Interstellar Expansion WITHOUT Faster Than Light Travel

Check Out Space: The Longest Goodbye on the PBS KZbin channel: • The Psychology of Spac...
Watch Space: The Longest Goodbye on Independent Lens: pbs.org/longestgoodbye
In the far future we may have advanced propulsion technologies like matter-antimatter engines and compact fusion drives that allow humans to travel to other stars on timescales shorter than their own lives. But what if those technologies never materialize? Are we imprisoned by the vastness of space-doomed to remain in the solar system of our origin? Perhaps not. A possible path to a contemporary cosmic dream may just be to build a ship which can support human life for several generations; a so-called generation ship.
Sign Up on Patreon to get access to the Space Time Discord!
/ pbsspacetime
Check out the Space Time Merch Store
www.pbsspacetime.com/shop
Sign up for the mailing list to get episode notifications and hear special announcements!
mailchi.mp/1a6eb8f2717d/space...
Search the Entire Space Time Library Here: search.pbsspacetime.com/
Senior Creative Producer (ITVS): Andrea Bloom
Creative Director (ITVS): Carol Paik
Executive Producers (ITVS): Carrie Lozano, Lois Vossen
Vice President, Marketing and Communications (ITVS): Lisa Tawil
Original Production Funding Provided By:
The Corporation for Public Broadcasting
Acton Family Giving
John D. and Catherine T. MacArthur Foundation
Ford Foundation
Wyncote Foundation
National Endowment for the Arts
Hosted by Matt O'Dowd
Written by Christopher Pollack & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini & Stephanie Faria
Directed by Andrew Kornhaber
Associate Producer: Bahar Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
Executive in Charge for PBS: Maribel Lopez
Director of Programming for PBS: Gabrielle Ewing
Assistant Director of Programming for PBS: John Campbell
Spacetime is a production of Kornhaber Brown for PBS Digital Studios.
This program is produced by Kornhaber Brown, which is solely responsible for its content.
© 2024 PBS. All rights reserved.
End Credits Music by J.R.S. Schattenberg: / multidroideka
Space Time Was Made Possible In Part By:
Big Bang Sponsors
First Principles Foundation
John Sronce
Bryce Fort
Peter Barrett
David Neumann
Alexander Tamas
Morgan Hough
Juan Benet
Vinnie Falco
Quasar Sponsors
Mark Rosenthal
Grace Biaelcki
Glenn Sugden
Ethan Cohen
Stephen Wilcox
J Tyacke
Mark Heising
Hypernova Sponsors
Daniel Muzquiz
Michael Tidwell
Frank Plessers
Chris Webb
David Giltinan
Ivari Tölp
Kenneth See
Gregory Forfa
Alex Kern
Bradley Voorhees
Scott Gorlick
Paul Stehr-Green
Ben Delo
Scott Gray
Антон Кочков
Robert Ilardi
John R. Slavik
Donal Botkin
Edmund Fokschaner
chuck zegar
Gamma Ray Burst Sponsors
Jordan Young
Arko Provo Mukherjee
Mike Purvis
Christopher Wade
Anthony Crossland
Grace Seraph
Parliament
Stephen Saslow
Robert DeChellis
Tomaz Lovsin
Anthony Leon
Leonardo Schulthais Senna
Lori Ferris
Dennis Van Hoof
Koen Wilde
Nicolas Katsantonis
Joe Pavlovic
Justin Lloyd
Chuck Lukaszewski
Cole B Combs
Andrea Galvagni
Jerry Thomas
Nikhil Sharma
John Anderson
Bradley Ulis
Craig Falls
Kane Holbrook
Ross Story
teng guo
Harsh Khandhadia
Matt Quinn
Michael Lev
Rad Antonov
Terje Vold
James Trimmier
Jeremy Soller
Paul Wood
Joe Moreira
Kent Durham
jim bartosh
Ramon Nogueira
The Mad Mechanic
John H. Austin, Jr.
Diana S Poljar
Faraz Khan
Almog Cohen
Daniel Jennings
Russ Creech
Jeremy Reed
David Johnston
Michael Barton
Isaac Suttell
Oliver Flanagan
Bleys Goodson
Mark Delagasse
Mark Daniel Cohen
Shane Calimlim
Tybie Fitzhugh
Eric Kiebler
Craig Stonaha
Frederic Simon
Tonyface
John Robinson
Jim Hudson
Alex Gan
John Funai
Adrien Molyneux
Bradley Jenkins
Amy Hickman
Vlad Shipulin
Thomas Dougherty
King Zeckendorff
Dan Warren
Joseph Salomone
Patrick Sutton
Julien Dubois

[@pbsspacetime]

Hey Space Timers! If you enjoy thinking about the realities of human space travel, then check out the documentary Space: The Longest Goodbye. And if you head over, let them know (politely) that Space Time sent you! kzbin.info/www/bejne/g4WQoYlqbb11f5Y&ab_channel=PBS UPDATE: Currently the YT Link is only accessible in the US. We're working to see if we can get full international access.

[@osmosisjones4912]

What about traveling as fare back in time as time is moving forward with . Moving at light speed with warp and thrust molecular vibration. Against The rotation of galaxy

[@utube7930]

No worky linky

[@frogz]

dont make it app ONLY, plenty of people would happily go to a pbs webpage but wont install another app just to view videos

[@cyanah5979]

Video not available

[@geroffmilan3328]

"This video is not available" is what I see when clicking the link

[@kapsi]

What I never see in discussions of long time space travel, is how to keep machines going for hundreds, thousands or more years. Everything eventually breaks down from usage, and you'd have to keep many spares, or manufacture needed components on the ship, which also seems hard to do. Here in current reality, it's a miracle that Voyager 1 still works (barely) after 50 years, and that's a super simple machine, compared to a generational ship to Alpha Centauri.

[@Drew_goo]

I have heard capturing asteroids can provide material for an advanced 3d printing machine, possibly two for when one needs a part replacement

[@Giantcrabz]

easy. Make the whole ship out of Gameboys and Nokia bricks

[@catmacopter8545]

Thats really interesting!! I would think that a lot of the materials could be recycled from.... Human waste maybe? That takes care of the carbon, but the copper i dont know. Very cool question!

[@SebastianKrabs]

You need 10x of all systems in reserves for repair. Making the ship larger for storage... complicating the systems .... Requiring additional parts for repairs...#DoomLoop

[@randar1969]

Eventually yes, but our experiences here a skewed as well , a factory that operates for profit will not design things to last forever instead it will design to break down faster even. Want an example here lightbulb source wiki 'The world's longest-lasting light bulb is the Centennial Light located at 4550 East Avenue, Livermore, California. It is maintained by the Livermore-Pleasanton Fire Department. The fire department claims that the bulb is at least 121 years old (installed 1901)' In this case we will even design to last. How far we can push that when our future depends on it is everyone's guess.

[@savionhathorn6945]

I wonder if the generations who live and die on the ship would feel a little similar to the phrase at the start. Too late to see earth, too early to see the destination.

[@scaper8]

That would actually be an interesting idea for a longer short story or short novella. Open with the "Too late to explore the Earth; too early to explore the stars," and go from there, then close with, "Too late to see Earth; too early to see ProxCent B."

[@arcan762]

Sad...

[@Scorch428]

Even our generational ship of Earth hasnt made it 100 years in yet with nuclear weapons :P

[@Ylyrra]

@@scaper8 Pretty sure I've read a few short stories with that premise during the wave of "new hard sci-fi" of the early 2000 to 2010s, can't think of the titles though I'm afraid. Probably Charles Stross or Ken MacLeod or someone of that era. Alastair Reynolds also did a bunch of novels featuring around exploring slower-than-light travel and the social ramifications.

[@SolaceEasy]

The plan would be to keep the mutinous middle generations properly drugged.

[@Maladjester]

"We'll have to have a society based on teamwork, harmony, and mutual respect." Well, there goes that idea.

[@OrosTheAvengerX]

Societies like Japan could probably do it. Homogeneous and high-trust.

[@gfries4906]

@@OrosTheAvengerX japan is not "high trust". they have made exclusively-female train cars due to the staggering rate of SA. japanese workers are overworked, underpaid, and depressed. its also rare for a homogeneous society to stay intact. there will be outcasts, and those who deviate from the norm.

[@8ManFan]

Another issue, especially with the 6000-year trip: The first generation or so will have attachments to Earth and the motivation and training to keep things going. A few generations into it and it'll be, "What's Earth?", "The heck with future generations, what about my needs?", and "Dad, I don't want to be an engineer, I'm an artist." Chaos Theory and Murphy's Law are undefeated.

