Journey to Alpha Centauri

Journey to Alpha Centauri

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The Alpha Centauri Star System may be  the closest star to us after our own Sun,   nevertheless the journey there will  require covering a longer distance than   every human voyage ever made before…  combined. To achieve such a mission,   to travel to another star, we will need to  harness the power of stars to drive our ships.  Welcome back to Science & Futurism with Isaac  Arthur, and today we will be looking at how   we will get to our nearest neighboring star  system, Alpha Centauri, what sort of ships and   technologies might get us there, and some of the  misconceptions we often have on this topic from   science fiction and even real modern spaceflight. Some years back we did an episode on Colonizing  

Alpha Centauri and it went on to be  one of our most popular episodes,   and one of our longer ones too. We had to cut a  lot of material to get it down to a reasonable   length for one episode. One of the things we left  out was the trip there, focusing instead on what   we would do when we arrived. We’ve recently  been looking at Interstellar Colonization  

Strategies and there I emphasized that we were  contemplating later scenarios, strategies we   would use as we colonized the billions of  systems in this galaxy, not the first one.  There is a big difference between the  journey Magellan and other explorers   took to try to circumnavigate Earth and the  vastly faster and more reliable trade of even   a couple centuries after, not only because  engines replaced sails on ships. So too,   there is a big difference between the Apollo  Missions, or even the new Artemis missions, and   the trip made by some future spacecraft that might  land travelers on the Moon for a weekend vacation.  I’m not sure we will have reached that point when  the time comes to send people to Alpha Centauri   or not, but it’s hard to imagine we would send  out a colony around another star before we even   had an established presence on a few other local  planets, let alone our own Moon. It is a journey   that will take a large portion of a human  lifetime, or even longer than one lifetime,   and require so much self-sufficiency, redundancy,  and precision that I can’t really see us trying   it – short of some solar system wrecking  emergency – until we had a couple generations   of interplanetary manned missions under our belt  first. And not like our experience going to the   Moon where we did it half a dozen times in a  few years and then waited over half a century   to set foot on it again, which still has not  happened though does seem to be ever more likely. 

So we might want to ask what might make us  try a journey to Alpha Centauri before we   had absolute confidence in our abilities and  technology. We might also ask if we would ever   do a scout mission, manned or unmanned, or crewed  or uncrewed, before we sent a full-blown colony.  Barring an emergency though, it is important to  understand that while we already have many of the   technologies needed for interstellar flight,  these technologies require such a degree of   improved mastery and casual efficiency that we  can’t ignore the differences this improvement   implies about the civilization launching that  ship, or ships. Emphasis on ships, plural,  

both in the sense of sending a squadron or  fleet of colony ships rather than a lone   ark to one destination, and of sending  colonization fleets to neighboring stars   rather than waiting for the Alpha Centauri  Fleet to send back a report of success.  But the civilization with steam engines instead  of sails for their ships is also the civilization   that has steam engines running its factories and  trains as well. Getting from one solar system to   another requires you to check the box on at least  one of the following options: faster than light   travel, extreme energy abundance, artificial  intelligence, super recycling, or the ability   to put people into stasis or freezers  and bring them back to life on arrival.   Check any one of those boxes and interstellar  flight becomes at least somewhat practical.  Now, there are ways we could do it even without  that but if we tried to do it now we would have   to use the Super Orion Drive method, which is a  great big cylinder ship spinning for artificial   gravity powered on uranium, plutonium, or  thorium fission reactions. For this method,   we would need a reactor running power and life  support and actual nukes being fired out behind   it to propel it along, see our episode on  Revitalizing the Orion project for details. 

Now, ships using the Orion Drive Method  are probably the most common type of ship   to be discussed when contemplating travel to  Alpha Centauri outside of science fiction,   although it is pretty common there too.  One of my favorite video games was Sid   Meier’s Alpha Centauri, where you colonize a  planet there after arriving on the UNS Unity,   which I’m pretty sure was meant to be an Orion  Drive vessel. I was very fond of that game,   so much so that it partially inspired our Life  in a Space Colony Series which features the   spaceship Unity in homage to it, and like  many tales of traveling to Alpha Centauri,   it assumes some calamity that collapsed  civilization back home, here on Earth.  Sometimes that’s the inspiration for the mission  and how they were able to get the resources and   cooperation to make the mission happen, but it  is very difficult to come up with a plausible   scenario where some kind of calamity happens,  which only interstellar colonization can help   with. For instance, when we were writing the  Colonizing Alpha Centauri episode 4 years back,  

