"Lorentz invariance" X = (2,0,0,3) g = ((1,0,0,0),(0,-1,0,0),(0,0,-1,0),(0,0,0,-1)) check(dot(X,g,X) < 0) beta = X[1] / X[4] gamma = 1 / sqrt(1 - beta^2) beta Lambda = ((gamma,0,0,-beta gamma),(0,1,0,0),(0,0,1,0),(-beta gamma,0,0,gamma)) Lambda "Transformed vector" dot(Lambda,X) Run