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On Wed, Mar 08, 2006 at 10:18:15PM +0000, Kevin Tunison wrote: > I like the water/ripple ananology for just starting out with the > physics of waves. it's a good visual. A subtle but definite > difference. At first I wanted to argue your point but I found you to > be right :-) I came across this good visual resource for the physics > behind waves. > > http://www.physicsclassroom.com/Class/waves/U10L1a.html > > On 3/8/06, Neil Williams <linux@xxxxxxxxxxxxxx> wrote: > > On Wednesday 08 March 2006 8:51 pm, John Botwright wrote: > > > A good analogy is ripples on water. The water may be stationary, but the > > > ripples are travelling. > > > > ?? The water is moving vertically. Only when it gets into shallow water does > > the wave cause lateral movement, and that's only due to gravity. Don't > > confuse waves with tides. > > > > The "movement" of the ripple is an illusion arising from surface tension. > > Yes that is a good point about the tides, Neil. I imagine I could prove it by measuring the tidal rate in a calm coral lagoon, while someone else measures the tidal rate of a blustery N.Devon shore... I must object to your second statement though. The "movement" of a wave is no more an illusion than the "speed" of sound is. If you can measure it, then it is real*. If you can't, then it is an illusion. Practical experiment using a skipping rope makes it a bit easier to understand, but I don't suppose anyone other than the most hardcore physics geek would go and buy a skipping rope just to understand their broadband!!! Cheers, JB * And Descartes can get lost!!!
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