Physics

The most important advances in theoretical Physics during the last thirty years have been connected with the consideration of waves in the ether. In 1873 and even before, J. Clerk Maxwell developed his theory that electricity like light is a wave in the ether. The main proof of this theory rested upon the fact that it could be made to account for electrical phenomena and that the speed of light and electricity seemed to be approximately the same. In 1888 Hertz of Germany succeeded in actually detecting waves in electricity by the method described below. The gradually acquired knowledge of their production and control have resulted in the wireless telegraph, the details of which are given under this head.

The discovery of Crookes’ rays and of the X-rays by Röntgen points the way to a knowledge of new forms of radiation.