Page:Popular Science Monthly Volume 34.djvu/202

190 live, it experiences the same number of things as we do from the cradle to the grave. Its measure of time, compared with ours, would be infinitely smaller.

Such a being could live on an atom just as conveniently as we live on this planet of ours. If, for instance, the quickness of its sensations were to ours as one thousand trillions is to one, it would experience in the time of one light-vibration—that is, in one five hundred billionth of a second—as much as we in eight months. The atom on which it lived would be its world; the molecule to which the latter belonged, its solar system; and by the revolution of atoms it could count its days and years. Above him, our atom-citizen would see other similar and far-distant worlds; for, the molecules, perhaps all belonging to one tiny air-bubble, would form the star-cluster of his firmament.

A magnification of ten thousand trillion diameters would enlarge the little air-bubble to the dimensions of our entire stellar system, the star-cluster of which the limits are the outermost regions of the milky way. But, great as the host of our stars may appear to us, the firmament of our atom-inhabitant would be still more densely crowded; for while we, with the aid of our best telescopes, can not see more than about twenty million stars, the little air-bubble would harbor at least fifty thousand billions.

Now, you might object that, to an atom-inhabitant, the molecules of a gas could not possibly appear as the fixed stars do to us, inasmuch as these molecules experience, on an average, about eighty million collisions in every second. However, it must not be forgotten that we have reduced the time of life and observation of our atom-inhabitant to one thousand trillionth that of our own. During this brief moment the relative positions of the visible molecules—to him far-distant suns—will appear just as unaltered, and their courses or orbits to the atom-astronomers just as linear, as those of our fixed stars appear to us.

What is the short space of time, the trifling moment, that we know of the life-history of the earth, compared with the eternities which must elapse before two fixed stars approach sufficiently close to render a collision inevitable? Our records of human history read back only a few thousand years, and of the age of our planet we only know that it must be measured by thousands of centuries. Of the courses of the fixed stars we know absolutely nothing; we only infer from certain data that their average velocity is about a hundred times greater than that of our molecules.

Thus the atom-inhabitants are about as wise as we are. The life of the entire human race, so far as our historical records are concerned, would, if condensed to one thousand trillionth, occupy about the one thousand millionth part of a second—less than one twentieth of the time which elapses, on an average, before the