Infrared Waves

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By Caroline Ayinon, Deanna Cortina, Jackie Ly, and Tatiana Yugay

Characteristics of Infrared Waves

•Infrared waves lie between microwaves and visible waves.

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•Wavelength: 7.5 x 10 -7 to 0.001 Meters

Shorter Wavelengths

• “Near infrared” light is not hot at all.

• Waves are about the size of microscopic cells.

Longer Wavelengths

• Waves are able pass through clouds of dust, water vapor.

• Waves are thermal.

• Waves are about the size of a pin head.

•Frequency: 8 x 10 10 to 4 x 10 14 Hertz

Applications of Infrared Waves

Astronomy: Infrared Telescopes

•Telescopes reveal information about the universe which the visible light technology cannot detect.

•Objects like the center of our galaxy, which we can't see in visible light because dust clouds are in the way can be

"seen" by looking at the infrared light given off.

•Infrared Telescopes are typically placed in high and dry areas like the mountains of Hawaii.

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Heat

•The higher the temperature, the more rays. If the temperature is very high there will be rays of visible and infrared light.

•The biggest source of radiation heat is the sun. Its infrared radiation heats the earth’s atmosphere.

•There are infrared heaters that are used to treat muscle injuries. The heat stimulates blood flow, speeding up the heating process.

Applications of Infrared Waves

Photography: Thermography

•Thermography is used to determine the relative temperature of objects by detecting amounts of radiation it produces.

•Thermograms use light sensitive crystals to generate electrical information which converts into an image.

•Theromography is also a form of night vision.

Warfare: Heat Seeking Missiles

•Missiles are sent out to follow their targets based on their infrared radiation.

Meteorology: Weather Satellites

•Infrared technology is used to determine water temperature, map cloud patterns, and make weather predictions.

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Visibility

Animals

•Snakes in the pit viper family, like rattlesnakes, have sensory “pits” to seek prey.

•Snakes with two sensory pits have depth perception in the infrared.

•Flickering tongues of snakes are equipped with infrared heat sensors that help with finding warm bodies of their prey.

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Humans

•Infrared is an invisible form of energy.

•Humans cannot see infrared light with the naked eye, but can feel it as heat.

Technology

•Infrared can be seen through special cameras and film that detect the difference in temperature and assign different colors to them.

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History

Discovered by William Herschel, a German born British musician and self-taught astronomer in 1800.

• He split sunlight using prism into a spectrum of visible light.

• He placed a thermometer just outside of the red end of color spectrum and there was a large temperature increase.

•He noticed that the temperature was high even if there was no light. This meant invisible rays were also emitted.

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Facts

•Infrared waves are not dangerous to humans unless concentrated in one spot.

•Humans, animals, the Earth, the Sun, stars and galaxies and even ice radiate infrared light.

Infrared Spectroscopy

• The study of how materials respond to exposure to infrared light.

•Different materials absorb infrared differently.

•Example:

Glass allows visible light to pass through but traps infrared light instead of transmitting it

Bibliography

Bloomfield, Louis A. How Things Work: the Physics of Everyday Life. New York: J. Wiley, 1997. Print.

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<http://www.marshallcavendishdigital.com/articledisplayresult/2/685/3928>.

 "Cool Cosmos." Welcome to Cool Cosmos! Web. 07 May 2010. <http://coolcosmos.ipac.caltech.edu/cosmic_kids/learn_ir/index.html>.

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<http://www.ehow.com/facts_5454589_uses-infrared-light.html>.

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 "radiation." Compton's by Britannica. Encyclopædia Britannica Online School Edition. Encyclopædia Britannica, 2010. Web. 8 May 2010 .

< http://school.eb.com/all/comptons/article-207068?query=infrared&ct=>

 "SHORT AND MEMORABLE LIGHT FACTS." Center for Science Education at SSL UC Berkeley Home. Web. 08 May 2010.

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 "Electro Magnetic Spectrum." Discovery Education Classroom Resources. Web. 07 May 2010.

<http://school.discoveryeducation.com/lessonplans/interact/electromagneticspectrum.html>.

 Netting, Ruth. "Infrared Waves." NASA Science. 27 Mar. 2007. Web. 07 May 2010.

<http://science.hq.nasa.gov/kids/imagers/ems/infrared.html>.

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