16 Comments

(imagine the cost of coal if those third world coal miners were paid as much as the people who build solar panels)

Uhm, where do you think are solar panels being made and at what working conditions?

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You can stack multiple layers that capture light at different wavelength ranges

Yes, but they require exotic materials made of rare elements. Anyway, according to Wikipedia, the current efficiency record, using multiple junctions and lens for light concentration, is 43.5%. Given that the Carnot limit is 86%, I doubt actual efficiency is going to improve much more.

plus if you can just make them cheap enough per m^2 (this is where nanotech comes in), low efficiency doesn't matter.

IIUC, solar cell materials are not particularly complex at molecular level, thus I don't think that nanotech would be of much help.

Indeed it does not, but I thought the whole premise here was to see what would happen to a world that does have that kind of technology.

Drexler seems to believe that we are headed to a future where each one of us is going to have a nanofactory in their house (or in their smartphone) which can manufacture arbitrary things from cheap goo, little energy and blueprints downloaded from the internet.

I think that even if atomic manipulation technology advances greatly (which is itself uncertain), the energy and material constraints will still be significant.

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Energy will bound the world's total wealth, you can get somewhere with better organization but in the end you'll need more energy to "do things". But here's the thing, solar power is already cheaper than 5x times the cost of conventionals, it's more like 1-2x the cost, depending on geography and the inclusion of external costs (pollution, lung disease). There's also still room for technological advancement and scale increase in solar while fossils become ever more dependent on expensive deep-sea drilling, fracking and grossly underpaid coal miners (imagine the cost of coal if those third world coal miners were paid as much as the people who build solar panels).

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"By the way, modern photovoltaic cells perform at an efficiency within a factor of two/three of the theoretical maximum (approx 33%)."

You can stack multiple layers that capture light at different wavelength ranges (some of the will also work at night) and get more than 33%, plus if you can just make them cheap enough per m^2 (this is where nanotech comes in), low efficiency doesn't matter. It's not unlikely we'll see highrises and roofs covered in cheap solar foil that has a low efficiency but collectively generates a tremendous amount of power.

"Yes, but that doesn't seem to imply that the type of cheap, massive atomic level manufacturing Drexler loves to talk about is feasible."

Indeed it does not, but I thought the whole premise here was to see what would happen to a world that does have that kind of technology.

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Well, even if massive solar (PV and thermal) comes in at 5x the expense of conventionals, it looks just about ok for a generally richer future in the absence of fissile/fossil...?

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I agree that in the short-run fossil and fission look like most cost-effective. With enough capital development (and rare earths), there's a terrestrial solar abundance at theoretical max recovery for something like 10B people at current US consumption levels with a generous 10-factor for waste, hardware limits etc.

Fissile, properly managed, and accounting for sea water uranium, should give >10K years, depending on how you mix with solar.

The capital cost of this is all enormous of course, but not unbelievable for a richer future. In the longer run ( > 10K years) there's fusion or non-terrestrial solar to step for the fossil deficit. But frankly at those timescales I think Robin and Eric would regard all bets as off. ..

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Fossil fuels and fissiles WILL run out, so we have to find something else.

This doesn't mean that the replacement will be as much abundant and cheap.

A hyper-advanced civilization will have very cheap, highly efficient solar power and nuclear fusion that can easily power the world for many millions of years to come.

I'm always wary of cornucopian predictions like that. Are they based on science or mere wishful thinking and blind extrapolation from the historically exceptional industrial revolution?

By the way, modern photovoltaic cells perform at an efficiency within a factor of two/three of the theoretical maximum (approx 33%). Photosynthesis in biological organisms (that is, natural nanotech) has a maximum theoretical efficiency (sunlight-to-biomass) of approx. 11%, actual efficiency for typical crop plants is 1-2%, while sugarcane and algae can reach 8-9% under ideal conditions.

Controlled nuclear fusion might never become practical.

Advanced nanotech will allow for a graphene revolution (and probably bio-revolutions of algae and bacteria producing things like plastics for us) and very efficient recycling. Also, the further you go into the future, the more stuff like coltan will be on scrap heaps and in appliances all around the world instead of under the ground in a few countries.

Yes, but that doesn't seem to imply that the type of cheap, massive atomic level manufacturing Drexler loves to talk about is feasible.

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1) Fossil fuels and fissiles WILL run out, so we have to find something else. A hyper-advanced civilization will have very cheap, highly efficient solar power and nuclear fusion that can easily power the world for many millions of years to come.

2) Advanced nanotech will allow for a graphene revolution (and probably bio-revolutions of algae and bacteria producing things like plastics for us) and very efficient recycling. Also, the further you go into the future, the more stuff like coltan will be on scrap heaps and in appliances all around the world instead of under the ground in a few countries.

Naturally some countries will have some advantages over other countries but on the whole the differences will be smaller than they are today.

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That's far from obvious.

1) Energy is scarce. Modern technological processes are already quite efficient, there is room for improvement but not so much. Solar, wind, and other forms of distributed energy sources are intrinsically limited. Unless world population is greatly reduced or we settle for much smaller energy consumption per capita (which doesn't exactly sound like "radical abundance") we'll have to rely on things we dig up from the ground: fossil fuels and fissiles.

2) Even in the most optimistic Drexlerian nanotech scenarios, you can't transmute elements. You need specific elements to construct certain materials or perform certain chemical reactions. Substitutes might not be competitive. These specific elements might be rare in economically usable forms (think of Coltan).

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It's by manner of speaking. The point Drexler and I were making is that a world with advanced technology, especially nanotech is less likely to depend on a few highly localized natural resources.

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(the nanotech can work with sand, water and air, so to say). This is what Drexler means.

This looks more like magic than plausible technology.

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Yeah, it's pretty much wrong. As with everything else, you can now know a hell of a lot about music and that informs the music being produced. And that's without even mentioning the technical advances in the production of music. The mere fact that anyone can record now, whereas this was literally not true thirty years ago.

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"what gains we see in software are likely because of hardware gains, not because we can share software files fast"

What about github, open source, package managers, etc.? By what definition of software progress have they not accelerated software progress?

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I wrote this as a comment on Hanson's original critique:

"Yes, relative poverty will always motivate people to bring change. People will always demand a fair distribution of everything technology has to offer. But it is not clear from the quote that Drexler is actually saying people won't care about relative poverty anymore, it sounds more like he's saying people won't fight anymore over trade routes or some rare resource that can only be found in some locations because nanotech can work with abundant materials."

It seems like I was right: Drexler was talking about international conflict.

"I find it hard to imagine nations not caring about resources if their citizens still care greatly."

Again, it's about international relations: people in every country can be putting the rich to the guillotine, and still there can be world peace between the countries if no country controls a rare substance or trade route (the nanotech can work with sand, water and air, so to say). This is what Drexler means.

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That's shockingly obtuse. You don't think the last 20 years have shown progress in music and software, even though I can now store months of music on something that will fit in the palm of my hand and your own links states "a factor of 43,000 was due to improvements in the efficiency of software algorithm". How long did electricity or running water take to reach the level of global market penetration that smartphones have hit in under a decade?

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"and what gains we see in software are likely because of hardware gains, not because we can share software files fast."

In order to have good software, we both need to develop the software, and have the hardware to support it. The fact that the gains we see are correlated with the hardware would suggest that the hardware is the bottleneck, and the gains in software would be even more rapid, if we had the hardware to support it.

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