Question
Describe why a flower appears green with white light and black with red light.
Answer
When white light falls on a flower, the pigments in the petals absorb certain colours of light and reflect others. In the case of a green flower, the pigments in the petals absorb all colours of light except for green. Green light is reflected, which is detected by our eyes, resulting in the perception of the flower as green.
On the other hand, when a flower is illuminated with red light, which contains only the red wavelengths of light, the pigments in the petals will absorb all the red light and not reflect any. Since the flower is not reflecting any light in this case, it appears black to our eyes.
