Agua. Wai. L'eau. Wasser. Mul. Water.
No matter how you spell it or how you pronounce it, H2O is a wonder: a beautifully simple, simply beautiful element that, when all is said and done, means nothing less than life.
We drink it. We swim in it. We inhale it with the air we breathe, and exhale it when we sleep, when we talk, when we laugh, when we stand outside on a cold night watching the stars, our breath made visible. We sail on it, ski on it and whitewater raft on it. We are, to a large extent, made of it.
Our planet is a shining blue marble in the darkness of space because of it.
And now, today, we're messing with it. The sheer number of human beings on Earth (seven billion, with another two billion likely by 2050) is adding unsustainable stress to the supply and the quality of fresh water all over the globe. While water is life, the limited—and in too many cases, nonexistent—availability of clean, potable water means lingering sickness and even death for countless people in scores of countries.
Here, LIFE.com offers a gallery celebrating the most wondrous of all the classic elements—a small, humble gesture of gratitude toward dihydrogen monoxide, without which we, and everything we know and love, would simply dry up and blow away.