Question

Diffraction is defined as the bending and spreading of waves around small items, slits, or corners. Sound exhibits diffraction just as light does. In your initial discussion post, address the following:

• Identify two everyday phenomena that exhibit diffraction of sound and explain how diffraction of sound applies.
• Identify two everyday phenomena that exhibit diffraction of light and explain how diffraction of light applies.
• Comparing your examples, what are some significant differences between diffraction of light and diffraction of sound, if any?

Answer 1

Diffraction of sound is the bending or spreading of sound waves around any obstacles in order to reach the observer. Everyday, we listen to radio at home and we are able to listen to the radio even if we are in different room as that of radio because sound waves can bend around any obstacle and opening of room door will help the sound wave to spread more acting as localized sound source.

The second phenomena can be the thunder we hear during lightning. The thunder from a close bolt of lightning will be heard as a  crack which is due to high frequency, whereas thunder from a distant bolt will be like a rumble because due to long wavelength, the waves can bend around trees, houses etc to reach our position.

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Diffraction of light is almost same as bending of light around the edges of an object. The only difference is sound suffers more diffraction due to long wavelength.

The silver lining we see around the clouds is because light is diffracted around the edge of the cloud. Sometimes, we are able to see different colors also.

Another example would be the observation of rings of light usually known as corona around celestial bodies like sun etc. This is caused by diffraction due to presence of small , tiny particles.

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As we already know one major difference is the difference in wavelength. The wavelength of sound waves is much more as compared to light , so diffraction of sound is much more pronounced.