Time travel is possible.
Lets say the Earth orbits the sun at a speed of 30 mph. It takes 90 miles around the sun for a complete orbit, and a full year. Lets say your on Mars, and its full orbit is after 120 miles around the sun, in orbit. It goes at 20 mph. Now your friend is on Earth, and you were born in the same year. After three hours, its a new year on Earth, but on Mars, it has yet to go around the sun yet. You are a time traveler in the future.
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