De Broglie Orbits
De Broglie's idea that matter has a wavelength explains why atoms have stable orbits at all. This simulation shows the electron wave wrapping around the nucleus and lets you test which radii allow it to close on itself.
How to use this simulation
- Step through the allowed quantum numbers
- Set an arbitrary radius to see the wave fail to close
- Change the electron's momentum and watch the wavelength respond
What to look for
- Only whole numbers of wavelengths produce a stable standing wave
- The n = 1 orbit fits exactly one wavelength around the circumference
- Faster electrons have shorter wavelengths, so more fit into the same orbit
The physics behind it
Every particle has a wavelength λ = h/p. An electron orbit is stable only where the wave joins up smoothly after a full circuit, requiring 2πr = nλ. At any other radius the wave interferes destructively with itself and cannot persist. This is why atomic energy levels are discrete rather than continuous.