On the Freeway

Once in a while, an ambulance has to come through traffic on the freeway. This was the case for today.

From far away, I can never tell what direction the ambulance is coming from, but as it gets closer, I realize that it's coming from behind me. This is due to the Doppler Effect because as the moving object (the ambulance) is coming to the stationary object (me in the car that has pulled over), the frequency from the siren goes higher. The equation used would be the velocity of the sound's frequency divided by the frequency's velocity minus the velocity of the ambulance. Then all that is multiplied by the actual sound's frequency to get the frequency that I would hear as it approaches. Thus the sound seems more high-pitched and loud when it is coming toward me. After it passes me, the frequency that I hear becomes less.

Clarinetting and Physics

Whether I am playing by myself, in band, or at a concert, I am applying physics as I blow air into the clarinet.

Sound in the clarinet is made by oscillating motion or air flow. The reed is bendy and is normally controlled by resonating air in the clarinet. Once the air in the clarinet is vibrating, some of the energy leaves through the bell and any open holes (keys) The vibrating column of air flow determines the frequency and in effect the pitch. A sound wave can travel down through the clarinet and reflect and go back up. The longer the clarinet, the longer it takes to make a round trip. The length can be changed by lifting my fingers off or on keyholes and thus shortening or lengthening the distance. If all the holes are closed, the pitch is at its lowest (the lowest frequency). Frequency is the number of vibrations per second. The lower the note, the less vibrations there are per second. The higher the note, the more vibrations there are per second.

If I squeak (which is most likely on accident), that means the reed vibrated at its own resonance. By putting my lower lip on the reed, I am dampening the strength of the reed's natural resonance.

Describing exactly how the clarinet works is complicated, especially if I tried to add in the register key which takes the clarinet up another octave, so I am not sure if I said everything right.