Have you ever wondered why water expands as it freezes? Or why it changes temperature more slowly than other liquids? Science has known for years about water’s weird properties, but they haven’t been able to find a reason.

Until now. Evidence has been found that water is actually two liquids, one denser, and one less dense, that keep switching places. This is only now being figured out for two reasons: these switches are taking place at the molecular level, making them very hard to observe, and help has come from artificial intelligence.

“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 who has been studying water for over two decades. But now he and four colleagues have published findings in the June 4 edition of the journal Nature Physics that could not only help prove this molecular change is real, but also help explain water’s other weird behaviors.

We live in a fascinating world — even our most basic substances can have their secrets.

For the full explanation, see “Water Might Secretly be a Mix of 2 Different Liquids, Scientists Say” by Larissa G. Capella at https://www.livescience.com/physics-mathematics/water-might-secretly-be-a-mix-of-2-different-liquids-scientists-say?