Why don’t fluorescent tubes produce a shadow?

  • Filament bulbs are point sources, which means that the light comes from a single point and spreads out in all directions. Because light only travels in straight lines, it casts a shadow when an object obstructs it. Whether it’s a filament bulb or a fluorescent bulb.
  • Because no light ray falls on the darkened area in the case of a filament bulb, the shadow is sharp. In the case of a tube light, the light source is lengthy. Therefore there is no potential for it to diffuse into the darkened zone (and even if it does, it is extremely modest).
  • Even if light from one end of the bulb casts a shadow, the darkened area may be illuminated by light rays from the other end or section of the bulb. As a result, the shadow is hazy.