we had a devil of a time coming up with a scenario  where it would actually make sense to send a   colony mission out of the system as opposed to  doing some prevention or repair here at home.   I eventually had to suggest a rogue black  hole was on path to pass through our inner   system as the most plausible, if improbable,  reason for us sending a mission as the passage   of a black hole inside Earth’s orbit of the  Sun is very likely to not only disrupt the   solar system massively, but also shower the  whole area with crazy amounts of radiation.  You can still find ways to survive here and  it would probably be easier than moving to a   new system, but it was better than the normal  rationales given in scifi. Basically it almost   never makes sense to flee the solar system to save  humanity. Having backup colonies tends to make  

sense, but fleeing an alien invasion or murderous  AI in a spaceship – which are incredibly easy to   spot – is unlikely to work well. It might be worth  trying but it basically requires indifference or   incompetence on the part of the AI, Aliens,  or Alien AI. As for terraforming new worlds,   if we wreck our own, it would be easier to  make Earth habitable again, even if we turned   the whole atmosphere into a smog bank or even  outright nuked the air and seas off the planet,   than making a place like Mars livable. For that reason I just don’t see us trying   to throw together some desperate mission to  Alpha Centauri. So I think we need to instead   think of things in the context of what sort  of civilization is sending a mission to Alpha   Centauri in the context of something more like  the Age of Sail explorers or the Space Race.  We should imagine ourselves on the committee  planning to approve such a mission or send them   back to the drawing board to await further  advancement to make it cost-feasible, and I   think that means we have to also assume we would  never spend more than 1% of our economy doing   that. Whether that was the GDP, or Gross Domestic  Product for a year, of a major nation like the US,  

or the entire Earth, or even the colonized solar  system, the Gross System Product perhaps, really   is more of a political question. Unity tends to  come to mind for the simple reason that a unified   humanity has a lot more resources combined than  separate, and presumably doesn’t need to spend   as much on defense or watching their neighbors, so  has more to spare - in theory anyway. But you can   also make a good case for competition initiating  progress too -- just look at the Space Race.  Trying to estimate the cost of any spaceship  that’s never even been fully modeled is a bit   of a futile process, and one likely to end up  doubling or more when production time comes,   but we generally feel we could make an Orion  Nuclear Pulse Vehicle, equipped with 300,000   megaton nuclear devices and massing 500,000  tons, for about a tenth of the US’s current GDP,   a few trillion dollars. I do think that’s  conservative, but it does mean that given   a few years and global cooperation we probably  could make that happen without it bankrupting us. 

That is an enormous ship, 5 times the mass of an  aircraft carrier and comparable to the largest   ships ever made, giant supertankers like the  Seawise Giant or Batillus-class. And yet it’s   pretty tiny for a ship that not only needs  to bring along many hundreds or thousands of   colonists, but those colonists all need to survive  on a multi-decade journey and make a home on some   strange new world at the other end. This implies  a lot of cargo needs to come along, and is part   of why advanced automation, manufacturing,  or nanotech is so handy if you've got them. 

And multi-decade journey is being generous,  that design from the late 60s and has seen some   informal improvements since then that we discussed  in the aforementioned episode on Revitalizing the   Orion Project, but the best guess for speed is  about 3% of light speed and an arrival time of   around 130 years. That is insanely quick too,  roughly 10 thousand kilometers per second and   hundreds of times faster than we usually get  out of our spaceships. That speed is achieved   by a couple weeks of launching nuke after nuke  out the back of the ship and riding the energy   from the detonation… which is not too dissimilar  from what rockets already do, just scaled up.  The century-long journey means you also  need a ship that can last for that long,   and that includes maintaining the portion  of the bombs needed for slow down,   maintaining the reactors that power it for  decades, patching leaks in the hull and   replenishing the air and water that seeped  out through them, growing food to replace   what’s been eaten and recycling the waste,  and ten thousand other minor details. Many   of which we probably don’t even know yet, and  time and experience with interplanetary ships   and colonization will make us far wiser in  that regard. Odds are good even then though,   that some of those minor details won’t be known to  us till that first interstellar voyage of decades,   and being trillions of miles from home is a bad  place to have a breakdown. Little problems have  

a way of becoming big ones when we’re far  from home and short on backups and manpower.  And this is why I would tend to feel such a voyage  would not happen till we were a bit beyond the   Orion Drive level of interstellar ships, or had  been using them so long as to be very comfortable   with both them and space travel in general.  It is also why multiple ships would be nice,   though generally, bigger ships will be more  efficient than an equal mass in smaller   ones. And I’d really emphasize that bigger is  better when it comes to human colony ships. 

