Laser (IMAGE) Moscow Institute of Physics and Technology Caption Molecules of carbon dioxide emitting photons of infrared radiation in a fluorescent glass tube of a gas laser, and trees that ignite as a fire approaches are both part of active media. They all have a certain amount of energy that can be released during a particular process. Blood is also an active medium and can also be described using the methods of non-linear dynamics. Credit None Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.