Chapter 14, Problem 8TE

Solution

To determine: The method of producing the colors when wing is viewed from different angles.

Answer:

The colour of Morpho butterfly fly’s wings appears to change upon changing the viewing angle is due to constructive and destructive interference.

Explanation:

Wings of a Morpho butterfly are thin and transparent. When white light is incident on butterfly wings, it is reflected by the upper and lower surface of the wing, and there is a slight path difference between the two reflected light rays. Due to the path difference between two light rays, light corresponding to some colors interfere destructively, and the corresponding color is absent from the light reaching the eye of the observer. Thus, the wings of a Morpho butterfly appear to have bright colours.

When the angle of viewing the wings is changed, the path difference between the two reflected light rays also changes. Thus, the color which was bright earlier would be absent later, and its complementary color will appear. Further, the color, which was destructive interference, would become constructive interference now and appear bright. Hence, this is how the color of Morpho butterfly fly’s wings appears to change upon changing the viewing angle.

Conclusion:

Therefore, the colour of Morpho butterfly fly’s wings appears to change upon changing the viewing angle is due to constructive and destructive interference.