And when a wave meets an obstacle of about the same size as its wavelength, it is scattered in a process known as diffraction.

ECONOMIST: REPORT: PROTEOMICS: After the genome | The

The other is a novel diffraction technique, known as holographic projection.

ECONOMIST: Monitor

Known as Photo 51, it's an X-ray diffraction image of DNA and has at least a claim to be the most important image ever taken.

BBC: The most important photo ever taken?