this post was submitted on 08 Aug 2023
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In this preprint, the authors synthesize samples based on the claimed room temperature superconductor LK-99, and observe half-levitation similar to that seen in other recent videos, which has been ascribed to the Meissner Effect (a signature of superconductivity).

However, they performed a careful magnetization measurement and found that the sample is ferromagnetic. They also did a resistance measurement on a larger sample, and found that the majority of the material is a semiconductor. This points to a simpler explanation for the half-levitation phenomenon: it is a consequence of ferromagnetism (+ mechanical effects due to friction and sample shape), rather than the Meissner Effect.

Unless someone can demonstrate full levitation or better resistivity data for LK-99, this is arguably fatal for the claims of room temperature superconductivity.

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[–] cyd 8 points 1 year ago (3 children)

In unrelated news, did you see the fusion news! We did it! Net positive energy! Fusion will be in our toasters in a few short years!

Now they simply have to figure out how to get that super-powerful laser, which can fire only once a day, to firing once every milisecond ;-)

[–] [email protected] 7 points 1 year ago

Easy! Run it on fusion!

[–] [email protected] 4 points 1 year ago (1 children)

Do you have more information on said laser? I work on lasers that I would consider quite powerful and they fire at 6 kHz, soon to be 8 on the next model. I'd like to compare the specs

[–] cyd 3 points 1 year ago (1 children)

The National Ignition Facility has an explainer here. Typically, these facilities operate at petawatt peak powers by using lots and lots of pulse amplifiers. From what I heard, after every shot, the staff have to comb through the facility making sure things are still working, replacing blown out components, etc...

[–] [email protected] 3 points 1 year ago

Oh wow a few Joules, that's orders of magnitude bigger than ours

[–] jpeps 1 points 1 year ago

You may know more than me on this, but I believe multiple fires per day are possible now. Besides, tokamak reactors show more promise.