Sand can sing, whistle, squeak and bark when stepped on.
Beaches are known for the sound of the water, but sand can make some interesting sounds as well. Sometimes.
Associate Professor of Physics Martin Kamela spoke to a Physics & Astro Tea audience about the singing, whistling, squeaking and barking sounds that some sands can make. Researchers have found that, in order to make these sounds, sand granules need to be nearly spherical, small, and nearly uniform in size. These sounds seem to come from the friction between granules arranged in slip planes and are unrelated to other surface effects.
But sound is not the only trip up sand’s sleeve. Like some other granular materials, the empty volume between granules of sand will expand under shear deformation, explaining why sand seems to dry out when it is stepped on.
Hosted weekly by the Department of Physics and Astronomy, Physics & Astro Tea promises engaging discussions, thought-provoking ideas and a delightful spread of refreshments. Open to all students, faculty and staff, this gathering is the perfect opportunity to connect with fellow physics aficionados in a relaxed and informal setting. Meetings take place in the third-floor lounge of Innovation Hall at 3:20 p.m. on Wednesdays.