Personally I dont believe that paradox's can exist in nature, it just means something has been missed. Senario - we will use a velocity where 1 year in space = 10 years on earth. The earth will be our control clock. The space traveller just has to be able to see the earth, in orbit if this does not cause to many problems. The person on earth and the traveller both have counters which they use to count the number of earths rotations, and clocks showing the passage of time. After the 10 years have passed on earth the traveller comes back to earth. Both counters must agree on the number of earths rotations and both people must agree that the earth has orbited the sun 10 times. The clocks however will show 10 years passed on earth and ! in space. Is the traveller 9 years younger or has he been robbed of 9 years, he has after all seen the earth orbit the sun 10 times in his 1 year.