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Ringworld goes into this topic quite a bit, so it was interesting to me to see that the author is an astrobiologist who wrote "The Knowledge", about restarting

by wcarss 6y ago

Ringworld goes into this topic quite a bit, so it was interesting to me to see that the author is an astrobiologist who wrote "The Knowledge", about restarting civilization from scratch. Niven (who wrote Ringworld) also co-wrote "Lucifer's Hammer" with Jerry Pournelle, which was like a fun book version of a big-cast disaster movie, about a comet colliding with the earth in the mid-1970s. Lucifer's Hammer had some fairly realistic assessments of life in the following 5-10 years after the event, centred around restarting production. One big point was about some books very similar in concept to "The Knowledge" being used to preserve necessary information, and another was about recapturing some existing nuclear facilities to try to sustain life at all, given the big energy requirements for agriculture and basic personal heat after the event (because of e.g. huge amounts of atmospheric dust) Reading this article also made me realize, with surprise, that I've never thought about this aspect of Fermi's paradox! One of the many variables that led to our civilization's rise may be the simple fact that we had hundreds of millions of years of abundant life before us that failed to industrialize. Imagine if human-like life had evolved a billion years ago, when the reservoirs of petrochemicals were a billion years less developed? If it turns out that both life and sentient life are actually surprisingly common, it might be the case that most civilizations are borne unto planets not yet ready to support their technological advancement, and all they can do is burn out the wick before they reach a powderkeg moment. The great filter could work the other way -- we could be the rare success merely by dint of having shown up 'late'. Fun article!