Now, I mentioned a few things that would take  us to the next level for interstellar travel   and which I think would make it practical,  but the Orion Drive is our fall back if we   still haven’t made any major improvements to  drives after a few centuries of spaceflight   and settling our solar system, and our Oort  Cloud. See our episodes Crawlonizing the Galaxy,   or Colonizing the Oort Cloud, for more discussion  of very slow interstellar colonization for making   the trip to Alpha Centauri the slow way at less  than 1% of light speed, by building outpost   after outpost in deep space till there’s  an effective interstellar highway there.  Even without something better than an Orion  Drive pushing your ship along, some of those   improvements I mentioned earlier could allow that  ship to be done far bigger and cheaper, relatively   speaking. If you’re sending a few hundred O’Neill  Cylinder sized ships out to Alpha Centauri,   dispatching a new one every few months, simply  because your economy and industry is so impressive   you can pull that off, then fast or slow, you’re  going to succeed at colonizing Alpha Centauri.  The ability to produce a spaceship by asking some  artificial intelligence to convert a big rock of   an asteroid into a ship is also the ability to  tell it to mass manufacture space habitats for   people in space to live on and that’s going to  rapidly improve your knowledge of life support,   and how to grow food and keep animals and  people healthy in space. But it also means  

your civilization can churn out vast  amounts of solar collectors in space,   or that you can build so many space habitats that  you can support trillions of humans in comfort.   And those same trillions probably don’t have  to work as much, since that superior automation   can produce all they need of most things far  easier and cheaper and quicker than nowadays.  In that sort of context, if a civilization  of trillions with superior automation and   interplanetary space travel can’t find a way to  get a colony ship out, either by having millions   of geniuses researching new technologies, or by  using the raw brute force of throwing resources   at the problem, then it’s probably impossible. I  tend to assume we’ll probably have licked the key  

problems before we even have a Mars Colony worthy  of the name though, and that’s the other aspect   of this. Why are we going to Alpha Centauri? In the long run, as you just get better and   better at space travel and grow your knowledge  and numbers, interstellar colonization seems   an inevitability if we don’t kill ourselves off  first. However, that first colony isn’t the same   story. We’re not talking about the conditions  needed for us to do the trip in style and total  

safety, but rather the conditions that apply just  enough to convince some powerful group – be it a   specific nation, corporation, or unified humanity  – that the effort is now viable and worth doing.   And that’s quite a limiter too because again,  we could have gone back to the Moon anytime in   the last half century as could really any of the  major economic powers, if they felt it was worth   the investment. There’s not much to be said  about being second, most people don’t know who   the second person to climb mount Everest was,  either the Sherpa who went with Edmund Hillary   or the next expedition to succeed. The problem with Alpha Centauri,   as things stand now, is that you’re not likely  to still be alive when that expedition arrives   and reports back that it succeeded if you were  the politician who risked your political capital   to make it happen or if you were the CEO who  convinced their board or got the investors. Heck,   you probably wouldn’t even have your grandkids  around by then. Missions to the Moon or Mars   you get to see happen and people whose tax  dollars made it happen get to experience it. 

Which inclines me to think that if there is  a better option than the Orion Drive we will   be using it to get to Alpha Centauri, because  we probably will discover it sooner than not.   We’ve had some successes with fusion, including  some recent ones producing more energy than put   in for ignition, and I am optimistic we’ll  have working fusion this century. However,   if practical fusion doesn’t get invented 20 years  from now but instead 200, I’d still expect that   Orion Interstellar vessel to be waiting on a  drawing board or have only been deployed as an   unmanned probe and prototype. I’d bet if one ever  does get launched it’s either many centuries from   now when everyone feels better options can  be ruled out, or because someone has managed   to basically prove fusion, antimatter, black  hole drives, and laser pushing systems are all   eternally impractical pipe dreams so it’s shooting  nukes out the back of a big spaceship or nothing.  

