Properties of Infrared Waves
- Frequency: 430 THz down to 300 GHz & Wavelength: 7.5x10^-7 meters to 1x10^-4
- Infrared waves are given off by all warm objects and produce heat in all objects they strike. The waves cause heat by increasing the movement of molecules in the substances they strike.Dangers: The thin gold films on spacecrafts reflect infrared rays from the sun which can harm both people and the equipment on the craft.
- Doctors use infrared lamps to treat skin diseases and relieve the pain of sore muscles
Uses of Infrared
Background:
- Infrared red was first discovered in 1847 by Sir Frederick William Herschel in the 1800's.
- He decided to investigate the temperature of each color of the spectrum produced when sunlight is passed through a prism.
- He placed one bulb directly in the color and the other two past the spectrum to act as controls. Herschel noticed two trends, first that the temperature of the thermometer placed in the color was greater than the controls. The second trend was a temperature increase from violet to red.