Infrared

Electromagnetic Spectrum

What emits infrared?

• All objects with a temperature greater than absolute zero emit infrared radiation.

• Humans, animals, stars. Even cold things, like ice cubes.

• Far infrared waves are thermal (they emit heat). Near infrared waves are not hot at all.

How is it used?

• TV remote controls use near infrared waves.• Burglar alarms use infrared to sense people.• Some snakes have sensory “pits” which

allow them to sense their prey even in total darkness.

• Heat-sensing military missiles.• The earth/stars/celestial bodies that may be

unclear due to atmospheric haze can be photographed using infrared photography.

Infared Photography

• Cameras detect heat emitted by objects.

• Since we cannot see infrared, colors are assigned to the different temperature ranges. This is calledfalse color.

Sources

• http://www.smgaels.org/physics/infrar_1.htm• http://science.hq.nasa.gov/kids/imagers/

ems/infrared.html• http://coolcosmos.ipac.caltech.edu/

image_galleries/ir_yellowstone/lessons/background.html

• Databases: Grolier, Proquest• Books: Deciphering the Senses by Robert

Rivlin and Karen Gravelle, Notes on Color by Verner Panton