Could anyone help with the Stars example in Vpython

[Benjamin Anderson]

I'm trying to decipher what the programme is doing at each stage, i'm not that experienced with simulations so i would like some help with a step by step explanation, i realise this is more physics than Computing but if anyone is really good at this sort of thing their help would be greatly appreciated. Thank you

[Bruce Sherwood]

Study the example program "BinaryStar-VPython", which contains the essence of "Stars-VPython", namely that one calculates the (vector) force that one star exerts on another, increments the momentum of each star by adding the vector impulse (F*dt), then increments the vector position of each star by adding the displacement (v*dt, where the velocity v is the momentum p divided by the mass).

There are two additional aspects of the stars program: the creation in a loop of all the sphere objects used to represent the stars, and the check for collisions (the criterion being that the center-to-center distance is less than the sum of the two stars' radii), with calculations to give the merged stars the sum of the momenta of the colliding stars.