Mass Pulls

Our planet is a pretty blue ball that does nothing. Time to give it some pull.

Newton's pull

Every mass pulls on everything else. The pull gets weaker with distance, and fast: go twice as far and it drops to a quarter. That is Newton's inverse-square law.

In numbers, a mass M pulls with GM/r², where r is the distance to its centre. The game sets G to 1, so a mass's mass field is its whole pull. For our planet, with mass 1100:

r = 10  (the surface)       1100 / 10²  = 11
r = 11  (a mountain top)    1100 / 11²  = 9.0909
r = 20                      1100 / 20²  = 2.75    twice as far, a quarter of the pull

Pulls from several masses just add up.