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6 March 2014 1:04 pm ,
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Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
- 6 March 2014 1:04 pm , Vol. 343 , #6175
- 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]