Video narration
Put a candle near a wall and shine a light: the candle body makes a clear shadow, and the wick does too—but the flame seems to vanish. A shadow happens when something blocks light coming from another source. The trick is that a flame isn’t a solid object. It’s mostly hot gases that are fairly transparent, so a lot of the light just passes through instead of being cut off. On top of that, the flame is also a light source. It glows and fills in the dark area where its shadow would be, so the “missing light” is harder to notice. Can fire make a shadow? Yes—if there’s a much brighter light behind or beside it. Then tiny soot or smoke particles can absorb and scatter light, and the hot air can bend light and create a faint, wavy silhouette. So fire does have a shadow—it’s usually just hidden by its own light and its transparency.