In honour of (American) football season, Jimmy Stamp went over some of the history behind, and the dynamics of, the football field:

• American football owes its origins to rugby and soccer. This is evident in the field that the game is played on – a grassy green rectangle.
• Football doesn’t require a flat surface, because the ball doesn’t have to roll. Instead the field’s purpose is to mark territory and show which team has more of it.
• When indoor stadiums became popular natural grass became too expensive to maintain. Artificial grass popularly known as “Astroturf” was developed.
• The rubber base of modern artificial grass provides cushioning that helps protect the athletes as they tumble around on the field.
• While this artificial grass could, in theory, be painted any colour, the rules mandate that the grass be green. This is to prevent sponsors from taking over the field itself.

Read more about developments in goal posts and other changes in the game over here.

Source: Smithsonian