Hi Doctor, I know it been a while since you posted this but no one answered specifically to some problems in the context of your scenario. It appears you know the man could not travel at the speed of light but rather a speed close to it instead. That will be the assumption, a relative speed that results in a gamma of 876000 (about 99.99999999993483C pretty fast!). I’ll use your light-like calculations as approximations for the man traveling “near the speed of light”. You made a mistake in the reconciliation for the man in orbit relative to the observer on Earth; saying the number of orbits witnessed on Earth (25,200), which was 1 hour for them was 100 years for the man in orbit. That is incorrect; the correct observation for the person on Earth after 1 hour of Earth time would be to see the man age 1/876000 of an hour or .000411 seconds for the equal number of orbits they both witnessed during those relative time periods. When 1 hour has passed for the orbiting man they will still both agree on the number of orbits seen 45 million (assuming your math was correct); however they will not only disagree on the time that passed (1hr vs 100 years), what you didn’t recognize is they will also disagree on the distance traveled . The distance traveled around the Earth for the orbiting man would have been 1/876,000 less than the distance seen for the observer on Earth. This might help you re-evaluate you conclusions. As for the comment “The faster you go the "slower" YOU age, not slower you go through time”; in your relativistic example, ageing more slowly is a direct result of the relative difference in the space-time, meaning time was passing “slower” for the orbiting man.