[@henryfleischer404]

That's why I think the ship would need to be extremely big. Over 10,000 crew and passengers.

[@MrCmon113]

Those are stupid examples, but in general the concern with mutation is relevant. And mutation can happen whether you send biomatter or artificial agents or simply people.

[@brandontylerburt]

@@henryfleischer404 The number of crew necessary is difficult to gauge, but considering that maintaining a baseline of happiness, psychological health and commitment to the mission is so vital as to render the distinction between "crew" and "passengers" meaningless, that number would need to accommodate artists, poets and visionaries among the ship's inhabitants without considering a life's devotion to the arts as some kind of failure when compared to that of an engineer, and to assimilate the tangible and intangible fruits of that devotion ranging from new symphonic compositions and theatrical productions to more palatable ways of preparing mealworms and improvements in propulsion efficiency.

[@etienne9747]

you need religion. you get far with that, even if atheist dont like it

[@sprolyborn2554]

​@@MrCmon113How is that stupid? That's exactly what would happen. Why would the 4th or 5th generations have the same motivation or drive of the 1st that actually got to physically see what they were trying to preserve?

[@billyfugate4823]

One of my favorite things to think about is a generation ship arriving at their new world only to be absolutely baffled by finding an even more advanced human civilization because FTL was figured out during the generation ships journey

[@jasonp7091]

I read a short story about that. There were three people on the ship in cryo sleep. They would wake up every 50 years or so, make sure everything still worked, and go back to sleep. One guy woke up to alarms and saw a burning spaceship, but couldn't do anything about it. When they arrived, they found the planets already colonized, and their arrival had been predicted. The burning ship had tried to stop and pick them up but something had gone wrong. The crew spent a little time there but then were able to go back in time to the earth in the past again.

[@Arquinas]

@@jasonp7091 "Yeah we thank you for your service but it wasn't really needed. Here, you can go back if you want. The future is safe and secure." "Oh ok..."

[@azambon]

@@jasonp7091 It's intriguing, do you remember its author and title?

[@WastelandSurvival2]

this happens in a quest in Starfield, you find an earth colony ship that got lost & arrive to find the entire solar system is full of people already that created a faster technology

[@DougHoffman]

@@WastelandSurvival2 Worst. Quest. Ever.

[@Feefa99]

What we need is lots of spice

[@VolkerHett]

And this is only available on Arakis and we need FTL to get there.

[@noellenn2122]

Five spice is 5x better than spice

[@TehJumpingJawa]

@@noellenn2122 Even if it's old?

[@WolfeSaber9933]

Or use a warp manifold to generate the vast amounts of energy need to run the advance systems necessary to warp the space-time fabric.

[@nonojustno1766]

​@@noellenn2122does that mean KFC is faster than warp factor 5?

[@eirrenia]

Realistically, I think our best first step would be building space colonies/stations. Once we have those working reliably we can start thinking about generation ships.

[@noiJadisCailleach]

Children of Time by Adrian Tchaikovsky. Multi-generational ship? Check. Traveling to another world? Check. Disasters happening en route? Check. Humongous sized ship? Check. Psychological stability issues due to environmental conditions? Check. Ship has AI? Check. If the things in the vid somewhat intrigues you, I highly recommend that book!

[@KaichouClips]

Great recommendation. The ins and outs of generational ships are very well thought out in that series, along with what could happen before and after the journey. Adrian Tchaikovsky is also great at showing development in terms of biology, psychology, culture, etc.

[@colonagray2454]

Everything that man writes had so much depth and world building that im yet to read a book I dint like. Really makes you look at things. Children of time was wild

[@paragsatyal6891]

Thanks! This is going to be the next book I read, I haven't read fiction in a while! Also seems like it (or atleast the broader concept of multi generational spaceship would really make a good game.

[@davidharvey3743]

Sweet Child of Time by Deep Purple. The rest? whatever you said.

[@addisonmartin3200]

The Gilgamesh wasn't really supposed to have an AI... let alone a couple dozen babbling half-born AIs.

[@TehJumpingJawa]

Given how accurate Humanity's prior estimates have been for future space endeavors, I'm confident that 30 year countdown would be just long enough for us to realize we'd need another 70.

[@Briskeeeen]

And then we need another 90 after that

[@anonts5050]

Well we finally have the technology for the moon :o)

[@PaulZyCZ]

We were supposed to have Enzmann ships a decade ago, based on how Apollo was going before the Oil crisis. :)

[@tunnfisk]

Just enough time for us to greet the Trisolarans with open arms. (we became extinct)

[@h14hc124]

Those trying to build the ship would be under constant attack from those screaming fake news, and who want to divert all the funding away.

[@SmartMaterial]

I predict future colonists will be groups of cells in a petri dish.

[@Pidgey95]

Wouldn't be that bad after all. Letting some organisms colonize a planet so that us humans might disappear but at least know that some life forms would survive

[@MichaelDeHaven]

Or send frozen embryos that are raised by advanced robots after terra forming. But in the end it'll likely just be a slow expansion of livable space habits. After Sol fills up, or gets too crowded, just move some out of the system. They'll have the systems, culture, etc. All they really need is some propulsion. They don't really even need much of that. A medium size group orbiting a small resource body could probably make the transition to another star system fairly easily. Once there they can just start the process over again.

[@ryanhouston2437]

Maybe I've had one too many whiskeys but this is brilliant. Maybe it's where we came from.

[@freebreezy2k155]

Yea, frozen embryos grown when the ship is 20-25 years out from destination seems simpler than trying to keep generations of humans alive, sane, and motivated on a ship for thousands of years. You'd just need to keep the ship and AIs/robots working for thousands of years and then only raise, teach, and feed a single generation instead of 200+.

[@mcblaze1968]

Algorithm in a chip.

[@sciteceng2hedz358]

Remember Spacetime, a common mistake @3:51 : cryogenics is not the technology that froze Hans Solo. That's cryonics. Cryogenics is the study of production and usage of really cold non-biological material, like liquid H2 and O2 rocket fuels and cooling the magnets in the LHC.

[@bannor99]

I think that's a common mistake because most assume the "genics" part to refer to biology

[@krowland7584]

6,300 year travel is a comically long mission timeline. Though I think this could be a fun and thrilling sitcom.

[@markcentral]

The existential threat scenario is the only one where this analysis makes sense. If this wasn't the case, you'd expect in the 6400 years it takes the slower ship to arrive, humans will devise a much faster form of propulsion -- and so the second or third ship they send will overtake the first one and get there first. Imagine the feeling of being on spaceship one, arriving at the destination, and discover there's been an existing human colony there which arrived 5000 years earlier 😂

[@MisterZimbabwe]

Yeah generation ships are a last resort method of space travel. I know I certainly don't want to be stuck on board a sweaty cramped ship my whole life.

[@JMurph2015]

​@@MisterZimbabwe what makes you think it would be sweaty or even cramped? In building a generation ship, you basically need to pack up a small part of Earth's biosphere and put rocket engines on it. It's going to be large one way or another.

[@shipwreck9146]

It's kinda terrifying to think about forgotten generation ships. I'm sure there are some in space, (non-human of course) and there's probably even some cases of Donner party type situations in space. Think about the amount of information we lose over a period of 1000 years. There's little chance that we'd remember sending a specific ship. Eventually archeologists might find record, and then we'd go looking for the ship to see if it still exists. But more likely, we'd just assume it was lost.

[@hollownation]

Even with the short 140 year journey this could still happen and the colony that is already there would be far more evolved the people on the ship would be a relic of the past. Imagine some traveler’s in 1880 on there way to America got shipwrecked and stayed hidden on an island till now it would be like time travelling and not in a good way.

[@DrDeuteron]

and they're building a generational ship to GTFO.

[@stevesmith4600]

One of the concepts missed is "not putting all eggs in one basket". If the only constraints are time and technology, and not costs, resources and volunteers, then we're going to have to launch a number of these colonizing ships, just to increase the odds that one succeeds. Multiple ships with communication between the ships may help out with some of the human, psychological challenges too.

[@Comicsluvr]

Another advantage of this is that ships can trade people (for a better gene pool) as well as spare parts. If they take slightly different courses, but can still rendezvous in-transit, then you get the best of all worlds.

[@ristags]

This is actually a really great idea

[@jakublizon6375]

"Hey so, I found another job. Giving my 2 weeks.". Boss: Uhhhh....

[@leejamison8436]

One way to explore these ideas is to study what can be discovered of Pacific islanders. Small groups set out on long journeys into the unknown, found islands and established some richly independent cultures.

[@thebourgeoispunk]

When you stop to think about it, Earth is a pretty great spaceship except for that last part of figuring out how we’re all supposed to live together. that’s the hardest to figure out.

