I've thought about something that is a paradox to me. I think I know what would happen in reality but I can't explain why the other option is discarded. Imagine you are an observer that can live "forever". You are over the Earth and looking toward the Sun. For the sake of simplicity, let's assume the Earth doesn't rotate on itself, but only moves in orbit around the Sun. I've calculated (with special relativity only) that if the observer was to leave the Earth and wait for it to come back 1 year later, this observer would age 0.2 s more than someone that stayed on the Earth for 1 year. I assumed 1 year=365 days, the speed of the Earth with respect to the observer: 30 km/s. Since this outer space observer isn't moving with respect to the Sun, it also means (neglecting general relativity) that you will see the Sun aging 0.2 s less than you (you are still over the Earth), after 1 year. After 1000 years this makes 200 s, etc. So when you look at the Sun and it has been existing since say around 4.5 billions years ago (assume Earth too is this old); is the Sun older than 8 minutes, say several years old? I say 8 minutes because it's approximately the time that photons leaving out Sun's surface take to reach the Earth. I know that the answer is indeed around 8 minutes, but because of special relativity, I'm totally confused. Equation: [itex]\Delta t = \gamma \Delta t '[/itex].