rules. Maybe they don't take stars
Speaker 1: from systems with the inhabited worlds. I don't know, I
Speaker 1: could go virtually anyway. Yeah, maybe they only use stars
Speaker 1: from inhabited worlds. Now, of course, with an idea this
Speaker 1: far out there, you at least want to hear what
Speaker 1: some other scientists in the field have to say. Fortunately,
Speaker 1: there was a right of this in Science News that
Speaker 1: got some quotes from some other astrophysicists, for example, the
Speaker 1: theoretical astrophysicist Katie Mack of North Carolina State University. They
Speaker 1: asked her opinion and She pointed out that, you know,
Speaker 1: one thing is that you might have an easier time
Speaker 1: surviving if you just uproot your civilization and move it
Speaker 1: to a different galaxy cluster that's got a bunch of
Speaker 1: different stars you could use. So instead of bringing all
Speaker 1: the stars to you, you just go where they're already are,
Speaker 1: a whole bunch of already untapped stars the Marauder model, Yeah,
Speaker 1: and settle in there. But then again, you know, maybe
Speaker 1: they maybe there are reasons they want to stay where
Speaker 1: they are. It might be easier to send out autonomous
Speaker 1: star collection, you know, robots that would build Dyson's fears
Speaker 1: around stars and bring them home than it would be
Speaker 1: to move the conscious inhabitants of a place. Maybe they
Speaker 1: like where they are and the movement would be stressful. Yeah,
Speaker 1: I mean, ultimately, who's going to argue with them? Right? Right?
Speaker 1: Because they would be where would they be on the
Speaker 1: Kardashi of scale, they would be between two and three,
Speaker 1: Perhaps they would be threes. I don't know, three, it's
Speaker 1: pretty lofty. Oh yeah, I think we're talking about a
Speaker 1: level three cardship civilization right here. You're you're controlling a galaxy.
Speaker 1: If you're going out to other galaxies to get stars
Speaker 1: to bring home. Yeah, yeah, you would be Yeah, so
Speaker 1: I guess you would be a little beyond three. You
Speaker 1: would be up towards us. You would be moving towards four. Whatever.
Speaker 1: Four would be like if we can even comprehend such
Speaker 1: a thing, a mastery of the local group or something.
Speaker 1: The physicist Avy Loeb of Harvard University also points out
Speaker 1: the same issue that you know, it might not be
Speaker 1: necessary to go get stars from other places, because he says, quote,
Speaker 1: nature did it for us. You've already got There are
Speaker 1: places in the universe where they're huge clusters of galaxies
Speaker 1: that are all sort of near by each other, and
Speaker 1: maybe it would be better to go to one of
Speaker 1: those galaxy clusters that's got lots of stars already there.
Speaker 1: I mean, it's it's a relative lots of stars, because
Speaker 1: there are lots of stars in our galaxy. But if
Speaker 1: you're talking about this Cardassian you know, three point five
Speaker 1: or four type civilization and it's got ridiculous energy needs,
Speaker 1: then there are places you could go that would have
Speaker 1: more stars nearby already. Right. And again this is assuming
Speaker 1: they don't say, you know, guys, this is a bit nach.
Speaker 1: We don't need this much energy, let's scale back a bit. Yeah,
Speaker 1: But then again, our tribal ancestors could have said that
Speaker 1: about our world today and now here we are and
Speaker 1: we need the energy. True though there we do, see,
Speaker 1: I mean, there obviously is a movement to cut back
Speaker 1: on energy to find more sustainable ways. Uh you know,
Speaker 1: whether that will that argument will win out in the end,
Speaker 1: uh you know, remains an open question. But um, well,
Speaker 1: I would say, I don't know. Maybe maybe you can
Speaker 1: make the case to me, I don't know if any
Speaker 1: good reason that we need to cut back on energy
Speaker 1: itself is just like types of energy, you know, certain
Speaker 1: types of energy are more destructive than others. And if
Speaker 1: we had a truly I mean, I think there is
Speaker 1: no such thing as a perfect energy source, because even
Speaker 1: the most benign forms of energy maybe solar, wind power,
Speaker 1: whatever you have, have some kinds of construction and costs
Speaker 1: and stuff to build the panels. Um. But but there
Speaker 1: are relatively benign forms of energy that I don't I
Speaker 1: don't know. Is there an argument that we shouldn't even
Speaker 1: be trying to maximize our collection of solar energy or something? No?
