 | | | |
| |||
 | |||
| |||
| road and make it appear to be covered with jewels. There are all the wonderful forms that clouds take. I have flown over clouds when I was so exhausted that the only thing I wanted to do was get out of the airplane and lie down on their soft, billowy surfaces. Although rain and snow and ice and oceans can, of course, also fill us with terror and do us in, water in its various forms probably defines pleasure and beauty for us more than any other thing we know. It is the rushing of water that formed the castles in the Grand Canyon. It is the whitecaps on the sea and on the breakers. It is the broad reflected path of the moonlight that follows us. These are the images that set the stage for romance. There is no mountain range in the country that doesn’t have at least one blue lake. Of course, every one of the beauties provided by water is connected with the very special properties of water that enable it to evaporate and freeze and refract light, and cool and warm and condense. I have read that in the heyday of the Moorish civilization in Spain they had fountains of quicksilver (mercury) which must also have been very beautiful, and it is true | that mercury has special properties that make it fun to play with. But mercury is a poison and water provides the cradle of life. Water's strong surface tension makes possible the large tropical raindrops. Its large latent heat of vaporization releases the warmth that keeps the clouds on high. Its ability to dissolve minerals accounts in part for the Grand Canyon, and also for stalactites and caves. The fact that it swells on freezing accounts for our ability to skate on the surface of a frozen pond. And its low index of refraction, at least compared to glass, accounts for the-fact that there can be two concentric rainbows rather than just one. The shape and the index of refraction of ice crystals dictates the large size of the rings around the sun and the moon. Finally, the fact that we ourselves are so largely made of water enables us to stay afloat and enjoy swimming, especially in the salty (and therefore more dense) waters of the ocean. | ||