Possible Meissner effect near room temperature: copper-substituted lead apatite
A new arXiv preprint reports a “possible Meissner effect” near room temperature in a copper‑substituted lead apatite, reviving interest in LK‑99‑style materials and the dream of practical high‑temperature superconductors. Commenters weigh cautious optimism against burnout from past false alarms, emphasizing the need for independent replication, rigorous controls against mundane explanations like magnet impurities, and realistic expectations about how long it would take to turn any such material into useful technology. The thread also touches on geopolitical angles (e.g., China–US competition), funding incentives, and how public hype can both help and hinder serious materials research.
Overall sentiment
- Mix of excitement, cautious optimism, and strong skepticism, heavily colored by the LK‑99 saga.
- Many are interested but emotionally “sitting this one out” after feeling burned by previous room‑temperature superconductor claims.
- Some see the process itself as a good public window into how science actually works; others are tired of repeated “here we go again” cycles.
Relationship to LK‑99 and prior claims
- Material is closely related to LK‑99 (copper‑doped lead apatite), but with sulfur explicitly in the formula.
- Commenters note the original LK‑99 sample was accidentally sulfur‑contaminated, so this might explain earlier strange behavior.
- Some argue this work exists only because of the LK‑99 hype, making it an incremental step in that “family” even if LK‑99 was wrong.
- Others say LK‑99 was bad science, thoroughly discredited, and are therefore extra skeptical of anything derived from it.
What the preprint claims and evidence
- Claims a “possible Meissner effect” near 250 K at ambient pressure; authors emphasize “possible” out of caution and instrumentation limits.
- Two independent Chinese groups reportedly used different synthesis and measurements, then jointly reproduced each other’s results.
- 250 K is highlighted as revolutionary vs prior ambient‑pressure superconductors (~150 K per comments), since it’s reachable with dry ice or ordinary freezers.
- Photos and reports of full levitation, including sample floating upside‑down, are cited by enthusiasts as qualitatively different from LK‑99’s partial “wobble.”
Skepticism and methodological concerns
- Others warn levitation and hysteresis can be mimicked by diamagnetism plus ferromagnetic impurities (e.g., iron), and by photographic artifacts.
- Some point to a pattern of spectacular superconductivity claims that later fail, including unrelated high‑profile misconduct cases.
- Several stress that extraordinary claims require extraordinary tests and reproducible, independent confirmation; one working group is not enough.
- Debate over whether “possible” in the title is real caution or “false modesty”; many defend conservative wording as the only responsible stance.
“Near room temperature” and practicality
- 250 K (about −23 °C / −9 °F) is jokingly described as “a cold winter day” and for some climates nearly “room temperature.”
- Big practical draw: can be cooled with cheap methods (freezers, dry ice, conventional refrigeration) versus liquid helium.
- Discussion that high‑Tc ceramics can be made into usable cables via thin films on flexible tapes; not limited to brittle blocks.
- Even if real, commenters note many further hurdles: mechanical properties, stability, manufacturability, critical current limits.
Geopolitics and research ecosystem
- Speculation about China versus US/EU: whether such a discovery could be kept secret, used as strategic leverage, or quickly reverse‑engineered.
- Others argue economic benefits require openness and that secrecy would be hard to maintain for any widely deployed technology.
- Some see rising public interest and hype (HN, Twitter, YouTube) as a double‑edged sword: driving funding and curiosity but also grift and noise.