Pendulum Problem.... Hi all, I've written a little simulator (in C++) that demonstrates a simple pendulum swinging from right to left and back again. To simulate the motion I'm using the simple second order differential equation: accelaration = -(g/L) * theta and numerically integrating this using the RK4 method. However I'm having a problem in that the simulation is escaping really quickly. I just want to ask under what conditions would this happen?. I think I'm starting off the simulation with reasonable values and they are outlined below: angle = 22.5, start angular_vel = 0.0f, init accel = calculated using above formula. Any advice on why the simulation could be breaking so quickly is much appreciated. Thanks.