LW - My current LK99 questions by Eliezer Yudkowsky
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Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: My current LK99 questions, published by Eliezer Yudkowsky on August 1, 2023 on LessWrong.So this morning I thought to myself, "Okay, now I will actually try to study the LK99 question, instead of betting based on nontechnical priors and market sentiment reckoning." (My initial entry into the affray, having been driven by people online presenting as confidently YES when the prediction markets were not confidently YES.) And then I thought to myself, "This LK99 issue seems complicated enough that it'd be worth doing an actual Bayesian calculation on it"--a rare thought; I don't think I've done an actual explicit numerical Bayesian update in at least a year.In the process of trying to set up an explicit calculation, I realized I felt very unsure about some critically important quantities, to the point where it no longer seemed worth trying to do the calculation with numbers. This is the System Working As Intended.On July 30th, Danielle Fong said of this temperature-current-voltage graph,'Normally as current increases, voltage drop across a material increases. in a superconductor, voltage stays nearly constant, 0. that appears to be what's happening here -- up to a critical current. with higher currents available at lower temperatures deeply in the "fraud or superconduct" territory, imo. like you don't get this by accident -- you either faked it, or really found something.'The graph Fong is talking about only appears in the initial paper put forth by Young-Wan Kwon, allegedly without authorization. A different graph, though similar, appears in Fig. 6 on p. 12 of the 6-author LK-endorsed paper rushed out in response.Is it currently widely held by expert opinion, that this diagram has no obvious or likely explanation except "superconductivity" or "fraud"? If the authors discovered something weird that wasn't a superconductor, or if they just hopefully measured over and over until they started getting some sort of measurement error, is there any known, any obvious way they could have gotten the same graph?One person alleges an online rumor that poorly connected electrical leads can produce the same graph. Is that a conventional view?Alternatively: If this material is a superconductor, have we seen what we expected to see? Is the diminishing current capacity with increased temperature usual? How does this alleged direct measurement of superconductivity square up with the current-story-as-I-understood-it that the material is only being very poorly synthesized, probably only in granules or gaps, and hence only detectable by looking for magnetic resistance / pinning?This is my number-one question. Call it question 1-NO, because it's the question of "How does the NO story explain this graph, and how prior-improbable or prior-likely was that story?", with respect to my number one question.Though I'd also like to know the 1-YES details: whether this looks like a high-prior-probability superconductivity graph; or a graph that requires a new kind of superconductivity, but one that's theoretically straightforward given a central story; or if it looks like unspecified weird superconductivity, with there being no known theory that predicts a graph looking roughly like this.What's up with all the partial levitation videos? Possibilities I'm currently tracking:2-NO-A: There's something called "diamagnetism" which exists in other materials. The videos by LK and attempted replicators show the putative superconductor being repelled from the magnet, but not being locked in space relative to the magnet. Superconductors are supposed to exhibit Meissner pinning, and the failure of the material to be pinned to the magnet indicates that this isn't a superconductor. (Sabine Hossenfelder seems to talk this way here. "I lost hope when I saw this video; this doesn't look like the Meissner ...
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