Liquid water is part of our everyday lives and due to its lack of color, taste and smell, it is often assumed to be very simple. On a molecular level the water molecule is indeed very simple, However, when many molecules come together they form a highly complex network of hydrogen bonds. Typically, we consider that water molecules in the liquid state move randomly on ultrafast timescales due to thermal fluctuations. Now, scientists at Stockholm University have discovered correlated motion in water dynamics on a sub-100 femtoseconds timescale.
On this timescale, it was assumed that water molecules move randomly due to heat, behaving more like a gas than a liquid. However, the experiments (verified by computer simulations as well) indicate that the network plays a role even on this ultrafast timescale, making water molecules coordinate in an intricate dance, which becomes even more pronounced in the so called supercooled state. (1)
Two people dancing. What a nice site.
Another man is passing by.
Another one sleeping by the tree.
A woman on the other side of the planet falls.
A kid is running to catch the bus.
A party raging.
A city sleeping.
While a small pigeon tries to fly.
Unrelated moves. What a nice site…
[Written on 2019-04-06]