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KS3 Science - Electromagnetic Spectrum: Infra Red

A guide to resources on electromagnetic waves, from radio to gamma - their use, danger and occurrence, compiled by your librarians.

Discovery of infra red rays

Infrared light was discovered in 1800 by the British astronomer, Sir Frederick William Herschel.

Herschel noticed that the temperature of the region just beyond the red part of the spectrum was even higher than the red. Herschel demonstrated that these radiations can be absorbed, transmitted, reflected, and refracted.

Read more about Herschel HERE

Heat Applications of infra red

As infra-red rays make one feel warm on even chilly day, it raises the white blood cell count inside the body, which promotes greater immunity and healing.   Read more about infrared radiation and health...

Transmitting information through infrared

Most television remote control units work by means of infrared radiation.

Infra red radiation used to transmit information over short distances between computers or mobile phones...

Infra Red - Satellite Photos

  • Infrared satellites are used to measure ocean temperatures, providing an early warning for El Nino events that sometimes impact climates worldwide. 
  • Space-based cameras use infrared light to study vegetation patterns and to study the distribution of rocks, minerals and soil.



Sweetsearch a handy web search tool...

Properties of infra red rays

  • The part of the spectrum beyond the visible region of red light
  • Longer wavelength than visible light and is detected most often by its heating effect, it is sometimes called thermal radiation
  • Infra red radiations given off by warm objects (remember the temperature testing at airports ?). Watch the video below to find out more...

Find out about other application of infra red

  • In medicine, infrared technology is used for non-invasive analysis of body tissue and organs.
  • Infra red rays are used to diagnose eye diseases by taking detailed pictures of the deep, hard-to-see blood vessels at the back of the eye and in the treatment of certain conditions like haemorrhoids


Infra Red in Imaging

  • Infrared cameras are used in security-related observations work, and in military surveillance  as well as to locate people and animals caught in heavy smoke and for detecting hot spots in forest fires.
  • Infrared imaging is used to detect heat loss in buildings or to test for stress and faults in mechanical and electrical systems, and to monitor pollution.
  • In archaeology, thermal infrared imaging has been used to discover hundreds of miles of ancient roads and footpaths, providing valuable information about vanished civilizations.

Do you know?

* Rattlesnakes and other reptiles can see infra-red light ?

* Some species of fish, like piranha and goldfish, can see in infrared light 

* Some materials like glass which are transparent to normal light are opaque to infrared light?

* Boa snakes use infra red light to track their prey

** Vampire bats use infra red sensors to guide them to blood!!! read more....

Risks & Dangers

When your eyes are exposed to infrared light for lengthy periods of time, the longer wavelengths of this invisible light can damage your eyes. This can happen if you frequently use a welder with inadequate eye protection.

Read more HERE

Further Reading

Take a look at these webpages for some interesting information