Joseph John Thomson, better known as J. J. Thomson, was a British physicist who first theorized and offered experimental evidence that the atom was a divisible entity rather than the basic unit of matter, as was widely believed at the...

Karl Jansky discovered extraterrestrial radio waves while investigating possible sources of interference in shortwave radio communications across the Atlantic for Bell Laboratories, and is often known as the father of radio astronomy....

Electrical currents and voltage are defined and illustrated.