I remember the first time I saw the floaty rock. It was the middle of night, and I was facing the insomniac’s dilemma: to reach for the phone or not. I reached and opened Twitter—this was two weeks ago; the new name hadn’t yet sunk in—on the theory that a scroll through my feed might achieve some hypnotic effect, creating an opening for sleep to take hold. That’s when I saw the blurry video. In it, a scrap of material, small and misshapen like a pencil’s broken lead tip, hovers mystically above a thick wafer of polished metal. I scrolled right by. Despite following a fair number of “neat science thing” aggregators, in the wee hours I do not always thrill to edification. But a few minutes later, I saw the video again, and then a third time. I registered that this was not some didactic explanation of magnetism. This was news: The floaty rock was LK-99, a substance synthesized by a team of South Korean scientists, who believe it to be a room-temperature ambient-pressure …