Infrared Rays and Ultraviolet Rays
Infrared Rays
Infrared (IR) rays are electromagnetic radiations with wavelengths 700nm – 1mm. Almost half of the sun’s energy is made up of infrared waves. They have frequencies of 4-7.5 *10^14 Hz, which is lower than that of visible red light. Hence, IR rays are not visible to the human eye. However, there are several animals which can see IR rays like the snake which uses infrared rays to hunt its prey. IR rays travel with the speed of light which is 300,000,000 meters/sec. IR waves are found in almost every object in the universe which emits even trace quantities of heat. These rays are associated with low photon energies lying between 0.0012 – 1.64eV. This energy causes vibration of molecules within a substance, thus causing it to heat up. This principle is used widely in several fields. IR rays are used in night vision cameras to study heat emissions of the human body and several living organisms. They are widely used in medical diagnostic purposes, security cameras and in remote controls which make use of infrared pulses to send messages to electronic devices such as the television, computer or a blue-ray player. They are also used to study astronomical objects.
Ultraviolet (UV) rays are electromagnetic radiations with frequencies ranging from 7.5*10^14-3*10^16 Hz, higher than that of visible violet light. It is found in sunlight and cannot be seen by the human eye though several insects and birds can perceive it. UV rays have wavelengths of 10nm-400nm. Like the IR rays, they travel with the speed of light which is 300,000,000 meters/sec. UV rays are associated with very high photon energies in the range of 3.1-124eV. This intense energy can knock off the electrons in an atom, thus causing the molecule to split, resulting in cell damage and harmful genetic mutations in living organisms. Luckily, most of the harmful ultraviolet radiations are filtered by the earth’s atmosphere in the ozone layer. However, UR rays find constructive uses in various fields. It is used for sterilization and disinfection of various objects, surgical equipments and heavy machinery. They are used for diagnostic and therapeutic purposes in the medical field. It also finds varied use in lighting and curing processes.
Works Cited
Wood, David. “Infrared Waves: Definitions, Uses and Examples. Study.Com. Web. 6 Apr. 2016.
“Ultraviolet Radiation.” Student’s Guide: NSF Polar Programs: UV Monitoring Work. Web. 6
“Uses for UV.” Science Learn Hub, 29 July 2008. Web. 6 Apr. 2016.
“Cool Cosmos.” NASA: Infrared Astronomy. Web. 6 Apr. 2016.