[@eustab.anas-mann9510]

Duck "Earth"

[@Ylyrra]

Eventually all technical problems simplify into social problems. By that I mean they "complexify".

[@logancatron2239]

Capitalism has no answers for the problems it creates

[@SebastianKrabs]

It's called "Spaceship Earth", an old concept.

[@Hector-bj3ls]

There's a Chinese film about it. It's ridiculous, but a fun watch.

[@user-jq4fk3wb4u]

Going towards Proxima Centauri to escape from the tri-solarians seems like a bad idea...

[@ObjectsInMotion]

Its so crazy they'd never expect it!

[@chr1styn806]

Glad I wasn't the only one who thought that

[@EebstertheGreat]

Pull the old switcheroo. By the time they realize we've colonized their planet, they've already left to colonize ours. What could go wrong?

[@briondalion3696]

@@ObjectsInMotion It's the move they'd least suspect, and we wouldn't need to worry about them following us. They wouldn't want to drive home at 1% the speed they're used to

[@danm9006]

How about the Borg? Cylons?

[@gewinnste]

One issue Matt didn't mention is the _energy problem_ : In fact, if all the recycling necessary would be improved to at least 99.9(9?)%, then energy would be the only limiting resource. It's difficult to gauge whether a fission reactor would be suitable (lifetime of the reactor etc.) - But regarding the required fissile fuel, let's estimate the needed mass: Upscaled from the ISS, 500-1000 crew members would need very roughly 10 MW, but upscaled from a Virginia Class nuclear submarine, 500-1000 crew members would need ~115-230 MW. Most of the energy in a nuclear sub goes into propulsion, but then again, maybe almost as much (or even more?), fraction-wise per crew member, would be needed to keep homeostasis (growing food etc.) in a generation ship. So let's semi-optimistically say 100 MW for 500-1000 people. That would amount to very roughly 500-1000 tons of ~30% enriched uranium (nuclear subs use >20% enriched uranium, >50% would maybe be too dangerous (?)) for 6000 years for 500-1000 people: 1 kg pure U235 --> 24,000,000 kW/h = 86,400,000 MJ (~86 TJ) --> 864,000 seconds at 100 MW = 10 days --> 36.5 kg/year --> ~220 tons 100% U235 for 6000 years --> 730 tons 30% U235 for 6000 years. If that could be stored as one giant cube (which it won't), it would be a cube of edge-length ~3.4 meters, so very manageable. In reality the space for storing the equivalent in uranium rods would be a lot larger, but it's certainly not a deal-breaker (neither volume- nor mass-wise). An unknown factor is the life-time of the reactor though - that could in fact be a deal breaker. 6000 years is ~ 100-250x a regular nuclear reactor lifetime! Then, since fusion is always 30 years away ;-) it might not be an option, but even if, there's the reactor-lifetime problem again. What about solar panels? They only work efficienctly (energy per surface area) close to a star and the vast majority of the trip will be very, very far from either star (Sun and target star), so photovoltaics are under no circumstances feasible: Even at Earth-orbit distance from the sun, 100 MW would require the surface are of a ~700x700 meter square of 15% efficient solar panels and that area quadruples for every doubling of the distance to the sun. I.e. at Neptune that square would need to have an edge-length of 21 km and somewhere in the Kuyper belt of ~100 km edge-length. And that's just 0.05% of the trip to the nearest star! So it looks like we'd need a very, very long-lived fission or fusion reactor or one that can be "refurbished" with onboard resources hundreds of times; Or something like an Epstein drive, but that would bring about the problem of micro-asteroids or just dust grains doing a lot of damage on impact.

[@SergLapin]

Not much time ago we had no clue how to manipulate electromagnetic waves, and here we are with tech indistinguishable from magic. Finding timespace properties and looking beyond may open things unimaginable right now.

[@User-jr7vf]

Not trying to lecture you here, but this is a false analogy. We didn' know how to manipulate electromagnetic waves at a time when we hadn't even discovered them in the first place. Not long after finding out about them, we figured a theory which has been consistent since the time it was put together. As for space-time travel, we have Special and General Relativity, and they forbid faster than light travel, unless you have exotic matter/energy. It is not as if we haven't figured how to manipulate space-time, rather we just CAN'T do that (in a classical-macro level).

[@SergLapin]

@@User-jr7vf electromagnetism was described using aethir as an exotic medium, and this is after we practically discovered some effects. Same here, we don't know what maybe hiding behind the spacetime, but we can tell that mass is definitely affecting its shape.

[@User-jr7vf]

@@SergLapin but the aether didn't have any influence on what we wanted to do, it wasn't useful at all. That is why it was discarded (sorry for the analogy, specially if you are religious, but.. it is the same as God. We don't need him in any of our theories, so as far as Physics is concerned, he doesn't exist. Same for the aether.)

[@SergLapin]

@@User-jr7vf how do you know what you need from unknown physics? Aethir was discarded when the theory of electromagnetism was well developed and much more details were revealed. Without all that we would be unable to comment on the KZbin. Did Mr Maxwell need KZbin? Most likely not.

[@User-jr7vf]

@@SergLapin but the thing is, the physics of electromagnetic waves was not unknown in the late 19 century. Maxwell had put together the equations that came to be known as Maxwell's equations, and many interferometer experiments were being carried out, most notably, the experiments by Fizeau, Michelson, and Morley. The theory itself didn't predict an aether, it didn't require one, and an aether was never detected in experiments. That led the Physics community (after a long time of struggle) to discard the concept of an aether altogether. With regards to space-time travel, the theory does require something that is impossible (as far as we know) to obtain, which is exotic matter.

[@DobromirManchev]

Thinking about a 6000 years journey is absurd. Imagine how much humanity has changed on Earth in the last 6k years. The countless discoveries, wars, diseases, struggles and things... it's mindboggling. There's absolutely no way that you can get a tiny set of people, stick them on an isolated hunk of metal for 6k years and expect it to work. Tbh, they'll probably not even last 20 years.

[@Rampart.X]

I'd go nuts after two weeks.

[@ThePainqT]

This progression will not go on forever. We will hit stagnation eventualy, bcs of a war or simply not having enough resources.

[@istvanvincze7411]

@@ThePainqT Most of human history has been stagnation, actually. Our rate of progress has been exponential; Most of the things we have ever known were invented in the last 200 years. And the overwhelming majority of the things we know from before then were invented the last 200-800 years. And if we look at our evolution; in the prehistoric times humans were cavemen for what could be a mind boggling 200.000 years. Humans are no strangers to stagnation.

[@ProtoAlpha]

lobotimize them and use implants to give them back the functions 6000 years later. It's far more easy than you guys make it out to be😅

[@invisiblekincajou]

Inside closed starship you will not have too much things to discover. And crew will divide to "normies" and "mutes" very soon... :)

[@Roxor128]

One aspect of the generation ship: it'll need to be designed for constant maintenance, rather that just longevity. You don't want something to last so long that the crew forget about it. You want something that'll last a reasonable amount of time and can easily be replaced when it wears out. Design all your parts to last ten years and be easily recycled into new ones, and they'll stay on the crew's mind down the generations. And there's another side of things: the ship will need to include a complete industrial base capable of manufacturing anything and everything, plus raw materials to do so. If you're going to be colonising a place that far away, you'll need to be able to make everything from day one, because there's no way to get new supplies in any sort of timely fashion.

[@m.scottford9877]

I jumped into the comments to make this point as well. Nice to see another mind agreed. I'd like to add that some tools and systems needed to bootstrap resource gathering once the mission lands would need to be part of the mission payload. Small hand tools will not be adequate to jumpstart a mineral mining operation once the crew arrives at their destination. And that materiel would need to either be packaged in a way that would ensure its preservation or it would need to be regularly examined to look for degradation.

[@Roxor128]

@@m.scottford9877 As long as the ship includes the necessary industrial capacity and raw materials, it doesn't need to include every piece of equipment the colony will need, as the crew can make it along the way. They do have the time, after all.

[@cherriberri8373]

1. Why would longevity be a bad thing? You suggest those on the ship might forget as really the main reason for this, but... I'm sure you yourself have ways of reminding yourself of things you don't need to do very often. 2. You wouldn't need to carry everything one would need to Jumpstart industry, as plenty could be built themselves, just the more complicated things and necessities.

[@jumboegg5845]

Exactly my thoughts even just to colonise Mars. People dont understand the complex and heavy industrial machinery required to build and repair even simple things, let alone the machinery and equipment. Just a basic lathe weighs many tons.

