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The article has a detailed analysis

I sure didn't see one! I saw some analysis of the cost of energy used for grinding up rock, with no consideration of other costs. Can you point me to the section with detailed analysis of the costs of mining, crushing, and spreading the rock, or the capital costs of grinders? A detailed analysis would have numbers for these things, not just dismiss them.

If you think that analysis goes wrong, I'd be curious to understand exactly where?

OK then.

What is quite certain is that the vast majority of that expense, both financially and in terms of energy, comes not from mining or crushing but from milling the crushed rock down to particle size.

Digging up and crushing olivine to gravel would be $20-30/ton. We know this from the cost of gravel and the availability of olivine deposits. That alone makes this uneconomical, yet the author just dismisses them as negligible next to the cost of milling. So either the dismissal is wrong, or the milling cost estimation is wrong, or both.

for an all-inclusive energy cost of 61 kWh ($9.15) per tonne of rock – about $7.32 per sequestered tonne of CO2

Why is the cost per ton of CO2 lower than the cost per ton of rock, when 1 ton of rock stores much less than 1 ton of CO2?

And the largest rock mills are large indeed; the biggest on the market can process tens of thousands of tonnes a day. It should be clear by now that capital expenditures, while not irrelevant, are small compared to the cost of energy

That's quite a non sequitur! We know what grinding rock to fine powder costs. Use those costs, not the cost of electricity.

olivine weathering

Gravel costs money. Making olivine gravel costs maybe $20/ton. You'd need to dig up 2.3 tons of pure Mg silicate to potentially absorb 1 ton of CO2, and realistically speaking your "ore" won't be pure or react completely, so the correct ratio is >3.

Suppose you do that. Great, you exposed some fresh magnesium silicate to the CO2 in air, and now a very thin layer of carbonate will form on the surface as it very slowly reacts. If you crush it to fine particles and spread it over a large area, you can get it to actually react, but that involves transporting it to a grinder and then spreading it out, which would bring your cost to probably >$200 per ton of CO2 absorbed. Not great. (Plus, all this digging and grinding uses energy, and probably involves vehicles that burn fuel.)

The above link talks about the cost of electricity needed to grind up a ton of olivine. This is a weird approach because people already grind up a lot of rocks and we know a lot about how much that currently costs. You should always base cost estimates on the costs of the most similar existing things. (Why don't people do that?)

The point there was just that we don't see an inverse relationship, with smarter humans having slower development during childhood. Yet, we do see that inverse relationship when we compare humans to other animals.

Regarding the other half of D:prodigy...I was making an empirical argument based on a large volume of literature, but if you consider the energy landscape of ANN systems, plateauing at bad performance means getting stuck in bad minima, and increasing the number and quality of good paths through the energy landscape is both what makes that less likely and what increases the speed of gradient descent.

As I noted, this raises the question of what's different about human childhood development that requires it to be slow.

To me it seems a personality trait of well informed people, that they are not as interested in searching or building capital.

Yes, there's a tradeoff between putting effort into research and putting it into "hustle", and usually people specialize in doing one. But it's not like "ability to partner with someone who searches for capital" is the real bottleneck. I'd say instead that there are certain people in the position to raise capital, but they have to believe in the technology and pitch it themselves, and they need to be on the same wavelength as people like Bill Gates and the moral maze masters, and the people in those positions who can communicate with investors are more likely to be delusional than to understand technology really well.

Also as an aside, what is your interpretation of the Bill Gates article? I see no particular evidence of a lack of physics knowledge, are you referring to the take about the water comments or? It's definitely not an in-depth description of the problems with PWRs or BWRs, but I think is an acceptable explanation of the advantages of using LMRs. Maybe there is some other comment I am missing, but it comes across as an easily accessible article written to persuade the layman of the benefits of his endeavor?

Sure, I can explain.

First, water isn’t very good at absorbing heat—it turns to steam and stops absorbing heat at just 100 degrees C

Water is actually rather good at absorbing heat. It has a much higher heat capacity than sodium, boiling absorbs a lot of heat if you boil it, and in a typical BWR design it boils at 285 C.

