Scientists Use Light To Create Particles
A TRAILBLAZING experiment at the Stanford Linear Accelerator Center in California has confirmed a longstanding prediction by theorists that light beams colliding with each other can goad the empty vacuum into creating something out of nothing.
In a report published this month by the journal Physical Review Letters, 20 physicists from four research institutions disclosed that they had created two tiny specks of matter — an electron and its antimatter counterpart, a positron — by colliding two ultrapowerful beams of radiation.
The possibility of doing something like this was suggested in 1934 by two American physicists, Dr. Gregory Breit and Dr. John A. Wheeler. But more than six decades passed before any laboratory could pump enough power into colliding beams of radiation to conjure up matter from nothingness. The Stanford accelerator finally provided enough energy to do it.
Dr. Adrian C. Melissinos of the University of Rochester, a spokesman for the group, said in an interview that the weaker of the two light beams used in the experiment was produced by a trillion-watt green laser. That in itself fell far short of the needed energy, even though the pulsed green laser is one of the world’s most powerful.
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