The Kid Should See This

A colorful Chladni pattern demonstration

Watch as Chladni patterns form on a metal plate, a teaching demonstration “spiced up” with colored sand by associate professor of physics at UNC Charlotte skullsinthestars. The video is accompanied by Prelude from Suite No. 3 by Johann Sebastian Bach. (If you want to hear the tones that accompany the demo, watch this video from St. Mary’s University in Halifax.)

The technique was first discovered by Robert Hooke, who ran a violin-style bow along the edge of a plate with flour on it. Ernst Chladni took it one further by experimenting with and recording the nodal patterns, now called Chladni figures. From Skulls in the Stars in 2013:

A metal plate, supported by a post in its center, is vibrated at a single frequency by use of a mechanical driver. For most frequencies, nothing at all happens; when certain special frequencies are hit, however, standing waves appear on the plate, driving the sand away from the points of large vibration to the points of no vibration. By varying the frequency of oscillation, we can find a large number of the so-called resonance frequencies and their accompanying patterns, which become increasingly complex and beautiful as we up the rate of oscillation.

The Harvard Natural Sciences Lecture Demonstrations has Chladni Plates that more closely resemble the original bowed invention:

Four centrally mounted brass plates are driven into various resonant states with a violin bow. Sand sprinkled on the plates helps to visualize the nodes and antinodes for each state. Pressing a fingernail against the edge of the plate imposes a boundary condition (as does the location of the bow, for certain plates).

Next, watch Resonance, forced vibration, and a tuning forks demo, Mercury Hz: Sound waves passing around & through mercury, and Making sounds visible: Sound vibrations transform colorful sand patterns.

Plus: A waterless & chemical-free sound wave fire extinguisher.

h/t Boing Boing.

🌈 Watch these videos next...

A waterless & chemical-free sound wave fire extinguisher

Rion Nakaya

Resonance, forced vibration, and a tuning forks demo

Rion Nakaya

Brusspup’s amazing water-bending sound experiment

Rion Nakaya

Shattering glass with the World’s Largest Horn

Rion Nakaya

Breaking a glass with sound

Rion Nakaya

Go inside an ice cave to see nature’s most beautiful blue

Rion Nakaya

Chladni Plate: Sand Vibration Patterns

Rion Nakaya

CYMATICS: Science + music = audio frequency visualizations

Rion Nakaya

Kids Meet Opera Singer Angel Blue

Rion Nakaya

Get smart curated videos delivered every week.