The Poles [antikvár]

ntroduction One attribute makes the earth unique among all the satellites of the sun— the abundance of the molecule H2O in its three forms of water, water vapor and ice. Without these commonplace substances we could not exist, yet it is only by accidents of gravity and temperature that we have them. If our planet were appreciably smaller, and thus had weaker gravity, most of the water would have evaporated into space long ago (this is probably what has happened to our dry neighbor, Mars). The temperature range of our air is only one among an infinite number of possibilities, yet it luckily encompasses the relatively few degrees in which water, ice and water vapor can coexist. Even more delicate is the temperature balance between water and ice. Time and time again the balance has shifted to favor the ice, and it has advanced to cover much of the ground we now walk upon, then retreated for long periods when even Greenland and Antarctica were places of warm forests and plains. Why this balance shifts, we do not begin to understand. Today we are entering an era of unlimited power, when science may be able to alter the temperature balance and convert the cold regions to hospitable, productive ones. To do this would require the greatest political courage, for the rewards certainly would not be equally divided over all political borders. But if it were done, the problem of containing and feeding future generations could be solved. Unfortunately we as a nation are not yet confronted with the problem and we give it only token attention; but world storms generated by hunger are brewing. All this considers only one of the facets of the polar regions. Here also are concentrated the intricacies of the upper atmosphere—the pulsations of the ionosphere, the flickering auroras, the sweeping magnetic storms. These center above the magnetic poles, and they must be studied—for who can foresee the benefits to mankind that may come from the solution of all these polar mysteries? The polar scientist has many problems. His work is by nature uncomfortable and inefficient, and he works hard and long for scattered bits of data. He rarely is left alone to experiment, but too often is steered in the directions dictated by funds and facilities. Eventually these must be his to use as he desires if the work in these areas is to remain attractive to those who can best contribute. This book fascinatingly describes and wonderfully illustrates the polar regions as they are now and as they have been. Indeed, the beauties of the land' make us wonder if they were not meant to be left so, but history teaches otherwise, and the growth of mankind has no limits. Albert P. Crary Chief Scientist Office of Antarctic Programs National Science Foundation