What Happens If We Can't Leave Earth?

What Happens If We Can't Leave Earth?

Show Video

This episode is brought to you by Raycon. So much of our discussions of the future   here on this show and elsewhere assume  a grand destiny out among the stars.   But what if we’re wrong and that glorious  future on the horizon is merely a mirage? A few months back I asked our audience over  on our reddit group, r/IsaacArthur, for some   episode ideas, and there were so many good ones  that I decided to take 5 of the most upvoted and   put them on our Youtube Community page for a  poll, and the clear winner was today’s topic,   what happens if we can’t leave Earth? One  of the things I tend to be best known for is   talking about how to get us off Earth and to new  planets so I was a bit surprised by that being   a topic folks wanted me to discuss. Of course  another thing I tend to be well-known for is   being pretty upbeat about humanity’s future and as  we’ll see today, even if we can’t get off Earth,   that doesn’t make for a bleak future at all. We don’t really see a distant future on Earth   discussed very much, scifi in a galactic setting  rarely does much here in favor of strange new   worlds, and Earth tends to either be the distant  capital of some stellar empire or a distant memory   of a world long since destroyed. When we do  see Earth as the centerpiece of such stories,   it is usually the Dying Earth saga, inevitably  dystopian stories set in an exhausted planet   which is either spurned by its distant colonies  or unaided because they have the same exhaustion.  

Dead mined planets around dying stars, and Earth  a fading ember waiting to die by fire or ice.  Indeed so much of classic science fiction  drums that point in, to encourage us to   want to reach out to claim those stars. One  of my favorites quotes on the topic is from   Commander Sinclair of the 90s scifi show  Babylon 5, in the episode “Infection” when   asked by a reporter from Earth about the great  expense of keeping his space station running   and the cost and risk of other space endeavors. She asks,” I have to ask you the same question  

people back home are asking about space these  days. Is it worth it? Should we just pull   back? Forget the whole thing as a bad idea,  and take care of our own problems at home?”  And Sinclair replies, “No. We have to  stay here. And there's a simple reason   why. Ask ten different scientists about the  environment, population control, genetics,   and you'll get ten different answers. But there's  one thing every scientist on the planet agrees on.   Whether it happens in a hundred years  or a thousand years or a million years,   eventually our Sun will grow cold and go out.  When that happens, it won't just take us.   It'll take Marilyn Monroe, and Lao-Tzu, and  Einstein, and Morobuto, and Buddy Holly,   and Aristophanes, and all of this…all of  this…was for nothing. Unless we go to the stars.” 

I love that line, it’s very poetic. I think it  summarizes how a lot of us feel about space.   But in a couple of months we will ‘celebrate’  the 50th anniversary of the last time humanity   walked on the Moon, and I don’t think even  space pessimists of that time thought we   would be over half a century going back and  not have done a manned mission to Mars by now.  I firmly believe we need no new science and only  a handful of technological improvements to make   space a reality, that vast improvements  to both can only help but aren’t needed,   and we discussed the very low-tech  approaches in our episodes Crawlonizing   the Galaxy and Low-Tech Kardashev Civilizations. Nonetheless there’s no guarantee those things will   happen. That we will just find a way to make  space colonization viable, and we can show the  

practical engineering and raw numbers for travel  but there’s a big difference between inventing   a ship sail and actually creating large-scale  intercontinental oceanic trade. There are so many   tiny little problems with sailing a boat across an  ocean that took centuries to figure out and many   of those major problems weren’t visible until  we began early journeys. Space travel is hard,   and it's likely there are critical problems  with doing it we don’t even know of yet. 

So I remain confident it will happen but we can’t  casually ignore that we might just be wrong about   this. Indeed until those Apollo Missions were  done, we didn’t even have the term Fermi Paradox,   and Fermi himself was just of the opinion  that alien races were common enough but   that interstellar space travel wasn’t and  that species don’t long survive technology,   a bit of pessimism that is understandable from  one of the inventors of nuclear weapons who got   to see the arsenals and tensions grow in the  Cold War, but not live to see the Space Race.  And it wasn’t really a perspective that was  new, scifi was playing around with interstellar   colonization throughout the 20th century and  before then nobody really contemplated space   travel and settlement in a serious way, even  though we had an increasingly strong knowledge   that the Universe was huge and ancient and that  our sun was just another star. Indeed pre-20th  

