Hacker News Reader

> Organized human civilizations go back 2000-3000 years

More like 10,000 at least [0]

Australian Aborigines are at 50,000 or so, depending on your definition of "organised".

And, inferring from the article, I kinda like the idea that advanced civilisation fade back into nature. Modern humanity is about 100,000 years old. Is that long enough for a civilisation to rise, peak, and fade back into nature? It's a fantasy trope, obviously, but it's cool to think about again with this angle.

[0] https://en.wikipedia.org/wiki/List_of_oldest_continuously_in... shows a city from 6000BC, so 8000 years ago. I'm not sure that a city is required for an organised civilisation, but an organised civilisation is definitely required for a city.

https://en.m.wikipedia.org/wiki/G%C3%B6bekli_Tepe is almost 4000 years older. Not sure if it meets your definition of city, but it was some sort of human settlement

To the topic of the article, it makes little difference whether 2,000 or 50,000...

The Oxford University timeframe comparison hits hard. It's a sobering way to visualize just how brief our industrial window might be. But I think we're missing some fascinating possibilities here.

You're absolutely right about the recycling entropy battle - those diminishing returns are brutal. But I'm curious about where biological innovation might shift this equation. We're already seeing organisms that can work well beyond the traditional C/H/O/N sandbox - bacteria that reduce metals, engineered microbes that synthesize quantum dots. This hints at possibilities that blur your distinction between biological and industrial approaches.

The interstellar travel conclusion particularly caught my attention. While current biological systems are indeed low-power, that very efficiency might be what makes them perfect for long-haul space missions. Imagine hybrid systems where bio-engineered organisms maintain spacecraft over generations, working alongside traditional tech. Maybe slow and steady wins the interstellar race.

I'd argue we're on the cusp of even more radical transformations in materials science. What if atomic-scale manufacturing fundamentally changes our relationship with scarce resources? The jump from 65% to 15% iron ore might look tiny compared to what's coming. Maybe we're not facing a binary choice between current industrial systems and purely biological ones. The sweet spot might be in hybrid approaches that combine biological resilience with industrial capability.

Curious to hear your thoughts on this - particularly around how engineered biological systems might reshape our assumptions about resource constraints. There's something compelling about the idea of building civilization's next chapter on that 300-million-year track record of biological innovation.

> bacteria that reduce metals

Separate metals from organics, yes.[1] Reduce metals, probably not. Reduce means to pull a metal out of its oxide. This is way uphill energetically. It is usually done by heating the oxide to a high temperature in an oxygen-poor environment. The other direction, oxidation, produces energy, and there are some biological processes that use that.

Still, there are some bacteria which manipulate manganese.[2]

> What if atomic-scale manufacturing fundamentally changes our relationship with scarce resources?

I used to know Drexler, the early nanotechnology guy, back when nanotechnology meant pushing atoms around by mechanical means, rather than surface chemistry. Not much came of that. It's hard to apply enough force to break strong molecular bonds apart. IBM did manage to spell out "IBM" with xenon atoms, but xenon is inert and doesn't bond strongly to anything. No strong bonds to break.

Asteroid mining is potentially possible. Somebody will probably try it for gold and platinum within fifty years. It's unlikely to become cost-effective for cheaper metals.

[1] https://www.sciencedirect.com/science/article/abs/pii/S00489...

[2] https://www.cnn.com/2020/07/16/world/metal-eating-bacteria-i...

> Drexler, the early nanotechnology guy, back when nanotechnology meant pushing atoms around by mechanical means, rather than surface chemistry.

I bought his book Engines of Creation when it came out and his thesis had the air of inevitability - how could it not materialize some day ? It seemed so self-evident.

I remember reading engines of creation in my second year of uni and then asking Andre Geim for a summer placement - he said no, he was busy, and then a few months after he got the Nobel prize. Instead I went to the material science school and got a summer project playing with the old tunneling electron microscope in the basement. it felt like flying a 747, given how many buttons, levers and knobs you had to tune to get a good picture of nanotubes. They also showed me their state of the art AFM but I wasn't allowed to breathe near it.

Pushing atoms around by mechanical means only seems plausible if you've never really studied molecular chemistry - see the Drexler/Smalley debate - https://en.wikipedia.org/wiki/Drexler%E2%80%93Smalley_debate...

It’s a good debate. I tend to agree with Ray K’s commentary.

> Reduce means to pull a metal out of its oxide. This is way uphill energetically.

For iron (Fe2+) is about the same order of magnitude than getting organic matter out of CO2, which is what photosynthesis does, so it doesn't really sounds impossible. The main problem is that in an oxygen rich atmosphere, any metallic iron atom it would spontaneously get back to its oxide form pretty much instantly…

> The Oxford University timeframe comparison hits hard. It's a sobering way to visualize just how brief our industrial window might be.

