Answer
Because the wavelength of sound waves is much longer than the wavelength of light waves.
Work Step by Step
- Diffraction is the bending of waves around an obstacle or through an opening. The amount of diffraction that occurs depends on the size of the obstacle or opening relative to the wavelength of the wave.
- Sound waves have a much longer wavelength than light waves. For example, the wavelength of audible sound ranges from around 17 meters (56 feet) at the lowest end of the human hearing range to around 17 millimeters (0.67 inches) at the highest end.
- In comparison, the wavelength of visible light ranges from around 400 nanometers (violet) to around 700 nanometers (red). Because the wavelength of sound is much longer than that of light, sound waves can bend or diffract much more easily around an obstacle or through an opening.
- This means that sound waves can travel around corners and through small openings, while light waves cannot. Light cannot bend around corners as much as sound and get blocked by obstacles as it travels in straight lines.
- Therefore, you can hear sound around a corner, but you cannot see around the same corner because of the difference in the wavelength of sound and light.
