What was discovered?

The heat capacity of water - how much heat is needed to raise its temperature - is high due to the formation of attractions between water molecules, known as HYDROGEN BONDS.

But the water molecules are moving constantly, so it had never previously been possible to calculate how much energy was associated with a single water molecule and its four other water molecules attracted to it in a tetrahedral arrangement.

How?

By superfreezing water (down to -230 Kelvin) and measuring the tiny changes in the tetrahedral shape of the attractions that each water molecule has to the other four water molecules around it.

This data allowed the calculation of the entropy associated with individual molecules.

Why is it important?

By measuring how temperature and pressure changes affect the order of the water molecules, scientists will be able to understand much better how certain drugs can dissolve more (or less) easily in water, and also how the water can affect the folding of proteins so that they can work properly.

And for life?  If our proteins are not folded correctly, they cannot do their job correctly, and that can be... fatal!