Photo: Gary Settles/Penn State University/NY Times

This intriguing New York Times story (Oct. 27, 2008) arrived by way of imaginginfo.com recently. (If this doesn't make us all practice proper cough etiquette this cold and flu season, nothing will.) Here's an excerpt:

In Roald Dahl's novel "The B.F.G.," the title character, a big friendly giant, captures dreams in glass jars. At Pennsylvania State University, a professor of engineering has captured something less whimsical but no less ephemeral - a cough - on film.

The image, published online Oct. 9 by The New England Journal of Medicine, was created by schlieren photography, which "takes an invisible phenomenon and turns it into a visible picture," said the engineering professor, Gary Settles, who is the director of the university's gas dynamics laboratory...

For the full story and links to more photographs of phenomenon invisible to the naked eye, go here.

- Ugo