But would you see a shadow? Let's look at it from a biological standpoint. Fluorescent lights operate at 60 cycles AC in the US and 50 cycles per second in europe.In 60 cycles the current switches from running in one direction to running the other direction through the bulb 60 times every second. In the middle there is no current flow and the bulb is dark but you don't see it because the duration is too short for your biological system to detect. Motion picture film runs at 24 frames per second. You are shown a series of still images that your eyes and brain interpret as moving because you can't detect the gaps in between. If an object were big enough and flying at the right orientation relative to you and the light source it is possible it could either interrupt or deflect enough photons long enough to block the light and cause a shadow. It would have to be big enough or close enough and moving slow enough relative to the line between you and the light source to have a detectable shadow. If you did see the shadow, would we have six more weeks of winter?