Proper velocity by Hermann Minkowski's flat-space metric equation . Here a reference map frame of yardsticks and synchronized clocks define map position x and map time "t" respectively, and the "d" preceding a coordinate means infinitesimal change. A bit of manipulation allows one to show that proper velocity where as usual coordinate velocity . Thus finite "w" ensures that "v" is less than lightspeed "c". By grouping "γ" with v in the expression for relativistic momentum p, proper velocity also extends the Newtonian form of momentum as mass times velocity to high speeds without a need for relativistic mass. The proper velocity
C. N. Yang Institute for Theoretical Physics C. N. Yang Institute for Theoretical Physics The C. N. Yang Institute of Theoretical Physics (YITP) is a research center at Stony Brook University. In 1965, it was the vision of then University President J.S. Toll and Physics Department chair T.A. Pond to create an institute for theoretical physics and invite the famous physicist Chen Ning Yang from Institute for Advanced Study to serve as its director with the Albert Einstein Professorship of Physics. While the center is often referred to as "YITP", this can be confusing as YITP also stands for the Yukawa Institute for Theoretical Physics in Japan.