Hydrogen in a constant magnetic field

```from vpython import *

scene.fullscreen = True

G = 10 # Coulomb constant in analogy to gravitational constant

# edit initial conditions here
##########
spheres = [
]

B=arrow(color=color.green,axis=vec(0,10,0))

def acceleration1on2(sphere2,sphere1):
r = sphere2.pos - sphere1.pos
r_mag = mag(r)
normal_r = norm(r)
g = ((G*sphere1.charge*sphere2.charge)/pow(r_mag,2))/sphere2.mass*normal_r
return g

t = 0
dt = .5 # trade-off between simulation speed and numerical accuracy
while 1:
rate(100)
for i in spheres:
i.a = vector(0,0,0)
soi = vector(0,0,0)
for j in spheres:
if i!=j:
i.a = i.a + acceleration1on2(i,j)

spheres[1].a += .001*cross(spheres[1].velocity, B.axis) # Lorentz force due to constant magnetic field

for i in spheres:
i.velocity = i.velocity + i.a *dt
i.pos = i.pos+i.velocity*dt
i.trail.append(pos=i.pos)

scene.center=vector(spheres[0].pos.x,spheres[0].pos.y,spheres[0].pos.z)
```

Stroboscopic Interpretation of Quantum Mechanics

We can’t determine the position of a particle at one “moment” because it’s moving too fast.