It's majestically beautiful. The wingtip vortices formed when an Airbus A340 landed at Zurich Airport on a foggy night. (www.youtube.com) Plus d'info...
Isn't it amazing how beautiful the world can be? I could go into the complex equations, but that would ruin the sheer awesomeness of the spirals of fog.
Great stuff! I sent the link to my lady friend who lived in Zurich once upon a time (I've landed there more than once). Proof positive that a sizable vortex follows behind those big boys!