In the former case, you probably have  had time for humanity to grow to massive   numbers in an emerging Solar Empire  running on huge solar collectors too.  In which case it really is hard to  imagine how a power-rich system like   a multi-AU long Mass Driver or laser pushing  system for launch assist wouldn’t be viable.  Alternatively, if we have solar collectors and  have refined beaming technology to the point we’re   comfortably able to keep a beam on a ship to the  outer edge of the Kuiper Belt, either by very good   lenses or by relays, then we can launch, and the  same logic is true for fusion, but it really is   possible we might have artificial black holes or  straight matter to energy conversion by then too.  

I think almost anything that will turn out  practical with enough science is going to get   discovered inside the next few centuries, and  realistically we need that sort of timetable   to build up around the solar system even if we  have energy abundance and cheap spaceflight,   it’s just not the sort of process that  feels like it’s going to be rush-rush.  So by default we tend to assume a fusion powered  ship, drive and life support, but I would argue   it’s just as likely we would have power beaming,  as the drive and the power source for the trip   would be fission or fusion, beaming energy in  during acceleration just circumvents the whole   rocket equation issue so that it’s hard for me  to imagine anyone not using that. Breakthrough   Starshot wants to do that with a tiny microchip  sensor and thinks they can get to a third of   light speed using only known science and tech  and some reasonable near-horizon improvements.   I was a big fan of that approach even before I  got to meet and talk about it with Pete Worden,   the Former Director of NASA Ames and now Starshot,  and he made me an even bigger fan of the viability   of that concept. It’s not something happening  next year but it's definitely viable tech,   and it can be scaled up, everything can be. As  we like to say on the show, if brute force isn’t   working, you’re just not using enough of it. We’ve also detailed how to slow down with such  

systems if you have to, via a combination of  vanguard sacrifices to the Sun and Magsails and   other tricks. So that’s my best guess for the  future ship to Alpha Centauri, one running on   either fission or fusion to keep the lights on  and something else for speed up and slow down,   which would probably only take about 1% of the  mission timeline. Though it could be a longer   portion of the trip, many drive systems  work better when burning low and slow,   like ion drives, as do free braking options like  Magsails. Or maybe you have a higher top speed  

or need to go slow to avoid sloshing around  the air and water in your habitation drums.  Again, emphasis on plural, because while O’Neill  Cylinders are awesome, they’re definitely overkill   for a first colony in terms of size and you also  want to have multiple drums or rings anyway,   in case one is compromised. You can partition them  into segments too but it helps to have redundancy   and that’s a good way to do it especially since  you might want very different conditions in some   environments. Your optimized hydroponics hothouse  conditions are unpleasant to live in for humans,   and you also probably already know what  planet you’re planning to settle on and   what its day length and gravity are,  so having a hab drum that replicates   those conditions during the trip lets you start  experimenting and adapting to those conditions,   including having several generations of  organism living in them to see what adapts best. 

As it is quite likely we will have ever bigger  telescopes hunting exoplanets and small flyby   probes arriving long before the ships arrive  or even depart, we may already have habitat   cylinders devoted to mimicking conditions on some  world around Alpha Centauri before we even begin   constructing the colony ship. Indeed it would  seem logical to have purpose built spin gravity   environments back here around our sun mimicking  any planet we want to colonize long before sending   missions to those distant planets. A cylinder  habitat drum is likely to be far cheaper to build   and operate than its spaceship version. Which raises two other points. First,   is it actually a colony mission from the outset  or more of a classic exploration mission,   or even something else? And second, are we  actually going to Alpha Centauri or to Proxima?  Proxima Centauri is closer than the Alpha Centauri  Binary and not by a trivial amount. It’s a fifth  

