CompuServe Messages

ED, I am a little rusty on my physics, but I don't understand the eqns of motion you are using in PAR001.poc – in particular the ones in move_particles and move_mass The motion of a particle acted on by a single mass can be described as: F = ma = (constant)*M*m/d^2, where m=particle mass, M=mass, d = distance => a = (constant)*M/d^2 and decomposing vector into orthogonal components ax = (a)* dx/d = (constant)*M*dx/d^3 You use ax (delta vx) = (constant)*M*dx/d^2 Why? Working the other way around using your dx and dx(=M*dy/d^2) we get that the particle acceleration a is: a = sqrt(ax^2 + ay^2) = (constant)*M*sqrt(dx^2+dy^2)/d^2 = (constant)*M/d Aren't we off by a 1/d here? I tried putting in the 1/d^3 in move_particules and move_mass and the particles just spun off, I assume that means that the initial rotational acceleration was too great for them to stay in orbit – but like I said, I'm rusty on my physics, so I don't know what correction to make to the particle initial state to put them in stable orbit. Please feel free to correct me on this – I am NOT a physics expert, I am just trying to remember what I learned years ago, but it bothers me when stuff doesn't make sense to me.