User:Aswathi aravind/Sandbox

FAR INFRARED RAYS
Far infrared rays is a type of electromagnetic wave,like that of invisible rays. We know that FIR is a spectrum of sunlight. Sunlight can be categorised as visible and invisible rays. Visible rays include those we can see in the spectrum of sunlight such as red ,orange ,yellow,green,blue ,indigo and violet whereas invisible rays can either be gamma rays, X rays or ultraviolet rays. These have much shorter electrowaves as compared to visible rays and are extremely penetrative. Infrared rays named Sir William Hershel in 1800 while he was carrying out sun spectrograph research. His research led to discovery that there was a third previously unknown invisible rays. This ray has extremely strong heat reaction and is between 0.75 microns and 1000microns. It was later named infrared rays.