= 27d567bc2d48d9f40e9ccc20ea370b15)
multifoliaterose comments on Open Thread June 2010, Part 3 - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (606)
I mean "existential risk" in a broad sense.
Suppose we run out of a source of, oh, say, electricity too fast to find a substitute. Then we would be forced to revert to a preindustrial society. This would be a permanent obstruction to technological progress - we would have no chance of creating a transhuman paradise or populating the galaxy with happy sentient machines and this would be an astronomical waste.
Similarly if we ran out of any number of things (say, one of the materials that's currently needed to build computers) before finding an adequate substitute.
My understanding is that a large scale nuclear war could seriously damage infrastructure. I could imagine this preventing technological development as well.
On the other hand, it's equally true that if another existential risk hits us before we friendly AI, all of our friendly AI directed efforts will be for naught.
That's not how economics works. If one source of electricity becomes scarce, that means it's more expensive, so people will switch to cheaper alternatives. All the energy we use ultimately comes from either decaying isotopes (fission, geothermal) or the sun; neither of those will run out in the next thousand years.
Modern computer chips are doped silicon semiconductors. We're not going to run out of sand any time soon, either. Of course, purification is the hard part, but people have been thinking up clever ways to purify stuff since before they stopped calling it 'alchemistry.'
The energy requirements for running modern civilization aren't just a scalar number--we need large amounts of highly concentrated energy, and an infrastructure for distributing it cheaply. The normal economics of substitution don't work for energy.
It's entirely possible that failure to create a superintelligence before the average EROI drops too low for sustainment would render us unable to create one for long enough to render other existential risks inevitabilities.
"Substitution economics" seems unlikely to stop us eventually substituting fusion power and biodesiel for oil. Meanwhile, we have an abundance of energy in the form of coal - more than enough to drive progress for a loooog while yet. The "energy apocalypse"-gets-us-first scenario is just very silly.
Energy economics is interconnected enough with politics to make me lower my expectation of rationality from both of us for the remainder of the discussion due to reference class forecasting. Also, we are several inferential steps away from each other, so any discussion is going to be long and full of details. Regardless, I'm going to go ahead, assuming agreement that market forces cannot necessarily overcome resource shortages (or the Easter Islanders would still be with us).
Historically, the world switched from coal to petroleum before developing any technologies we'd regard as modern. The reason, unlike so much else in economics, is simple: the energy density of coal is 24 MJ/kg; the energy density of gasoline is 44 MJ/kg. Nearly doubling the energy density makes many things practical that wouldn't otherwise be, like cars, trucks, airplanes, etc. Coal cannot be converted into a higher energy density fuel except at high expense and with large losses, making the expected reserves much smaller. The fuels it can be converted to require significant modifications to engines and fuel storage.
Coal is at least plausible, although a stop-gap measure with many drawbacks. It's your hopes for fusion that really show the wishful thinking. Fusion is 20 years away from being a practical energy source, just like it was in 1960. The NIF has yet to reach break-even; economically practical power generation is far beyond that point; assuming a substantial portion of US energy generation needs is farther still. It'd be nice if Polywell/Bussard fusion proved practical, but that's barely a speck on the horizon, getting its first big basic research grant from the US Navy. And nothing but Mr. Fusion will help unless someone makes an order of magnitude improvement in battery or ultracapacitor energy density.
No matter which of the alternatives you plan to replace the energy infrastructure with, you needed to start about 20 years ago. World petroleum production is no longer sufficient to sustain economic growth and infrastructure transition simultaneously. Remember, the question isn't whether it's theoretically possible to substitute more plentiful energy sources for the ones that are getting more difficult to extract, it's whether the declining EROI of current energy sources will remain high enough for the additional economic activity of converting infrastructure to other sources while still feeding people, let alone indulging in activities with no immediate payoff like GAI research.
We seem to be living in a world where the EROI is declining faster than willingness to devote painful amounts of the GDP to energy source conversion is increasing. This doesn't mean an immediate biker zombie outlaw apocalypse, but it does mean a slow, unevenly distributed "catabolic collapse" of decreasing standards of living, security, and stability.
Upvoted chiefly for
but I appreciate the analysis. (I am behind on reading comments, so I will be continuing downthread now.)
I don't know why you focus so much on fusion although I agree it isn't practical at this point. But note that batteries and ultracapacitors are just energy storage devices. Even if they become far more energy dense they don't provide a source of energy.
Unfortunately, that appears to be part of the bias I'd expected in myself--since timtyler mentioned fusion, biofuels, and coal; I was thinking about refuting his arguments instead of laying out the best view of probable futures that I could.
The case for wind, solar, and other renewables failing to take up petroleum's slack before it's too late is not as overwhelmingly probable as fusion's, but it takes the same form--they form roughly 0.3% of current world power generation, and even if the current exponential growth curve is somehow sustainable indefinitely they won't replace current capacity until the late 21st century.
With the large-scale petroleum supply curve, that leaves a large gap between 2015 and 2060 where we're somehow continuing to build renewable energy infrastructure with a steadily diminishing total supply of energy. I expect impoverished people to loot energy infrastructure for scrap metal to sell for food faster than other impoverished people can keep building it.
That we will eventually substitute fusion power and biodesiel for oil seems pretty obvious to me. You are saying it represents "wishful thinking" - because of the possibility of civilisation not "making it" at all? If so, be aware that I think that the chances of that happening seem to grossly exaggerated around these parts.
