Comment by Justsignedup | Hacker News Reader

Comment by Justsignedup | Hacker News Reader

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I think it is important to understand differences:

The future of humanity is not only on earth. Too much risk, too limited resources.

HOWEVER the future of humanity in space is NOT "tomorrow we lift off a giant spaceship with everyone on it." If we survive a few hundred years we might see some amount of human civilization outside of earth, but for many hundreds of years after more practical space tech comes about most of humanity will still be born, live, and die on earth.

Maybe in a thousand years we'll see more humans outside of earth than on earth. But that's a long long long ways from now. If we are to become an "immortal" race (doesn't go extinct) then I can see the human race abandoning earth in a hundred thousand years or so due to many possible conditions. But even if we can colonize and terraform other planets, why would we want to when we already have a perfectly terraformed planet we're already on. Life has survived on earth farily well for billions of years, there's no reason why if we don't completely obliterate the climate we can't survive here till the sun blows up.

>The future of humanity is not only on earth.

Where are you going to go?

Outside of Earth, there is no place for us in the entire Solar System. Sure we may build some research stations here and there, just as we did in inhospitable places on Earth (like Antarctica), but there's no long-term option anywhere. Interstellar travel is science fiction, but even if it wasn't, there is no place for us to go as well.

You make the place. https://en.wikipedia.org/wiki/O%27Neill_cylinder

Obviously this is far beyond our current level of technology, though.

It's absolutely not beyond our current level of technology. Unfortunately, there are not economic incentives yet.

Now, this(1) it's beyond our current level, but one can dream.

It's obvious to me that this is the most probable future and I would not be surprise if, at some point, most humanity is living in this kind of environment instead of planets.

Planets have a lot of disadvantages.

(1) - https://en.wikipedia.org/wiki/Bishop_Ring_(habitat)

There can't be an economic incentive, only political ones.

Much like pilgrims who founded Massachusetts, founders of space habitats will be groups of people who don't enjoy living on Earth badly enough (due to persecution, or because of desire of some grand reforms) to fund a move elsewhere.

I bet the first Martian colony will quickly be recognized as a place not controllable by any Earth government, and that will be a huge selling point for tickets to Mars.

I would imagine that any colony would be dependent on Earth (for survival) for quite a while. I think that it would take a certain level of self-sufficiency in order to reach a point of not being controllable by earth.

Being far away is one thing, but when I look at how powers on Earth exert influence and control over others, it seems you also need to be self-sufficient (protection from blockades, trade embargoes, or other modern "seiges"), and also sufficiently defended/defensible to avoid military threats. Sure, your Martian buildings may be underground, but would they be safe from heavy objects flung at them at high velocity? Seems like it would be easy enough for Earth to "put down" any Martian activities that rubbed people the wrong way for the foreseeable future.

Maybe that will be MAD for the 23rd century - you blow up our habitats, we'll drop rocks on your cities.

It may be a bit more like the Triangle Trades of old [0].

Raw/rare materials and elements are mined in the Belt and are then sent to Earth for use in manufacture. You pick up the high quality goods and tools from Earth and ship them to Mars/Moon. Since there is water on Mars/Moon, you grow food, 'wet' supplies, and unfinished goods in the weaker gravity well for shipment to the Belt. These arrive in the Belt and you repeat the process, profiting at every spaceport.

As the metropole has overwhelming manpower/firepower due to it's high class manufacturing base and population, the threat of violence is just plain bad for business all around and is discouraged.

Now I'm gong to speculate very hard: Eventually, the lesser manufacturing base (Moon/Mars) will gain in economic and political power as their frontier life becomes more civilized and independent of the metropole. And they may try to declare independence fully. However, in the case of Moon/Mars, you're looking at a fully independent multi-generational extraterrestrial biospheres at that point and probably millions of people, if not 10s of millions, to run the whole thing. Lots of people that have never been to Earth and never plan on going. I really don't see that much trade/mining would be needed to go to Earth to build up and support permanently independent biospheres of a few generations of native Martians/Moonies.

[0] https://en.wikipedia.org/wiki/Triangular_trade

There are no known commodity items that can be profitably mined in space.[0]

There will almost certainly be stuff like gold and rare metals shipped from a Mars colony to Earth, but only because returning the ships from Mars makes vital resupply easier. From a total system perspective it'd be better to keep the ship on Mars and scavenge it, but Mars will be on such an economic imbalance that they will want to make it easy as possible for Earth to resupply them. And if you're going to return the ships anyways, you might as well put something in them.

