Hidetoshi Katori (香取秀俊, Katori Hidetoshi, born 27 September 1964) is a Japanese physicist and professor at the University of Tokyo best known for having invented the magic wavelength technique for ultra precise optical lattice atomic clocks. Since 2011, Katori is also Chief Scientist at the Quantum Metrology Lab, RIKEN. Recently, Katori's group performed a measurement of gravitational redshift with two transportable strontium optical lattice clocks over nearly the entire height of the Tokyo Skytree, setting a new record for the best ground-based test of general relativity. Source: Wikipedia (en)