Objective: Match the Size of Different
Light Wavelengths with the Sizes of Familiar Objects
Light Gives Us Information About Objects in Space:
Light provides us
with information about objects in the universe. For example, by studying
infrared light from a nebula, we can tell how hot its gases are. By studying
extreme ultraviolet light from a white dwarf star we can study what materials
it is made of. So, by studying the entire electromagnetic spectrum (all the
different types of light), scientists have been able to discover that the
universe is a far more vibrant environment than the eye can see. Data gathered
in non-visible wavelengths allows both a better understanding of known objects
and the discovery of new objects, such as gamma-ray bursters that radiate all
their energy outside the range of visible light.
But How Do Astronomers
Decide What Type of Light is Coming from these Objects in Space?
Different types of light differ in wavelengths (remember, this is the distance from the peak to peak or trough to
trough of a wave). For example, the wavelength of extreme ultraviolet light may
measure 100 angstroms, visible light has wavelengths that range from about 4,000
to 7,000 angstroms. How long is 100 angstroms or 4,000 angstroms? And just what
is an "angstrom?" Keep on reading and find out!
How Long Is An Angstrom?
Astronomers use a tiny unit of distance called the "angstrom" to measure wavelengths. Angstroms are abbreviated " Å" and named after the Swedish physicist
A.J. Angstrom. One angstrom equals .00000001 cm, a very tiny length. That
means that visible light may have a wavelength of 4,000 angstroms or about
.00004 cm. One angstrom is pretty small compared to our own body size. But just
how small is it? Take a look at the images below. See if you can find the
closest object in length to a visible light wavelength.
The
length of the body of this fly is about 60,000,000
(sixty million) angstroms
