In late July 2023, Korean scientists published preprints of two academic papers claiming to have synthesized a room-temperature superconductor working at ambient pressure, named LK-99 (arXiv, Science.org, Phys.org). The means by which the LK-99 is either doped or undoped is immaterial (Halbleiter.org). "Superconductor" means a material that 1) has no electrical resistance and 2) does not allow magnetic fields to penetrate it, which is called the Meissner effect (Live Science, Britannica - Meissner effect). A finding of negligible resistance consistent with findings for other established superconductors would count. For the purposes of this question, "major scientific journal" is any journal with a Scimago Journal & Country Rank (SJR) greater than 1.00 as of the publication of the article (SJR, Daemen.edu). Confused? Check our FAQ or ask us for help. To learn more about Good Judgment and Superforecasting, click here. To learn more about how you can become a Superforecaster, see here. For other posts from our Insights blog, click here.