By Alok Jha, Journalist and author of 'The Water Book'.

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It started with an idle observation one afternoon a few years ago. For no reason in particular, I remember wondering why water was the only thing I could think of that had a pH of 7 - completely neutral, neither acid nor alkali. Then something else, unrelated - water melts at a convenient 0 degrees Celsius and boils at an equally round number, 100 degrees Celsius. 

It all sounds very obvious, you might say. Of course it does. We’ve defined both our temperature scale and pH scales using water. It’s a common substance so why not?

Most of us (me included) relegate water into the background of our lives. Water is always just there, colourless, featureless and boring. Interesting things might happen on or in water but the stuff itself is just…nothing. Surely not worth looking at?

But I did look. The random thoughts about pH and temperature were just the start. As further examples of water’s unique role in our world floated through my mind that afternoon, I glimpsed something important about this substance, something that scientists, artists, novelists, swimmers, sailors and many more have each tried to understand in their own way since the beginning of human civilisation. Water has built us and our Earth. And we have used water to build our world. 

Just look at a few examples: we use water to grow our food, make our clothes and solidify the concrete in our buildings. All our power stations boil water into steam, which then turn the  turbines that make electricity. Ever since the first bands of humans stopped roaming the plains tens of thousands of years ago, they have always settled near sources of water. From Mesopotamia to London, New York, Mumbai and Tokyo - humans have always had to live near water. 

And when we are not near it, we build pipes and viaducts to bring it to us, the only sure way that a city survives. In that sense, we’re only mimicking what the natural world does anyway - water is continually moving around our world. It moves through trees and plants, sucked from the ground to feed their leaves. It moves across the surface of our world, distributing the Sun’s energy and creating what we know of as weather, turning much more of our planet habitable than it otherwise would be.

This substance created life too. Billions of years ago, somewhere at the bottom of one of our great oceans and next to a boiling hydrothermal vent that was spewing out energy and minerals from inside the Earth, water molecules guided the first living organisms into existence.

To this day, every living thing needs water. It works inside you, a thick treacle that looks unlike any other water you have ever encountered. It moves around in your blood (it is your blood), keeps your proteins and DNA working and in their correct shapes and transports nutrients and signals in and out of cells. Each living cell is mostly water, each one differentiated only a fraction from purity by a few chemicals.

And as we have begun to peer into water’s strange molecular world (which, in a sense, is also our own inner space), astronomers have been looking for water in outer space too.Water courses through us, our societies and our planet. But look at it closely and this is a profoundly strange chemical that bends and flexes the usual rules of chemistry: why does ice float on water? How can liquid water store so much more heat than anything else? How does it manage to so carefully choreograph the behaviour of so many biological molecules inside our cells? Why is water not a gas at room temperature, given how light its molecules are? Its complexity has defied scientists for hundreds of years. Only recently have we started to understand why the behaviour of its molecules makes this common, everyday substance so weird. And it’s that behaviour that has given water its unique ability to play so many roles in the evolution of life and in the physical development of the Earth. 

Beyond our solar system, we have been looking for worlds like our own orbiting other stars. A snapshot of the primordial Earth, perhaps, as it might have been before we evolved to colonise it, and change it beyond recognition. Much of the history of space exploration has been a search for water on other planets and it has now become the key chemical marker as we look for life among the stars. We know now that water exists in some form everywhere, from Mercury to the rocks of the Kuiper belt. There are oceans of it on Enceladus and Europa and (perhaps) the conditions there for life too. 

To us, water should be more than a mere chemical, and more than a functional ingredient for life. Rather it is a cultural object, constructed from the overlapping stories of hunters, poets, factory-workers, ecologists, water engineers, farmers, consumers, chemists, historians, theologians, divers and astrobiologists. Each will give you a different view. All will be correct. Put them together and you still have an incomplete picture. 

Perhaps it is strange that something so everyday and familiar remains so hard to describe or understand. But this is also the beauty of water. Its multifaceted, ever-shifting life reveals a story that will connect you, via one strange molecule, to everyone and everything else and the rest of the universe. As the author Tom Robbins (almost) said, perhaps this strange substance has created us in order to appreciate itself.



Hold a glass of water to the light now and look at this colourless, featureless, tasteless but ultimately remarkable material. Without it, none of us would be here and our world would not exist.

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'The Water Book' is published by Headline on 21 May 2015.

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