English: Much of a person's energy is radiated away in the form of infrared energy. Some materials are transparent to infrared light, while opaque to visible light (note the plastic bag). Other materials are transparent to visible light, while opaque or reflective to the infrared (note the man's glasses).
Transwiki approved by: w:en:User:Dmcdevit This image was copied from wikipedia:en. The original description was: == Summary == This image comes from a NASA "Cool Cosmos" website: http://coolcosmos.ipac.caltech.edu/cosmic_kids/learn_ir/index.html ==