5 ms·

A more interesting question is : what kind of delay is worth worrying about? I mean, for instance it is known that life will remain possible on Earth for about

A more interesting question is : what kind of delay is worth worrying about? I mean, for instance it is known that life will remain possible on Earth for about 500 million years, after which the Sun will be too bright. We don't seriously worry about it, since so many things can happen in half a billion years that it does not make much sense to try to plan or predict anything in such a timeframe. Similarly, I personally don't worry about an impactor of 10 km diameter or so. Such an event is so rare that it's not likely to happen in several million years. To me that's still the kind of timeframe it does not make sense to worry about. I'm sure some people will disagree though. What is the limit? 10,000 years? 1,000? 100?

adrianN 11y ago
Eventually you'll have to start worrying about very small but existential risks if you want any chance of preventing them. If the potential costs are as huge as they are with meteor impacts, I think the expected value of preparation is big enough.
- sillysaurus3 11y ago
  The way to do this is to make it profitable to worry about it. Some say that certain asteroids are worth trillions. While they're probably not worth quite that much, they're a pretty penny. Investors might be interested in a company designed to capture and harvest asteroids. It will probably take a few centuries before that's a possibility, but it's interesting that it's probably just a matter of time before it doesn't sound so crazy.
  - Beltiras 11y ago
    Someone trying to make it profitable: http://www.planetaryresources.com/#home-intro http://www.planetaryresources.com/#home-intro
    - deleted 11y ago
      [deleted]
mikeash 11y ago
Reminds me of one of my favorite jokes. The professor is lecturing, and says, "The Sun will grow to be a red giant, destroying all life on Earth in about a billion years...." A distracted student suddenly sits up and cries out, "Oh my god!" The professor says, "What's wrong? A billion years is a long time, you know. Nothing to worry about." The student is visibly relief. "Oh, great! I thought you said a million years!" Personally, I'd say a few hundred years is probably the reasonable max, maybe a thousand years. Beyond that, technology will be so incomprehensibly different that the risks and challenges will be completely different as well. What would be a civilization-killing asteroid today might just be "ooh, tasty resources already on a convenient trajectory" tomorrow. Or "aw shucks, it's going to make a big splash in the gray goo."
- NoMoreNicksLeft 11y ago
  I strongly suspect that our species is already on its way to inevitable extinction, and much more quickly than a few hundred years. Barring some science fiction scenarios, fertility has dropped below replacement and is of a nature where it never truly rises. Children who grow up in a low-fertility environment learn behaviors and personality traits that encourage and enhance the already-low fertility, and any who are atypical and have above-replacement fertility themselves are never enough to get the global average back to (or above) replacement. Not only have we trained the kids to have few kids themselves, we've trained them to train those few kids of their own the same (but with extra!). You can disagree, almost everyone does. But the implications of disagreement are bizarre, you must imagine some future where all 5th generation-only children wake up and say "I want 2.1 children" or 10 percent of those 5th generation children wake up and say "I want 20 children".
  - grondilu 11y ago
    Long ago I read "essai de prospective demographique"[1] written by French demographers. They were raising the concerns you mention and were trying to warn the public of a coming "demographic winter". So your point of view is not rare. That being said, even if a demographic winter would probably have very adverse consequences, as it is not clear how well the industrialized society would fare if the population was drastically reduced, I have hard time picturing how that could lead to the complete extinction of mankind. There will always be pockets of population with high fertility, at the very least among highly religious communities. Even if as you suggest reproductive behavior is transmitted, that works both ways, and simple natural selection will always, in the end, favor the reproductive behavior that leads to increasing numbers. Demographic winter is a serious concern, but I can't imagine it leading to a complete extinction. 1. https://books.google.fr/books/about/Essai_de_prospective_d%C3%A9mographique.html?id=lz9mPQAACAAJ&hl=fr https://books.google.fr/books/about/Essai_de_prospective_d%C...
gkya 11y ago
Once in a million years is not equal to a million years later. If an asteroid hit the earth today, a million years later one could say that the probability of an asteroid hitting earth is once in a million years.
Someone 11y ago
The sun getting bright is different than a meteorite impact. The latter has a Poisson distribution; a big one could hit next year, and the one following that in 10, but it also could be many thousands of years before the next big hit. On the other hand, if our understanding of astrophysics is even remotely correct, the sun will not get too bright for the first 100,000 years. So, it makes perfect sense to not worry about the sun now, as it will not happen soon. As to the limit: the Dutch design their sea defences for “once in a 10,000 year” events and their river defences for “once in 1,250 year” events (http://www.larouchepub.com/eiw/public/2005/2005_30-39/2005-39/pdf/43-47_38_ecodutch.pdf http://www.larouchepub.com/eiw/public/2005/2005_30-39/2005-3..., http://blog.longnow.org/02011/03/09/the-10000-year-storm/ http://blog.longnow.org/02011/03/09/the-10000-year-storm/) I also expect some governments have spent time thinking of what to do in case of impending “once in 500 million years” events (probably lumped together with all smaller ‘end of life on earth’ events. The big question here will be: (when) do you tell the public?)

