Effective mass (solid-state physics) from both sides gives where is the th element of , is the th element of , and are the th and th elements of , respectively, and is the total energy of the particle according to the Planck–Einstein relation. The index is contracted by the use of Einstein notation (there is an implicit summation over ). Since Newton's second law uses the inertial mass (not the gravitational mass), we can identify the inverse of this mass in the equation above as the tensor This tensor expresses the change in group velocity due to a change in crystal momentum. Its
Our Velocity game Our Velocity "Our Velocity" is the first single from "Our Earthly Pleasures", the second album from the band, Maxïmo Park. The single was released two weeks prior to the release of the album, on 19 March 2007. The music was written by Duncan Lloyd and the lyrics by Paul Smith of the band. The video of the song features the band being multiplied in a white room while playing the song. It was directed by Nima Nourizadeh. The song has been highly regarded and in VH1's "50 Greatest Songs of 2007 So Far" it placed at number 1. The