I recently filmed a short interview with Professor Mike Merrifield about Kelvin-Helmholtz instability.
Professor Merrifield - based in the University of Nottingham's Physics Department - nicely described the effect with pencil and paper.
My oft-collaborator Pete McPartlan later did some nifty work to "animate" this description.
But before releasing the video, we started looking at other videos which demonstrated the effect.
But then I found another video - this one - and to my surprise it was filmed by students at the University of Nottingham. (I notice the logo on the lab coats before reading the description)
I contacted them on Facebook and they told me the apparatus still existed in the university's Faculty of Engineering - they said I should contact Dr Barbara Turnbull.
So it was back to Nottingham for another day of filming. The result is a few videos.
This one is the main interview with Mike, now illustrated by both Pete's animations AND Dr Turnbull's demonstration.
Then a second video just showing how the experiment worked... I thought it was worth it's own extra film.
And for the real diehards, the full slow motions that can pored over in detail.