[@Roxor128]

@@cherriberri8373 There's a difference between "not very often" and "last done by your grandpa when he was your age". If something needs replacing ever ten years, each generation of engineers will have to replace it a couple of times. If it lasts 50 years, you'll have entire generations that never needed to fix it, and running the risk of the knowledge being lost, and having to rediscover it could take too long, jeopardising the survival of the ship.

[@Charity4Orphans]

So like... I love this channel because you answered my question in logical mannerisms. My brain is always racing and this channel keeps me grounded in sanity.

[@marceloliveros1057]

The possibilities for realistically sustaining life in an interstellar trip are daunting and feel highly unlikely for either the short and long trip. Humans are amazing and continue to demonstrate an ability for greatness, but I still don’t trust us because of our propensity to want to go stray. All you need is one “crazy” during this fantastic trip, for everting to just fall apart. And trust me, if our history is a sign, then we can count on plenty of “crazies” to screw this up. Let’s just focus on restoring, protecting, and preserving our lovely planet!!

[@erics3317]

There's an ethical side to this discussion that I think is just as important to explore as the feasibility of being able to pull all of it off. The first generation will, presumably, be volunteers, and that is fine. But every subsequent generation has been forced into what is likely going to be a dismal existence without any say in the matter. At some point there will be no surviving first-generation passengers and the ship will be filled with people who only know of living on a planet through second hand sources. It will be important for the success of the mission to try to understand how these people might react to being in that situation. I suspect there will be a lot of resentment, which will not bode will for the successful completion of the mission.

[@danielh.9010]

Also, when systems degrade or fail, the living conditions will degrade as well (or even fail catastrophically). I imagine it might be hard to replace all failed parts. I have a hard time imagining a ship that is not a death trap. Also, sabotage will be easy and easily fatal for the crew. I wouldn't even expect that the crew will survive the first generation.

[@sprolyborn2554]

That's a moot point as that's already commonplace and accepted here on earth. Nobody asked to be born and nobody requested the conditions in which they are born. There is some resentment for it but people work with what they were given anyway. So there is no point in trying to take it into account. Nobody asked to be born on that spaceship just like how nobody asked to be born into mining blood diamonds deep in the CAR.

[@k_a_bizzle]

Sounds just like being born on earth😂

[@leejamison8436]

Pacific islanders seem not to have thought their existence bleak.

[@austinbeige]

Essentially this video outlines why we aren't going anywhere.

[@timl2k11]

Exactly. We are stuck here on spaceship earth for better or for worse.

[@earthwormscrawl]

I work in the semiconductor industry and the failure rate of electronics could provide reliability fo a 140 year trip with the appropriate redundancy, but an entire semiconductor and electronics industry would be needed for 3,600 years.

[@ProfShibe]

@@timl2k11well definitely not stuck on earth, but in the solar system for a while

[@mpwilso]

​​​@@earthwormscrawlI feel technology isn't the main barrier here but rather ego and holding on to free will. Meaning our nature doesn't favor a Noah's ark scenario of populating the cosmos.

[@egalanos]

It's why AI/robotic probes will do the travel instead. The complexity and economics will dictate that. It seems more likely that instead of transporting our bodies, that we would develop methods of creating & transmitting digital representations that could be run at the other end.

[@Star_Skiing_Starskski]

The documentary listed is phenomenal. Thank you so much for exposing me to it.

[@markrix]

I enjoyed every minute of your productions over the years, the free form 'drink n discussions' where the best. Ty for taking time to transfer this knowledge.. keep being great, along whatever path you take.

[@foxdavion6865]

One story that explores generation ships is Knights of Sidonia. They have been on a generational ship for so long that not only had they forgotten their past, they have no idea what their destination is supposed to be either. So instead they live in constant fear of an enemy they believe is trying to destroy humanity and let that fear control them.

[@NeostormXLMAX]

also the side story aposimz, shame it got canceled and rushed

[@goldentrout4811]

Gaunaaaaa!

[@maciejbala477]

meh, that wouldn't happen with digital archives. i guess it could if crazy conspiracy theorists take over

[@michaeljurney8354]

Having fun imagining the first generation to make planetfall, feeling longing and nostalgia for the good ol days when they traveled the stars, and romanticizing the lifestyle that used to be.

[@oberonpanopticon]

So they refuel and half the crew goes on to the next nearest star! The cycle repeats for millions of years until the entire Milky Way is alive! And then, we turn our eyes to the universe at large…

[@athrunzala6919]

There is a sci fi series called "Ascension" that covers some of the social dynamics

[@emceeboogieboots1608]

After a couple of generations spent in front of floating volleyball therapists, and living in VR, we have to ask the question "Will they even want to live outside again?" "It's all yucky and dirty down there!"

[@Landaar1]

@@emceeboogieboots1608 I thought the same thing. Leaving the ship for a planet might even feel scary and dangerous. Better to stay in the safe well known environment of the startship! That might be something the 200th generation of the ship might think.

[@myuzu_]

​@@emceeboogieboots1608there are always those who want to leave their current environment for something new and different

[@johntomlinson2323]

I loved this episode. You basically just walked us through the synopsis of the awesome show, The 100!

[@zacharywong483]

Absolutely fantastic video, as always!

[@Nightscape_]

Isaac Arthur's videos on generation ships are really good.

[@daikucoffee5316]

Future women aren’t real

[@dallassukerkin6878]

I was wondering if these channels were aware of each other, aye. I am sure they are given the subject focus of both.

[@rodrigojimenez3965]

@@dallassukerkin6878 I think Matt did shout out Isaac Arthur´s channel in an episode a few years back. I was very glad to hear it

[@ToxicityAssured]

Most of his videos are top notch!

[@athrunzala6919]

There is a sci fi series called "Ascension" that covers some of the social dynamics

[@Perserra]

Otherwise known as 'crawl-onizing the galaxy'. Issac Arthur has a great video on this too.

[@manw3bttcks]

I'm skeptical because the slower you go, the worse the maintenance problems get. Just making a microchip takes a fab that takes many acres, so how can you keep a ship working for decades without any new parts and just the ones you can carry along.

[@Perserra]

@manw3bttcks First, that just slows down the pace of expansion. Maybe you have to stop and develop a colony for a couple decades before you feel confident you have enough infrastructure to move on. Second, this assumes modern technology, or not much higher. With advanced additive manufacturing capabilities, you can make any component you need out of basic raw materials, or even disassemble components to transform them into something else.

[@ozzy6852]

@@manw3bttcks I think that's why generation ships, if they are ever built, would have to be absolutely massive and would make them infeasible as a last ditch escape options that is so often depicted in science fiction.

[@ivoryas1696]

​@@ozzy6852 You see, that's one of the _neat_ things about Mr. Arthur; he acknowledges that making a last ditch fleeing of Earth _virtually _*_never_* makes more logistical sense than fortifying, adjusting, or even moving the planet as it is now. Earth is where we're made for, and chances are slim that a colony ship or structure would be guaranteed safety from whatever was able to take it out...

[@JaydragonM]

What if at any one time for example we could have 4/7 members of the crew in a medically induced coma and cooled to low temperatures. That way their metabolism runs more slowly. When we wake people up from the coma, they spend 3 days on working, excercising, sports, and recreation. And instead of keeping them at 1G we keep them at 1.1 G or 1.2 G. That way we combat/prevent muscle atrophy. That would drastically reduce food and water requirements without needing to develop true cryogenics.

[@Articulate99]

Always interesting, thank you.

[@greenfeller]

"Quite naturally, tasks PBS spacetime with..." is the best madlib I've heard in a while.

[@davidcerutti8795]

2:58 But if the Trisolaran fleet is coming to us, why would we try to colonize one of their planets?

[@marcusliu9782]

It’s called base trade

[@davidcerutti8795]

@@marcusliu9782 Always a good move to harass your opponent's natural.

[@RocketPropelledMexican]

Careful, the UN is gonna shut you down for promoting escapism

[@apokatastasian2831]

to eat their cheetos

[@skaiaks8934]

Power move, they surely wouldn't expect us coming to them

[@donald-parker]

6000 years living on worms and yams. Where do I sign up!

[@grooverkitty]

lol :D

[@cassert24]

The video feels like screaming that "forget it."

[@Sparkyicus]

Are we not forgetting the fact the ship could also carry 1000s of frozen fertilised eggs in a relatively smaller space to offset concerns with genetic diversity; and a form of cryogenics to reduce life support demands. These embryos could be “hatched” in artificial wombs (Sheep are already being done so now) as the ship neared the star. Educational courses created in VR would also give the younglings all the knowledge required to build a new settlement from scratch. A smaller caretaker crew could man the ship and hatch occasional embryos or clones to replace them as they aged.