of a light year from the two big binary stars,  hundreds of times further from them than Pluto is   from our Sun, and we’re not sure if it actually  is a part of the Alpha Centauri System, or is   maybe a new addition or passerby. They may not be  gravitationally bound together, as we initially   assumed, but it’s still a bit unclear. Whichever  the case, Proxima Centauri is also known as Alpha   Centauri C, with the bigger binary pair being  Alpha Centauri A and B, and they have actual names   too, Rigil Kentaurus and Toliman. You can call  them A, B, and C but if you’re calling the outer   red dwarf Proxima then A and B should be Rigil  Kentaurus, or Rigil Kent, and Toliman. If you’re   curious, that roughly translates as foot of the  Centaur and Two Male Ostriches, referencing their   Arabic constellation names. They weren’t known  to European astronomers till recent centuries,   and if you want to go have a look at our possible  new home system, you’ve got to be somewhere south   of the equator since Alpha Centauri is  not visible from the northern hemisphere. 

Incidentally Beta Centauri is an entirely  different Star System in roughly the same   direction, part of the Centaur constellation,  but nearly 400 light years away, not 4.   Alpha Centauri A and B are much closer to each  other in position and size, being about as far   apart as Pluto and the Sun are, and orbiting  every 79 years. One is 91% of the Sun’s mass and   the other 108%, though in terms of brightness that  means the smaller is half as bright as our sun and   the larger half again as bright. This does make  for some interesting Habitable Zone scenarios,   especially if we widen that outside the  classic surface water case of being just   a little warmer or colder than Earth so as to  not be covered in ice or have its ocean boiling.   Neither has any known planets, though we might  have a mini-Neptune or Hycean near Rigil Kent   at potentially a habitable distance. It is  even possible there’d be some viable colony  

options orbiting both stars. As we’ve  noted before, the best colony options   for interstellar civilizations aren’t  necessarily classic habitable planets.  Going back to the Alpha Centauri system,  Proxima is a fifth of a light year closer,   which might shave years off a voyage, and the  system does have multiple known planets, albeit   we don’t yet have great data to say too much  about them with certainty. Proxima b is a planet   20 times closer to its dim red star than Earth  is to our Sun, which is actually in the star’s   habitable zone because Proxima is so faint, and we  think it’s just a little more massive than Earth,   somewhere between 10-25% more, making it one  of the very few Earth-sized worlds rather than   the giants that we’ve found so far, as the big  planets are far easier to spot. We did select  

this planet for first colonization in our Alpha  Centauri episode some years back and you can see   that for more discussion of the topic. There’s  plenty of good reasons to think there might be   ice on its dark side – it is probably tidally  locked and if not then it probably has water and   air – we think those slow tidal locking down, but  we are pessimistic about planets near red dwarfs,   which tend to fluctuate in brightness a lot  compared to our sun, retaining their atmospheres.  There also appears to be either a Super-Earth or  Gas Dwarf, Proxima C, about 7 times more massive   than Earth orbiting out as far as Mars would be  in our system, though in this case that makes   it less well lit than Pluto. It could be a Hycean  Planet, which can hypothetically support life even   when quite cold, as we discussed a few weeks  back. It is also a gold mine for anyone with   fusion technology, and it probably has moons.  Proxima D is a newer and softer discovery,   from about a year ago, and would be a Sub-Earth  probably bigger than Mars but not by a lot and   it’s even closer than b, getting nearly double  the light that Earth gets, mostly in infrared   as that’s virtually all the light Proxima  gives off. That makes it a good candidate  

for terraforming using methods we contemplated in  Winter on Venus for terraforming that hot planet.  So all in all, as things currently stand,  it would seem like Proxima would be the   better candidate than the main pair, Rigil  Kent and Toliman. It might be ironic then   if it turned out Proxima wasn’t even in the  Alpha Centauri system but just passing by. 

That would generally mean we’re not making the  journey with any hope of making an Earth 2, and   it’s worth asking if we’re even sending colonists  on mission 1. The usual notion is that since the   trip takes lifetimes, there’s no reason to even  contemplate Apollo style missions. Instead,   you get to other star systems and stay, period, a  permanent colony from the drawing board. I think   that is true but also feel obliged to point out  that a civilization in the 22nd century is very   likely to have radical life extension technology  as well as stasis options like freezing,   they’re fairly interconnected tech that are likely  to be something where you have both not either.  So, a mission there is viable as you could be  coming home to your actual family and we might   be talking a round trip of a couple decades, not  centuries. Indeed ‘manned mission’ might actually   be some uploaded human going out there with  von Neumann probes to get some infrastructure   in place for a future colony mission and then  might just shut down and transmit a current   copy of its mind back home at light speed to enjoy  a parade in its honor when that person reuploads   into some android or clone or cyborg body. Indeed that really does make a lot more sense  

