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New theory addresses frozen Earth paradox
PHILADELPHIA, Aug. 21 (UPI) -- U.S. physicists say they have discovered a new effect in the fundamental way that laser light interacts with atoms.
Kurt Gibble, an associate professor of physics at Penn State University and lead author, analyzed the speed of an atom after it absorbs a photon of light.
"When a photon hits an atom, the atom recoils with a speed that is determined by the photon's momentum, similar to two balls colliding on a billiard table," Gibble said, noting his research looked at what happens to an atom when it is pummeled by photons coming from multiple intersecting light waves.
"You might think that an atom would absorb a photon randomly from only one of the beams, but this paper shows that the atom feels the effect of the photons from all of the beams simultaneously and, surprisingly, that it recoils with a speed that is less than it would get from the momentum of any one of the infinitely wide photons."
Gibble's discovery, which has implications for the accuracy of atomic clocks, appears in the journal Physical Review Letters.
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