Note 20 — MODERN SCIENCE: A CRITICISM

It is not generally realised how feeble a force gravitation is. It is calculated (Encycl. Brit., Art. Gravitation) that two masses, each weighing 415,000 tons, and placed a mile apart, would exert on each other an attractive force of only one pound. If one, therefore, was as far from the other as the moon is from the earth, their attraction would only amount to 1/57,600,000,000th of a pound. This is a small force to govern the movement of a body weighing 415,000 tons! and it is easy to see that a slight variation in the law of the force might for a long period pass undetected, though in the course of hundreds of centuries it might become of the greatest importance.