Laser punches holes in a human hair

A new laser-powered chemical analysis technique is so sensitive that it can take dozens of samples from a single strand of hair, distinguishing between the chemical signatures of each...

Forensic scientists should find the technique useful, Moran said. “The carbon you eat goes into your hair, so hair is a record of carbon ratios. If you’ve been traveling, I could guess which countries you’ve been to or what you ate.”

The team is developing its laser-ablation system to work with other chemical isotopes, including nitrogen, oxygen and sulfur.

“Carbon tells you what you’re eating, but nitrogen could tell you whether it’s meat or plants. Oxygen isotopes vary with the water cycle, and sulfur with bedrock, so they’re location proxies,” Sessions said. “Put them together, and you’ve got some really powerful data in space and time.”

Text and video via Wired Science.