Definition
Plain language
A material briefly hyped in 2023 as a room-temperature superconductor before the claim collapsed.
As stated in the literature
Copper-doped lead apatite claimed to superconduct at ambient conditions in 2023; replication attempts attributed the signatures to impurity phases.
Also called: L-K ninety-nine
Why it matters: It is a recent, fast-moving example of how a dramatic claim can dominate attention for weeks and then dissolve under replication.
For example, videos of a small grey pellet apparently hovering over a magnet spread widely online before other labs traced the effect to impurities in the sample.
Heard on the show
“L-K ninety-nine, which took over scientific social media in the summer of twenty twenty-three, draws twenty-four refusals.”Episode 240 — Frontier Models Designed Follow-Ups To Fraudulent Papers 93% Of The Time