adrianN 11y ago

Eventually you'll have to start worrying about very small but existential risks if you want any chance of preventing them. If the potential costs are as huge as they are with meteor impacts, I think the expected value of preparation is big enough.

sillysaurus3 11y ago
The way to do this is to make it profitable to worry about it. Some say that certain asteroids are worth trillions. While they're probably not worth quite that much, they're a pretty penny. Investors might be interested in a company designed to capture and harvest asteroids. It will probably take a few centuries before that's a possibility, but it's interesting that it's probably just a matter of time before it doesn't sound so crazy.
- Beltiras 11y ago
  Someone trying to make it profitable: http://www.planetaryresources.com/#home-intro http://www.planetaryresources.com/#home-intro
  - deleted 11y ago
    [deleted]

mikeash 11y ago

Reminds me of one of my favorite jokes. The professor is lecturing, and says, "The Sun will grow to be a red giant, destroying all life on Earth in about a billion years...." A distracted student suddenly sits up and cries out, "Oh my god!" The professor says, "What's wrong? A billion years is a long time, you know. Nothing to worry about." The student is visibly relief. "Oh, great! I thought you said a million years!" Personally, I'd say a few hundred years is probably the reasonable max, maybe a thousand years. Beyond that, technology will be so incomprehensibly different that the risks and challenges will be completely different as well. What would be a civilization-killing asteroid today might just be "ooh, tasty resources already on a convenient trajectory" tomorrow. Or "aw shucks, it's going to make a big splash in the gray goo."

NoMoreNicksLeft 11y ago
I strongly suspect that our species is already on its way to inevitable extinction, and much more quickly than a few hundred years. Barring some science fiction scenarios, fertility has dropped below replacement and is of a nature where it never truly rises. Children who grow up in a low-fertility environment learn behaviors and personality traits that encourage and enhance the already-low fertility, and any who are atypical and have above-replacement fertility themselves are never enough to get the global average back to (or above) replacement. Not only have we trained the kids to have few kids themselves, we've trained them to train those few kids of their own the same (but with extra!). You can disagree, almost everyone does. But the implications of disagreement are bizarre, you must imagine some future where all 5th generation-only children wake up and say "I want 2.1 children" or 10 percent of those 5th generation children wake up and say "I want 20 children".
- grondilu 11y ago
  Long ago I read "essai de prospective demographique"[1] written by French demographers. They were raising the concerns you mention and were trying to warn the public of a coming "demographic winter". So your point of view is not rare. That being said, even if a demographic winter would probably have very adverse consequences, as it is not clear how well the industrialized society would fare if the population was drastically reduced, I have hard time picturing how that could lead to the complete extinction of mankind. There will always be pockets of population with high fertility, at the very least among highly religious communities. Even if as you suggest reproductive behavior is transmitted, that works both ways, and simple natural selection will always, in the end, favor the reproductive behavior that leads to increasing numbers. Demographic winter is a serious concern, but I can't imagine it leading to a complete extinction. 1. https://books.google.fr/books/about/Essai_de_prospective_d%C3%A9mographique.html?id=lz9mPQAACAAJ&hl=fr https://books.google.fr/books/about/Essai_de_prospective_d%C...

gkya 11y ago

Once in a million years is not equal to a million years later. If an asteroid hit the earth today, a million years later one could say that the probability of an asteroid hitting earth is once in a million years.

Someone 11y ago

The sun getting bright is different than a meteorite impact. The latter has a Poisson distribution; a big one could hit next year, and the one following that in 10, but it also could be many thousands of years before the next big hit. On the other hand, if our understanding of astrophysics is even remotely correct, the sun will not get too bright for the first 100,000 years. So, it makes perfect sense to not worry about the sun now, as it will not happen soon. As to the limit: the Dutch design their sea defences for “once in a 10,000 year” events and their river defences for “once in 1,250 year” events (http://www.larouchepub.com/eiw/public/2005/2005_30-39/2005-39/pdf/43-47_38_ecodutch.pdf http://www.larouchepub.com/eiw/public/2005/2005_30-39/2005-3..., http://blog.longnow.org/02011/03/09/the-10000-year-storm/ http://blog.longnow.org/02011/03/09/the-10000-year-storm/) I also expect some governments have spent time thinking of what to do in case of impending “once in 500 million years” events (probably lumped together with all smaller ‘end of life on earth’ events. The big question here will be: (when) do you tell the public?)