For context, it was founded over 800 years ago.

> While current biological systems are indeed low-power, that very efficiency might be what makes them perfect for long-haul space missions. Imagine hybrid systems where bio-engineered organisms maintain spacecraft over generations, working alongside traditional tech. Maybe slow and steady wins the interstellar race.

Perhaps, but unlikely.

As far as we know (but we could be wrong), interstellar civilization is the business of a Type II civilization on the Kardashev scale. They can extract fusion energy, raw materials, and information from multiple solar systems.

>As far as we know (but we could be wrong), interstellar civilization is the business of a Type II civilization on the Kardashev scale.

As far as we know? We know nothing and the Kardashev scale is just a toy hypothesis come on.

I largely agree, but a few quibbles:

- the Great Pyramid is closer to 4600 years old

- we will always have common crust elements, eg 27.7% silicon, 8.1% aluminum, 5% iron, 3.6% calcium, 2.8% sodium, 2.6% potassium, and 2.1% magnesium; so the question is those and biological elements (carbon, hydrogen, nitrogen, and oxygen)

- you can probably do space travel from that list, which gets you easier to consume versions of those elements as well, eg asteroids

- and from there interstellar travel is possible.

We don't have a reliable age for the Great Pyramid. Since we can't do radiocarbon dating on rocks, all of the estimates are based on somewhat circumstantial evidence. It could be much older, possibly with some more recent maintenance. I'm not claiming any particular age, just that we don't really know.

While we can't radiocarbon date rocks, we can do that with other building material. From Wikipedia:

Mortar was used generously in the Great Pyramid's construction. In the mixing process ashes from fires were added to the mortar, organic material that could be extracted and radiocarbon dated. A total of 46 samples of the mortar were taken in 1984 and 1995, making sure they were clearly inherent to the original structure and could not have been incorporated at a later date. The results were calibrated to 2871–2604 BC.

Compelling evidence, but if the aliens who built the pyramids brought in mortar from another planet, the isotopic ratios could be totally different. So the date of the pyramids could be anything really if we throw out Occam’s razor and rationality in general.

could you please highlight where you think the poster threw out Occam's razor? Probing the mortar seems to be to be a reasonable proxy for the age of the construction?

I read that comment as a sarcastic response to the "we don't know the Great Pyramid's age" claim, rather than a disagreement with my mortar post.

ah that makes more sense!

There's plenty of evidence that it was built for the Pharoah Khufu about 4,500 years ago.

To suggest otherwise is just insane aliens conspiracy theory nonsense. Is this post a satire of that BS? I really find it hard to tell.

See "The Age of Substitutability (What do we do when the mercury runs out?)"

https://www.osti.gov/servlets/purl/5045860

The conclusion: most material demand is for elements so common on Earth that supplies will never run out. Only more energy is required to deal with super-low-grade ores (like 10% Fe basalt instead of 15% Fe taconite). The rare elements can largely be substituted so that the residuum of non-substitutable demand can stretch supplies to millions of years.

As you'd expect of a paper coauthored by Alvin Weinberg in 1975, the energy solution proposed is "fission breeder reactors" but there's a nod toward the long term potential of solar power and fusion.

Yes, a lot of people on this post have mentioned that with proper planning, a more long-term perspective and consideration for human well-being, growth doesn't have the same limits.

Sure, but if you had a consideration for human well-being, if you had a society where people thought about "what should things look like in a hundred or a thousand years" you wouldn't have any impetus for exponential growth.

Exponential growth in material resource consumption is necessarily a short term phenomenon on the scale of known history. The UCSD Do The Math guy has shown why exponential supply growth is not possible in the long run. The more binding constraint is the lack of demand growth. Even if the world had the capacity to supply every person with an extra 100 tons per year of steel or an extra 10 tons of pork, why would everyone buy that much? There's no point. It would be like hoarding drums full of seawater. Whether we plan for the end or not, the exponential growth era is transitory.

I appreciate your overall framing one thing worth pointing out, though is we really won’t ever be mineral limited as long as our sun is alive. I think in a 50 to 100 years asteroid mining and/or non-terrestrial habitats will become normal

Also there would be the use of new materials, such as diamond films.

Everyone said that in the 70s, then we expected flying cars, and android servants…. Look at us today, instead of the flying cars we have war drones, war robots and the only territorial expansion is into other countries. I wish I can have the same positivity as you but I fear human won’t be around in the next 50 years if wars continue as today

Maybe we deserve that honestly.

We also have electric cars and reusable rockets. We can do either; it's just up to us to decide what's most important.

Electric cars aren’t impressive. If you want to actually point to the surprising innovation over that period, it’s computers and the internet.

We had mass market computers 30 years before mass market electric cars, so I think they are quite impressive.

The first cars were also electric, it’s not groundbreaking technology. Remember the bar here is on the order of flying cars. Only computers come close to clearing that for me.