Speaker 1: I mean it kind of comes down to though, to
Speaker 1: like how much energy can we conceivably harvest? And then
Speaker 1: how are we living our lives in accordance to it?
Speaker 1: You know? Um? So I yeah, I don't see anybody
Speaker 1: as saying let's stop harvesting energy, but but also asking
Speaker 1: the question, is our consumption lining up with our current
Speaker 1: and even near future ability to harvest it? Maybe the
Speaker 1: answer to that is no, right, yeah, but but it's
Speaker 1: certainly based on our own model of intelligent um technological behavior,
Speaker 1: it makes sense that uh, an alien species, we just
Speaker 1: continue to jack as many stars as as as possible
Speaker 1: to sustain itself. I mean, I I like I was
Speaker 1: saying earlier, I think we want to avoid making too
Speaker 1: many assumptions about future civilizations or alien life, because there's
Speaker 1: a lot we just can't know about their minds, about
Speaker 1: their culture and all that. But one thing we pretty
Speaker 1: much know no matter what is they need energy. Yes,
Speaker 1: but I'm saying they could scale back if they if
Speaker 1: they really wanted to. I mean, it's I think that
Speaker 1: is a possibility. And certainly if they see the writing
Speaker 1: on the wall, you know that that energy is going
Speaker 1: to become less abundant, and then it's about survival. Now,
Speaker 1: speaking of survival, um, I do have one last survival
Speaker 1: scheme dimension here, and this one was exploring in that
Speaker 1: Adam Becker BBC article their referenced earlier. Alan Gooth of
Speaker 1: m I T contends that the laws of physics might
Speaker 1: imply that that this is possible, uh, that you could
Speaker 1: essentially escape into a universe of your own making. Yeah. Now,
Speaker 1: it would require vast amounts of energy, which of course
Speaker 1: is we're discussing the players in this kind of game
Speaker 1: would have have. But it might go down like this.
Speaker 1: First of all, you need to create an incredibly dense
Speaker 1: form of matter, so dense that it barely avoids collapsing
Speaker 1: into a black hole, and you quickly clear the matter
Speaker 1: out of the way, forcing the region of space to
Speaker 1: start expanding, and this would jump start, in theory a
Speaker 1: new universe. Quote. As the space in the region expanded,
Speaker 1: the boundary would shrink, creating a bubble of warped space
Speaker 1: where the inside was bigger than the outside, which is
Speaker 1: kind of like it reminds me of the bag of
Speaker 1: holding from Dungeons and Dragons. The Gooth actually compared it
Speaker 1: to the tartest dr who looked it looks bigger on
Speaker 1: the inside. Yeah, yeah, and they on the outside it's
Speaker 1: what a phone phone booth, and then on the inside
Speaker 1: it's this large, expensive room and so forth. So eventually
Speaker 1: the new universe would pinch off from the old doomed universe.
Speaker 1: But he stresses that this might not be possible at all. Sure,
Speaker 1: it depends on a lot of assumptions that could be true,
Speaker 1: but we don't know for sure. But then also the
Speaker 1: other way of looking at things, he says, is it, Uh,
Speaker 1: you know, if if the multiverse model holds true, then
Speaker 1: that's probably our best bet. The universe may end, but
Speaker 1: the multiverse continues eternally. No way that that might mean
Speaker 1: though we can't get there, just some other version of us. Yeah,
Speaker 1: and but that might be the best we can you know,
Speaker 1: for in the end is just to realize, all right,
Speaker 1: we've we've we've jacked a thousand stars, we've hoarded them,
Speaker 1: we've done what we can. But hey, the writings on
Speaker 1: the wall, we're gonna blink out. But somewhere out there
Speaker 1: in the multiverse, Uh, this thing called life is still going.
