So our professor showed us wave patterns on a vibrating plate, by sprinkling powder over it. I'm curious as to why it behaved as it did.The powder moved to nodes, but I'm not sure why. I think it just gets bounced around until it lands on a node, which is stationary, so it then stays there. Is there a slightly more scientific way of explaining this? Or at least a different way of wording it (if I'm right at all) ?