The science and technology of using light particles (photons) to
carry information over hair-thin fibers of glass (fiber-optics).
Optical networks are the driving force behind broadband, and
over the coming years, photonics will become as much a part of
the popular lexicon as electronics is today. Historical
Perspective: Time travel: Not in this universe? Sorry, science-
fiction fans: Time travel is impossible. That is the sobering
conclusion, anyway, of a Hong Kong–based team of physicists in
August 2011. They found that the maximum speed of a single
photon, the basic unit of light, “obeys the traffic law of the
universe,” Agence France-Presse reports. The photon cannot go
faster than the speed of light--186,282 miles per second--and
thus provides no way around the law of physics that an effect
can’t come before its cause. Previously, scientists had noticed
that in certain mediums, light appeared to exceed its set limit.
But when the Hong Kong researchers shot photons through atoms
chilled to one ten-thousand