It seem very doubtful that we'll have practical fusion power any time soon or necessarily ever. The technical hurdles are immense. Note that any form of fusion plant will almost certainly be using deuterium-tritium fusion. That means you need tritium sources. This also means that the internal structure will undergo constant low-level neutron bombardment which seriously reduces the lifespan of basic parts such as the electromagnets used. If we look at he form of proposed fusion that has had the most work and has the best chance of success, tokamaks, then we get to a number of other serious problems such as plasma leaks. Other forms of magnetic containment have also not solved the plasma leak problem. Forms of reactors that don't use magnetic containment suffer from other similarly serious problems. For example, the runner up to magnetic containment is laser confinement but no one hasa good way to actually get energy out of laser confinement.
That said, I think that there are enough other potential sources of energy (nuclear fission, solar (and space based solar especially), wind, and tidal to name a few) that this won't be an issue.
Um.. not sure what you mean. The energy out of inertial (i.e., laser) confinement is thermal. You implode and heat a ball of D-T, causing fusion, releasing heat energy, which is used to generate steam for a turbine.
Fusion has a bad rap, because the high benefits that would accrue if it were accomplished encourage wishful thinking. But that doesn't mean it's all wishful thinking. Lawrence Livermore has seen some encouraging results, for example.
EDIT: for fact checking vis-a-vis LLNL.
Yeah, but a lot of that energy that is released isn't in happy forms. D-T releases not just high energy photons but also neutrons which are carrying away a lot of the energy. So what you actually need is something that can absorb the neutrons in a safe fashion and convert that to heat. Lithium blankets are a commonly suggested solution since a lot of the time lithium will form tritium after you bombard it with neutrons (so you get more tritium as a result). There's also the technically simpler solution of just using paraffin. But the conversion of the resulting energy into heat for steam is decidedly non-trivial.
I see, thanks.
Imagine what people must have thought in 1910 about the feasibility of getting to the Moon or generating energy by artificially splitting atoms (especially within the 20th century).
Two problems with that sort of comparison: First, something like going to the Moon is a goal, not a technology. Thus, if we have other sources of power, the incentive to work out the details for fusion becomes small. Second, one shouldn't forget how many technologies have been tried and have fallen by the wayside as not very practical or not at all practical. A good way of getting a handle on this is to read old issue of something like Scientific American from the 1950s and 1960s. Or read scifi from that time period. One of example of historical technology that never showed up on any substantial scale is nuclear powered airplanes, despite a lot of research in the 1950s about them. Similarly, nuclear thermal rockets have not been made. This isn't because they are impossible, but because they are extremely impractical compared to other technologies. It seems likely that fusion power will fall into the same category. See this article about Project Pluto for example.
These are perfectly valid arguments and I admit that I share your skepticism concerning the economic competitiveness of the fusion technology. I admit, if I had a decision to make about buying some security, the payout of which would depend on the amount of energy produced by fusion power within 30 years, I would not hurry to place any bet.
What I lack is your apparent confidence in ruling out the technology based on the technological difficulties we face at this point in time.
I am always surprised how the opinion of so called experts diverges when it comes to estimating the feasibility and cost of different energy production options (even excluding fusion power). For example there is recent TED video where people discuss the pros and cons of nuclear power. The whole discussion boils down to the question: What are the resources we need in order to produce X amount of energy using
power. For me, the disturbing thing was that the statements about the resource usage (e.g. area consumption, but also risks) of the different technologies were sometimes off by magnitudes.
If we lack the information to produce numbers in the same ballpark even for technologies that we have been using for decades (if not longer), then how much confidence can we have about the viability, costs, risks and competitiveness of a technology, like fusion, that we have not even started to tap.
Re: "Second, one shouldn't forget how many technologies have been tried and have fallen by the wayside as not very practical or not at all practical. [...] It seems likely that fusion power will fall into the same category."
Er, not to the governments that have already invested many billions of dollars in fusion research it doesn't! They have looked into the whole issue of the chances of success.
Automatically self-repairing nanotech construction? (To suggest a point where a straightforward way of dealing with this becomes economically viable.)
You would need not only self-repairing nanotech but such technology that could withstand both large amounts of radiation as well as strong magnetic fields. Of the currently proposed major methods of nanotech I'm not aware of any that has anything resembling a chance to meet those criteria (with the disclaimer that I'm not a chemist.) If we had nanotech that was that robust it would bump up so many different technologies that fusion would look pretty unnecessary. For example the main barrier to space elevators is efficient reliable synthesis of long chains of carbon nanotubes that could be placed in a functional composite (see this NASA Institute for Advanced Concepts Report for a discussion of these and related issues). We'd almost certainly have that technology well before anything like self-repairing nanotech that stayed functional in high radiation environments. And if you have functional space elevators then you get cheap solar power because it becomes very easy to launch solar power satellites.
I'm not talking about plausible now, but plausible some day, as a reply to your "It seem very doubtful ... any time soon or necessarily ever". The sections being repaired could be offline. "Self-repair" doesn't assume repair within volume of an existing/operating structure, it could be all cleared out and rebuilt anew, for example. That it's done more or less automatically is the economic requirement. Any other methods of relatively cheap and fast production, assembly and recycling will work too.
There don't seem to be too many electromagnets at the NIF: https://lasers.llnl.gov/
It seems to me that the problems are relatively minor, and so that we will have fusion power - with high probabilty this century.
[Wow - LW codebase doesn't know about https!]
I would have thought that those 'cheaper alternatives' could still be more expensive than the initial cost of the original source of electricity...? In which case losing that original source of electricity could still bite pretty hard (albeit maybe not to the extent of being an existential risk).
Yes.