In order to celebrate my LAST ORCHESTRA CONCERT, I guess I will do a journal entry on the physcis of playing the violin...When you pluck or bow a string on the violin, you create standing waves. If you place a finger on the string (like I did in the picture), you shorten the length of the string, decreasing the wavelength but increasing the frequency of the fingered string. Playing a note an octave higher means you doubled the original note's frequency. When you tune, you also try and match the frequency of the note being played so that you don't hear beats. Playing a piece "spicatto" even involves torque because you must play the notes at the bow's center of mass so that the bow can rotate and move freely.

This is a metronome (obviously). Besides setting a steady beat that helps me to play my violin in tempo, it also has a setting that plays the note A which allows me to tune my instrument. I never realized this before, but on the dial, right below where it says "A", it says 440 Hz, the frequency of the note A (!!!). This past week of physics has also made me realize why tightening the tuning pegs on my violin increases the pitch of the string. The wave speed of the string increases with the increase in tension. By winding the string around the tuning peg, I am increasing the tension of the string and increasing its wave speed. Increasing the wave speed of the string also increases its frequency. This higher frequency is picked up by my ear as a higher pitch.

This isn't the best picture, but I had to (yet again) post another picture of a lame ticket stub because I forgot my camera (!!!). So, this weekend I went to the Chris Tomlin concert with my Youth Group from church. It was my first time at a, umm, "religious" concert, but I was surprised to find that I enjoyed it. The electric guitars used electromagnetic induction to produce the music. A permanent magnet magnetized the guitar strings so that when the strings vibrated back and forth near a coil, it induced an emf in the wire. The current in the wire created a signal which was transmitted to the loudspeakers to amplify the sound. I could hear the music because of sound waves which were created by the oscillation of the loudspeakers. When the sound waves reached my ear, they vibrated my eardrum, generating signals that were transmitted to a part of my brain that interprets them as sound.