Sound Wave Shadow

Most recent answer: 08/30/2009

Q:
Why can only light waves cause shadow.Why cant sound waves cause shadows.
- Prudhvi Raj Borra (age 16)
Machilipatnam,Andhra,India
A:
In fact, shadows of sound waves exist.   However in order to observe (hear) the effect the shadow casting object must be considerably larger than the wavelength of the sound.
Like light waves, sound waves can reflected, bent, refracted, diffracted and focused. Audible sound wavelengths are in the range of  about 10 meters to about 2 centimeters, compared to less than one millionth of a meter for visible light.

LeeH

(published on 08/30/2009)