Physicists Create Great Balls of Fire

dylanduck writes "Talk about having fun at work. These guys have created luminous clouds of ball lightning up to 20 centimetres across and lasting up to half a second, longer and more realistic than before. There's a cool video too. They say it may even help understand how to contain the plasmas needed for nuclear fusion."

Comments

Video?

[ironwill96]

The video is more of a 19 second slideshow of 6 pictures. I was hoping to see an actual high-speed video of the event not a "video" of pictures.

Re:Video?

[Tx]

Pointlessly late reply, but for the benefit of anyone stumbling on this thread in the future:

Modern ultra high speed cameras of at least one type (the type with which I'm very familiar) consist of several effectively separate digital still cameras looking down the same optical axis via a beamsplitter. Special image intensifiers are used on each still camera module to provide "shuttering" and coincidently to amplify the light enough to get a decent picture at the ridiculously short exposure times used. In order to achieve frame rates of up to 1 billion frames per second (yes, billion), and exposures down to a few hundred picoseconds, a pulse is applied to each of the image intensifiers in rapid sequence. Although the exposure times may be less than a nanosecond, the captured image glows on the phosophor screen for many milliseconds, plenty of time to capture it on the CCDs.

Film-based cameras involving a rapidly spun reel as mentioned in the parent aren't capable of speeds of more than a few thousand fps. However film-based cameras involving a rapidly rotating mirror and a stationary loop of film can achieve frame rates in the millions.