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
This Is What Rock n' Roll Looks Like been used by Lady Gaga. Ian Drew of "Us Weekly" called the single "shocking" and "electric". Allison Stewart of "The Washington Post" gave "This Is What Rock ‘n’ Roll Looks Like” a mixed review, describing Porcelain Black as a "girl-fronted version of Mötley Crüe circa Dr. Feelgood". Jon Wiederhorn of "Inked" dubbed the song "a euphoric digital feast of raspy melodic vocals, four-to-the-floor beats, and keyboards that buzz like electric guitars." "This Is What Rock n' Roll Looks Like" debuted on the U.S. "Billboard" Hot Dance Club Songs at number forty-six, on the week ending July 18, 2011. The following