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Science
Friday > Archives
> 1999
> April
> April 16, 1999:
Hour One: The Biggest Bacteria / Quantum Computing
Researchers have located the largest bacterium known - a
single-celled organism that can grow so big it can be seen
with the naked eye. The bacterium, named Thiomargarita
namibiensis (or "Sulfur Pearl of Namibia") after its
home in sediments off the Namibian coast, can be as large as
a typewritten period. The discovery is described in this
week's Science.
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The giant bacterium is one of a group of
organisms that use sulfide molecules in the water
for food. In order to digest sulfides, however,
these organisms also need nitrates. Some species of
bacteria have developed ways to shuttle back and
forth between nitrate-rich water layers and
sulfide-rich sediment layers to get the food that
they need. Thiomargarita, however, does not
move. Most of the volume of the cell is taken up
with a large vacuole, or liquid container.The
organism lies in the sediment layer waiting for a
storm or other disturbance to bring nitrate-rich
water into its area, and then uses the large
vacuole to store away the nitrates that it needs.
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The white dot in the upper left is
a single cell
of the newly discovered giant bacteria.
Image © Science
.
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We'll talk to one of the researchers that discovered the massive
microbes about her discovery, and about what role these mighty midgets
might play in the environment.
Then... It should be no big surprise to anyone that computers are
getting more powerful and smaller every day - but what about a computer
that isn't measured in chips - but in molecules? Some researchers
say that using the power of quantum mechanics, they may some day be
able to have a computer faster than even the zippiest Pentium III.
Researchers at the University of Notre Dame announced last week that
they had successfully constructed a quantum-based logic gate, an essential
part of any future quantum computer - but that future still lies years
away.
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In normal, plain-vanilla computing, the switches that represent
pieces of data are either on or off. Yes or no. Zero or one.
These chunks of data, called bits, are the basic units of all
computer processing. But quantum information doesn't exist in
such a cut-and-dried format. Quantum bits (called qubits) can
have many different properties at once - like spin, location,
and color. Adding to the complexity, instead of being entirely
on or off, they can exist in both states at once. They don't
take on a set character until you try to measure them.
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Though it might seem like an incomprehensible situation to most of us,
some researchers say that all that uncertainty can be harnessed to build
very powerful computers The ability to exist in several states simultaneously
would allow computers to compute several calculations simultaneously,
in parallel, instead of having to wait. Massively parallel computers
already are being used for complex calculations like code-breaking -
but quantum computers would be faster and more powerful still.
On this segment of Science Friday, join Ira Flatow as he tries to
break through the uncertainty surrounding quantum computing.
Guests:
Heide Schulz
Graduate Student
Max Planck Institute for Marine Microbiology
Bremen, Germany
Seth Lloyd
Professor, Mechanical Engineering
Massachusetts Institute of Technology
Cambridge, Massachusetts
Raymond Laflamme
Technical Staff Member
Los Alamos National Laboratory
Los Alamos, New Mexico
Books/Articles Discussed:
Related Links:
A
quantum leap for computation
CQCIntroductions
and Tutorials
Quantum
Computation/Cryptography at Los Alamos
No
Information Without Representation - AIP
Bulk
Spin Resonance Quantum Computation - MIT
This segment produced by:
Karin Vergoth
Web producer:
Charles Bergquist
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