vendredi 13 avril 2012

Light invariance principle

Galilean reference frames In classical kinematics, the total displacement x in reference frame R is the sum of the relative displacement x’ in R’ and of the displacement vt of R’ relative to R at a velocity v : x = x’+vt or, equivalently, x’=x-vt. This relation is linear when the velocity v is constant, that is when the frames R and R' are galilean. Time t is the same in R and R’, which is no more valid in special relativity, where t ≠ t’. The more general relationship, with four constants α, β, γ and v is : The Lorentz... [Lire la suite]

dimanche 12 décembre 2010

Special Relativity (derivations)

From Wikiversity Special relativity is an extension of rational mechanics where velocity is limited to the speed of light c, a constant in the vacuum of matter and radiation. Speed limit In classical mechanics, the absolute velocity is the sum of the velocity of the moving reference frame and the velocity relative to the moving reference frame. In special relativity one has to take into account the speed limit, e.g. the light speed. For colinear velocities, we get, as we shall show below : where vx is the"absolute" et v'x the... [Lire la suite]