[@SimonClarkstone]

Or the DNA could be stored as computer data. If it only need to be accessed slowly you can store data even more densely and durably than nowadays. You could offer huge numbers of people the opportunity to have genetic descendants even if they personally can't leave Earth.

[@pawelstuglik4737]

Indeed, also the crew of the ship wouldn't necessarily have to reproduce via their own offspring. They, too, could use embryos from the bank.

[@mvmlego1212]

There's a movie from 2019 called "I am Mother" with a similar premise--though its setting is post-apocalyptic rather than outer space. It has good acting and visuals, but the large-picture story isn't very cohesive. I don't think I'd recommend it to a general audience, but you might enjoy it.

[@d_andrews]

This was the "plan B" option in the film Interstellar

[@Deadlyish]

True, but you do still need a large enough caretaker population on the ship during the 6000 year flight to keep the ship maintained. 100 or more people maintaining a ship hundreds of times larger than the ISS would probably work out to the same requirements regardless of whether they brought extra frozen dna too

[@esurfrider7687]

I think a generation ship would probably be a collection of human frozen embryos maintained by autonomous robots, they would be revived and incubated several years before the journeys end, the humans would be raised by ai robot parents and taught lessons required for their survival on the exoplanet. That would be pretty cool and I think it would be very effective strategy to populate exoplanets

[@GeneralJarrett1997]

Could even still have a human crew, just one that doesn't need to be massive. We don't quite have artificial wombs yet (though with notice we probably could get them working and reliable pretty quick). Still, with frozen embryos (or just sperm and eggs) you could drastically increase genetic diversity as well as lower the minimum requirement for re-population.

[@kubhlaikhan2015]

Go another step. The ship only needs to contain a machine to assemble DNA. Only after arrival does it begin to assemble life forms based upon the environmental conditions that have to be overcome. Proxima B - and every other poetential destination - will NOT be amenable to human life and terraforming is an absurdity in realistic timeframes. Therefore it is life that must change.

[@esurfrider7687]

@@kubhlaikhan2015 good point!

[@barelyafloatfarm809]

You could also have a base crew with fetuses unrelated to any on board to be used through the mission with planned pregnancies. It does present it's own challenges of caring for the surrogates as they go through the process but mitigates some of the initial drain on resources caring for the large crew.

[@johnsmith-sp6yl]

@@barelyafloatfarm809 the problem is most life on earth is programmed genetically to reject or mistreat other people's offspring. you would end up with a class system of people who had fathers on board the ship, and those who didn't. those who didn't would have many of the same psychological issues as children of single mothers.

[@TheMorpheuuus]

Fantastic interview with a brilliant structuralist realist geopolitician, so refreshing to hear different point of view from mainstream media. Thank you.

[@zoranmitrovski704]

Of all the souls I’ve encountered in my KZbin videos, Matts was the most human.

[@marvinadams4784]

Sending a fleet of generation ships together would make the journey so much more palatable.

[@h14hc124]

As each ship progressively failed and became lost, the rest of the fleet would become more and more alone.

[@AthAthanasius]

Perhaps have two of them exchange young adults to keep up the genetic diversity. Just try not to have the third one be run by a brain in a bottle feeding management executives into the mix as leaders ....

[@solsystem1342]

​@@h14hc124 How would you lose them? They'd be headed in the same direction at the same speed (presumably all lined up together so you don't need multiple physical shields for space debris). It doesn't make sense that you would lose one unless it was intentionally pushed off course because of some catastrophic disaster. I think what they're trying to get across is that allowing people the choice of 5 different communities means that you have some choice on where to live.

[@briondalion3696]

Yeah, I don't want to be on just one solitary ship in space, even with other people on board. It would make me feel infinitely better with a fleet of ships. That way, I could look out a window and not lose my mind....and we could have a local internet up there amongst all the ships and better believe a lot of them would probably want to game in their spare time.

[@h14hc124]

@@solsystem1342 I mean through system failures - life support, disease, war, famine, etc.. we're talking about 6000 years potentially. that's a lot of time for things to go wrong.

[@c0d3r1f1c]

It’s always a good day when there’s a new episode of Space Time.

[@matiaswagner9810]

Indeed

[@pulsar7632]

Indeed

[@flufffycow]

A smaller crew could be used if frozen fertilized eggs were keep in storage for longer then we currently can. The next generation could have children naturally and from that set up pairing until the diversity gets low, at that point frozen eggs mixed in and so forth. As long as the original code is mixed in evolution could continue.

[@mattmaas5790]

Indeed

[@ivocanevo]

It's always a good day when there's a new episode of...

[@ioresult]

2:43 "The Trisolaran" fleet. For people who only saw the Netflix series, it's the "SanTi" fleet.

[@r1b3y38]

6:10, yeah about the only practical use for our nuclear weapons arsenal that I've very heard of.

[@tinu5779]

You forgot a few important points: - Energy: The plants need light and electricity is needed for all the systems. - Repair: Things will break. There must be specialists who can repair things and they need tools and material. - Landing: How will the ship slow down and land on the planet? Every part of the ship could be useful on the planet so better not just abandon the ship. - What things would be helpful on the planet to get a good start?

[@ArgzeroYT]

Energy can be absorbed during travel (but likely not fuel) Repair can be limited by reducing decay in function *(likely costs more energy) For landing you could find some way to modify current reusable rockets to be completely automatic or semi automatic (more resources / energy)

[@happmacdonald]

*especially* energy. I'd like to see stats on how much power we would be able to pull per square meter from our absolute most efficient (thus expensive) solar panels from nothing but deep field starlight in interstellar space. Then divide that by the power needs of such a ship to figure out the absolute minimum solar panel area we'd have to cover the ship in.

[@mshepard2264]

energy for the plants and humans is nothing compared to the power for the drive to get to any percent the speed of light.

[@smitasitara]

We will need to plan for their landing and settlement alo- building, power generation, oxygen and water production equipment, some means of protective dome formation, terraforming...

[@donaldhobson8873]

@@happmacdonald Look. If you have an interstellar spacecraft, you need some fuel with a lot of kick to it, likely antimatter, or fusion. Perhaps fission. Given any of these, you can run the lights off the same power source that runs the engines. And no the lighting doesn't need much fuel compared to the engines.

[@iNeo1]

One aspect of the challenge missing here is the repair and maintenance of the ship. Most machines we have today last less than a human lifetime. Cars and computers don't work much more than 20 years, so a much more complex ship will need a self sufficient way to recycle not only water and air, but also every single one of its electronic and mechanical components. Let's say a computer on board needs a motherboard. The ship will need a machine that can melt down this mother board after and build a new one. That machine will need to be able to rebuild itself too. It will be the spaceship equivalent to eating your own arm in order to regrow the other. Such a ship can't just pull over next to an asteroid and mine new resources.

[@brandontylerburt]

Imagine building a ship like manufacturers built washing machines in the 1940s, before the invention of planned obsolescence. I've encountered a few of them in my life and every one was in good working order, which is not surprising considering that they're so bulky and heavy it's easier to figure out how to repair one than it would be to figure out how to dispose of it. Still, they are solid and imposing enough that it's hard to imagine a household catastrophe severe enough to permanently break one. I'm not saying an old Bendex would survive long in space for generations, but on the plus side, they often have interesting aesthetic details built in.

[@gumbooter5562]

I'm not an AI trumpet blower, but I think physics & material science will be cracked open in the next 5-10 years with some epic AI based discoveries.

[@ivoryas1696]

@gumbooter5562 If we don't mess up the beginning of the revolution in these next 5 or so years... I agree. 👍🏾

[@JonCofer]

Generations of humanity born on a spaceship, learning about earth from VR and getting life advice from a growing AI therapist is the most SciFi thing I’ve ever heard. I love it

[@rreece90]

0:10 the remaining part of that quote: "... born just in time to explore the internet!"

[@AapoJoki]

I thought it was "to browse dank memes".

[@jogeem5480]

@@AapoJoki Same thing

[@SimonClarkstone]

...Born just in time for sub-second comunications to anywhere. If all goes well, our lifetime is the most quickly-connected humanity will ever be. If we run a base on the Moon like we do in Antarctica, it'll be the end of an era. We'll never be all within 1 light-second again. Ever.