The diagram at the top of [1] is a good illustration of import vs make in situ vs export.

[0] https://caseyhandmer.wordpress.com/2019/08/27/there-are-no-k...

[1] https://caseyhandmer.wordpress.com/2020/08/23/progression-of...

There are hundreds of asteroids that have more wealth than the entire US federal debt.

Consider all the precious metals ever mined on the planet. Now consider this is litterally scratching the surface of the total contained within the planet. Note, these dense metals will be concentrated toward the planets core, due to gravity.

The asteroid belt easily holds our planet's mass, but it is all spread thinly and relatively easy to access.

> The asteroid belt easily holds our planet's mass

That seems...quite high:

https://en.wikipedia.org/wiki/Asteroid_belt

"The total mass of the asteroid belt is approximately 4% that of the Moon."

I don't think the mass is as important as accessible mass - let's say you can mine up to 4 km deep (the deepest mine on Earth at the moment) & you can't easily do that any, there might be ocean, glacier, or even a city on top of the resource you want to mine. That limits you even further for terrestrial mining.

Asteroid on the other hand are mostly just a few kilometers in size with a very few being bigger than tens of kilometers. That might quite possibly open much bigger mining volume than what's currently avalable on earth - rather than a big sphere with much stuff inaccessible due to being too deep, you now have millions of chunks floating around with a lot of stuff to dig through in the 4 km limit. No oceans, cities or glaciers to block you as well.

And the arbitrary 4 km limit most likely does not really apply for asteroids - they are all long cooled down & the gravity is negligible so nothing should really limmmit you from digging hundreds of kilometers through Vesta looking for valuables. Also some findings indicate that processes that lead to dilution of minerals on earth might have taken place after asteroids formed, so it might be possible to find the stuff we look for in quite a pure and ready to use state.

Imagine that you deliver 100 thousand tons of gold, platinum, etc to Earth. How would the prices change?

Inside the asteroid belt there's nobody to trade in gold with, at least not yet.

Well, it should enable many things that are currently prohibitively expensive due to the cost of materials.

You know, people don't buy stuff (just) because it looks nice and shiny but to use to to do things. Aluminium used to be more expensive than platinum yet we survived it's price tanking & it made practical airplanes and drink cans possible!

There's still the minor detail of transporting it back to Earth in a cost effective way…

Ideally you would use it for building up space infrastructure primarily. You might still ship some finished products back to Earth, that would be much more mass efficient.

BTW, once you can have your payload trajectory intersect with Earth, you will get braking for free thanks to the atmosphere, effectively shaving half of the needed delta-v. Same thing on Mars.

Has anyone demonstrated manufacturing non-trivial centrifuges in space yet? Or mining and refining in space, given we can’t possibly afford to launch that much mass from the ground? Or fully modelled the lifecycle of that sort of megastructure to find out how, why, and when the chemistry of the occupants/internal farms/etc. causes fatal problems?

I’m eager to live in one of these, but I don’t think we actually know enough to build one at all yet, never mind safely.

There is a FDM 3D printer on the ISS & there have been many material science experiments done. A centrifuge module was planned for the ISS but later cut on cost reasons: https://en.wikipedia.org/wiki/Centrifuge_Accommodations_Modu...

Humble beginnings.

I think it might be better to say that's not beyond our current level of scientific understanding (it doesn't require any exotic materials or new physics). However it's likely beyond our practical engineering capabilities.

Early spaceflight up through Apollo was done with an army of humans with slide rules and rivet guns. We did it because there was a political imperative to do so. A lot of new technology was developed as a result. But it ended up being unsustainable because it was too expensive.

I think the key to making O'Neill cylinders feasible will be large scale outer space resource mining and in-space manufacturing. Both will require advanced robotics and AI. We could throw a bunch of money into developing that ... or we could just wait for the technology to develop here on Earth and then apply it to space.

Likewise, as much as I'd like to see a Mars outpost in my lifetime, it would be a lot cheaper and safer if we didn't rush it. Maybe by 2075 we'll have cured cancer and radiation won't be an issue, and we'll have self-repairing life support systems and one of those automated medical pods from the Alien movies.

Yeah - I'm a bit alarmed on how many people can't think out of the blue ball (sorry for the pun) - there are many many ways we can build our own environments as needed about anywhere in space given some resources and energy.

