This experiment shows how a substance called luminol glows when it reacts with certain chemicals. The same reaction is often used in crime scenes in order to detect blood.
“Light sensing” is a demonstration performed by staff of the Interactive Science and Technology Exhibition, Eugenides Foundation. The demonstration is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at sciencetweets.eu.