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I love Centauri Dreams. It's hopeful, makes me feel perspective, and realize how small and primitive we are. We fret every day about consumption, waste, and en

I love Centauri Dreams. It's hopeful, makes me feel perspective, and realize how small and primitive we are. We fret every day about consumption, waste, and energy, and here are some people discussing methods of moving planet-sized objects. It's a kind of optimism that's so rare it almost feels outdated.

theothermkn 8y ago
> We fret every day about consumption, waste, and energy,... I'm afraid we have to keep fretting. In the Numberphile video about the number of particles in the Universe (https://youtu.be/lpj0E0a0mlU?t=378 https://youtu.be/lpj0E0a0mlU?t=378), they take an interesting diversion to ask "How long until every particle in the Universe is inside a human being?" In other words, when will we reach the ultimate limit to growth? Well, at the current annualized population growth, it's less than 9000 years! And that scenario involves every human being at that future time floating around naked in the vacuum of space. There is no food to eat, water to drink, nor air to breathe left over. Practically, this means a couple of things that are less than obvious. First, the best case is that we will reach a point where the growth in volume of the space we occupy will exceed the speed of light. In other words, "long" before 9000 years from now, we will either establish some sort of equilibrium, or we will run up against a hard Malthusian limit. We will absolutely be concerned about "consumption, waste, and energy" in a way that is far more focused than it is now. (The only economic models that are permitted to work are zero-growth models, practically speaking.) Second, to give you an idea of how soon this is coming, the Universe is much larger than 9000 light-years across. That is to say, even if we could manage the resource usage of our 1.011% growth rate optimally, we could never actually fill the Universe in that time frame, as it would take about 15 billion years or so if we were all flinging ourselves outward at very near the speed of light. (n retrospect, these two are restatements of the same idea.) Finally, and most dismally, the analogous calculation for the Solar System (an infinitely more reasonable calculation to perform) must be abysmally worse and monumentally more urgent. To give you an idea, the current doubling time of human population is something like 60 years. That means, for example, that if we were to anticipate that we'd run out of meaningful room on Earth in 60 years' time, we'd have to start working on our "second home" now, to have it ready. Once it was ready, we'd have to be working on two more. Then four, and so on. Good luck with that! (Note: After we have consumed the Earth and converted it to habitats, we will have to consume Jupiter in a similar way in about 500 years. This gets out of hand very quickly.) EDIT: El-oh-el at the few people who's fee-fees were hurt enough by this back-of-the-envelope analysis of growth rates and resource use to downvote it. Keep fighting the good fight, no matter how lonely!
- twodave 8y ago
  Of course, "current annualized population growth" is a hilariously bad assumption to make for the next 9,000 years. I would expect population controls long before having our "second home" prepared that would limit the rate of our population growth to the speed we can realistically expand. I also don't think humanity will last this long, but as an academic problem it's fun to think about.
  - perl4ever 8y ago
    It's not like humans are the only thing that grows exponentially for a limited period of time. If the yeast in a loaf of bread continued growing, it too would fill the universe very quickly. The saying is "trends that can't continue, won't".
  - antt 8y ago
    >Of course, "current annualized population growth" is a hilariously bad assumption to make for the next 9,000 years. I would expect population controls long before having our "second home" prepared that would limit the rate of our population growth to the speed we can realistically expand. Funny I would have expected that to happen when we started consuming more than the primary production of the planet: https://www.nationalobserver.com/2017/08/09/opinion/heres-how-many-earths-we-need-meet-our-populations-demand https://www.nationalobserver.com/2017/08/09/opinion/heres-ho... We didn't.
    - twodave 8y ago
      This is not a planet-scale phenomenon, though. Any student of geography would know that as nations become more mature their birth rates stabilize to more or less match the death rate. It is the less-developed countries that would suffer first in a world where our planet can no longer support our population, in which case I would expect that either they would go to war with each other over whatever resources can be taken from each other (and also reducing their populations in the process) or else face starvation (again, reducing population). Either way there's a large difference between starvation and saturation. The human race is not endangered by the fact that we'll soon saturate our planet, and those that do starve as a result would simply join a long line of people who have already met the same fate.
wallace_f 8y ago
If you do fret about those, the article was inspiring, free, and creates little waste. Unlike most of what is for sale in this world, which happens to be uninspiring garbage.

