Chapter 25, Problem 34P

25.6 Polarization and light reflection

* BIO Spider polarized light navigation The gnaphosid spider Drassodes cupreus has evolved a pair of lensless eyes for detecting polarized light. Each eye is sensitive to polarized light in perpendicular directions. Near sunset, the spider leaves its nest in search of prey. Light from overhead is partly polarized and indicates the direction the spider is moving. After the hunt, the spider uses the polarized light to return to its nest. Suppose that the spider orients its head so that one of these two eyes detects light of intensity ${\text{800 W/m}}^{\text{2}}$ and the other eye detects zero light intensity. What intensities do the two eyes detect if the spider now rotates its head $20°$ from the previous orientation?