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 in 1873. The international unit of frequency, one cycle per second, is named in his honor.Know More
Hertz engineered the oscillator used to prove Maxwell's theory. The oscillator – two brass knobs connected by induction coils – created tiny sparks that jumped between the knobs when it was turned on.
He designed a circular receiving wire, also with two knobs separated by a gap, and placed it away from his oscillator. Hertz powered the oscillator, and it generated a spark that traveled the distance to the receiver, thus proving the existence of electromagnetic waves.Learn more about Inventions
It is unknown specifically who discovered coal, but evidence of its use as a light and heat source is documented as far back as several thousand years ago. Archaeological evidence exists of the use of coal by the ancient Chinese and the Romans.Full Answer >
No one person can take credit for the discovery of math. However, mathematics has developed over time, and many people have contributed to its different fields or branches that include algebra, geometry and trigonometry.Full Answer >
Robert Altmann discovered mitochondria in 1886, thinking that he was seeing parasites. Altmann called his discovery "bioblasts" and posited that they were found in almost all cells. His ideas laid the groundwork for further discoveries by scientists.Full Answer >
The existence of sulfur dates back to ancient times and is referred to in the Bible as "brimstone." In 1789, a French chemist named Antoine-Laurent Lavoisier recognized it and added it to his famous list of elements. In 1823, a German chemist named Eilhard Mitscherlich discovered sulfur's allotrophy.Full Answer >