Experience curves, large populations, and the long run

If our civilization avoids catastrophe, will we generally be able to advance technology to close to physical limits, match or exceed observed biological abilities, and colonize the universe? Or will we be stuck in a permanent technological plateau before that, reaching a state where resources are insufficient to make the breakthroughs to acquire resources and continue progress? Experience curves, which forecast cost improvements in technology as a function of cumulative production, are a popular tool for technological forecasting and perform relatively well compared to other statistical approaches, although they inevitably have significant and increasing error as one extrapolates further. If we consider the maximum energy resources and population of the Earth, combined with the potential lifetime of human civilization (absent existential catastrophe), experience curves extrapolate to immense technological improvements (constrained by physical limits), more than sufficient to colonize the rest of the solar system, which in turn yields a billionfold increase in potential scale to fund interstellar colonization. Such extrapolation would suggest matching or exceeding biological capacities we currently lack, such as the computational efficiency of brain tissue, or the rapid energy payback of algae as solar energy and manufacturing devices.

Terrestrial solar energy could eventually support extremely large economies and populations

If we are interested in whether Earth's civilization could ever reach various technological milestones, or long run economic output and populations that Earth could sustain, the terrestrial solar energy resource can provide helpful information. Using efficiencies of the best lab solar cells, covering the earth with solar panel platforms could provide a thousand times as much energy as our civilization currently uses, and more than a hundred times the production of the terrestrial biosphere. Historical experience curve and cost data suggest this energy supply could be much cheaper than current energy prices, although with increasing overhead costs as less desirable areas such as ocean platforms and less sunny lands are used. Energy payback times are already under a year for energy-efficient solar in good locations, and have been falling along with prices, so solar energy can power its own construction, and with advanced robotics and AI might eventually grow at extremely rapid rates. 

The High Frontier, space based solar power, and space manufacturing

The High Frontier, published in 1976 by Gerard K O'Neill, lays out a vision of economically profitable space colonization in artificial orbital habitats, and guessed (while disclaiming it as prediction) that it was "unlikely" that a space community would not be established in 30 years. I was interested in why those forecasts were made, and why they turned out wrong, as data points for thinking about forecasting future technological developments. The book lays out a case that in the long run space habitats can support immensely larger populations and wealth than the planets in the Solar System. In the medium term it argued that a government program to invest hundreds of billions of dollars to build space factories and Lunar mining facilities would eventually let them produce solar power a few times more efficiently than terrestrial solar power production, and that this would drive space colonization. This seems to have been doomed for multiple reasons, radically underestimating launch costs and likely fatally underestimating the increased costs of space production (to be paid for out of a 2-3x improvement in solar radiation), as well as requiring immense government funding. As a means to improve solar power cost-effectiveness, it would have been far inferior to solar cell R&D. Subsequent orders-of-magnitude improvement in launch costs per kW of solar cells make space-based solar more plausible than at the time, but the challenge of competing with terrestrial solar and especially terrestrial scale economies of industry remains high.

Financial returns of interstellar colonization for the sedentary

Summary: In thinking about the likelihood of interstellar colonization by our civilization, or possible alien civilizations, one question is motivation: how strong are the incentives to do so? If moderately fast self-replicating probes can build infrastructure in a new solar system and send back information or material goods requiring extensive experimentation or computation to produce, then even at current market interest rates a colonization mission could deliver extremely high return on investment. For patient long-lived decision-makers with strong property rights or stability, returns could be overwhelming.

Spreading happiness to the stars seems little harder than just spreading

Imagine there are two advanced interstellar civilizations near one another who begin outward colonization around the same time, in an otherwise uninhabited accessible universe. One civilization likes to create convert star systems into lots of people leading rich, happy lives full of interest and reward. Call them the Eudaimonians. The other is solely interested in expanding its sphere of colonization as quickly as possible, and produces much less or negative welfare. Call them the Locusts. How much of a competitive advantage do the Locusts have over the Eudaimonians? How much of the cosmic commons, as Robin Hanson calls it, would wind up transformed into worthwhile lives, rather than burned to slightly accelerate colonization efforts? If the Locusts will inevitably capture almost all resources, then little could be done to avert astronomical waste, but an even waste-free split of the accessible universe could be half as good as a Eudaimonic monopoly.

I would argue that in our universe the Eudaimonians will be almost exactly as competitive as the Locusts in rapidly colonizing the stars. The reason is that the Eudaimonians can also adopt a strategy of near-maximum colonization speed until they reach the most distant accessible galaxies, and only then divert resources to producing welfare. More below the fold.

Can catch-up growth take us to the stars?

Will our civilization ever be able to colonize the stars and avert astronomical waste? Will we create computer programs more intelligent and energy-efficient than ourselves, enabling much larger and smarter sapient populations? We don't know exactly how hard it will be to engineer interstellar probes, or build AI, and we probably won't be sure until we actually do so.

However, we can shed some light on the question of whether humanity will ever be able to colonize the stars by asking how existing methods and technologies could increase our capacities, if they were deployed widely and to their limits. Here's a thought experiment: if we imagine that we were magically frozen in roughly our current technological regime for a time, long enough for Malthusian population growth and competition, how much would our economic and scientific production grow? By Malthusian, I mean that population would keep increasing until food costs started to price people out of reproduction, with higher-income folk reproducing more, and institutions that lead to high incomes spreading through migration, imitation or conquest.

Below the fold, I consider several dimensions where existing systems could simply be scaled up to increase global output and R&D: bringing poor countries up to the standards of rich countries, increasing population, and increasing average human capital within countries to near the level of the best-endowed households. Collectively, I estimate they could increase global R&D efforts by more than one hundred fold.