AGE OF THE EARTH

Waipa Post, Volume 43, Issue 3327, 25 July 1931, Page 6

AGE OF THE EARTH

BILLIONS OR TRILLIONS?

Huxley once remarked that the zoologist must take his time from the geological clock; The Victorian geologist decided that the earth could not be older than 100,000,000 years. Estimates based on the time it must have taken for the ocean to become as salty as it is gave a similar result. Lord Kelvin considered the rate of the earth's cooling and likewise arrived at the cabalistic 100,000,000. Later he accepted a reduction to forty and'even twenty million years on the basis of tidal studies made by Professor Carl Barus. The evolutionists were humiliated and outraged. "Too little,'' they cried. " We need hundreds of millions." The adamant Kelvin refused to give them even a century more (writes N.T. in the Auckland Star). Discoveries in chemistry, physics and astro-physics made after Kelvin's time have forced a revision of the old estimates. Tens of millions of years have been added to the earth's probable age as the result of the newer views of Chamberlin, Jeans and Jeffreys, that the earth was literally pulled out of the sun by a passing giant star. Jeans thinks that this filching of solar matter must have occurred 7,000,000,000,000 years ago. Jeffreys holds that the earth as we know it—a cooled globe with a crust —must be 2,000,000,000 years old. With this allowance even the evolutionists are content. '

The problem of the earth's age is of such importance that a committee oi the National Research Council has been studying it for the last four years. The method employed to solve it is not new, dependent, as it is, on the time it takes radioactive minerals to decay into lead. Analyse a rock for uranium and lead and the rest is almost a matter of arithmetical calculation. When a chemist thus decides that a given specimen of mineral is 800,000,000 years old he may be wrong by two or three million years, but not by ten or a hundred million. Decaying uranium is a very good clock as cosmic timepieces go. Until a few years ago the oldest known uranium-bearing rock was a vein of Norwegian broggerite. Now it seems that the uranite of Sinyaya Pala, Carelia, Russia, is even more venerable. The National Research Council's committee places its age at 1,852,000,000 years. Since this primordial relic was buried in still older rock, the conclusion is inevitable that the earth must be at least 2,000,000,000 years old. On the whole, this new estimate agrees with that of Jeffreys and with that made by Sir Ernest Rutherford, some years ago, on the basis of research conducted by his associate, Sir F. W. Aston. "If we suppose that the production of uranium in the earth ceased as soon as the earth separated from the sun, it follows that the earth cannot be older than. 3,400,000,000 years," was Rutherford's verdict. Here we have a maximum. The National Research Council's figure probably strikes something like an acceptable average. *