Strobe Patterns on Aircraft
 

My wife claims that the belly strobe on our flight a few days ago was flashing in random patterns. I've never paid that much attention to it, and my limited aircraft knowledge couldn't answer the question. So...

Are there patterns to the flashes? Or is it continuous and she was just hallucinating? :D

There are quite a few lights on an airplane. There is a red beacon used to indicate that the engines are running. On older airplanes this is actually a rotating red light but newer airplanes use a red strobe. The white strobes aren't random but on any particular airplane, each strobes (one on each wing tip) will independently discharge at different times. So all together they may appear to be random. Some airplanes (light twins and a few Southwest 737 models) will even "blink" their landing lights to be more visible.