Also while Earth is pretty ideal, it is not perfect - for example some places in Japan can be regularly hit by earthquakes, tsunami, flooding, Typhoons and even volcanic eruptions!

If done right, habitats could be much better than planetary environments.

We can change Mars in large ways. Lots of stuff written about that. Heck, we could redirect an icy asteroid to collide, providing water, atmosphere and heat. On the order of decades from now.

>We can change Mars in large ways.

No we can't. The gravity of Mars is always going to be a problem. The lack of magnetic field is always going to be a problem. Most of its atmosphere was lost to space and there is not enough water on the planet to replenish.

>we could redirect an icy asteroid to collide, providing water, atmosphere and heat.

I read the Mars trilogy too.

>On the order of decades from now.

Sure.

We could make an artificial magnetic field for it. Beyond current technology but seems like a viable option a hundred years from now.

I agree low gravity would be a problem, but life finds a way, right? Current generations of humans wouldn’t do well in 1/4 G, but maybe we’ll see significant adaptations 100 generations down the line! Who knows?

In principle, the cities themselves could have angled bases and be spinning, adding mass-gravity to centrifugal-gravity. I’m not sure if this is actually a good idea (and why would you want to build on a planet if you’re going to live in spin gravity?) but in principle it can be done.

> We could make an artificial magnetic field for it. Beyond current technology but seems like a viable option a hundred years from now.

How? Because to me, that seems extremely far-fetched. My understanding as to why Earth has a magnetic field and why Mars does not (or has a weak one) is that Earth has a highly dynamic molten core surrounding a solid inner core, whereas Mars only has a molten core with not as much activity. It is my understanding that Earth's geodynamo plus its rotation helps create the magnetic field that protects our atmosphere.

So unless humans are able to alter planets in such...planetary ways, then I don't see how we'll suddenly be able to give Mars a sustainable magnetic field.

Literally google it, come on. "Mars artificial magnetic field." We'll wait.

No need to be so snappy.

And that isn't giving Mars a magnetic field in the implied sense. It's building an external structure to perform a protective field that would have similar effects. You may consider it semantics, but they're different.

It is an interesting idea, but this seems to simply be a proposal with a lot of "ifs" and "mights" and "possibles", with even the proposer calling it "fanciful". So indeed, I suppose we will wait. Even with this novel idea, it doesn't seem possible in 100 years. The articles I see came out three years ago from the conference it was presented at, and I didn't see any immediate results returned as to the progress of the idea.

Blood pressure, bone growth are managed by genetics. Which we (will) have control over soon. So that's hardly a stumbling block.

>>We can change Mars in large ways.

>No we can't. The gravity of Mars is always going to be a >problem. The lack of magnetic field is always going to be a >problem. Most of its atmosphere was lost to space and there >is not enough water on the planet to replenish.

Nothing a world house could not fix:

https://www.orionsarm.com/eg-article/51f7d32f54b72

Bonus point - it can be built incrementally, so you get immediate results instead of waiting for generations of effort to get anything back as with planet wide terraforming!

It took tens to hundreds of millions years for the atmosphere to disappear. If we can make a new one, we ca. Keep it replenished

Human climate management shouldn't give anyone hope.

We've demonstrated that we can heat planets up.

Unfortunately what we’ve demonstrated is that we make bad decisions if they’re cheap; that we have heated up the plant is merely because it happened to be the case that fossil fuels could power a population growth from 1 to 8 billion in a century and a half.

The tech is available, it’s the politics that I doubt.

The politics of terraforming a barren plant to make more suitable for colonization is going to be different from that of our home world.

Of course. My concern is: will the politics remain aligned in the long term with keeping it habitable after it’s been terraformed?

Agree with you but keep in mind we can also change humans to be better suited to the environment there. So in the long term we can work both sides of the problem.

What do you think would prevent a self sufficient colony on Mars in a few hundred years? I don't see any fundamental obstacles to it.

Self sufficient requires a manufacturing base to include everything needed to sustain it’s self, including redundancies. Going from zero humans on mars to 100’s of millions is a massive bootstrap problem with minimal incentive for the the people involved or the multiple years worth of earth’s GDP to get to that point.

It’s like the “self replicating” 3D printers where they can produce 98% of the structure by weight and approximately 0.001% by complexity. A base that’s producing it’s own food is doable, shipping machines to say build solar panels or a specific chip isn’t a problem.

