Question

You are sunbathing in the late afternoon when the sun is relatively low in the western sky. You are lying flat on your back, looking straight up through Polaroid sunglasses. To minimize the amount of sky light reaching your eyes, how should you lie: with your feet pointing north, east, south, west, or in some other direction? Explain your reasoning

Short answer

The direction a person should lie down, in this case, is East-West direction.

Step-by-step solution

(a) Concept of Polarization of light.

The transverse waves are the waves in which the oscillation direction and the direction of the propagating wave are perpendicular to each other. Polarization is the concept of property applied to the transverse waves for specifying the orientations of the oscillations specifically.

(b) Explanation of the argument.

The sunlight is polarized when it reaches the earth’s surface and while passing through the air medium it gets scattered everywhere in the space by air molecules. The direction of polarization is the standardized north-south direction which can be considered the vertical axis direction. The Polaroid sunglasses have a polarized axis mounted vertically. Therefore, the best direction of lying down is in the east-west direction which will minimize the transmitted light in the eyes.