where <math>\tau</math> is proper time of distant galaxy, <math>t</math> is our time (in our Galaxy), <math>r</math> is distance to this remote galaxy, and <math>R_E</math> is the mentioned already [[Einstein's radius]]. | where <math>\tau</math> is proper time of distant galaxy, <math>t</math> is our time (in our Galaxy), <math>r</math> is distance to this remote galaxy, and <math>R_E</math> is the mentioned already [[Einstein's radius]]. |