Tell me about acoustic manipulation

[mindwanderer]

I understand the basics of what goes on when sound passes through various mediums (pressure waves etc) but I'm wondering if any of you have any in depth knowledge of manipulating matter (solids and fire) through acoustic means. ' I've seen a video where sand or salt is placed on a flat surface and it is acted upon by sound waves and it 'snaps' into various symetrical shapes depending on the specifics of the sound waves. But what I need to know is the effects of sound waves of fire, or gases... Any help is appreciated!

[slayer]

Can you link some of those videos you're talking about? This sounds interesting.

[mindwanderer]

Cymatics on sand Cymatics on Water and Non-neutonian fluid "Acoustic Levitation" That's showing sound (pressure waves) acting on solid, liquid, and partial matter. There's also an understanding that sound can have 'unique' effects on living things... but I won't get into that. I want to remind you there is no 'wind' in any of these experiments. These are all done with vibration and frequency.

[Replicon]

They mention in the description of the sand video exactly what's going on. Standing waves. Imagine two people holding a long rope, one on each end. If one person wiggles his end up and down, he'll send a wave travelling along the rope towards the other person. If just the other person wiggles his end, the same thing will happen. Now, if both people wiggle their ropes at just the right frequency, the waves will "add up" and will often end up as standing waves. This means some points in the rope will be moving up and down, while others will remain stationary. That's sort of what's happening to the sand on that metal plate. When they hit the right frequency, some parts of the metal plate are vibrating a lot (pushing sand away), while others are pretty still (allowing sand to accumulate).