#physics demonstration

As they gradually desynchronize, the resulting phase differences generate the captivating "wave" illusion you observe. Ultimately, they realign after approximately two to three minutes. It's a classic physics demonstration!

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In the video demonstration above, you’ll see how a tall, thin tube containing only 1 liter of water is able to shatter a 50-liter container of water. Not only does this show just how powerful height is in creating pressure in a fluid, but it shows how a fluid can be used to transmit pressure over a distance -- one of the fundamental principles of hydraulics! (Video credit: K. Visnjic et al.; submitted by Frederik B.)

Video explaining the concept.

Amazing!

Mode shapes of a square membrane (n1 = 2, n2 = 2). 

It's hard to see but you can hear that the two items nearly hit at the same time. I am very pleased with these students.

This video has a fun and simple demonstration of the importance of fluid density in buoyancy and stratification. Fresh water (red) and salt water (blue) are released together into a small tank. Being lighter and less dense, the red water settles on top of the blue water, though some internal waves muddy their interface. After the water settles, a gate is placed between them once more and one side is thoroughly mixed to create a third fluid density (purple), which, when released, settles between the red and blue layers. In addition to displaying buoyancy, this demo does a great job of showing the internal waves that can occur within a fluid, especially one of varying density like the ocean. (Video credit: UVic Climate Modeling Group)