Question

The coloring of the blue morpho butterfly is protective. As the butterfly flaps its wings, the angle at which light strikes the wings changes. This causes the butterfly’s color to change and makes it difficult for a predator to follow. This color change is because
A. A diffraction pattern appears only at certain angles.
B. The index of refraction of the wing tissues changes as the wing flexes.
C. The motion of the wings causes a Doppler shift in the reflected light.
D. As the angle changes, the differences in paths among light reflected from different surfaces change, resulting in constructive interference for a different color.

Answer 1

Answer:

D. As the angle changes, the differences in paths among light reflected from different surfaces change, resulting in constructive interference for a different color.

Explanation:

The color of body of butterfly is not due to pigment . It is due to optical effect called interference . The same phenomenon is responsible for coloration of films of oil on water or soap bubble etc. Here interference is caused by multiple slits . As the angle changes, the differences in paths among light reflected from different surfaces change, resulting in constructive interference for a different color.