The Doppelgangers

{this is a photo reenactment; no original photos remain after the fire of 2001}
Alan and Roy are depicted here entertaining at the Unfoina, South Dakota train depot. The Doppelgangers had a great gig. They used to play just as the trains were arriving. While this was very entertaining for the folks standing at the depot, The Doppelgangers, as they were called then, performed for exclusively the train passengers.

It was originally Roy’s idea. “Every time a train goes by while honking the horn, we on the ground hear a Doppler Effect. The people on the train cannot hear this cool effect, so that’s what we do. We provide the Doppler Effect for them!” Roy says with a smile.

Roy, who’s a bit of a science buff, went on. “Remember how the train horn’s pitch changed as the vehicle raced towards, then away from you? First the pitch became higher, then lower. Originally discovered by the Austrian mathematician and physicist, Christian Doppler, this change in pitch results from a shift in the frequency of the sound waves.”
Roy’s findings hold water, as illustrated in the following picture.

Roy continues. “As the train approaches, the sound waves from the tubas are compressed towards us who are playing the tubas. The intervals between waves diminish, which translates into an increase in frequency or pitch. As the train recedes, the sound waves are stretched relative to the observer, causing the tuba’s pitch to decrease. By the change in pitch of the tuba, the passenger can determine if the train is coming nearer or speeding away. If you could measure the rate of change of pitch, you could also estimate the ambulance’s speed. This of-course is difficult, as the tuba outputs a varying range of tones.”

“By analogy, the electromagnetic radiation emitted by a moving object also exhibits the Doppler effect. The radiation emitted by an object moving toward an observer is squeezed; its frequency appears to increase and is therefore said to be blueshifted. In contrast, the radiation emitted by an object moving away is stretched or redshifted. As in the train/tuba example, blueshifts and redshifts exhibited by stars, galaxies and gas clouds also indicate their motions with respect to the observer. ”

Alan’s comments on The Doppelgangers: “I like to make people smile with my music.”

The Doppelgangers played for thousands and entertained dozens. Their careers ended over a simple contract negotiation, as they were signed to entertain at a barbeque function in Manchester. There was apparently a labor dispute with a train union boss. No one was available for questioning.