Of the Earth

Like all its inhabitants and all its swift and luminous companions, this earth must discover an eventual disaster. How the disaster will arrive, and when, is a matter for astronomers to ponder. Dr. James Hopwood Jeans, famed British astronomer, Secretary of the Royal Society, pondered; last week, in London, he spoke sadly of the dwindling universe. Said he:

"The sun is undoubtedly wasting away as it radiates energy." For each square inch of the sun's surface, it radiates enough energy to keep a fifty-horsepower engine going. This goes on century after century.

"This radiation of energy and matter makes all the stars poorer; but it is a kind of capital levy. It is graduated sharply, so those stars which are best able to bear the burden radiate the most and tend to become equal.to the poorer ones. . . .

"A million million years from now the sun will still be much the same as now, and the earth will still revolve around it. The year will be a little longer and the climate quite a lot colder, while the rich accumulated stores of coal, oil and forests will be long since burned up.

"Nevertheless, that is no reason why our descendants should not exist. Perhaps the earth will be unable to support quite so many people as now, perhaps fewer will want to live on it. Mankind, three million times as old, may be three million times as wise."

Dr. Jeans was not the only astronomer who, last week, was engaged in somewhat mundane speculations. Dr. Paul Renno Heyl, a physicist attached to the U. S. Bureau of Standards, began his second series of experiments to determine the world's weight. Last year he estimated this to be 6,592,000,000,000,000,000,000 tons. Now, by making a slight change in his apparatus,* Astronomer Heyl expects to achieve a slight but consequential difference in his result.

* Last year he used two steel cylinders, equipped with small platinum balls, pendent in a 35 foot pit. By measuring their mutual attraction and regarding the earth's pull as a constant, he could discover a unit in which to compute the earth's attraction. This time his steel cylinders are equipped with small glass balls.