century with Radio Waves and Relativity, ever  since Newton’s laws of gravity, we assumed the   universe was infinite in age and size. So when  it was discussed everybody assumed that life   was either the unique creation of the divine or  that life probably was all over the place but   that travel was impossible and of course travel  was the only way to communicate. There was no   phone or radio after all, communication by default  was done by walking or riding or sailing to either   talk to someone in person or hand them a letter. So the idea that our future was ‘space or bust’   is definitely a new one, and while just about  every religion and culture had some built in   doomsday event they expected, it was usually  nebulous and set to arrive whenever and while it   often involved the heavens it was in a different  mental context. The end was a thing to be welcomed   or dreaded or maybe both, but folks didn’t really  think in billion year timelines back then anymore   than we do now. With a few notable exceptions,  the same as we had a few for non-travel based   communication, like beacon fires or semaphore. None of this past-history speaks to our future  

survival buts it’s a reminder that a belief  our world will end and we have nowhere to flee   to doesn’t mean civilization falls into ruinous  despair awaiting the inevitable end, whether that   is from divine wrath or a fiery consumption by our  Sun or a frigid dissolution a trillion-trillion   years from now in a dark and entropic Universe. One day our sun will end, and with it all the   days and nights of Earth, and indeed even most  of the tricks we have discussed on this show   for extending that like starlifting and refueling  rely on technologies that make interstellar travel   a piece of cake. We estimate in a billion or so  years, maybe half that, maybe double, the Sun will   have brightened enough to burn off our atmosphere  and seas. And we have tricks for preventing that,   like shading the planet with orbital shades &  mirrors or even moving the planet, but both imply   a skill at space travel beyond what we have now. We tend to assume we wouldn’t even make it that   long though and that’s a fair point, if the  Sun might boil our oceans away in as little   as half a billion years from now, well half a  billion years ago is when we crawled out of the   ocean and we don’t look or act much like we  did then. We often assume that this period,  

humanity’s rise to master Earth and then this  region of space, would be so significant that   all life descended from us afterward would view  humanity as very important, their most noteworthy   ancestors or creators, the form of life which  dominated our world then our galaxy and perhaps   beyond, or at least made the first big steps out  there, as Neil Armstrong so eloquently put it.  For a civilization looking back from the edge  of the end, one where we always dwelt on Earth,   life would have arisen in the seas billions of  years ago and those seas slowly disappeared with   various species and civilizations arising and  falling and humanity probably just one of them.   In another billion years, if humanity wiped  itself out and it took 10 million years for   the world to heal enough and some other critter  evolve enough to replace us and do it again, then   we’d just be one of a hundred great civilization  making species. And realistically it would be  

much shorter intervals. Probably more like tens  of thousands of years and tens of thousands of   iterations. As we saw in the Silurian Hypothesis,  it isn’t likely we would be forgotten, we would   still have our wikipedia page, possibly literally,  but we would probably not be noted as the grandest   or greatest or even necessarily the first. Let’s consider some scenarios though. First,   I can’t really accept that science and  technology don’t allow space travel,   so while we will discuss that scenario too, let’s  start by hypothesizing that we can not get off   Earth because we are told not to. This might  be that the programmers of the Matrix give up  

on trying to convince us there’s a real universe  out there to colonize and just stop bothering to   simulate it or maybe very powerful and eternal  aliens or divine agencies show up and say “No,   this is your one and only world, keep it or wreck  but no replacements and no returns.” and we might   contemplate if Earth’s orbital space, which we are  clearly very active in, should count, perhaps out   to the Moon, or even the whole solar system. We might also imagine that it is our own   decision. Let's imagine we do start finding  signs of life all over the place, exoplanets   seemingly teeming with them and even Mars and  Europa and Venus and more. Perhaps also that,  