[@derekwhidden9730]

Finally, an episode that I can understand about 99% of the data without having to guess. Seriously a cool episode but there are a couple of things you forgot. One is, when our interstellar heroes arrive at their destination, how are they getting to the surface? Now I'm assuming since our generation ship is going to be so large that it will have to be built in orbit, or maybe at a lagrange point like where the JWST is parked. Shuttles will ferry workers and materials, and eventually the crew. So docking bays should be included in the design. These shuttles could be used to explore along the way, in case they find something worth exploring. Then those same shuttles ferry the crew down to the surface when they arrive. Oops almost forgot another point. The crew will need machinery so they can build things as well, since replicators are not a thing. A CNC machine is a safe bet since it can be programmed to cut almost anything. 3d printers would be another. But here is my second point. What if the crew finds out that Proxima b is just like Venus? They get there and it's literally a dead end. They used their resources and fuel up, and made it there, only to find out the planet is too toxic to even mine for more resources. What kind of contengincy plans would need to be developed so that our heroes can continue on instead of being cancelled like Firefly?

[@paddy6295]

Your second point was my first thought.

[@ozzy6852]

You basically answered your first two ponts so for your third point, they might not even care that much. Because depending on how long it took them to get there it could be that there is no one left alive that remembers what it was like to live on a planet. They would more than likely be comfortable with the idea of living in spaceborne artificial habitats because that's bassically what their colony ship is. So without the strict need for an Earth-like planet to colonize any decently sized comet or asteroid becomes an ideal place to stop and either stay or resuply/refuel and move on.

[@ovidiu_nl]

I don't think it's that easy to "explore along the way". That would mean slowing down which would require energy, and you'd need to get back up to speed which would also require energy. Oh, energy and propulsion mass. About the second point: Venus would not even be that bad. You may arrive to find out that Proxima B is lacking one of the 19 chemical elements that are required for life that originated on Earth, like... phosphorus for example. That's not something you can just shrug off and endure. Without phosphorus there is no DNA and there is no ATP. Unless you can make more (in a huge collider for example) your population would forever be bounded by the phosphorus that left Earth in the bodies of the colonists and you'd have to be very careful about recycling every atom of that.

[@theslay66]

There wouldn't be a lot to "explore along the way". Just empty space. The probabibility of crossing the path of something of interest during travel is extremely low. However those shuttles may be invaluable when it comes to maintenance of the ship, or exploring the destination system -as well, of course, for bringing crew and material onto the surface of the planet, and maintaining a link with the main ship that will certainly stay in orbit and get dismantled for ressources.

[@thecodewarrior7925]

One thing I think people always forget is how much insane bootstrapping we’ve done on earth, especially in the semiconductor industry. The sheer complexity and insane precision required for semiconductor manufacturing seems like a huge bottleneck. We would have to bring along all the parts for a semiconductor fab and hope they survive the trip, or somehow survive without new chips until we can build a fab on site. In the end I feel like it might legit be easier to develop this tech for zero g and then live in space habitats. That or a hybrid where a lot of manufacturing happens in orbit or around asteroids, and the final products are delivered to the surface.

[@eamonnfanton2165]

I think the biggest problem that is always overlooked with a generation ship is that those descendents that actually do land on a habitual world will have absolutely no experience off the things and skills we take for granted. Want to grow crops, how do they plough fields? not something that could be taught or passed down while on a spaceship. How do they skin and butcher animals for clothing and food? again another set of skills that will likely be lost on such a voyage. This also goes for carpentry, building homes, mining, metal making and smithing. Taming, tending and caring for animals they might find. Weaving and making cloth. Fishing and hunting. Yes they will have books or their digital equivalent, but there are so many skills that simply not mastered from reading, and its likely they will need many of these skills from day one

[@generic_account2138]

They'll just plant pizza trees and voila!!

[@AfterBurnettAsks]

Plot twist 1 - the radiation renders everyone sterile and there's no one left alive when the ship reaches its destination. Plot twist 2 - when they finally arrive, they are met by fellow Earthlings who have been there for over 100 years as a couple of decades after launch, warp speed travel was invented.

[@wjockusch]

You need to maintain a large variety of human professions in the travelling ship. This raises the needed population considerably.

[@wtspman]

Like hairdressers and telephone sanitizers?

[@denysvlasenko1865]

No, you do not. You just need to carry encyclopedia with technical info.

[@sebastienh1100]

@@wtspmanI love you 😂

[@jogeem5480]

I think the initial 100 is enough to cover the essentials. I'd say most jobs aren't that important for starting a new civilization. Also a lot of knowledge can be stored in a relatively small amount of space on the ship.

[@ip6289]

​@denysvlasenko1865 try to fix any of your home appliances next time it breaks with this information. 😉

[@matthewparker9276]

In adition to insects, a generation ship diet would probably also feature fungus and algae as space efficient crops to grow.

[@maciejbala477]

don't fungi have little nutrients of note though?

[@jahosaphat]

This is the best channel in the known universe.

[@eclairwolf]

if i've learned anything about the feasibility of generation ships from video games it's that the two biggest challenges are ensuring that future generations don't reformat their shipboard ai, and that they never un-thaw any mysterious frozen princesses

[@tr48092]

If the planet is ending, I don’t think constructing 500 space ships, or even 50,000, would be unreasonable. More importantly, I think that the biggest threat to such a project wouldn’t be the engineering challenges of designing, building, and operating space craft for interstellar travel; it would instead be the sabotage as the rich and powerful but unqualified forced their way onto the ships

[@user-fc8xw4fi5v]

"Or the Trisolaran fleet" Nice reference. Great book series

[@georgeashley6643]

A series that has quite literally completely changed how I look at the universe and feel about my own existence in it.

[@lyrimetacurl0]

​@@georgeashley6643 overly pessimistic and dangerous idea

[@georgeashley6643]

@@lyrimetacurl0 who said I meant that as a negative? Since when was introspection dangerous?

[@user-fc8xw4fi5v]

@georgeashley6643 True. The only thing that upsets me was the "reduced light speed" section. Author missed a cool opportunity to discuss how the measured value of light "speed" doesn't change anything because all of our equations and perceptions are dependent on c to begin with

[@NeostormXLMAX]

@@georgeashley6643 its still pretty good for a first contact series, although imo blindsight is much better of a first contact story. the trisolarians are still too "human" the scramblers are literal alien cosmic horrors, not even living but "the structure of the honey comb instead" a literal emergent system that is given life through chance

[@Wroredko]

It seems as though Matt saw the longest farewell and wondered, "What if this, but longer?" And it is a complement, I hope.

[@mrstock7986]

The idea of Generation Ships is one of the major plot-lines in Alastair Reynolds' SF novel 'Chasm City' from 2001. The story chronicles the first ever 5-generation-ship mission to 61 Cygni, interleaved with an interplanitary man-hunt (taking place years after the flotilla's arrival at their destination) and much, much more food for thought. Without giving away too much, i cann tell you that the generation-ship mission doesn't end well. And that, indeed, the mental health of the crew is probably the most critical and most difficult aspect of the whole endeavour. I'd say 'Chasm City' sits firmly in the top-5 of the best SF i've ever read. (Along with the 'Dune' saga and other works by Reynolds, set in his 'Revelation Space' universe.) I highly recommend it. And once you've read it, you'll _never_ want set foot on a generation-ship, i reckon.

[@Fika_Break]

The movie Voyagers was interesting movie about a generational ship. It was a sort of Lord of the Flies in space.

[@athrunzala6919]

There is a sci fi series called "Ascension" that covers some of the social dynamics

[@PaulZyCZ]

The Colony by Rob Grant comes to mind. He's co-author of Red Dwarf, so it's no surprise there are similar tropes. The main character wakes up on the ship by accident, as a head in a jar, far from Earth and surrounded by all kinds of messed up crew. Short novel and fun read.

[@mithrillis]

I suppose an easier but potentially "dystopian" way of handling long interstellar journeys is to carry only embryos on the ship, and grow a new generation cared for and educated by AI & robotic systems as we get close to the destination. A lot of upsides like no stress of interstellar travel, no risk of disease outbreak or ideological drift, acceptable risk if the mission ends catastrophically midway, reasonable likelihood of artificial wombs being feasible in the not so distant future, etc. But it might be very difficult getting approval to raise hundreds of newborns with AI parents in a test run...

[@jonatand2045]

Or just send [only] AIs. They could live and grow in space just fine.

[@zerochan2915]

current technology only allows us to freeze oocyte/semen/embryo for less than 20 years so no.

[@pauljazzman408]

Have you seen the series Raised by wolves devised by Ridley Scott?

[@terdragontra8900]

This is true, but also, there are many bad human parents on earth that have children: at some point of advancement, raising kids by AI would be *more* ethical once the probability of abuse/other bad things is small enough.

[@Magus_Union]

Yeah, the frozen embryo/AI solution would be the safest bet. Either that, or using hollow out asteroids that would contain an entire city sized ecosystem that would take a decade to build post orbital capture.

