Science fact: Scientists achieve 'Star Trek'-like feat
<Picture: 'Beam me up' graphic>December 10, 1997
Web posted at: 9:29 p.m. EST (0229 GMT)
NEW YORK (AP) -- Scientists have pulled off a startling
trick that looks like the "Beam-me-up, Scotty"
technology of science fiction.
In an Austrian laboratory, scientists destroyed bits of light
in one place and made perfect replicas appear about three
feet away.
They did that by transferring information about a crucial
physical characteristic of the original light bits, called photons.
The information was picked up by other photons, which took
on that characteristic and so became replicas of the originals.
The phenomenon that made it happen is so bizarre that even
Albert Einstein didn't believe in it. He called it spooky.
In addition to raising the rather fantastic notion of a new means of
transportation, the trick could lead to ultra-fast computers.
The experiment is reported in Thursday's issue of the journal
Nature by Anton Zeilinger and colleagues at the University of
Innsbruck in Austria. Another research team, based in Rome,
has done similar work and submitted its report to another journal.
The work is the first to demonstrate "quantum teleportation,"
a bizarre shifting of physical characteristics between nature's
tiniest particles, no matter how far apart they are.
Scientists might be able to achieve teleportation between atoms
within a few years and molecules within a decade or so, Zeilinger said.
The underlying principle is fundamentally different from the "Star Trek"
process of beaming people around, but could teleportation be used on
people? Could scientists extract information from every tiny particle in a
person, transfer it to a bunch of particles elsewhere, and assemble those
particles into an exact replica of the person?
There's no theoretical problem with that, several experts said.
But get real.
"I think it's quite clear that anything approximating teleportation
of complex living beings, even bacteria, is so far away technologically
that it's not really worth thinking about it," said IBM physicist Charles
H. Bennett. He and other physicists proposed quantum teleportation in 1993.
There would just be too much information to assemble and transmit,
they say. Even if it were possible someday, it would be so
expensive that "probably it's just as cheap to send the real person,"
said Benjamin Schumacher of Kenyon College in Gambier, Ohio.
Besides, Schumacher said, teleportation would "kill you and take
you apart atom by atom so you could be reassembled at the other
end, one hopes. It doesn't seem like a good idea to me."
Much more likely, experts said, is using teleportation between
tiny particles to set up quantum computers. These devices would use
teleportation to sling data around, and they could solve certain complex
problems much faster than today's machines.
In the new work, scientists transferred the trait of "polarization"
between photons. Light behaves like both a photon particle and as
a wave. A light wave has peaks and troughs like an ocean wave, and
polarization refers to the directions in which these peaks and troughs
point. Photons retain this trait. To transfer the polarization between
photons, the researchers used a phenomenon called entanglement,
which a disbelieving Einstein derided. Since then, however, it's been
shown to be real.
When two photons are entangled, "they have opposite luck," said
IBM's Bennett. Whatever happens to one is the opposite of what
happens to the other. In particular, their polarizations are the opposite
of each other.
Here's how the Austrians took advantage of that:
Call three photons A, B and C, and assume the goal is to transmit A's
polarization to C. The researchers created B and C as entangled photons.
Then they entangled B with A.
That second step destroyed A, but not before B took on the opposite
of A's original state. This change meant B's entangled partner, C, had to
change polarization to remain the opposite of B's. So C's polarization
ended up the same as A's used to be. The polarization was transmitted.
The process worked only 25 percent of the time because of how the
experiment was set up. It's possible to go to 75 percent and scientists
will shoot for that, Zeilinger said.
If the notion of entanglement leaves your head spinning, don't feel bad.
Zeilinger said he doesn't understand how it works either.
"And you can quote me on that," he said.
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•Univ. Prof. Dr. Anton Zeilinger •IBM - Quantum Teleportation
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I don't know if it's related precisely, but if one of
you can find the time to explain me a bit more regarding
this "scale", see also my last posting (picture of atom robot-arm)
I would be very thankful.................
Best regards,
Berrie
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Berrie Staring Email : staring@worldonline.nl
Co-founder : (Excedo?) Dutch >H
Site: present in December 1997
" So you own the seed.......It will not become
a Bonsai, unless you let it grow and cut wise.... "
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