>>21543689Astrophysicist here.
As the pokemon world is likely somewhat smaller than Earth, but is about the same distance from the sun as our planet then a single orbit around the sun takes longer than one of our years.
As it is a smaller planet but a day takes the same time to pass in the pokemon world as our own this means the planet is spinning on it's own axis slower than earth does and with less centrefugal force, thus meaning an orbit or year of the sun in the pokemon world is conducted at fewer km/h than the Earths is.
As we have no way of knowing, based on current data released by GF or TPC, exactly how long a year is on the pokemon world compared to that of Earth we must base our estimates on social conventions.
In the pokemon world it is considered fine to send a boy of about 10 or 11 off into the world to fend for themselves and for them to own dangerous creatures trained to cause harm.
If we can compare that to the UK then a person can be legally responsible for their actions and treated as an adult by law from the age of 16. People are also not allowed to buy a pet without the consent of their parents before the age of 16 either and not aloud to buy knives or other items that can cause harm before the age of 21.
therefore in the pokemon world 10 years old must be the equivalent in time of being 18 years old, meaning a year in the pokemon world is about as long as almost 2 earth years.