However, even just the effort to figure out a minimal slice of earth’s technology to be self significant is hard. Aka building even a single type of LCD requires a massive number of different components, and the ability to build all the machines to make those components, and machines to make those machines, ... Now realize that’s just for an LCD, manufacturing every type of Medicine is a whole other list.

Finally you need to accept everyone on Mars living in relative poverty for generations due to the inefficiencies involved.

Why does it need hundreds of millions of people?

That’s not a requirement, that’s the goal. In theory you could have a self sufficient base with 0 people and AI, or 100,000+ people for long term genetic diversity and an automated wonderland, or ...

Elon's estimate is that 1 million people are needed for Mars to industrialize sufficiently to become self-sufficient.

A good reference is Casey Handmer's blog or book.

https://www.amazon.com/How-Industrialize-Mars-Strategy-Self-...

https://caseyhandmer.wordpress.com/2020/08/23/progression-of...

1 million in a few centuries seems feasible given the likely advances in technology. Hundreds of millions would require terraforming, which will likely take millennia. But those timescales are relatively short if human civilization persists. Even if Mars does not end up being ideal enough, Venus could be on a longer time scale. The article is short sighted.

> [Y]ou need to accept [that] everyone on Mars [will] live in relative poverty for generations.

I think this point is by far the easiest one to address. Historically, there have always been people willing to do dangerous things (ie exploring the Arctic / Antarctica). I don't think you'd have any trouble finding people willing to give up their Earth lifestyle for a chance to explore the "frontier" even with the knowledge that they couldn't come back.

Those explorers always have the luxury of going back to civilisation after relatively short excursions into the unknown.

I doubt many people are willing to live the entirety of their lives in constant danger and constrained resources. And even fewer of those people will have the skills needed to run a complex technological society (and you will need a lot of technology to survive on Mars).

Colonists to the new world of the Americas didn't count on going back.

There was a constant string of boats going back to England and many people did so. What kept people in the America’s was they where better off there than Europe not the inability to leave.

>Those explorers always have the luxury of going back to civilisation after relatively short excursions into the unknown. I doubt many people are willing to live the entirety of their lives in constant danger and constrained resources.

Yet a very large majority of North America is descended from people who did exactly that.

The very large majority comes from people who settled way after the early colonists.

And those, who settled, came here looking for a better life, which should tell you about the conditions they were coming from.

And that is especially true for the many of the early colonists.

But the most important thing: we no longer live in the 1500-1600s which is a very important factor overlooked by everyone breathlessly talking about enduring hardships on Mars

I agree with you that complexity is a thing and not quite a simple hurdle but once the gears start turning I believe we have enough smart people among humanity as a whole to figure something out.

I also think you take the idea of poverty way too seriously. People adapt to their environment remarkably quickly and the idea of poverty and wealth with it.

Modern automated production techniques and additive manufacturing can help reduce this dependency a lot. You can also do some compromises - the stuff might be less elegant than cutting-edge Earth product, but it will work.

Also people now have much better mental picture of the manufacturing tech tree than ever before thanks to Factorio. ;-)

you're moving the goalpost from self sufficient to 100 millions humans, and the two are very lightly correlated.

beside, earth manufacturing is biased toward efficiency and low cost, with the driver of capital gain, not sustainability, you don't actually need lcd if crt are good enough and could be manufactured in situ.

sure it won't make for a good nor a pleasant standard of living, but then again, that's moving the goalpost.

If the standard of living is bad enough people will simply fail to immigrate. You need not just young men seeking adventure, but educated and talented people willing to have a family there across long timeframes as infrastructure is slowly built up.

The US for example is below replacement rate, which is fine if you has constant immigration or it’s going to increase as the population falls. Less so if having 10% fewer people means everyone else dies.

Technology is only half the battle you also need to avoid negative feedback loops where if conditions are bad enough you don’t get doctors and surgeons immigrants. Which then makes things worse. A few year shift is fine for a token settlement, less so if you’re shipping 100,000 people there and 100,000 people back every year.

Right. That was modded down, but it's realistic. All the off-earth real estate in the solar system is inhabitable only at huge cost. Mars barely has an atmosphere.

> why would we want to when we already have a perfectly terraformed planet we're already on

Sure, you can stay here. But then in a few thousand years the descendants of the people who did leave turn up with advanced weapons and ideas about bringing you the “benefits of civilisation”.

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