Hello Zanket, This is MacM. I have just busted James R for several flip-flops. One involved a post by you. Would you please join our discussion and clarify your post. I have to shorten this message. Thanks. ********************************** http://www.sciforums.com/showthread.php?p=1266953&highlight=non-inertial#post1266953 # 15 :"Originally Posted by zanket Let a lab be in free fall in an inertial frame “X”. A thrusting rocket............The rocket hovers above the horizon. Originally Posted Reply by James R:"Then the rocket .............rest frames of both are non-inertial. ******************************************************* http://www.sciforums.com/showthread.php?t=94193&page=51 #1020 "Originally Posted by James R:"There is no orbit here...........directly above the hole. *******************************************************