a complete revolution / orbit of the earth around the sun takes one year
world is in_orbit_about_sun. sun is over_5_billion_years_old. earth is over_5_billion_years_old. sun is orbited_by_earth. earth is 4.5_billion_years_old. earth's_year has 365_days earth is billions_of_years_old. sun is 93,000,000_miles_from_earth. earth_year is 365_days_long. universe has sun_and_earth