[@LukaJandric]

Can we talk about propellant? Not sure what exact exhaust velocity / specific impulse of our best future theoretical engines would be, but to get 1kg to 0.1c you would need more than 10 Earth's masses of propellant?!

[@darrennew8211]

Fun story: Voyage from Yesteryear by Hogan. We send embryos to a nearby star system. They grow up without all the culture from here, but with enough robots etc that they build a post-scarcity society. Then a couple generations later Earth sends another ship. Hijinks ensue.

[@NWAWskeptic]

Essentially the ship would have people in charge of landing the ship who learn how to do so without ever once piloting the ship in an atmosphere and by watching training videos and maybe simulators, instead of pilots who have flown other flying objects like planes/helicopters/etc, they’re putting all their fates into the best gamer of their generation.

[@patnor7354]

As if humans will be piloting anything in the far future. I very much doubt SpaceX are landing their rockets by manual control these days.

[@Step_n_up]

... like a gamer winning Le Mans - that happened

[@glasses685]

Going by the way Matt says "Just build a ship that can support human life for several generations" as if it's no huge feat, he must have a badass secret laboratory like Dexter

[@Giantcrabz]

Dr. O' Dowd what does THIS button doooo?

[@WackoMcGoose]

@@Giantcrabz DEE DEE GET OUT OF MY LA-BOR-A-TO-RY!

[@spacechannelfiver]

I'd give it 10 years before they start eating each other.

[@ariochiv]

Yes... it's firmly in the domain of science fiction. The problem is not solvable with current technology in the proposed time limitation.

[@DneilB007]

He’s a theoretical physicist; his brain is his laboratory.

[@ian2372]

Pandorum was a great film and a warning about a generational ship. Also, never eating bugs. Mission over.

[@TheReluctantCoder]

Great video!!

[@michaels.3709]

14:45 - I actually just went and toured Biosphere 2 the other day! While the close-loop experiment is considered a "failure" because the amount of food grown didn't meet ideal calorie levels for the 8 Biosphereians, and the CO2 removed by plants was insufficient (dropping O2 levels from around the nominal 21% in air down to around 14%), they did still remain (relatively) sane and healthy for _two full years_ , which is pretty insane to me. If the experiment were ever conducted again (and a Biosphere 3 were ever constructed), I feel like the lessons learned at Biosphere 2 would help the next iteration achieve a much higher, healthier level of success! If you're ever visiting Tucson, Arizona, it's a must-see location!

[@haileycollet4147]

Seconded on the recommendation! I think the project was honestly a success, in that it was close enough to working that it seems obviously possible at something close to that scale.

[@gptiede]

There was also all sorts of ridiculous politics involved in the closed-loop experiment at Biosphere 2, not to mention many of the people involved were not actually scientists. Considering all of this, I believe that the experiment went quite well, and that it definitely needs to be done again. This time correctly, and with the lessons learned.

[@HeliSal700]

It's interesting that the ethical issue is not considered here. We are essentially 'condemning' several hundred people (or thousands for a 6300-year travel) to a confined space, stripping them of the freedom to choose their actions. This is at least one of the biggest issues. Second, it shouldn't be a problem for four or five generations: How can we ensure that there will be no rebellion? Look at ourselves when we approach an age over 50 or 60 years. There is some sort of resignation to cope with whatever is out there is a strict adherence to what we know, without accepting any change. Then look at our youngest. They always aim to change something. I believe that we can overcome the technological hurdles, but the sociological issues are much larger.

[@matthewona]

A lot of times we always assume that exploration is always targeted towards finding new worlds. If we do generational ships maybe the ships itself become the world and the outer space that we explore is just an avenue for us to extract raw resources to build more space habitats grouped together in the future.

[@iburuma3621]

What if we're sleeping on these ships right now, and all our lives are just taking place inside of a VR simulation to keep us occupied for the thousands of years it takes for us to reach the destination.

[@kevincronk7981]

This feels like Matt just watched the longest goodbye and thought "what if this, but longer?" And I mean that as a compliment

[@djdedan]

Why does lord of the flies keep popping up in my mind while I listened to this

[@ElementalAngelKashi]

interesting tidbit in the game Starfield there is a mission related to a generation ship being sent out before a major technological leap makes travel faster. Basically they arrive after human already got there using the new tech. it is a fun side mission.

[@EliotHochberg]

In addition to using water for survival both for food and water, and for radiation protection, the water could also be valuable for a back up fuel source both on the ship for propulsion, and also potentially for electrical power if you were able to harness heat from the nuclear pulse propulsion as well as Maintaining temperature without overheating within the ship itself. One of the big problems of space travel is radiating heat. Since it’s a vacuum, there is no medium for releasing heat, so you would need massive heat sinks for black body radiation. However, it seems to me you could Somewhat reduce that need by using some of that heat to turn water to steam and run turbines to create power.

[@Noblenote0]

you will breed in the spinning pod. you will eat the bugs. you will be happy.

[@r000tbeer]

How is the ship expected to last 6300 years? That itself would be a deal breaker.

[@glenneric1]

duct tape

[@CoalOres]

There's people on board (hopefully) maintaining it.

[@Kirhean]

One must wonder how realistic a constant acceleration of 1g might be, turning halfway to decelerate at 1g. It'd remove the need for a mechanically complex rotational gravity system, not to mention the fact that over long periods of time rotation will alter the trajectory of the craft.

[@QueenAI-ph1xi]

' propelling by blowing the umbrella' type of concept

[@Nightweaver1]

And once again, both the strongest and the weakest link in the chain would be humans themselves. Remember that this is just to get us to the NEAREST exoplanet. Space is massive beyond imagining, and this really demonstrates how difficult it would be to explore even the local group of stars in our own galaxy.

[@memitim171]

Yeah, in all likelihood the nearest habitable planet is much further away, I don't think this idea can work, there's just too much that can go wrong in 150 years, let alone thousands. And that's before you consider the impracticality of it all and the fact people be crazy, you can select the initial crew but that doesn't prevent them birthing a generation of psychos further down the line...

[@crypto66]

I've always wondered about the continued march of progress in this subject; imagine being the crew of one of the first attempts at colony ships, by the time you arrive at your destination, you're either old AF and/or had to spend your entire existence in your ship. Then another ship produced later with more advanced tech arrives at the same time or shortly after, with inhabitants whose experience seemed like a commute relative to yours. Or maybe your ship spends 6000 years in transit, only to find a colony that was sent out just a hundred years ago.

[@AthAthanasius]

This is a not uncommon trope in science fiction.

[@crypto66]

@@AthAthanasius Can you give some examples? I don't really consume much SF media beyond video games. I'd love to see how it's usually handled.

[@arifbagusprakoso2308]

Considering the scenario in the video, the moment the crews fly out from earth, the catastrophe is starting. There is no more competitor (or even crews' loved ones) afterward. They're all dead sooner than later.

[@AnthonyFlack]

@@crypto66 - One random example I can think of was in Terry Pratchett's "Strata".

[@gustavopolanco6925]

Great video

[@derekbender]

The social aspect may be the biggest hurdle.

[@TheHigherSpace]

The 6300 year journey is funny lol .. By the time they get there earth will be a legend and people will question if it ever existed ..

[@xxxnyanthecatxxx]

If any records will remain at all, as all tech must be recycled and rebuilt mamy, many times by then.

[@christopherrogers532]

Even funnier is what'd happen to any religion that makes it aboard. :)

[@mcwornex2123]

even funnier than both is the war that'll be sparked on earth the moment they try to do this idea (knowing the earth is going to be unlivable). The moment the idea becomes real, countries will launch nuke at each other and civil war will be rampant everywhere.

[@dustanhoff9292]

@@christopherrogers532 There would be born a new ‘prophet’ that claimed he alone was given insight by god, and create additional and likely radical subsets of the old religions!

[@davec3226]

Not too late to explore the depths of the ocean, we've only begun.

[@douglasharley2440]

there's very little of interest in the depths of the ocean...lol, why would we go there?

[@mpmpm]

"Not too late to explore the depths of the ocean, we've only begun.": We will find massive amounts of plastics (at the bottom of the oceans), cluttering up everything there.

[@mpmpm]

@@douglasharley2440 "there's very little of interest in the depths of the ocean...lol, why would we go there?": Oceans are covering 71% of the earth surface. Of course we want to go there, at least to see if we can live there.

[@douglasharley2440]

@@mpmpm lol, there ain't anything down there other than salt water, dirt and rocks, and unimaginable pressure. just because something is "unknown" doesn't mean it's interesting. also, no we cannot live down there...everything a human needs to survive is on land, not at the bottom of the ocean.

