Salam,
Kecepatan cahaya yang dinyatakan oleh Albert Einstein sebagai mustahal untuk
dilampui berhasil dipecahkan oleh Wang et al., dari NEC Research Insititute,
U.S.
Untuk lengkapnya, silahkan tengok majalah Nature bagian Feature of the Week.
http://www.nature.com/nature/fow/
Jabat erat,
Ahmad Syamil
Toledo, OH
http://www.geocities.com/asyamil/
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Travelling over c
There was a young lady named Bright,
Whose speed was far faster than light,
She set out one day,
In a relative way,
And returned home the previous night.
Arthur Buller's well known limerick highlights the contradictions inherent
in faster than light travel which could violate Einstein's theory of special
relativity and the principle of causality. According to this theory, no
object should be able to travel faster than the speed of light in vacuum,
300 million metres per second, or 'c'. This has not stopped physicists
experimenting with superluminal pulses of light for almost 20 years, though
the interpretation of these results has been equivocal. Now comes what looks
like a clear demonstration of superluminal light propagation in atomic
caesium vapour by Wang et al.
The peak of a laser pulse leaves the exit face of a vapour cell before the
peak of the incident laster pulse enters the entrance face of the cell.
Effect proceeding cause should be impossible, but the explanation may be
that no actual signal is moving faster than c, rather the electromagnetic
response of the atomic system is producing the appearance of such an event.
An accompanying News and Views piece by Jon Marangos and a selection of
related content from our electronic archive make up this weeks web feature.
