def three_body(t, Y, G, masses): x1, y1, x2, y2, x3, y3, x1_dot, y1_dot, x2_dot, y2_dot, x3_dot, y3_dot = Y r12 = np.sqrt((x1 - x2)**2 + (y1 - y2)**2) r13 = np.sqrt((x1 - x3)**2 + (y1 - y3)**2) r23 = np.sqrt((x2 - x3)**2 + (y2 - y3)**2) dxdt= [x1_dot, y1_dot, x2_dot, y2_dot, x3_dot, y3_dot, G * masses[1] * (x2 - x1) / r12**3 + G * masses[2] * (x3 - x1) / r13**3, # acceleration of m0 due to m1, m2 G * masses[1] * (y2 - y1) / r12**3 + G * masses[2] * (y3 - y1) / r13**3, G * masses[0] * (x1 - x2) / r12**3 + G * masses[2] * (x3 - x2) / r23**3, # acceleration of m1 due to m0, m2 G * masses[0] * (y1 - y2) / r12**3 + G * masses[2] * (y3 - y2) / r23**3, G * masses[0] * (x1 - x3) / r13**3 + G * masses[1] * (x2 - x3) / r23**3, # acceleration of m2 due to m0, m1 G * masses[0] * (y1 - y3) / r13**3 + G * masses[1] * (y2 - y3) / r23**3] return dxdt G = 1.0 # Gravitational constant (for stable orbit demos) masses = [1.1, 0.9, 1.0] # masses m1, m2, m3 initial_conditions = [-1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, -1.0, 0.0, 0.0, 0.0, 1.0] # stable figure eight, euler solution time, tspan = np.linspace(0, 50., 1000), (0.0,50.) solution = solve_ivp(three_body, tspan, initial_conditions, method='Radau', args=(G, masses), t_eval=time)

thank you and good luck with your exam

I'm glad they helped

thank you

he is pronouncing it wrong, it is a French name, so it should be mer sen

no, its a single pendulum

thank you!

colab.research.google.com/drive/1skXRKCM67Dv0D06d72SMKe03W1ohSvrW?usp=sharing

its described the accompanying video kzbin.info/www/bejne/pH3HZKl6iKdlkMU

oops - you are right its 9e9*3e-6*3e-6/0.01 = 8.1 Joules not 0.1 Joules - thank you!