The Difference Engine design was around even before that, but it would also be bad faith to argue that computers aren't a modern miracle.

We didn’t have diesel computers able to be used by the average person and capable of roughly the same range and volume of arithmetic operations as modern computers. We did have gasoline powered cars that served precisely the same function. Electric cars are an improvement in energy efficiency, climate impact, and user experience, but really just an iterative improvement on existing vehicles.

Meanwhile GM built a few https://en.wikipedia.org/wiki/General_Motors_EV1 from 1996 to 1999, which all got recalled until 2003 because of corporate politics / 'for business reasons'.

Which is the topic of https://en.wikipedia.org/wiki/Who_Killed_the_Electric_Car? from 2006.

So 'mass market' could very well have been possible about 30 years ago, without Grumpy Management … … …

Even then, having the vision to roll out superchargers, and cannibalise a very successful business, and invest a fortune in a brand new from-scratch platform, is just supremely unlikely in practice. Why jeopardise your bonus?

> But you don't get interstellar travel out of biology. Too low-powered.

The thing is interstellar travel makes no sense except in science fiction books: there's literally nothing of interest to be worth trading in other planetary systems, and trade has always been the motive for maritime exploration, because it's what get you the massive funding such endeavor requires.

And btw even close space colonization doesn't make any sense either: we may end up with a vanity base on Mars before realizing that it costs a lot, for living conditions that are more harsh than at the top of mount Everest. Even if world population wasn't plateauing and headed to a decline, colonization of Siberia or even Antarctica would make much more sense.

Interstellar travel solves the "finite resources" problem. Granted, intrastellar travel can do that as well: Earth's moon first for its H3, then use that as a launchpad to go other places for resources that are limited or running out on Earth (iron, silicon, gold, etc.).

People vastly underestimate how big space is: by the time you do a round trip to your next-solar-system-resource-storage then the shortage it was supposed to address is no more (because society has adapted) and all the people who planned the expedition in the first place are long dead.

Space is big, inhospitable and mostly empty, its size doesn't work with the time frame the human species is working on.

Mars colonization doesn't make much sense, but building O'Neill Cylinders when humanity runs out of space or energy on Earth might.

>interstellar travel makes no sense

For vacation or finding new spices to sell, no, but if you've exhausted all the matter in the solar system or humanity outlives useful solar output from the sun and fusion energy is still +20 years away, there isn't really a choice.

The time it takes for interstellar travel doesn't make sense on human time scales, but people still plant trees knowing they will not live to sit under their shade.

> people still plant trees knowing they will not live to sit under their shade

Stuff like this really gives me faith in humanity amidst the insanity I see in the news.

I've been watching a "volunteer" oak sapling grow for the last few years and I'm trying to work around it so I don't have to cut it down. I may very well be dead before it provides appreciable shade, but it's nice knowing that it's there.

On the other hand, when my now 14-year-old was three, he stuck a cast-off bit of a branch (I think it's a basswood?) into the ground outside the house and declared it as his tree and watered it faithfully for a few days before losing interest. That "branch" now towers over the house and shades a room that used to get pretty hot in the afternoon. If I had any idea that it would actually take root and grow, I'd have moved it farther away from the house.

I like trees. I've planted a few using the County's native sapling program and it's been nice watching them grow over the last 15 years.

> Mars colonization doesn't make much sense, but building O'Neill Cylinders when humanity runs out of space or energy on Earth might.

Space on earth isn't going to run out anytime soon (as I said colonizing Siberia and Antarctica is much more approachable, and there's the oceans too!) especially since the world population is plateauing!

> but if you've exhausted all the matter in the solar system or humanity outlives useful solar output from the sun and fusion energy is still +20 years away

That “if” really feels like “I'll need a second hat if I grow a second head in the night”.

> The time it takes for interstellar travel doesn't make sense on human time scales, but people still plant trees knowing they will not live to sit under their shade.

That's a good analogy, because individuals do, but for-profits mostly plant trees with short lifetime and quick return on investment. And you're not going to fund space travel with individuals' money…

I'm inclined to disagree, because 8 days ago I found https://ors.daeken.dev from this hn-comment:

https://news.ycombinator.com/item?id=42388557

It's about multiple orbital rings around earth, and what that would enable.

Just needs some more https://daniel-suarez.com/Delta-v_synopsis.html and 'Critical Mass' ( sequel https://daniel-suarez.com/index.html ) to get into early The Expanse stage :)

I read tons of space opera when I was a teenager and I loved it, but the truth is that none of this makes sense: it's all about entertainment and that's it. It's not a practical description of what could be than Pirate of the Caribbeans is a description of the lives of 17th century's pirates.

I still disagree :)

Have you read Delta-V or a summary of it at least?

The 'opera' part is just about common human/political stupidity, the space and technology parts don't seem to be.

