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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
New Light on Blue Light
8 July 1999 7:00 pm
Today is the birthday of Igor Yevgenyevich Tamm, a physicist born in Vladivostok, Russia, in 1895 who helped explain the weak, bluish light observed in water shielding some nuclear reactors.
In 1934, Soviet physicist Pavel Cherenkov discovered that light is emitted when charged particles pass through a liquid medium. But the glow of "Cherenkov radiation" was not understood until Tamm and Ilya Frank explained it in 1937. The two proposed that the glow is caused by electrons traveling faster than the speed of light in water. These energetic electrons displace electrons in some of the water atoms along their path; the electromagnetic radiation emitted by the displaced atomic electrons combines to form a light wave, similar to a bow wave generated by a speedboat traveling faster than water waves.
Tamm, Frank, and Cherenkov shared the Nobel Prize in physics in 1958. Tamm died in 1971.
[Source: Britannica Online]