The Natrium plant uses liquid sodium, whose boiling point is more than 8 times higher than water’s

Gates is using unspecified temperature units and pressure, presumably Celcius at 1 bar. Divisions of temps in C aren't meaningful - does water have -3x the boiling point of ammonia?

Unlike water, the sodium doesn’t need to be pumped, because as it gets hot, it rises, and as it rises, it cools off

Water does that too. It's an almost universal property of liquids. You can do natural convection cooling with water.

Safety isn’t the only reason I’m excited about the Natrium design

The TerraPower Natrium design is much less safe than current reactors, and using sodium does nothing to improve safety. The sodium reduces reactivity so if the coolant boils off then reactivity increases. That's bad. The neutrons are fast so neutron lifetime is short so response time needs to be fast. That's bad. IIRC the design still involves robots moving fuel rods around during operation. That can fail.

It's just a really terrible design. Bad safety, and very expensive design decisions. Supposedly in the future they plan to use a "Pascal" heavy water moderated CO2 cooled reactor, which I always considered a better approach, but I have little faith in TerraPower doing a good job on it.

Like other power plant designs, it uses heat to turn water into steam, which moves a turbine, which generates electricity. ... It also includes an energy storage system that will allow it to control how much electricity it produces at any given time.

If you're using steam, the low-pressure steam turbines are big and have a lot of inertia compared to the low-pressure steam going through them, so they take a long time to spin up. That's a big reason why coal plants aren't load-following like gas turbines.

They're also expensive, so you really want to avoid them for cost reasons, and if you do have them you want to run them all the time. So with natural gas, the combined cycle plants with steam turbines also tend to run continuously.

But in that sense I should reassert that my model applies most directly only to any device which conveys bits relayed through electrons exchanging orbitals, as that is the generalized electronic cellular automata model, and wires should not be able to beat that bound. But if there is some way to make the interaction distance much much larger - for example via electrons moving ballistically OOM greater than the ~1 nm atomic scale before interacting, then the model will break down.

The mean free path of conduction electrons in copper at room temperature is ~40 nm. Cold pure metals can have much greater mean free paths. Also, a copper atom is ~0.1 nm, not ~1 nm.

The amount dissipated within the 30-meter cable is of course much less than that, or else there would be nothing left for the receiver to measure.

Signals decay exponentially and dissipation with copper cables can be ~50dB. At high frequencies, most of the power is lost.

I made a post which may help explain the analogy between spikes and multiply-accumulate operations.

I think we're on the same page here. Sorry if I was overly aggressive there, I just have strong opinions on that particular subtopic.

People say AI concerns are a weird silly outlandish doomer cult no matter how everything is phrased.

No, you're dead wrong here. Polls show widespread popular concern about AI developments. You should not give up on "not seeming like a weird silly outlandish doomer cult". If you want to actually get things done, you cannot give up on that.

the last few times people tried naming this thing, people shifted to using it in a more generic way that didn't engage with the primary cruxes of the original namers

Yes, but, that's because:

"AI Safety" and "AI Alignment" aren't sufficiently specific names, and I think you really can't complain when those names end up getting used to mean things other than existential safety

(Which I agree with you about.)

the word is both specific enough and sounds low-status-enough that you can't possibly try to redefine it in a vague applause-lighty way that people will end up Safetywashing

OK, but now it's being used on (eg) Twitter as an applause light for people who already agree with Eliezer, and the net effect of that is negative. Either it's used internally in places like LessWrong, where it's unnecessary, or it's used in public discourse, where it sounds dumb which makes it counterproductive.

And, sure, there should also be a name that is also, like, prestigious and reasonable sounding and rolls off the tongue. But most of the obvious words are kind a long and a mouthful and are likely to have syllables dropped for convenience

Yes, that's what I'm trying to make a start on getting done.

as a joke-name, things went overboard and it's getting used more often than it should

Yes, that is what I think. Here's a meme account on Twitter. Here's Zvi using it. These are interfaces to people who largely think it sounds dumb.

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