This Day in Science History - January 13 - Paul Niggli

January 13^th marks the passing of Paul Niggli. Niggli was a Swiss mineralogist who was a pioneer of x-ray crystallography. He developed the mathematical system of space groups that defined 230 different atom arrangements based on x-ray diffraction patterns. X-ray crystallography works by shining x-ray radiation through a crystal structure and detecting the interference pattern generated by the gaps between individual atoms. This information can tell you the position of atoms in a crystal, the width of atomic bonds, and even the size of the atoms themselves. All this information can give detailed help in determining the structure of a molecule. All that is really needed is a pure sample that can be crystallized.

1927 - Sydney Brenner was born.

Brenner is a South African biologist who shares the 2002 Nobel Prize in Medicine with H. Robert Horvitz and John Sulston for their discoveries of how genes regulate organ development and cell death. His research centered on the use of the nematode Caenorhabditis elegans and the identification of which genes control programmed cell death.

1900 - Peter Waage died.

Wikimedia Commons

Waage was a Norwegian chemist who, together with Cato Guldberg, discovered the Law of Mass Action. This law relates the rate of a chemical reaction is proportional to the amount of active mass, or concentration, of the reactants. This law became the basis for determining rate constants of chemical reactions.

1864 - Wilhelm Wien was born.

 

Wien was a German physicist who was awarded the 1911 Nobel Prize in Physics for his laws involving the radiation of heat. He determined a blackbody curve at any temperature is determined from the blackbody curve at any other temperature by displacing the wavelength of the emission energy. This is known as Wien's displacement law.