this post was submitted on 08 Aug 2023
101 points (99.0% liked)

science

14689 readers
101 users here now

just science related topics. please contribute

note: clickbait sources/headlines aren't liked generally. I've posted crap sources and later deleted or edit to improve after complaints. whoops, sry

Rule 1) Be kind.

lemmy.world rules: https://mastodon.world/about

I don't screen everything, lrn2scroll

founded 1 year ago
MODERATORS
 

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.

you are viewing a single comment's thread
view the rest of the comments
[โ€“] 6mementomori 11 points 1 year ago (1 children)

i hate to break it to you, but net positive isn't exact here. the "energy in" used to calculate it is the energy of the actual photons, but to actually fire those lasers, you need 100 times the energy, so it's a net 1%

[โ€“] [email protected] 4 points 1 year ago

The fusion definition of "net positive" has always been heavily inflated so that investors and governments will actually put money into these dreams