Kaibeezy 6y ago
Fossil fuel depletion is also a key impetus for the action in Pastwatch: The Redemption of Christopher Columbus by Orson Scott Card. TV Tropes calls this a "Morton's Fork" and describes it for this book as: What spurs the decision to change the past even though it'll erase our timeline and existence is the fact that Earth is doomed to an even worse apocalyptic scenario than the one they've already experienced. The human population will be reduced to under 10 million, and humanity will be plunged back into the Stone Ages with little hope of ever rising to civilization ever again, as they have exhausted all easily available energy sources and climate change means they will soon be facing a new ice age. https://tvtropes.org/pmwiki/pmwiki.php/Literature/PastwatchTheRedemptionOfChristopherColumbus https://tvtropes.org/pmwiki/pmwiki.php/Literature/PastwatchT...
jobigoud 6y ago
Another "if" I'm often wondering is about the size of the Earth. Had we shown up on something the size of the Moon or Ganymede, the amount of resources we would have had at our disposal would have been a lot smaller. We would probably have figured that we weren't the center of the Solar system much sooner though. On the other hand if an intelligent species spawns on a much larger planet they can progress much longer before depleting their resources.
- godelski 6y ago
  Those bodies are too small to have a real atmosphere. Nor would they have molten cores which provide the magnetospheres essential for their radiation shielding and being able to have an electric ground. While neither of these are necessary, per se, they are extremely helpful (especially having an electric ground) and I think make a big difference when we're talking about advanced life vs microbial.
- TeMPOraL 6y ago
  Conversely, were we born on a world a bit larger than Earth, we wouldn't be able to reach orbit the way we did, due to limits of chemical rocket propulsion.
  - bsder 6y ago
    I thought this, too, but someone did the math and were not as close to the boundary as you think. It's something like the Earth would have to be 10x bigger to prevent chemical rocketry from working.
    - philwelch 6y ago
      From working at all, sure, but how big would those rockets have to be? Rocketry doesn’t exist just because some idealists wanted to go to space. It exists because governments wanted to invent new ways to bomb their enemies. A V-2 allows you to bomb England from continental Europe (and wasn’t even a cost-effective solution for that); nobody was going to build a Saturn V-sized rocket for that use case, and even if they wanted to, it’s not clear that they could get it to work without lots of testing with smaller prototypes.[1] Compounding this issue is that, on this hypothetically larger planet, whatever enemies you’d want to bomb in the first place could also be much farther away! Whereas on Earth it’s not hard to reach any other point on the planet; a little over a decade from the V-2 we had ICBM’s. [1] By way of analogy, Lofstrom loops are theoretically much more efficient than rockets, but to find out for sure we’d have to build a full scale example, and that would be extremely expensive even if we didn’t run into any unforeseen cost overruns or delays—which we inevitably would because this would be the first time we built anything like this. It would be like ITER except at least ITER has a practical application if it works.
Ekaros 6y ago
Add to this. With many of works of sci-fi and really really old species I wonder what is the realistic from stellar formation standpoint. So how long ago was there first planet with sufficient amount of metals to form an advanced civilisation? Or even hypothetical species living in space. It does take some time for stars to form go through life cycle and the release the heavier elements.
walleeee 6y ago
> Imagine if human-like life had evolved a billion years ago, when the reservoirs of petrochemicals were a billion years less developed? Perhaps then we (they?) would have had time to contemplate the consequences of burning through that massive biochemical battery with wild abandon! > The great filter could work the other way -- we could be the rare success merely by dint of having shown up 'late'. Personally I like the idea of a middle ground between this and the more common inversion: that there's an optimal planetary resource balance wherein a species can develop enough technology to keep the wick from burning out, but energy densities are not sufficient to ignite the same kind of powder keg we have. Filter-traversing civilizations would be even rarer, then. But yeah, super fun to think about.
njarboe 6y ago
One interesting thing to contemplate along these lines is that the U235 to U238 ratio of naturally occurring uranium changes through time on Earth. They had about the same abundance when the Solar System was created but they have different half lives. U235 is about 0.70 billion years and U238 at about 4.47 billion years. Currently U235 is only 0.7% of natural uranium, but one can make a nuclear reactor with natural water as a regulator with ratios of about 3%. So for most of Earth's history an intelligent race could probably develop nuclear power at the wood burning level of energy production. If nuclear and coal were developed in tandem, I can't imagine coal winning out. It is so much less safe and dirty. There is even geologic formations where natural nuclear reactors existed in the past[1]. [1]https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...
- whatshisface 6y ago
  >It is so much less safe and dirty. When people say "nuclear reactors are safe," they mean advanced modern designs with computers everywhere and precise engineering, not a Bronze-age clay kiln filled to the brim with enriched material.
  - njarboe 6y ago
    You would be amazed how dangerous smoke is for human health. Even today burning coal is estimated to kill a few million people per year.
    - whatshisface 6y ago
      I know how bad particulate matter is, but I'm not sure if you've thought through the implications of running a nuclear reactor in biodegradable containment and without any way to safely access the inside. I guess it might make a nice dystopian novel, perhaps the bronze age nuclear power company sends in war captives or something like that.
      - njarboe 6y ago
aruggirello 6y ago
Mandatory read, the Silurian Hypothesis: https://en.wikipedia.org/wiki/Silurian_hypothesis https://en.wikipedia.org/wiki/Silurian_hypothesis

by wcarss 6y ago

Kaibeezy 6y ago

Fossil fuel depletion is also a key impetus for the action in Pastwatch: The Redemption of Christopher Columbus by Orson Scott Card. TV Tropes calls this a "Morton's Fork" and describes it for this book as: What spurs the decision to change the past even though it'll erase our timeline and existence is the fact that Earth is doomed to an even worse apocalyptic scenario than the one they've already experienced. The human population will be reduced to under 10 million, and humanity will be plunged back into the Stone Ages with little hope of ever rising to civilization ever again, as they have exhausted all easily available energy sources and climate change means they will soon be facing a new ice age. https://tvtropes.org/pmwiki/pmwiki.php/Literature/PastwatchTheRedemptionOfChristopherColumbus https://tvtropes.org/pmwiki/pmwiki.php/Literature/PastwatchT...

jobigoud 6y ago

Another "if" I'm often wondering is about the size of the Earth. Had we shown up on something the size of the Moon or Ganymede, the amount of resources we would have had at our disposal would have been a lot smaller. We would probably have figured that we weren't the center of the Solar system much sooner though. On the other hand if an intelligent species spawns on a much larger planet they can progress much longer before depleting their resources.

