Background
. . . .

Warning:
This animation is an applet that requires the Java 2 plugin. If you do
not have this free software, go to <http://www.java.com/
> and click on "Get It Now." Follow the onscreen instructions
to
download and install for YOUR browser. Please note that the Java
2 plugin is not available for Mac OS 9 applications, e.g. Netscape 4.7. 

Significance
Many
different physical phenomena may be measured by their wave
motion. Perhaps the best known examples are those of radio waves,
television waves or microwaves. Indeed, radio
stations are named for their types of wave transmission. For an
AM station, the amplitude of the wave is varied to carry
different sounds. An FM station has its frequency
modified. Thus, AM stands for amplitude modulation
and FM represents frequency modulation.
The
difference may be illustrated using the sliders on the above graphic.

Observation:
Any book on
trigonometry will have these two, much studied functions.
However, in the physical sciences where math is often applied, the sine
function, or cosine function may be "squared." The x
value often represents time and the y value, i.e., the
function value, is the periodic signal being studied.
In the case that the
sine or cosine function is "squared," the student may recognize
this as being similar to the "piecewise" function, or "step"
function studied in earlier algebra courses.
The more advanced
student will also recognize the function as an expanded Fourier series
with a periodic cycle.

Students will recognize a familiar
piecewise function from Precalculus
can easily be applied to time and a time
function.

Links and Printed References

Animated Unit Circle
< http://curvebank.calstatela.edu/unit/unit.htm
> 
Another animated Unit
Circle < http://curvebank.calstatela.edu/sine/sine.htm
> 
Square Functions and other
Fourier applications for the advanced student. See < http://www.falstad.com/mathphysics.html
>. 
John Johnson,
Jr., "COLUMN ONE: Gravity's Field of Dreams," Los
Angeles Times, June 10, 2006, p. 1.

Donald A. McQuarrie, MATHEMATICAL
METHODS for Scientists and Engineers, University Science
Books, Sausalito, CA, ISBN 1891389246, 2003. 
Waves on a Cosmic Scale
Waves and wave
equations have significance far beyond the mathematics of the trig
classroom. In fact, the study of gravitational waves is currently
one of the largest projects in experimental physics in the United
States. The project is called LIGO for Laser
Interferometer Gravitational Wave Observatory. In order to
collect good data, a minimum of two large facilities had to be
built. One is in the State of Washington, and the other in
Louisiana.
LIGO Hanford Observatory,
Washington
California Institute of Technology
LIGO Livingston Observatory,
Louisiana
Massachusetts Institute of Technology
LIGO Animations of gravitational
waves <http://www.ligo.caltech.edu/LIGO_web/aaas0203/
>.
To view the animations you must
have RealPlayer
or RealOne Player installed on your computer. You can download a
free copy at < http://www.real.com
>. The link to download is located on the upper right hand
corner
of the page labeled as "free RealOne Player". Once you have
successfully
installed the player you can visit the LIGO website. Click on the
"animations" link and select the appropriate speed that applies to your
internet connection. Most campuses use a LAN connection.
For more information please see LIGO
:
< http://www.ligo.org
>

Photo courtesy of Caltech,
Pasadena, CA.



Matthew Nelson
Jonathan Liu
Mahan Hajianpour

