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Patterns - Even in Sound!

Resonance Sound Experiment
As you know, all math is based on patterns.  In fact, patterns are everywhere.  This year, my husband is going to do an experiment with his students on sound and vibration.  He was looking for some ideas on You Tube, and came across The Amazing Resonance Experiment.

If you click under the picture on the left, you will see an incredible thing happen when salt is put on the surface of a metal plate connected to a tone generator and then vibrated with different sound frequencies. Different patterns emerge in a seemingly graceful dance.  As the plate vibrates at different frequencies, the salt particles fall into different resonant patterns.  It is mind-boggling how the frequencies create such detailed and meticulous patterns of the salt grains. When the video began, I expected all of the patterns to be symmetrical, but many were not (although, as a mathematician, I thought they were trying!).  I do think it is beautiful how one pattern morphs into the next. Notice how the patterns become more complex as the tone increases in frequency.  Also take note of how the individual shapes (circles, squares, etc.) that form the patterns keep getting smaller and smaller as the frequency becomes higher.

According to physics, everything is frequency and vibration. "These salt patterns are a result of micro bendings in the material due to the vibration waves going through it. The salt gathers at stationary points on the plate where there is the energetic most convenient place. In other words, the salt gathering results from vibrating the plate at different frequencies.  However, the patterns are not connected solely to the frequency, but rather to the frequency combined with the shape of the metal plate.  Using the same frequencies on differently shaped plates (round, triangular, etc.) would produce different patterns. Even changing the material would affect the result." The experiment has been tried with flour, sand and sugar with the flour forming clumps (not a desired result). 

So take five minutes to watch the video and see the shape of sound which is beautiful, remarkable as well as fascinating !  Don't you love science?  It's just as amazing as math!! 

Not on the Test

Not on the Test
While watching my granddaughter at her tennis lesson, I was visiting with two teachers.  One was a retired fourth grade teacher and the other currently taught Algebra in middle school.  Both we decrying the fact that each year the students come with knowledge that is more narrow than broad.  They both felt this was because more and more time is now spent on testing or getting ready for testing.  As I stated in my January 25, 2012 posting entitled The Pros and Cons of Testing, "High stakes tests have become the “Big Brother” of education, always there watching, waiting, and demanding our time. As preparing for tests, taking pre-tests, reliably filling in bubbles, and then taking the actual assessments skulk into our classroom, something else of value is replaced since there are only so many hours in a day.  In my opinion, tests are replacing high quality teaching and much needed programs such as music and art."

A long time ago, a friend sent me a song written by Tom Chapin with John Forster called Not on the Test. I saved it, and I listen to it often, especially when I am having a "down" day.  Tom and John wrote the song to express their disappointment in the lack of arts education in many public schools.  Even though the song refers to No Child Left Behind, with Common Core approaching with its own set of tests, I think you might get a much needed laugh from the song.  Just click on the link under the picture, and let me know what you think!