I am very pleased to get an answer so quickly, I wonder if you could clarify one or two points.

1, am I right in assuming that the amount of time dilation (younging!) depends only on how closely I approach c.

2, as it is required for the object to be decelerated to zero velocity when it returns should there be a factor of two in the energy equation.

3, I looped my object around a black hole to get it to return this would seem to take one from special relativity general relativity or is it of no consequence.

4, my arithmetic is very weak could you please give a worked example of a body acquiring a time dilation of one second in 1000 seconds to give some idea of the magnitudes involved.

Many thanks for solutions of a very intriguing problem

syhprum