Chladni

[tudur]

i suppose you've heard of the famous chladni figures, formed on vibrating plates, because of resonance...
well, i just wanted to know if there have been experiments with "oscilating" instead of vibrating plates. do we recieve the same waves across the surface, if, let's say we have an amplitude of 15 cm?

[HallsofIvy]

You can't answer that without knowing how large the actual plate is. The key point is the ratio of the height of the plate to the the size of the plate. The mathematics of the problem assumes that ratio is small.

[tudur]

How about the size of the grains? i suppose it matters a lot if they are not sand, but let's say balls, with a few milimeters diameter