than sending some AI out there as a vanguard or  some big colony ship full of thousands there as   first on the scene, with no existing supplies  or infrastructure to rely on when they arrive.  As for the journey itself, there is a lot to be  said about freezing but at the same time, the same   technology that offers massively longer human  lifespans or restoration from decades of being   a frozen corpse also imply the ability of the  ship to self-repair a lot, in which case the main   advantage of staying frozen – less wear and tear  from a warm ship and living crew – becomes less of   an issue. And again, those automation and nanotech  options that permit that are the same types of   tech that let you start engaging in massive  post-scarcity space civilization, able to churn   out gigatons of spaceships and habitats. So, I’m  guessing anyone making the trip frozen is doing   so from a specific desire to help minimize their  footprint on that ship or that ship’s footprint   in their own life and experience. And I would be  surprised if there wasn’t an awake and active crew  

there for the entire journey, even if they’re  rotating who’s not a popsicle at the moment.  This does not necessarily mean we have a large  awake community including children born on the   voyage. Indeed if the ship is a prototype many  might feel it reckless to have kids until they   arrive and are settled in, especially if they  have no shelf-life on their fertile period   from technological improvements to fertility  methods and lifespan. As I’ve recently learned,   little kids are very good at finding  ways to poke at and break things,   not a good combination with a prototype vessel. You do need a lot of power to keep the lights on   in a habitation drum, probably no less than  100 watts per square meter, or 10 watts per   square foot of cylinder living area or ring area.  Some lifeforms are not going to do well getting   frozen or being raised from embryos in some vat or  bag without existing parents. They are generally  

going to be larger ones too, who would need more  habitat space. This is a very tricky topic and one   we explored more in our episode Exporting Earth,  and we tend to handwave the assumption that our   biology and genetics will just get way better  before we launch colony ships or that we will   do it the big way, tons of giant space habitat  ships flying entire ecosystems to the destination.   Though we explored alternatives, including animal  androids raising small critters, or even people.  I tend to assume a bit of both, better biology  and bigger habitats, not because you might not   have the technology to stitch life together  from scratch via nanotech when you arrive,   but because again, that same technology means  you could stitch together continent-sized   space habitats and massive engines, with a  little more patience and no more actual human   effort. You just grow the ship from a template by  supplying some asteroid to grow in along with a  

power supply. Then load it and fire it off. As a journey on a tiny spaceship of half a   megaton of mass, like the original interstellar  Orion design, is going to be way different than   flying on some McKendree Cylinder as large in  living area as Eurasia, but the technology for   sending them is the same. The only difference  is one of scale: the difference between pouring   a sidewalk from your house to your garage and  pouring a multilane freeway to the other side   of the continent. And the distance to Alpha  Centauri is on such an immense scale too. The   Moon is 20 times further from Earth than any two  points on Earth’s surface are from each other,   and Mars is vastly more than that, more like  10,000 times as far from us as we are from any   distant corner of our own world. Alpha Centauri  is more like a couple billion times as far away. 

That raises all sorts of other issues like  what’s keeping the crew from having a mutiny,   or going rogue, when they’re a hundred billion  times further from the nearest sheriff as any   town in the Wild West was. That’s a lot of  time for folks to get weird or get crazy too,   one reason why freezing the crew might be wiser,  as you can probably make a more reliable AI that   needn’t have much more brains and free will  than what’s needed to thaw out a skeleton   crew if various preset failures happen,  or signals arrive, or you do, and so on.  As to what might drive folks crazy on such a  voyage, well as we saw in our episode Staying   Sane in Space, the laundry list of psychological  issues and agitators even on the space station   orbiting a couple hundred miles over Earth  is bad, much like the submarines that prowl   around deep in our seas for months. And  this is like submarine 1 or spacewalk 1,   so there’s going to be a lot of tight budgets  to make it happen and shave off any fat,   and a lot of unknown unknowns to face  with less resources than you wanted.  So, an interstellar mission can dial  that up a lot, and this is Mission 1,   so while you probably have decades of practice  with space mission mental health issues, even deep   space missions of a year or two to the Kuiper Belt  perhaps for comet mining, you haven’t got tons of   practice handling options related to interstellar  travel. Like being a teenager born on a small ship  

