Science of Infrared

What are Infrared Waves?

We experience infrared waves everyday as heat. On the electromagnetic spectrum infrared waves lie between microwaves and visible light. The wavelength of these waves span from 0.75 µm to 1 mm which is on the larger side compared to the rest of the electromagnetic spectrum. These waves are emitted by all objects, but aren't visible to the human eye. Typically, the hotter the object, the more infrared radiation is being emitted. This is why when you see a hot object, such as a stove, visible light is given off because it is 'red hot'.

Courtesy of http://missionscience.nasa.gov/images/ems/ems
InfraredWaves_mainContent_thermal-imaging.png

How are Infrared Waves used?

Infrared waves are used in everyday life. You use them while you are cooking some steak on the barbeque or when you are flicking through the channels on TV with your remote control. Special lenses allow us to see the infrared waves emitted by objects which will create thermograms which show the heat signatures given off by the object in the focus of the lens. These are used for night vision or seeing planets that may be far off in the distance which regular telescopes cannot see without visible light.

                                                     Ghosts!?

http://nexus404.com/Blog/wp-con
tent/uploads2/2010/10/ghost-in-infrared.jpg

One of the very interesting phenomena about infrared waves  and night vision is that you can see the faint heat signatures of ghosts or which are also known as aberrations. The lens will pick up a somewhat dim outline of a figure which is believed to be a ghost. This is not exactly proven to be a true statement but is just an idea that is something cool to think about when talking about infrared and night vision.

Courtesy of http://news.nationalgeograp
hic.com/news/2011/10/pictures/111021
-best-space-pictures-planets-comets-star
s-science-166-mars/

Astronomy

Infrared waves are beginning to be use more frequently in studying outer space due to the benefits of infrared vision which can pick up heat signatures. When the heat signatures are given off and picked up by the cameras or telescopes they can be put together to make a picture which shows what the camera was seeing in heat signatures. The main benefit to this is that this thermal imaging can show what normal cameras can't without visible light. This allows astronomers to see planets, stars, and much more which can be farther off then what a regular telescope can see. An example of this is shown here to the right.

Safety Precautions

Infrared waves are like Ultraviolet and Microwaves in terms of problems due to exposure. They will not affect you when exposed occasionally, but if exposed for significant amounts of time can cause long term problems such as thermal excitation where the body starts growing black spots, similar to long term radioactive radiation. Other things to be aware of are to be ready to experience heat due to the radiation.

Links & Sources
http://www.youtube.com/watch?v=jX0gIWU49iI
http://science.hq.nasa.gov/kids/imagers/ems/infrared.html
http://science.nationalgeographic.com/science/space/universe/spitzer-space-telescope/
http://physics.tutorvista.com/waves/infrared-waves.html