as many suggest, ethics and right and wrong are  things that can be logical deduced and universal,   that humanity will reach that ethical code and  other aliens all converge to that and everyone   really does say “It is wrong to take other  worlds, even from an Amoeba, even from where   an amoeba might be likely to one day appear.” Or perhaps we come to fear what colonies will   turn into once away from us, and us powerless  to stop it. Space travel is possible but we   forbid it and shoot down any ship seeking to  leave, so that their distant descendants don’t   in turn surround us with possible enemies. After all, we talk of how space will benefit   humanity but the reality is that’s only true if  we pick a broad definition for it. Realistically a   future of space colonization in a no-FTL universe  is one where humans spread to the stars and mutate   and genetically engineer and cyborg themselves  up till in even a few thousands years they act,   look, and think little like we do now. On our lone world we probably still have  

all the science we need to discover how to become  post-scarcity, living vastly extended lifetimes   in prosperity with robots doing the grunt work and  us free to pursue higher aspirations. We can still   make a world of many layers and arcologies, still  have a trillion virtual realms for us to explore,   weirder than nature will produce and not  requiring centuries of expensive travel to   reach. We can still live extended and augmented  lives. Here on Earth Alone we can still rise   to Olympian Heights. Claiming more worlds  on which new research and development and   experiments with civilization can occur may help  speed that up, but there is danger there too.  Some may say it is better to have this one world,  surrounded only by silence, then to have a future   where we still have only this one world, but are  surrounded on every side by our mutant offspring   and vulnerable to whatever abominations of  technology some reckless or ambitious colony   might unleash upon us and their neighbors. There is a good deal of sense to that,  

mathematically. An AI which takes over a  planet as a single megamind has to think   twice about expanding that domain since their  own mind can stretch only so far from light   lag restraints and their progeny may be as  deadly to it as it was to us, and surely   more so statistically than empty space would be. Is it any different of an equation for us, truly?  We might imagine a future where any ship on a  trajectory past the Moon is destroyed by great   sky fortresses looming over our world, and this  is a future where we can hold back the Sun with   solar shades all the way to the final sunrise  they are burned away and our world with them,   4 or 5 billion years hence. Or we might  imagine that even satellites are forbidden,  

and that instead huge towers permit communication  between themselves as nodes like in the pre-space   days. For communication, this would be no great  limitation, as we might cocoon our planet with   fiber optic cables to allow far denser and faster  communication than our satellite grid allows.  We talk of solar shades in orbit but perhaps  instead we might make high-stratospheric balloons,   reflective on one side to sunlight or those  frequencies of it we value less. Indeed we   might decide the best approach would be to dome  our whole world over, a worldhouse as we call it,   and permit no air to leak and to reflect away  any light we didn’t want before it was absorbed   by land or sea or air as heat. Indeed we might  build radiating trunklines and masts on these to   let us move heat from hot to cold areas or remove  it from the world by radiating it into the vacuum.   Done correctly, and without ever needing  spaceships, we could slowly push Earth from   the Sun by means of reflected light or superheated  helium or other gases vented toward the Sun at ion   drive speeds. Earth would lose mass, like  any rocket, but it has so much and the sun  

provides so much power to drive that process. Indeed it is worth remembering that once you   remove all the material in the Sun and the Gas  Giants, hard to reach and use, Earth makes up   much of the remainder. Indeed Earth outmasses all  the rocky planets combined, and very nearly ever   rocky planet, moon, and asteroid combined, with  the majority of the remainder being in Venus. So   it isn’t that our solar system’s mineral resources  are really necessary to keep Earth going.   Nor do we need hydrogen or deuterium  or helium-3 from other worlds to run   our hypothetical fusion plants, though I  can’t imagine how we could have those and   not be able to do space travel with them. We mostly only want all those rocks in   space for new places for humanity and to help  fuel that expansion. Gold and platinum from  

asteroids sure would be nice for encouraging  and assisting early space expansion but every   asteroid combined doesn’t have as much gold  and other precious metals as Earth’s own crust,   which is roughly ten times the mass of  the entire asteroid belt, while still   being less than a percent of Earth’s total mass. We’ve discovered around a quarter of a million   tons of gold to date, but that is only around  a millionth of what’s in the crust alone and   the same is true of basically everything we mine,  albeit not in dense and easily reached ore veins.   As long as you have energy, you have the ability  to keep refining and recycling and centrifuging   those minerals, and on geological timelines they  do shift around with the mantle. In truth as long   as the sun keeps shining we should be able  to support our current population and more,   but even if we did need to go back to a lower  population density, say a billion people,   to be a stable ecology while still having  plenty of room for crops, livestock,   biofuels, solar, wind, geo, and hydropower,  that remains a very impressive civilization.  We believe perhaps 100 billion people have  lived thus far, with around half in the last   two thousand years but the other half spread  over far longer. Most since we learned farming   and agriculture, but more humans lived before we  had agriculture than live now. Maybe not by much  