Speaker 1: I believe in the thing called technological civilization. One final
Speaker 1: note is a side tangent. Well, one thing I loved
Speaker 1: about the Freeman diys in paper we talked about earlier
Speaker 1: from seventy nine, is that at the end he invokes holdings, uh,
Speaker 1: quoting of of G. K. Chesterton on the role of
Speaker 1: human intellect in the future of of of civilization quoting
Speaker 1: from the Ballot of the White Horse by Chesterton, where
Speaker 1: he writes, so rides my soul upon the sea that
Speaker 1: drinks the howling ships, though in black jest at bows
Speaker 1: and nods under the moons with silver rods. I know
Speaker 1: it is roaring at the gods waiting the last eclipse.
Speaker 1: Oh that's nice. So maybe find peaceful ways to survive
Speaker 1: that last eclipse. All right, So there you have it.
Speaker 1: If you want to hear more episodes like this dealing
Speaker 1: with the the long term future of humanity and this
Speaker 1: universe of change and hostility, uh, then you can check
Speaker 1: out all the episodes of Stuff to Blow Your Mind
Speaker 1: at Stuff to Blow your Mind dot com. That's the
Speaker 1: mother ship. That's where you'll also find social media links
Speaker 1: to our Facebook, Twitter, Instagram, you name it. Huge things
Speaker 1: as always to our wonderful audio producers Alex Williams and
Speaker 1: Tary Harrison. If you want to get in touch with
Speaker 1: us to let us know feedback on this episode or
Speaker 1: any other, or to suggest a topic for future episodes,
Speaker 1: or just to say hi, let us know where you
Speaker 1: listen from. You can email us at blow the Mind
Speaker 1: at how Stuff Works dot com. And I want to
Speaker 1: close out here with a really cool tray guy came
Speaker 1: across from the group We Plants Are Happy Plants, titled
Speaker 1: an Incredible Pearl, which makes use of a passage from
Speaker 1: American writer philosopher in ethnobotanist Terrence McKenna, who who we
Speaker 1: discussed on the show in the past. Kind of a
Speaker 1: wizard figure. Yeah yeah, so, uh so check this out.
Speaker 1: If you want to hear more from We Plants Are
Speaker 1: Happy Plants to simply look them up on Spotify or iTunes,
Speaker 1: wherever you get your music. You can also go to
Speaker 1: YouTube dot com, slash w P a h P. We're
Speaker 1: going to have to make a decision about human nature
Speaker 1: to wit. Is this our home to be cherished and nurtured,
Speaker 1: an incredible pearl flung out in a universe of ashes
Speaker 1: and darkness? Or is this a hell world, a tiny,
Speaker 1: confining prison at the edge of a dying universe from
Speaker 1: which it is our destiny to break free and recover
Speaker 1: our higher and hidden nature from which we have become separated.
Speaker 1: You know, this is a choice which as a culture
Speaker 1: we face. Are we to go into the divine imagination
Speaker 1: and create you know, starships the size of Manitoba that
Speaker 1: will apply between here and Andrama and exist in a
Speaker 1: world of our complete syntactical self expression. Or is man's
Speaker 1: place humbler than that? Is that grandiose steeped with megalomania,
Speaker 1: touched with the kind of political taint that's had this
Speaker 1: raping and pillaging ever since we got out of those
Speaker 1: miserable ice bound villages in Jutland or wherever it was.
Speaker 1: Is it that? Or is it our challenge and our destiny?
Speaker 1: It's really a choice about human nature.