This quantity is raised to the negative fourth power in the definition of Einstein’s gravitational constant. (-5[1])The slope (-5[1])of a 45 degree line (10[1])on a Minkowski diagram (10[1]-5[1])equals (10[1])this quantity (10[5])because Minkowski (10[1])time (10[2])is scaled (10[2])by this quantity. (10[1])The (10[1])ratio of velocity to this quantity (10[1])is denoted (-5[1])by (10[1])beta. (10[4])By comparing (10[1])interference patterns, (-5[1])this quantity was found (10[1])not to depend on the direction (10[1])of measurement (-5[1])in the Michelson-Morley (10[1]-5[1])experiment. (10[7]-5[1])The mass-energy equivalence states (10[2])(read slowly) (10[1])rest energy equals mass times (10[2]-5[1])this (10[8]-5[1])quantity squared. For 10 points, (10[1])name this universal (10[4])speed (10[1])limit (10[2])equal to about (10[1])three times ten to the eight meters (10[1])per (10[6])second. ■END■