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Why he got a speeding ticket

The story goes that Robert W. Wood, a famous physicist at John Hopkins, had been caught running a red light. He appeared before the judge, and gave an explanation of the Doppler effect, explaining how his forward motion toward the red light had shifted the color toward the blue end of the spectrum, causing him to see it as green.

The judge was about to let him go, but it turns out one of Wood’s students was present (apparently Wood had flunked the student). The student pointed out the speed at which Wood would need to be traveling in order to shift the light from red to green (anyone want to calculate this? Be sure to use relativistic redshift). The judge dropped the original charge, and fined Wood for speeding.

This page was last updated September 6, 1998.