physics engine

the total mechanical energy of the system is was changing. euler integration has an energy drift problem for second order systems.

i've switched to verlet now. two body orbits are mostly stable. total energy fluctuates, especially at high velocities, but is stable over time.

for 3-body systems.

• integration basics by gafer on games
• https://adamsturge.github.io/Engine-Blog/mydoc_symplectic_euler.html#symplectic-euler