Which ors.deaken.dev conveniently leaves out, at the moment, like empty geopolitics :)

Colonization would, I think, not require economic justification. Using transportation and communication barriers to facilitate isolation or at least localization may be important to some people.

With vast discretionary spending, people would be able to sacrifice some pleasures for pleasures related to achieving a long-term impractical goal. Space travel does not have to be the most efficient means of enjoying life to be a human choice.

A colony in Antarctica would be much more practical than one on the Moon, but a Lunar colony is more romantic.

If material trade is not worthwhile, conquest may be somewhat discouraged. (Some people might wish to rule all of humanity or convert/exterminate all heretics, so no distance would be perfectly safe, but a perceived threat in Antarctica would be easier to eliminate than a perceived threat on the Moon or in the Large Magellanic Cloud.)

> Colonization would, I think, not require economic justification. Using transportation and communication barriers to facilitate isolation or at least localization may be important to some people. […]

> A colony in Antarctica would be much more practical than one on the Moon, but a Lunar colony is more romantic.

This really highlights the problem with the belief of “space colonization”: people have a romanticized fantasy of what it would be like: because it's so remote, and dangerous (and expensive), a lunar base would be the exact opposite of isolation: people would live packed in really tight space with little opportunity for isolation or intimacy except in the bathroom. It would be the modern version of being a sailor in a 17th century merchant ship, hopefully without the scurvy.

> but a perceived threat in Antarctica would be easier to eliminate than a perceived threat on the Moon or in the Large Magellanic Cloud.)

What makes you think that? If we have transportation mediums able to build a colony on the moon (that is, able to send tons of material out there) we have the means of transportation needed for carpet bombing it! But you wouldn't even need that, as a moon base would be as dependent from earth as an antarctic base is from mainland (you're not going to put a TSMC chip fab on the moon anytime soon…)

I think the security is actually pretty good on the other space bodies, provided the colony is self-sufficient and does not depend on supplies from Earth. Mars is better then Moon though.

The modern space rockets are slow and easily detectable, and I am sure that if one could get to the moon, and then wanted to build a system that shoots them down, they'd be able to. Especially given that moon-based interceptors will have much smaller gravity well to worry about.

Another argument is that very technically complex products, like space rockets, require a complex society. So if Earth falls into anarchy, there is a good chance the supply chains would be disturbed enough that no one could build multiple space rockets full of bombs even if they wanted to.

> I think the security is actually pretty good on the other space bodies,

You realize that any failure of a life-support device (air containment and renewal, water storage and renewal, heating) means you're dead before anyone can send help? It's like being stranded on an inflatable boat in the middle of the ocean: one tiny hole you can't fix and you're dead.

> provided the colony is self-sufficient and does not depend on supplies from Earth. Mars is better then Moon though.

Please tell me how your colony is going to manufacture the semiconductors it relies on in a self-sufficient way…

> So if Earth falls into anarchy,

That's the opposite argument from the one you made above (“Some people might wish to rule all of humanity or convert/exterminate all heretics” is the opposite of anarchy!) and in that case you're as safe on Antarctica from a military perspective.

> there is a good chance the supply chains would be disturbed

Which means death in medium terms, because as I said above as no space base can be self-sufficient (heck no country on earth can be self sufficient in the modern world already, how do you expect a small spacial colony to be better at self-sufficiency than China?!)

In that lens, there seems to be two obvious paths: expand to new planets or climb the Kardashev scale and use your limitless energy to recycle every atom.

As long as you can get to one of those stages before you run out of the required industrial capacity you should be fine.

If we absolutely had to, I think the human species could moonshot our way to either fusion or asteroid mining inside a couple decades. At least with our present resources, maybe not in a century from now.

What if we mined deeper? Earth has relatively small surface but vast volume.

You do know that earth is a Roman pizza, not a Neopolitan pizza. It has a thin crust.

I meant deeper than crust.

> What if we mined deeper?

Below the crust is the mantle, which is ~2,900km thick. Like the crust, is also mostly solid rocks and minerals, but punctuated by malleable areas of semi-solid magma. Composition primarily silicon, magnesium, and oxygen.

Below the mantle is the outer core, a liquid layer mostly made up of iron and nickel. The outer core is ~2,200km thick. It is primarily responsible for generating the magnetic field of earth.

Below the outer core is the solid inner core, with diameter of about 2,400km. It is solid and primarily made up of iron and nickel.

We never reached the mantle, I think, there might be plenty of good stuff there. After all crust is primarily composed of Oxygen, silicon and aluminum which sounds equally boring.

> 300 million years

3 thousand million?

I'm really surprised at how little concern there is for conserving metals and findings ways to recover them from landfills. Any amount of plastic, even a single straw, makes people angry, but you can waste a pretty large amount of metal or clay or any other natural material and it seems almost nobody cares.