Learn about the history of science by reading about the significant scientific events that took place on this day in history.
1874 - António Caetano de Abreu Freire Egas Moniz was born.Egas Moniz was a Portuguese neurologist who was awarded half the 1949 Nobel Prize in Medicine for the discovery of the therapeutic effects of leucotomy for certain psychoses. A leucotomy is also known as a lobotomy which is a surgical procedure where the connections between the prefrontal cortex and anterior of the frontal lobes of the brain are severed. Moniz developed the technique as an attempt to treat severe mental illnesses.
1849 - John Ambrose Fleming was born.Fleming was an English electrical engineer who was the inventor of the thermionic valve vacuum tube as an electronic device. The device functioned as a diode used as a rectifier to convert AC current into DC current. Fleming's diodes were used in early radio receivers and radar systems before the invention of solid state semiconductors. He was also the originator of the familiar "right hand rule" used by mathematicians and physicists to determine the direction of vectors that are multiplied together.
1803 - Christian Andreas Doppler was born.
Doppler was an Austrian physicist who is best known for the Doppler effect, or the change in frequency of a wave as it moves relative to the observer. He showed that the frequency of a wave source moving towards the observer would have a higher frequency than the same source stationary with the observer. As the source moves away from the observer, the frequency would be lower.