The Divine Expansion of Water

An article from one of my favourite reads - The National Geographic took me back in time to a Science lesson I had during my teenage years: "The Anomalous Expansion of Water".

In a nutshell…while most substances contract when cooled, water does so too BUT only until it drops to 4 Degrees Celsius and then for some mysterious reason, it starts to expand!

As a student, I remember swallowing this concept without much question...but it was only recently when I really started chewing on this. Unlike any other substance which obediently contracts WITHOUT exception with each decrement on the mercury, why is it that water has to be the black sheep and defy this?

Yes, you could go on to tell me about the hydrogen bonds, the lattice structure of the molecules and whatsoever scientists have speculated, but really it would just answer the hows but not my whys.

Interestingly, going further back in time, I remember watching a cartoon where I saw an Eskimo sawing off a chunk of ice and dropping his fishing-line into the resulting hole and in a jiffy dangling at the end of the rod was a huge fish – alive and squirming! Fresh fish beneath frozen lakes? I had thought that with the ice all the way down, the only fish would be fozen ones!? Or was it really ice all the way down...

See, what I’ve learnt is that during winter, the cold winds beat down on seas, lakes etc. The water at the surface cools and then contracts like any other normal substance. And as it contracts, its volume is reduced and well by simple application of the formula: Density = Mass / Volume, it correspondingly becomes denser…. As this water at the surface becomes denser, it sinks, being displaced by the relatively warmer and hence lighter layers of water. And the cold winds beat down again and the process continues.

But when the water at the surface reaches 4 Degrees Celsius, now here is when the fun begins as the anomaly kicks in and water stops contracting and instead starts to expand. When the expansion happens, the volume increases and this water at the surface now becomes less dense than the water beneath it and hence instead of sinking it continues to stay afloat shielding the warmer layers of water beneath from the cold winds. The water at the surface continues to expand until it reaches 0 Degrees Celsius – ice, while the water below stays at a comfortable 4 degrees Celsius conducive for marine life to live on.

Amazing isn’t it? The anomalous expansion of water. I would call it the Divine Expansion of Water.