For years, scientists have suspected that, at the molecular level, water is two different liquids — a denser one and a less-dense one — that are constantly switching places. Catching real molecular evidence of this microscopic transformation has been hard. But now, with help from artificial intelligence, researchers say they've finally found it.
"It's hard to imagine — here is just one water, right?" said Xiao Cheng Zeng, a physical chemist at the City University of Hong Kong and co-author of the new study, told Live Science while holding a water bottle in the air. That puzzle sent him digging through scientific literature, where he found the possible explanation: the two-state hypothesis. "That got my attention. We have literature to talk about it but no evidence."
