The "Bell Telegraph."
Matthew X
profrv at nex.net.au
Sun May 9 06:48:34 PDT 1999
'Bell Telegraph' May Enable Cosmic Communications
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By Mike Martin
NewsFactor Sci::Tech,
Part of the NewsFactor Network
August 19, 2002
Einstein's special theory of relativity strictly forbids anything from
traveling faster than the speed of light. A quantum mechanical Bell
telegraph, however, may defy this prohibition with a twist -- literally.
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No ; not that one...
The future of telecommunications may hinge on a clever new version of a
device from its past, physicists claim. What the Bell telephone is to
communication across town or overseas, the Bell telegraph -- named for
British physicist J.S. Bell -- may become to communication across the solar
system or even the Milky Way.
John Bell first proposed that the strange properties of quantum mechanics
might permit subatomic particles to interact instantaneously over distances
so vast that signals between the particles had to travel faster than light
speed.
"A device that transmits information faster than light speed has always
been possible, at least in theory," telecommunications engineering
professor and former Bell Laboratories director Ira Jacobs told News
Factor. "In practice, such a device would present monumental engineering
hurdles that might be overcome by futuristic engineers," he added.
Defying Einstein with a Twist
Einstein's special theory of relativity strictly forbids anything from
traveling faster than the speed of light. A quantum mechanical Bell
telegraph, however, may defy this prohibition with a twist -- literally.
The so-called up and down "spin" states characteristic of quantum particles
would substitute for telegraphic dots and dashes. Spin is a particle's
intrinsic angular momentum and may be visualized as a left or right-handed
rotation -- or twist -- about an imaginary axis.
In theory, a Bell telegraph could send an instant signal from a particle on
Earth entangled with a second particle on a planet light years away -- a
special configuration called a "Bell state."
Spooky Physics
"A Bell state is a particular kind of quantum state that describes two
particles in which measurement of some quantity in one of the particles
instantly affects the distant particle, no matter how far away it is,"
physicist Daniel Badagnani, a visiting professor with Argentina's National
Research Council (CONICET), told NewsFactor.
The very act of observing the Earth-bound particle's spin -- up or down --
instantaneously causes the distant particle to occupy the opposite spin
state, a circumstance of quantum mechanics so mystifying Einstein called it
"spooky."
Spin "up down up" measurements on the Earth-bound particle instantly become
spin "down up down" readings on the distant particle. Assigning dots to
"spin up" and dashes to "spin down" leads to a "dash dot dash" with another
amazing twist -- the dots and dashes appear instantly to a receiver -- no
matter how far away.
Quantum Hurdles
However, future engineers will have to overcome another strange quality of
quantum phenomena to construct a functional Bell telegraph. In theory, spin
up is a "pure" state, a certainty like the left- or right-handed rotation
of a planet or spinning top. In practice, however, quantum spin exists as a
high or low "probability" of up or down, never guaranteed until an actual
measurement occurs.
Quantum states may be visualized as fuzzy, statistical "waves" that only
collapse into hard data after a definitive observation -- hardly the stuff
of reliable information. "Due to the probabilistic outcome of the collapse,
or quantum measurement, no information can be transmitted through a
collapse," University of Missouri physics professor Peter Pfeiffer told
News Factor.
'Informed Crazies' Agree
To surmount this hurdle, Daniel Badagnani has searched for an "ingenious
setting that could distinguish between the pure state and the statistical
mixture," he explained. The prospect of such an innovation heartens
National Science Foundation Electrical and Communication Systems program
director Paul Werbos.
"I am one of those informed crazies who thinks that there is a 2-to-1
chance we should be able to build something to do what Badagnani wants to
do, sooner or later, by exploiting basic phenomena of quantum dynamics and
quantum measurement," Werbos told News Factor.
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