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I didn't quite get why a vortex isn't a wave... She said something about how a wave is a transfer of energy but not matter, but this seems incomplete. Obvious

by bronson 12y ago

I didn't quite get why a vortex isn't a wave... She said something about how a wave is a transfer of energy but not matter, but this seems incomplete. Obviously matter is transferring while the wave is passing. I guess the technical difference that a wave will mostly return to its original state after one wavelength? But, doesn't the vortex mostly return to its original state after one rotation? Otherwise the food coloring would disperse a lot faster. Hoping there's an easy explanation.

Flenser 12y ago
With a wave, water is displaced a short distance as the wave travels. Think of loose sping, (e.g. a slinky spring) and how if you stretched it out a bit a compression wave would travels down it[1]. Each part of the spring moves only a little, but the wave travels the length of the spring. With a vortex the material spinning in the vortex stays together, that's why the dye droped into the vortex stays in the vortex and you would see it travel across the pool, and you see smoke rings travel through the air. [1] http://www.youtube.com/watch?v=rd3afUct2l8 http://www.youtube.com/watch?v=rd3afUct2l8