Catch a Wave...
Light is electromagnetic radiation whose wavelength can be sensed by the human eye. There are many other
wavelengths that can be detected using instruments. The study of electromagnetic wave spectra is called
"spectroscopy". Spectroscopy can provide information about the chemistry of planets, the speed of comets,
the temperatures of stars, and much more. For example, at infrared radiation wavelengths a heat-generating
body is easily detectable against a non-heat-generating background*. Photographs of other planets and stars
are only part of the whole picture!!
This chart shows the types of waves and their sizes on a logarithmic scale... that's why the distance between 1
and 10 is the same as the distance between 10 and 100. Each tick mark represents a factor of 10 increase or
decrease from the one next to it. For example, Short Waves are 10 times longer than FM & TV waves and
visible light is 100 times (two tick marks =10 X 10) shorter than infrared radiation.
How many times larger than bacterium are grains of sand?
Next page Contents
How many times larger than bacterium are humans?
Which of Galileo's instruments would you use to take photos of the Great Red Spot? Why?
Could we hear Jupiter's radio emissions?
Last modified prior to September, 2000 by the Windows Team
The source of this material is Windows to the Universe, at http://windows2universe.org/ from the National Earth Science Teachers Association (NESTA). The Website was developed in part with the support of UCAR and NCAR, where it resided from 2000 - 2010. © 2010 National Earth Science Teachers Association. Windows to the Universe® is a registered trademark of NESTA. All Rights Reserved. Site policies and disclaimer.