Question

When you see your shadow on a sunny day, it has a fuzzy edge. This is?

1) an example of diffraction.
2) not caused by diffraction because the wavelength of visible light is too small to produce visible diffraction around a person.
3) not caused by diffraction because diffraction only occurs for openings, not objects blocking light.
4) not caused by diffraction because there are too many wavelengths in sunlight to see the effect.

Answer 1

The fuzzy edges of a shadow you see on a sunny day are due to diffraction—specifically, it happens because light waves bend around the edges of the object creating the shadow, causing the edges to appear soft and fuzzy.

Step-by-step explanation:

When you observe your shadow on a sunny day and notice it has fuzzy edges, this is an example of diffraction. This diffraction effect occurs because light waves spread out after passing by the edges of an opaque object, such as a person or a building. In this case, option 3 of your question is correct; diffraction is indeed what causes the fuzzy edges of shadows.

Each edge of the object casting the shadow acts as the point of origin for new wavefronts due to diffraction. While the wavelengths of visible light (390 to 770 nm) are generally too small to be noticeably diffracted by large objects, the edges of these objects can still create a diffraction effect, resulting in a shadow with fuzzy, soft edges.

Diffraction is often more noticeable with light waves passing through small apertures, as their dimensions are more comparable to the wavelength of visible light. However, the phenomenon of diffraction is not limited to small apertures; it also occurs at the edges of large objects, contributing to the fuzzy appearance of shadows in sunlight.