December 16 is Johann Wilhelm Ritter’s birthday. Ritter was a German scientist who invented one of the first dry pile galvanic batteries. Early batteries used electrodes dipped in an acid solution where the energy is produced through oxidation reactions. A dry pile uses just enough moisture to function without the dangers of spilling acid solutions. Ritter’s pile used alternating pieces of silver and zinc foil separated by pieces of paper.
Ritter was also responsible for the discovery of the ultraviolet region of the electromagnetic spectrum. While investigating the discoloration of silver salt crystals exposed to sunlight, he discovered there was a part of sunlight beyond the violet range responsible for the discoloration. He initially called this part of the light spectrum ‘de-oxidizing rays’ because of their chemical reactivity.
Notable Science History Events for December 16
1969 – Adam Riess was born.
Riess is an American astrophysicist who shares the 2011 Nobel Prize in Physics with Saul Perlmutter and Brian Schmidt for providing evidence the rate of expansion of the universe is accelerating. Prior to his and Schmidt’s discoveries, the prevailing theory had the universe’s expansion rate as decreasing. They made their discovery while monitoring supernovas and monitoring their Doppler shift
1928 – Bruce Nathan Ames was born.
Ames is an American molecular biologist known for the Ames test. The Ames test is a biological assay test that quickly identifies whether or not a chemical compound is a potential carcinogen. Bacteria are exposed to the test substance and allowed to multiply. The later generations are checked for genetic damage caused by the test substance
1826 – Giovanni Battista Donati was born.
Donati was an Italian astronomer who discovered several comets. He also took the first spectroscopic reading of a comet. He identified three main spectral lines that were later attributed to the presence of carbon. He also noticed the lines became more pronounced as the comet approached the Sun and heated up. He determined at least part of a comet was gaseous.