We know from our early science classes that water exists as a solid, liquid, and gas. But an international team of 19 scientists say that’s not the case. They discovered that liquid water actually has two phases – low and high density – and can fluctuate between them. While providing new information, the research reminds us how much we still don’t know about a substance that covers over 70 percent of the planet.
There’s still a lot we don’t have a clue about when it comes to water. The substance has around 70 properties as a liquid that are utterly unique from other liquids, according to the team led by physicists at Stockholm University in Sweden, who used X-ray imaging to scrutinize water molecules in new detail to discover water fluctuates between high density and low density liquid forms.
Physicist Lars G. M. Pettersson said in a statement, “In a nutshell: water is not a complicated liquid, but two simple liquids with a complicated relationship.” He said their research supports the idea of water at room temperature being unable to decide which form it should be in, so it changes between the two distinct phases. The two phases differ in their density and structure.
There have been hints of water’s second liquid phase in the past. In 2016 Oxford University researchers found liquid water could switch states between 104 and 140 degrees Fahrenheit, with each state exhibiting different properties.
The journal Proceedings of the National Academy of Sciences of the United States of America published the research online this week. Scientists at institutions in the United States, Germany, and Austria were also part of the study. Their findings are intriguing but for now, there’s still a lot about water that remains a mystery. Nature consultant editor Philip Ball once said in an article, “No one really understands water.”