[@MrFishyEater]

Why cant we do both 😂

[@scottfranco1962]

Another issue with interstellar travel is it is likely that whatever propulsion method we use, in time a better method will come along such that a newer craft using that would arrive before the previous vehicle does. This tends to reward doing nothing.

[@fleachamberlain1905]

I like mealworms, crickets and garden snails. I didn't enjoy scorpion though. So choose wisely. The former three can be fed on scraps too, so that could be handy.

[@Its__Good]

The more I watch videos like this the more I realise just how little point there is in endeavours like this until our technology becomes way, way, way more advanced.

[@neandrewthal]

Don't worry. Due to the movement of the stars, when the faster ship we just built passes the one we sent hundreds of years ago on its way to the same destination they won't even pass anywhere near each other :D

[@TheMelnTeam]

Automated probes shouldn't be too far off in principle. Much cheaper and fewer engineering challenges, with much lower stakes if some (or even the majority) fail.

[@jimmyholloway8527]

The point of such endeavor is the advancement you mention. The 50-year hiatus of manned planetary exploration is precisely why so little has changed since the 70's and why news of just a new style of EVA suit is seen as significant.

[@Its__Good]

@@jimmyholloway8527 A ton of stuff has changed since the 70s?? There are far more rewarding things that we could choose to set as 'missions' for humanity if we wanted. I'd rather spend a trillion dollars trying to perfect cold fusion than travelling to Alpha Centuri.

[@LabGecko]

The point is that currently any number of very likely disaster scenarios could wipe out all life on this planet. All our eggs are in _this_ basket. Without getting people off it, we won't get do-overs.

[@MorphSenior]

"When the first fish left the ocean they ceased to be fish; when the first humans leave earth for good, they will cease to be human" -a sentence from the three body problem that stuck with me.

[@altrag]

Not necessarily true though. It depends on how similar the destination planet is to Earth. Obviously it needs to be _somewhat_ similar, but small changes in the environment can certainly lead to big changes in the species over time. That is unless the ship itself is different enough from Earth conditions to trigger speciation, but we'd almost certainly do everything we can to either prevent that or - if we know enough about the destination - to have the ship slowly adjust from Earth conditions to destination conditions (modify rotation speed to change "gravity", modify air composition, that kind of thing. In that case we wouldn't really be "human" any more by the time we land, though it would be difficult to pinpoint an exact time when we "changed" as the change would intentionally happen over the course of centuries.

[@MorphSenior]

@@altrag the author actually didn't mean humans would change biologically into a new species, but that the struggle to stay alive on a generational voyage could completely change our society and morality to the point where it wouldn't be compatible with earth civilization anymore.

[@altrag]

@@MorphSenior I can't read the authors mind, but comparing to a fish leaving the water (a very explicit reference to biological evolution) doesn't suggest to me that they were talking about merely cultural differences. Especially since that wouldn't make sense in the first place - Earth has had plenty of cultures that were divided by thousands of years and while we generally didn't get along well when cultures ran into each other, nobody would claim that they're different _species._ (At least not until the eugenicists came on the scene, but pretty much everyone agrees early eugenicists were just wrong - including most modern eugenicists.) My guess is that they were indeed thinking in terms of biology, along the lines of the Martians in The Expanse - ie: some aspect of space travel made the people on board genetically diverge from the humans on Earth. And that's not really _wrong._ Whatever new environment those people end up in will impose evolutionary pressures and if those pressures are great enough for long enough, people there would indeed eventually diverge enough to be called a different species. It just wouldn't be the "first people to leave Earth". It probably wouldn't even be the first people to land on the new planet. Even if the ship adjusted parameters during flight to try and acclimate the crew to the new world, 6000 years just isn't long enough to cause major genetic drift in a species as complex as our own. Maybe some minor drift in things like bone density or muscle mass, but not enough to call them a new species. (Of course the quote is misleading even before that - the first "fish" to leave the ocean was already not a "fish" long before it set foot on land. It would have already needed to evolve lungs - or at least a precursor to lungs - in order to make that first step, which would make it not a fish.) And yes, I'm aware I'm pedanting way too hard on a silly quip :D.

[@adamkral4]

"Maybe there are some gourmet yam and grub recepies just waiting to be discovered" xD

[@tomsamario]

That was amazing!!

[@CartoonHero1986]

Something I find a little funny when talking about space travel and colonizing other planets is in the majority of these hypothetical scenarios we seem to forget to take into account if we discover a planet that is already habitable and with nearly identical conditions to Earth's... unless we are from the same genetic "tree of life" and make up; we won't be able to colonize and live on that other planet. Because of the difference in genetic make up the introduction of 2 alien biospheres on a single planet would result in one eventually destroying or destabilising the other. Long and short of it; either we kill the biosphere on the new planet by introducing a new element it can not handle, or that biosphere on the new planet kills all of us with something our physiology can't handle. In these scenarios from a human's point of view the former is the "better" of the two possible outcomes so long as they brought enough of Earth's biomass in the form of viable plants and animal stocks to replace the former native biosphere once it is dead and sterilised. In the latter scenario we just get a prolonged death that results in us becoming out of place relics and fossils on that planet to confuse the crap out any intelligent life that planet might eventually evolve if there is anything left to find by that point.

[@TheMelnTeam]

I'm not so sure...we don't have enough data points. It's not clear how similar is "too similar" before microorganisms and such become a threat. If stuff is too different from each other, it would mostly interact with physical force if at all. If it's too similar, we might find a scenario more comparable to invasive species situations on Earth - some things from each side compete too well, but neither has 100% of the "most competitive niche" versions. Humans could just immediately die out due to disease. But failing that, they could probably make it work unless the target environment has sentient populations that resist the attempt or some other factor like "turns out humans can't live long-term in gravity even a bit different from Earth's" comes into play. It's probably an academic question...any planet we can reach hasn't turned up evidence of being "habitable" to anything remotely analogous to humans or life on Earth. We'd not be competing with native flora/fauna, we'd be trying to get any flora/fauna to survive off the ship in any capacity at all. If we can trivially colonize Mars, I'd start to believe maybe we could similarly live using another star's energy. I would love to be alive for that tech to be around, but that's probably not happening unless we stop the aging process in our lifetime (I won't bet on it, but I won't turn that down if we manage it haha).

[@CartoonHero1986]

@@TheMelnTeam Very true that at this point this discussion is just Academic as we have no way to test working theories, and the best analogue we have to go on is uncontacted peoples encountering colonists carrying diseases that are novel and extremely virulent to the uncontacted people for a time, and zoological transmission of novel diseases mutating to infect humans. So we can only speculate at this point, I just find it interesting that we tend to be more optimistic about finding and eventually colonizing Earth like planets that are essentially pre terraformed as the easier option for galactic expansion. When the reality is this would take just as much technology, and time/energy to solve as Terraforming "dead" worlds, or building stations or dyson objects; just instead of massive technical engineering focuses to the problem, we'd have A LOT of genetic modification and medical science R&D to focus on instead

[@blobishlybelfer2717]

reminds me of "scavangers reign". this would defidently be a problem, unless we scout the planet and make gentic alterations. we can isolate our food from the enviorment untill we figure out how to eat the native stuff. but consider that the "it's perfectly habitable" assumption doesn't necessarily mean it has its own biosphere. it could just miraculusly have the right atmosphere composition, temprature, and light shielding. it's an unrealistic miracle, but so is an alien biosphere that creates those conditions (before even getting to the problem you mentioned).

[@TheMelnTeam]

@@CartoonHero1986 Agreed on that. Or maybe the worlds with life are even harder, if we're already at feats of engineering like general AI and dyson swarms. At that point maybe you don't live on worlds at all, instead just having the machines strip asteroids and such to build more "generational" ships to orbit a star. It would make a lot more stars viable! If we're at the tech to do interstellar travel somewhat feasibly, this stuff shouldn't be out of bounds most likely.

[@cheffrey82]

Imagine being one of the crew members alive at the end of its epic journey. You've survived the ravages of interstellar space, kept the ship together, are somehow physically and psychologically intact... only to discover that Proxima Centauri b has a surface more hostile than that of Venus. I'd be pretty bummed out by that.

[@lk9650]

On our multi year journey we will need to watch a new episode of spacetime once a week to help us pass the time.

[@danejohnson6035]

Heinlein wrote a fantastic short story about life on a generation ship and how future generations might diverge from the original mission. There's also a role-playing game called Colony Ship which was inspired by the book. If the topic interests you, I'd recommend both.

[@cocodevs]

One of the issues is that what can go wrong will go wrong and with enough time it's highly possible a ship will fail. The best bet is to send out multiple ships, but then we start getting into some fallout territory, only with ships instead of vaults