1) Newton discovery 
Use it or lose it.
(from the article `Locke, John`) ...understand man, however, it is not enough to observe his actions; one must also inquire about his capacities for knowledge. Locke had been ...
Scientific generalization that both explains and predicts physical phenomena; laws of nature are generally assumed to be descriptive of, and applicable to, the world. The three laws of...
noun a generalization that describes recurring facts or events in nature; `the laws of thermodynamics`