Dear Friends, I appologize for my two mistakes. 1. vigyanayentatan =Vigyan+Ananta+Ayatan= Consiousness+Infinite+Space, instead of 5th absorption Samadhi, it shoud be sixth absorption Samadhi. 2.Thank Passingthru for correcting me! I agree with you, when the spaceship retardate before stopping and accelerate while returning, the frame of refrence truns non-inertial and the problem is delt by general theory. Thanks again! Vishontar