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 »

Electromagnetic waves carry electromagnetic energy, also known as electromagnetic radiation, through matter, empty space, momentum and angular momentum. Depending on their frequency and wavelength, electromagnetic waves ... 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 »

Galileo Galilei was an Italian astronomer and physicist who worked as a lecturer in 1589 at the University of Pisa. From 1592 to 1610, he worked at the University of Padua. 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 »