At speed of light why wont there be any more acceleration , meaning : Why there wont be any further opposite reaction on a space ship that is thrusting matter in opposite direction at an enormous rate in order to gain more speed. Is it as if god wont allow it ? Even if the time there stops, why wont the space ship people feel the speeding up ? Admitted that mass will increase, but at what location on each atom of the space ship will these new mass appear ? Or how will the ship understand that it has reached the light barrier ; will actually say so by becoming alive ?