theothermkn 8y ago

> We fret every day about consumption, waste, and energy,... I'm afraid we have to keep fretting. In the Numberphile video about the number of particles in the Universe (https://youtu.be/lpj0E0a0mlU?t=378 https://youtu.be/lpj0E0a0mlU?t=378), they take an interesting diversion to ask "How long until every particle in the Universe is inside a human being?" In other words, when will we reach the ultimate limit to growth? Well, at the current annualized population growth, it's less than 9000 years! And that scenario involves every human being at that future time floating around naked in the vacuum of space. There is no food to eat, water to drink, nor air to breathe left over. Practically, this means a couple of things that are less than obvious. First, the best case is that we will reach a point where the growth in volume of the space we occupy will exceed the speed of light. In other words, "long" before 9000 years from now, we will either establish some sort of equilibrium, or we will run up against a hard Malthusian limit. We will absolutely be concerned about "consumption, waste, and energy" in a way that is far more focused than it is now. (The only economic models that are permitted to work are zero-growth models, practically speaking.) Second, to give you an idea of how soon this is coming, the Universe is much larger than 9000 light-years across. That is to say, even if we could manage the resource usage of our 1.011% growth rate optimally, we could never actually fill the Universe in that time frame, as it would take about 15 billion years or so if we were all flinging ourselves outward at very near the speed of light. (n retrospect, these two are restatements of the same idea.) Finally, and most dismally, the analogous calculation for the Solar System (an infinitely more reasonable calculation to perform) must be abysmally worse and monumentally more urgent. To give you an idea, the current doubling time of human population is something like 60 years. That means, for example, that if we were to anticipate that we'd run out of meaningful room on Earth in 60 years' time, we'd have to start working on our "second home" now, to have it ready. Once it was ready, we'd have to be working on two more. Then four, and so on. Good luck with that! (Note: After we have consumed the Earth and converted it to habitats, we will have to consume Jupiter in a similar way in about 500 years. This gets out of hand very quickly.) EDIT: El-oh-el at the few people who's fee-fees were hurt enough by this back-of-the-envelope analysis of growth rates and resource use to downvote it. Keep fighting the good fight, no matter how lonely!

twodave 8y ago
Of course, "current annualized population growth" is a hilariously bad assumption to make for the next 9,000 years. I would expect population controls long before having our "second home" prepared that would limit the rate of our population growth to the speed we can realistically expand. I also don't think humanity will last this long, but as an academic problem it's fun to think about.
- perl4ever 8y ago
  It's not like humans are the only thing that grows exponentially for a limited period of time. If the yeast in a loaf of bread continued growing, it too would fill the universe very quickly. The saying is "trends that can't continue, won't".
- antt 8y ago
  >Of course, "current annualized population growth" is a hilariously bad assumption to make for the next 9,000 years. I would expect population controls long before having our "second home" prepared that would limit the rate of our population growth to the speed we can realistically expand. Funny I would have expected that to happen when we started consuming more than the primary production of the planet: https://www.nationalobserver.com/2017/08/09/opinion/heres-how-many-earths-we-need-meet-our-populations-demand https://www.nationalobserver.com/2017/08/09/opinion/heres-ho... We didn't.
  - twodave 8y ago
    This is not a planet-scale phenomenon, though. Any student of geography would know that as nations become more mature their birth rates stabilize to more or less match the death rate. It is the less-developed countries that would suffer first in a world where our planet can no longer support our population, in which case I would expect that either they would go to war with each other over whatever resources can be taken from each other (and also reducing their populations in the process) or else face starvation (again, reducing population). Either way there's a large difference between starvation and saturation. The human race is not endangered by the fact that we'll soon saturate our planet, and those that do starve as a result would simply join a long line of people who have already met the same fate.

wallace_f 8y ago

If you do fret about those, the article was inspiring, free, and creates little waste. Unlike most of what is for sale in this world, which happens to be uninspiring garbage.