While the usual Doppler effect means that the frequency increases if the observer approaches the source – and decreases as they move away from each other – theorists have speculated, since 1943, about the possibility that these rules may be interchanged. That would create an inverse Doppler effect.
An experiment that claimed to have detected this effect was conducted by Nigel Seddon and Trevor Bearpark in Bristol, United Kingdom in 2003.
Researchers from Swinburne University of Technology and the University of Shanghai for Science and Technology showed that this effect can be observed in optical frequencies as well. This was made possible by growing a photonic crystal and projecting a laser beam into the crystal. This will make the crystal act like a super prism and the inverse Doppler effect can be observed.
Famous quotes containing the words inverse and/or effect:
“The quality of moral behaviour varies in inverse ratio to the number of human beings involved.”
—Aldous Huxley (1894–1963)
“To get time for civic work, for exercise, for neighborhood projects, reading or meditation, or just plain time to themselves, mothers need to hold out against the fairly recent but surprisingly entrenched myth that “good mothers” are constantly with their children. They will have to speak out at last about the demoralizing effect of spending day after day with small children, no matter how much they love them.”
—Wendy Coppedge Sanford. Ourselves and Our Children, by Boston Women’s Health Book Collective, introduction (1978)