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
Potentiality and actuality In the works of Thomas Hobbes then, the traditional Aristotelian terms, ""potentia et actus"", are discussed, but he equates them simply to "cause and effect". There was an adaptation of at least one aspect of Aristotle's potentiality and actuality distinction, which has become part of modern physics, although as per Bacon's approach it is a generalized form of energy, not one connected to specific forms for specific things. The definition of energy in modern physics as the product of mass and the square of velocity, was derived by Leibniz, as a correction of Descartes, based upon Galileo's investigation of falling