The obvious way to avoid getting a speeding ticket is to always obey speed limits. But there's no science or thought in that, there is just conformity.
Instead, figuring out how to fool a speed camera is the very essence of liberty.
And you can do it, concluded University of Leicester physics students in their final year paper for the Journal of Physics Special Topics, a peer-reviewed student journal run by the University’s Department of Physics and Astronomy. Theoretically. You just have to drive really fast and then you are basically invisible to the camera. Unfortunately, the science answer is not always practical. You'd need to be motoring along at 119 million miles per hour to make the number plate invisible, one sixth of the speed of light. Your Prius is just not going to cut it.
Their calculation is based on the Doppler Effect, the physical effect where the frequencies of light or sound waves emanating from an object increase or decrease when it moves towards or away from you. This effect is at work when you hear an ambulance – its siren will appear to lower in pitch as it drives past you.
With light, this process creates “red shift” – where the frequency of light from an object traveling away from the observer is shifted towards the red end of the color spectrum. The faster an object is traveling, the bigger the shift in frequency. This means it would theoretically be possible for the light from a fast-moving car number plate to be shifted out of the frequency range which speed cameras are able to detect.
The group assumed the camera would be able to detect a similar frequency range as the human eye – roughly 400 terahertz at the “red” end of the spectrum to 790 terahertz at the violet end.
Car number plates are generally yellow – which has a frequency of around 515 terahertz.
To work out the necessary speed of the car for the number plate to be “shifted” past the 400 terahertz boundary of the visible spectrum, the group utilized the equation used by astronomers to calculate how fast stars are traveling away from the Earth.
They found the car would need to be traveling at 53 million meters per second – equal to 119 million miles per hour, or one sixth of the speed of light. Given that the fastest man-made object – the Helios Probe – is only capable of traveling at one five thousandth of the speed of light, physicists clearly have some way to go before that can happen.
Citation: D. Worthy, R. Garner, J. Gregory and J. Taylor-Ashley, 'P3 10 Red-shifted Speed Cameras', Journal of Physics Special Topics, Vol 12, No 1 (2013)
