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 can travel and transport energy without a medium through which it may travel. This contrasts with mechanical waves, such as sound waves, which cannot travel through a vacuum. If electromagnetic radi... More »

The spectrum of electromagnetic radiation is comprised of waves or particles that carry different amounts of energy. The visible spectrum is what humans and most animals see. The least energetic range of electromagnetic ... More »

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 »

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

Barometric pressure was discovered in about 1644 when physicist and inventor Evangelista Torricelli invented the first mercury barometer. Torricelli was an assistant to Galileo Galilei who suggested that Torricelli try u... More »

www.reference.com History Inventions

Albert Einstein was a German-born physicist who became well known after earning his Ph.D. and publishing scientific articles. His theories on relativity and photoelectric effect are his most famous discoveries. More »