High Speed Imaging
This is a test as much as real content, but I have started to upload some of the videos that my group took last summer when we had a very nice high speed camera on loan from the EPSRC loan pool (http://www.eip.rl.ac.uk/). The reason for the loan was ostensibly to look at the interaction of aerosol droplets, and we got some nice if inconclusive data from this work. In fact, although our camera could run at around 100,000 frames per second we actually need a slightly faster one to see individual mixing events.
So the ‘real’ science was interesting, and is what we spent most of the time on, but as any good physicist will tell you, when you get a new toy, you like to play with it. My group were very inventive in the range of things they looked at with the camera, and you can see a range of these over at my youtube channel. I will add more in due course.
We looked at a number of objects: a bubble bursting, an ink drop hitting a bowl of water, a lighter igniting and each is fascinating and often very beautiful in its own way. I have watched the ink drop video a number of times now and the way the waves propagate out and the drop bounces back are just, I think, astonishing.
Arguably the best video is one I’ve not put on yet, which is a bumble bee in flight. the way in which the wings flap and glint in the light are just fabulous. In fact we were able to use this to answer a question form a visiting school kid yesterday who had been told that the buzzing bees make occurs when their wings hit each other. Our video shows quite clearly they never touch.
Here is the ink drop video.
One last comment on these videos is that typically they are all taken at 5000 frames per second, even though our camera can run much faster. There is a trade off to be made with the speed and the physical size of the data you wish to collect, but perhaps more importantly the illumination becomes an issue. With very fast acquisition comes the need to illuminate very brightly and once you get above about 5000fps for the types of everyday objects we were looking at (including one of my postdoc’s face) you more or less need an arc lamp! The illumination for some other experiments we do on microbubble dynamics is also fun, where we run at ~4 millions frames per second…