though, even over hundreds of thousands of years.  It varies a lot on vague estimates of prehistoric   populations and where you draw the line on what’s  human, but the most recent calculation I saw   was 117 Billion, currently growing by about 82  million a year, with 34 million dying each year,   and us set to hit 8 billion humans alive  shortly after this episode comes out.  For simplicity of numbers though we might  assume a steady population of around a billion,   each person living a century, for a billion  births and deaths each century and in a billion   years that would mean 10 million centuries or ten  million-billion people, or 10 quadrillion, or a   million times our present population or a hundred  thousand times as many people as have ever lived.  

Rough numbers and for my part I think we  could support a lot more folks than that.  So consider this, ours is not a great civilization  but rather the most recent and mighty collection   of many civilizations who are heirs to thousands  of great cultures who are spread over thousands   of years, and mostly unknown to us. Few empires  numbered a billion souls over their entirety,   and most folks lived in realms and times far less  grandiose. Millions of those could rise and fall   and overlap each other in time and space before  ever the Sun finally set on Earth. That is not a   future to be depressed about or sad for, anymore  than a person should lament having a million   dollars because someone suggested they might make  billions and a million is all that materialized. 

Nor is our longevity or sheer numbers  the measure of our worth. Many a person   has striven for immortality in the form of  being remembered by statues and histories,   and if that is a good way to persist, then to have  our history recorded for a few billions of years   before being burned up is also nothing to be  sad about, simply because it falls short of the   trillions of years or even longer that we often  contemplate on the show. And as I’ve mentioned   before, digital data and cheap data storage  plus the internet mean that unlike virtually   everyone who lived before, you have good odds  of being remembered until this world is no more.  But I don’t think the measure of man is only in  how tall his statue is or how long his tale is   kept, and the same for all mankind. Our forgotten  and unrecorded civilizations are our loss,   not theirs, we are made less by not knowing them,  and while it would be a great shame if a fire   burned every copy of Shakespeare or Tennyson or  Mozart or Bach, it doesn’t make their works any   less grand, it just makes the world that follows  poorer. And if the sun burns up our whole world,   and everything we were with it, then it  is no loss to us today, merely to those   on that day and on all the tomorrows that follow  somewhere on some other world we never got to see. 

If we stay here, it doesn’t mean we are vulnerable  to having all our eggs in one basket. There’s   really only a few improbable scenarios that  would sterilize our world, even on billion   year timelines, and being planetbound doesn’t mean  you are defenseless against those scenarios. Great   big orbital space guns or missile platforms  work wonders. As we looked at in our episodes  

Asteroid Defense and our Collab with Joe Scott  on 5 Doomsday Scenarios and how to prevent them,   with a bit of forewarning and detection there’s  very few ways a natural calamity can endanger   us that can’t be managed and survived. Man-based  cataclysms alternatively, ones able to threaten   whole worlds, can also threaten whole interstellar  empires, and have more place to originate from in   one. The hyper-intelligent self-replicating  swarm that devoured your whole world and   which you cannot resist probably is still  irresistible when it gets to your other colonies,   or if it came from one of them. Indeed if it is a choice,  

like we considered in our episode years back  on Stay-At-Home civilizations who could expand   into the galaxy but choose not to, then their  technology renders them safe from natural disaster   even if bound to one world. And when it comes to  technological threats, the nightmares we might   spawn, a billion worlds might spawn them a billion  times faster, and far harder to detect and kill in   weaker embryonic states then some homogenizing  swarm or von Neumann berserker probes might be   once they got rolling on some lightly settled  colony planet far from oversight and control.  Alternatively many would say the nightmare  we might spawn is us, and that any world we   go to will suffer the same fate as ours. But  if that is so then colonizing worlds really  

