Question

candle flame having doesnot shadow,why??

Answer 1

Answer:

I'm going to jump in and say that most of the answers I'm seeing here are wrong. The reason a candle flame doesn't cast a shadow has nothing to do with the amount of light it gives off. Those qualities are unrelated. Otherwise a lightbulb wouldn't cast a shadow, but if the lightbulb was not the only light source in a room, it would definitely cast a shadow. The only thing that is related is the light reflected off of, or given off by objects that you can see. A flame can interfere with objects you can see though the flame by being brighter.

William L. Weaver is correct when he points out that for something to cast a shadow, it has to interfere with the rays of light given off by another object. It can do this by absorbing the light, reflecting the light or refracting the light. In fact a flame does cast a partial shadow because the heat it gives off can alter the density of the air column to significantly refract the light. But the shadow isn't an effect of the incandescent nature of the gas, it is caused by the optical effects of light passing through the different densities of heated air, which more or less conforms to the shape of the flame. On any sunny day when you have hot coals in an outdoor grill, you can see the same types of shadows as sunlight passes through the hot air above the grill onto any surface in its path, even though no flames are visible.