Yet Another of Water’s Weird Ways Remains to Be Explained
According to one scientist’s count, water exhibits more than 80 unusual properties, one of the strangest of which is that it can exist in all three states of matter (solid, liquid,gas) at the same time. Another example–it’s surface tension allows insects to walk on its surface and the property called “capillarity” makes it possible for water to rise up from the roots into the leaves of trees and other plants.
In another strange turn, scientists have recently proposed that water can go from being one type of liquid into another in a so-called “liquid-liquid” phase transition. It is impossible to test this with today’s laboratory equipment because these things happen so fast, but it has been tested by computer simulations.
Here’s Science Daily’s description of the experiment:
[The researchers] found that when they chilled liquid water in their simulation, its propensity to conduct heat decreases, as expected for an ordinary liquid. But, when they lowered the temperature to about 54 degrees below zero Fahrenheit, the liquid water started to conduct heat even better in the simulation. Their studies suggest that below this temperature, liquid water undergoes sharp but continuous structural changes whereas the local structure of liquid becomes extremely ordered — very much like ice. These structural changes in liquid water lead to increase of heat conduction at lower temperatures.
The researchers say that this surprising result supports the idea that water has a liquid-liquid phase transition.
Actually, water’s weirdness isn’t just a parlor game. As Gene Franks wrote in “The Gazette’s Great Water Article,”
It is water’s perverse and consistent refusal to go along with science’s laws that makes our lives possible. The awesome fact that water expands when it freezes in a world where things are supposed to contract as they get colder allows life to flourish beneath the frozen surface of lakes and rivers: if ice sank, many bodies of water would never thaw. This is virtually a unique property of water, an entity that follows its own design and dances to its own tune.
See “The Gazette’s Great Water Article” for a lot more about water’s strange behavior.