offers no escape from that and what’s more,  colonizing a planet is always going to be   harder than repairing one you already had but  damaged. The technologies and wisdom humanity   needs to spread to the stars is the same that  permits us to keep our world the wonder that   it is. If we don’t get that then it doesn’t  matter if we’re stuck on this planet or not,   we would carry our doom with us whether we stayed  or went, and not for far or long either way.  This to me though is the greatest  loss. If you see humanity as a plague,   replicating itself over a galaxy that will descend  into eternal war among its greedy divergent spawn,   then all the better if we are stuck on this world  until our Sun burns it up and us with it. But if  

you see us instead as gardeners and sculptors,  and the galaxy beyond as our garden and quarry,   then even if we were swept away by  some descendant or creation of ours,   then we still are victorious in seeding that  garden, even if in the end we are only the seed.  That’s what truly happens if we can’t ever leave  Earth. It isn’t the end of humanity or a doorway   to despair, merely a door to heavenly heights  we must pass on, while still having so many   more great paths available to us even here,  on our one lonely world, our pale blue dot. So yesterday I was at the store in the check  out line with my wife when my phone lights up   with a call from my bank. They never call me  and it was after hours so I was immediately   worried they were about to tell me my identity  was stolen or were calling to tell me they just   successfully wired all my funds to my new bank  on non-extradition island. I’m half deaf from   my time in the military and pretty much always use  my speakerphone but I didn’t want to put that call   on speakerphone so I had to ask them to wait while  I got outside. Thankfully it turned out they were  

just calling to wish me a happy birthday and I  could catch my breath again. Then kick myself,   because I’ve got a very nice pair of Raycon  Everyday Earbuds with noise isolation,   which have this very pocket-friendly  carrying case and charger that makes   it easy to carry them around everywhere  and everyday, but I’d left them at home.  Earbuds are just plain handy for leaving you both  hands free and for letting you hear things around   loud or changing noise levels, and Raycon’s noise  isolation is superb, I’ve used it for listening to   audiobooks while mowing or running drills and  saws, or taking a conference call while going   for a bike ride, and Rayon Earbuds let you  reject calls or navigate audio tracks just   with their earbuds, leaving your hands-free. Raycon’s Everyday Earbuds have optimized gel   tips for the perfect in-ear fit, so they  are comfortable and they will not budge or   fall out. They’re water resistant,  I’ve washed my on accident before,   and they give you high quality audio at half  the price of other premium audio brands. That’s  

probably while Raycon Everyday Earbuds have tens  of thousands of 5-star reviews, including mine.   They’re just all around great earbuds in terms  of quality, versatility, comfort, and cost.  The individual earbuds have a 8 hour playtime  battery life and they recharge in their compact   carrying case, for 32 hours of listening  time without needing to plug into a wall,   plus a wireless charging feature for the case  you can try out. Raycon Everyday Earbuds are   Siri and Alexa compatible, and have both noise  isolation immersion mode and awareness mode   for when you need to hear the noise around  you, plus three sound profiles, pure sound,   for podcasts and audiobooks, a bass-boosted mode  for music with a lot of beat, and balanced mode.  So if you’re looking for a great and  affordable listening experience and   want to help support our show while you’re  at it, just click the link in the description   box or go to buyraycon.com/isaacarthur  to get 15% off your Raycon purchase!

So today we asked what happens if we have  to remain on Earth and this weekend for   our Scifi Sunday episode we’ll go the other  direction and ask what Alien Environments   might be like. Then next week we’ll go even  farther and ask if space travel might become   so mundane you could have Your Own Personal  Spaceship, which we’ll look at on October   20th. Then we’ll ask what would happen if  you damaged that spaceship on October 27th,   and then close out the month on Halloween  weekend with our Livestream Q&A, on Sunday,   October 30th, at 4 pm Eastern Time. Join us  live to get your questions into the chat so   they can be answered. After that we’ll head  into November to discuss refueling the Sun,  

an option that could make it possible for us to  keep Earth going for trillions of years to come.  If you want alerts when those and other episodes  come out, don’t forget to subscribe to the channel   and hit the notifications bell. And if you  enjoyed today’s episode, and would like to   help support future episodes, please visit our  website, Isaac Arthur.net, for ways to donate,   or become a show patron over at Patreon. Those  and other options, like our awesome social media   forums for discussing futuristic concepts,  can be found in the links in the description.  Until next time, thanks for  watching, and have a great week!

2022-10-16 12:15

Show Video

Other news