and told you’re stuck there your whole life.  Like watching the clock mismatch a little more   every day between your ship’s clock and the news  and entertainment feeds coming in from Earth.  Like getting a message from your sister telling  you your niece or nephew just started college   and knowing that by the time you got it, they  either had already graduated or failed out.   Like finding out the relative or pen pal you’ve  been writing letters home to for decades and   getting messages from died some years back and  you just found out now. That even if you all have  

extended lifespans able to survive the voyage and  early colonization and take the trip home one day,   everyone you knew is so different that they may  as well not be the same person. Like meeting a   friend from elementary school decades later,  there’s just so much water under the bridge   that you could run a hydroelectric dam off  it, all of it spent apart from each other.  For all the technical challenges getting  to Alpha Centauri, I suspect the biology   and medicine of surviving the trip and forging  a new home at the other side will dwarf all the   physics and engineering needed for that starship,  and yet the difficulty of making that journey on   the humans on board it may make both seem trivial. In the End though, I am convinced we will have the   technology to do it one day, and no shortage of  volunteers for that first mission to a new star,   and that we will find people up to the  challenge of journeying to Alpha Centauri,   and that ship will unlock the gateway to a  galaxy of billions and billions of new worlds. So if we make a spaceship that could travel to  Alpha Centauri at around 10% of light speed it   would take 40 years to arrive. That’s about how  long someone’s entire career lasts in modern   times, and if this show ran for 40 years total I’d  have ended up producing about 3000 episodes and   presumably spent about 80,000 hours as that’s 40  hours a week, for 50 weeks a year, for 40 years. 

I love my job. I would be thrilled if I  got to keep doing it for decades to come,   and it really highlights what you can do with  80,000 hours, and I think most of us want to   feel like our career really mattered and made a  positive difference in the world, and would like   start or switch to one that did, but it’s hard to  pick one that our skills and interests align to,   make a plan we feel confident in, and get ideas  for high-impact careers. That’s where 80,000 hours   comes in. They’re a non-profit entity that spent  a decade alongside Oxford University researching   which careers have the most impact, and all  the research is on their website, for free.  80000 hours isn’t the cookie-cutter advice we  often see from schools or aptitude tests. No   generalized platitudes and dull repetitive advice  about how you should become a doctor, teacher,   or charity worker if you want to help the world.  If your career is going to last 80000 hours,  

it is worth spending many of those to find out  what real data and evidence suggest would be a   good high-impact path for you, and spend some time  with the curated resources you can find at 80,000   Hours, like their profile on space governance. Indeed their podcast has covered some fascinating   topics, like one of our favorite ones here,  the Fermi Paradox, where they had on Anders   Sandberg for a discussion of that topic, so  yes they’re definitely including the kind of   topics that fascinate us when helping folks  try to find a career they can love and feel   good about doing. And again, everything is free,  forever, because they’re a nonprofit — their only   aim is to help solve global problems by helping  people find the most impactful careers they can.   If you join the newsletter now, you’ll get a free  copy of their in-depth career guide sent to your   inbox - just sign up at So February is drawing to a close but there’s   still our Livestream Q&A coming up this weekend,  Sunday, February 26th at 4pm eastern time,   where we’ll take live questions from the audience  in the chat and answer them. After that we’ll  

start off March with one of my favorite topics,  Space Habitats, on Thursday March 2nd, then on   March 9th we’ll contemplate far longer voyages  than the interstellar one today to our nearest   neighbor star, by instead contemplating voyages to  other galaxies and even superclusters. Then we’ll   discuss how to survive various apocalyptic  scenarios that weekend, March 12th, for our   mid-month Scifi Sunday episode, here on SFIA. If you’d like to get alerts when those and   other episodes come out, make sure to hit the  like, subscribe, and notification buttons. You  

can also help support the show on Patreon, and  if you want to donate and help in other ways,   you can see those options by visiting our website, You can also catch all of SFIA’s   episodes early and ad free on our streaming  service, Nebula, at  As always, thanks for watching,  and have a Great Week!

2023-03-01 21:45

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