Shock wave from trombone filmed

I used to play the trombone, so I’m tickled by this report: an acoustic shock wave has, for the first time, been filmed emanating from a trombone. It’s not super-visible; you might need to watch fullscreen to see it.

Also, a warning: this will only be interesting to vibration nerds (and, possibly, trombonists). The rest of you will be underwhelmed.

It’s the long tubes in the slide of the trombone that allow this sort of shock wave to form. Other wind instruments, like tubas, have longer wind pathways, but they curl around more.

The physics of beer bubbles

This article is a year and half old, but it’s still cool. From ZDNet:

Pouring beer in a mug involves multiply scattered acoustic waves. They are more complex to study [than singly-scattered waves like radar], but they can be used to look at various phenomena, such as predicting volcanic eruptions or understanding the movement of particles in fluids like beer. They also could be used to monitor the structural health of bridges and buildings or the stability of food products over time.

Tasty and helpful.

Photo by Valentin Leroy, University of Manitoba