Heinrich Rudolph Hertz, a German physicist, discovered the existence of electromagnetic waves in 1887. This was a result of his expansion of James Clerk Maxwell's mathematical "Electromagnetic Theory of Light," published... More »

Electromagnetic waves form from the vibrations of electric and magnetic fields. Unlike mechanical waves, electromagnetic waves do not need a medium to propagate, allowing them to travel through air, solids and even outer... More »

Some characteristics shared by all electromagnetic waves are that they all travel at the speed of light and their transmission does not need a medium. These wave types can also travel through empty spaces. More »

Heinrich Goebel, a German inventor and mechanic, patented three inventions, including a sewing machine hemmer improvement, a Geissler system of vacuum pumps improvement and an electric incandescent lamp. The lamp patent ... More »

www.reference.com History Inventions

Two people are credited with the invention of the French horn: Heinrich Stoelzel and Friedrich Bluhmel. The French horn was invented in the 19th century based on designs that dated back to the 16th century. More »

Alessandro Volta, an Italian physicist and pioneer in the study of electricity, is credited with the invention of the first battery, the voltaic pile. Volts, the units used to measure electric currents, are named after h... More »

Sir Joseph John Thomson, a British physicist, discovered the electron in 1897. In experiments studying electric discharge in cathode tubes, he noted a high value for the ratio of charge to mass. His observation led him t... More »