billions of years is a longer period of time than 10 years
great_year is time_period. long_time is time_period. earth is billions_of_years_old. world is billions_of_years_old. century is time_period. world is not billions_of_years_old. world is millions_of_years_old. decade is time_period. earth is not billions_of_years_old. forever is long_time.