Comment by cpleppert | Hacker News Reader

Comment by cpleppert | Hacker News Reader

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They aren't reacting because this isn't really proof of anything. The test apparatus they used can't actually measure 0 resistance. Superconductivity is implied (thats the most straightforward explanation) but not actually demonstrated here. Its very hard to interpret from the limited data presented. There could be a whole host of contaminants, issue with the experimental setup etc etc. Its hard to go from look at the interesting material properties in this graph to room temperature superconductor. This is also the only confirmatory information we have from the team; their sample didn't show diamagnetism.

The reasons to be skeptical are: 1) lot of videos floating around that are just at the threshold of convincing 2) poor results from other teams 3) there is a history of superconductivity discoveries like this that never pan out 4) skepticism of the original paper

We are in the fog of war phase state of this discovery process so there are data points in every direction with the kpop X-itter drama and sensationalism thrown in to the spin for good measure. Hard to tell if this is geek meme stock phenomenon meets the Reddit Boston Bombers hunt or just the real-time globally hyper connected social media version of exactly what would have happened if social media and arXiv were around in Christmas 1938 when two German chemists noticed a flash and detected Krypton where it should not have been and the Nuclear Age began.

> The test apparatus they used can't actually measure 0 resistance.

Can you explain how you would make that measurement? It seems like your testing equipment would need to be made of superconductors as well, right?

Usually superconductor resistance is measured using four probes: current goes through the two outer probes, and voltage is measured across the two inner probes. Then V=IR.

Lead resistance can play a role, but superconductivity is a phase transition: there's a significant discontinuity. It's not a matter of something going from 0 + e (for small e) to 0 (which doesn't happen), but one of going from x (x >>> 0) to 0. When that phase transition happens, it's obvious.

Noob question: how do you know you're not going from x >>> 0 to 0 + e?

Not clear to me how you know the resistance is nothing at all vs just very small.

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