November 21 is Hieronymus Theodor Richter’s birthday. Richter was a German chemist who discovered the element indium with Ferdinand Reich. They discovered the element using the relatively new technique of spectroscopy. When a substance is heated, the light it emits can be passed through a prism to separate individual bands of color that are unique to each element. They isolated a substance that turned out to be a new element that gave off a vivid indigo spectral line and named it indium.
Indium is a shiny, silver-white metal with element number 49. It is a very soft metal that when bent emits a ‘cry’ that is a high pitched squeak when bent. It is commonly used in semiconductor electronics, mirrors and as a coating for high-performance bearings. It’s most common use today is in liquid crystal displays and touchscreens.
Notable Science History Events for November 21
2005 – Konstantin Petrovich Feoktistov died.
Feoktistov is a Soviet cosmonaut/engineer who worked part of the team who designed Sputnik, Vostok, Voskhod, and Soyuz spacecraft. He would go on to head the design team which designed the Salyut and Mir space stations. He also worked on a design for an ion-powered spacecraft for a manned Mars mission.
1996 – Abdus Salam died.
Salam was a Pakistani physicist that shared the 1979 Nobel Prize in Physics with Sheldon Glashow and Steven Weinberg for work in postulating the existence of W and Z bosons. W and Z bosons are the elementary particles that mediate the weak nuclear force. He was instrumental in forming Pakistan’s Atomic Energy Commission and nuclear weapons program.
1970 – Chandrasekhara Venkata Raman died.
Raman was an Indian physicist who was awarded the 1930 Nobel Prize in Physics for the discovery of Raman scattering. When photons strike a surface of molecules, most of the light will bounce off with the same frequency it started with. A small number of photons will give up their energy to the molecule and bounce back less energy. This scattering is called Raman scattering and can be used to measure the energy of molecular bonds.
1993 – Bruno Rossi died.
Rossi was an Italian-American physicist who pioneered cosmic ray research and x-ray astronomy. He showed cosmic ray intensity from the West is significantly higher than the intensity from the East. This demonstrated cosmic rays are mostly composed of positively charged particles.
Rossi designed the instrumentation on NASA’s Explorer 10 discovery of Earth’s magnetopause. His instruments also detected the first extra-solar X-ray source, Scorpius X-1.
1824 – Hieronymous Theodor Richter was born.
1555 – Georg Pawer (Georgius Agricola) died.
Agricola was a German doctor and natural philosopher who is considered to be the founder of mineralogy as a scientific discipline. He wrote extensively on everything that was currently known about mining techniques, rock formations, fossils and minerals.