Charles Francis Richter offered him a position as a research assistant there, where he began a collaboration with Beno Gutenberg. The Seismology Lab at the California Institute of Technology wanted to begin publishing regular reports on earthquakes in southern California and had a pressing need for a system of measuring the strength of earthquakes for these reports. Together, Richter and Gutenberg devised the scale that would become known at the Richter scale to fill this need, based on measuring quantitatively the displacement of the earth by seismic waves, as Kiyoo Wadati had suggested. The pair designed a seismograph that measured this displacement and
Absolute magnitude Absolute magnitude Absolute magnitude is a measure of the luminosity of a celestial object, on a logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly 10 parsecs (32.6 light-years), with no extinction (or dimming) of its light due to absorption by interstellar dust particles. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared on a magnitude scale. As with all astronomical magnitudes, the absolute magnitude can be specified