godelski 6y ago
Those bodies are too small to have a real atmosphere. Nor would they have molten cores which provide the magnetospheres essential for their radiation shielding and being able to have an electric ground. While neither of these are necessary, per se, they are extremely helpful (especially having an electric ground) and I think make a big difference when we're talking about advanced life vs microbial.
TeMPOraL 6y ago
Conversely, were we born on a world a bit larger than Earth, we wouldn't be able to reach orbit the way we did, due to limits of chemical rocket propulsion.
- bsder 6y ago
  I thought this, too, but someone did the math and were not as close to the boundary as you think. It's something like the Earth would have to be 10x bigger to prevent chemical rocketry from working.
  - philwelch 6y ago
    From working at all, sure, but how big would those rockets have to be? Rocketry doesn’t exist just because some idealists wanted to go to space. It exists because governments wanted to invent new ways to bomb their enemies. A V-2 allows you to bomb England from continental Europe (and wasn’t even a cost-effective solution for that); nobody was going to build a Saturn V-sized rocket for that use case, and even if they wanted to, it’s not clear that they could get it to work without lots of testing with smaller prototypes.[1] Compounding this issue is that, on this hypothetically larger planet, whatever enemies you’d want to bomb in the first place could also be much farther away! Whereas on Earth it’s not hard to reach any other point on the planet; a little over a decade from the V-2 we had ICBM’s. [1] By way of analogy, Lofstrom loops are theoretically much more efficient than rockets, but to find out for sure we’d have to build a full scale example, and that would be extremely expensive even if we didn’t run into any unforeseen cost overruns or delays—which we inevitably would because this would be the first time we built anything like this. It would be like ITER except at least ITER has a practical application if it works.

Ekaros 6y ago

Add to this. With many of works of sci-fi and really really old species I wonder what is the realistic from stellar formation standpoint. So how long ago was there first planet with sufficient amount of metals to form an advanced civilisation? Or even hypothetical species living in space. It does take some time for stars to form go through life cycle and the release the heavier elements.

walleeee 6y ago

> Imagine if human-like life had evolved a billion years ago, when the reservoirs of petrochemicals were a billion years less developed? Perhaps then we (they?) would have had time to contemplate the consequences of burning through that massive biochemical battery with wild abandon! > The great filter could work the other way -- we could be the rare success merely by dint of having shown up 'late'. Personally I like the idea of a middle ground between this and the more common inversion: that there's an optimal planetary resource balance wherein a species can develop enough technology to keep the wick from burning out, but energy densities are not sufficient to ignite the same kind of powder keg we have. Filter-traversing civilizations would be even rarer, then. But yeah, super fun to think about.

njarboe 6y ago

One interesting thing to contemplate along these lines is that the U235 to U238 ratio of naturally occurring uranium changes through time on Earth. They had about the same abundance when the Solar System was created but they have different half lives. U235 is about 0.70 billion years and U238 at about 4.47 billion years. Currently U235 is only 0.7% of natural uranium, but one can make a nuclear reactor with natural water as a regulator with ratios of about 3%. So for most of Earth's history an intelligent race could probably develop nuclear power at the wood burning level of energy production. If nuclear and coal were developed in tandem, I can't imagine coal winning out. It is so much less safe and dirty. There is even geologic formations where natural nuclear reactors existed in the past[1]. [1]https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...

whatshisface 6y ago
>It is so much less safe and dirty. When people say "nuclear reactors are safe," they mean advanced modern designs with computers everywhere and precise engineering, not a Bronze-age clay kiln filled to the brim with enriched material.
- njarboe 6y ago
  You would be amazed how dangerous smoke is for human health. Even today burning coal is estimated to kill a few million people per year.
  - whatshisface 6y ago
    I know how bad particulate matter is, but I'm not sure if you've thought through the implications of running a nuclear reactor in biodegradable containment and without any way to safely access the inside. I guess it might make a nice dystopian novel, perhaps the bronze age nuclear power company sends in war captives or something like that.
    - njarboe 6y ago

aruggirello 6y ago

Mandatory read, the Silurian Hypothesis: https://en.wikipedia.org/wiki/Silurian_hypothesis https://en.wikipedia.org/wiki/Silurian_hypothesis