The image of a burning matchstick that casts no shadow on the wall is capturing the attention of the online community. Many people are curious about the phenomenon where the glowing tip of the match does not create a shadow while the hand and body of the matchstick do cast shadows on the wall.
Some individuals have tried to replicate this. They lit a matchstick and held it 10-15 cm away from the wall while shining a light through the hand holding the match. You will notice that only the shadows of the hand and the matchstick appear on the wall, without any indication of the flame.
The flame of a burning matchstick does not cast a shadow on the wall. (Illustrative image)
Explaining this phenomenon, Mr. Đinh Hoàng Tùng, a physics teacher in Hạ Long, Quảng Ninh, stated that during this experiment, when lighting the match, it is certain that only the hand and the body of the matchstick will be visible on the wall, while there will be no shadow, because the flame does not have the ability to cast an image on the wall. In other words, due to differences in light intensity, in cases where external light is strong, it will not create a shadow. In some instances, if the light from the object is weak, it may still cast a shadow.
“Light intensity is a concept used to measure the level of illumination from a light source,” Mr. Tùng explained, noting that this parameter is used to determine the energy emitted from a light source in a specific direction.
Light intensity appears in many phenomena in life. It is considered one of the essential factors in various fields such as lighting technology, electronics, optics, and display technology. It is used to describe the level of light from a specific light source or in a lighted area.
Another teacher analyzed the intriguing phenomenon, stating that fire does not create a shadow because it does not obstruct the movement of light. Fire itself is a source of light, and light typically passes through it.
