group velocity – Adventures in Oceanography and Teaching

Why are they so much slower than I thought? Observing the group velocity vs phase velocity of waves

mglessmer — Thu, 04 Oct 2018 08:08:30 +0000

Have you ever seen a speedboat drive past, looked at its wake moving torwards you, then gotten distracted, and when you look back a little while later been surprised that the wake hasn’t moved as far towards you as you thought it would have during the time you looked away? Well, I definitely have had […]

Source

Shallow water waves

mglessmer — Thu, 08 Jun 2017 09:55:51 +0000

Have you ever noticed how, if you are at a shallow beach, no matter how choppy waves are further offshore, everything becomes nice and orderly on the beach? Below you see where the water depth suddenly increases, both from the color of the water and from the wave pattern. While in deeper water waves propagate […]

Source

Group velocity and phase velocity

mglessmer — Tue, 04 Apr 2017 11:03:47 +0000

When I recently wrote about observing waves in a different way, I talked about light being focussed by the waves on the sea floor. In the other post, I focussed on how looking at the light and dark pattern on the sea floor makes waves visible that are otherwise hard to see when just looking […]

Source

Why waves propagate so slowly into smooth patches of water

mglessmer — Thu, 09 Jun 2016 10:40:14 +0000

The morning I went to Heligoland I spent some time in the port of Hamburg, trying to film a phenomenon I had recently chatted about with the author of this inspiring guest post: How waves seem to propagate super slowly into smooth patches of water. It turned out to be really difficult to film (because ships didn’t […]

Source

Signal velocity

mglessmer — Wed, 18 Feb 2015 10:59:16 +0000

How can a signal travel faster than the phase of a wave, or individual particles? I remember having a really hard time with the concept of a signal traveling faster than the phase of a wave or than individual particles when I first heard about it during my first year at university. I know my […]

Source