[Paleopsych] NYT: Brighter and Blander: A Feathered Role Reversal
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Thu Aug 11 21:18:54 UTC 2005
Brighter and Blander: A Feathered Role Reversal
New York Times, 5.8.9
http://www.nytimes.com/2005/08/09/science/09obse.html
[There have been many novels and stories about a device that forces everyone to
tell the truth. The results are invariably disasterous. The article below is
yet another one about new technology to ferrett out deception. We should wonder
whether there will be too much of said technology.]
By [3]HENRY FOUNTAIN
A New Kind of Paper Trail
Companies have gone to great lengths, and expense, to develop
technologies to assure that checks, credit cards and important
documents are authentic. Most credit cards carry holograms, and checks
are often printed with security inks that cannot be easily duplicated.
But there may be a much easier way to prevent document forgery or
similar kinds of fraud. Scientists in England have come up with a
simple technique to scan the surface of paper or other materials for
the microscopic imperfections inherent in them. These flaws create a
built-in "fingerprint," a unique digital code that can be used for
authentication.
A piece of paper or plastic may look smooth, but under a microscope
there is a certain amount of roughness. Paper, for instance, is made
up of tiny fibers that are compressed into a sheet, creating countless
random high points and hollows. The technique, developed by
researchers at Imperial College London, Durham University and the
University of Sheffield, measures this inherent roughness using a
basic laser with four detectors.
As a section of material is scanned, the detectors continuously
measure the intensity of the reflections off the surface at four
angles. An average intensity is calculated, and changes from this
average are converted into a short digital code (requiring only about
200 to 500 bytes of storage space). The researchers, who described the
technique in the July 28 Nature, said the probability of the code
being the same for two pieces of paper or other material was basically
zero.
The technique worked even when the researchers crumpled up a sheet of
paper into a ball and smoothed it out, scorched it in an oven or
scribbled heavily on it with a pen.
The researchers say such built-in fingerprints would be highly secure,
since there is no way to control surface imperfections when
manufacturing paper or plastic. The technique could even be used with
cardboard packaging as a built-in tracking code.
Surf This
It's not that the world needs any more evidence of the power of
hurricanes, but scientists at the Naval Research Laboratory have
provided some anyway. Ivan, the storm that killed more than 90 people
in the Caribbean and United States last September, created waves as
high as 91 feet when it churned through the Gulf of Mexico, the
researchers report in the current Science.
The scientists were fortunate that an array of pressure sensors they
set up on the seabed some 75 miles south of Gulfport, Miss., for
another research project were in the path of Ivan. (They were even
more fortunate that the sensors survived the hurricane, which when it
passed through the area was a Category 4 storm, the second most
powerful.) Measurements of the water pressure can be used to calculate
wave height.
The sensor data showed that of 146 waves at three of the sensors, 24
were higher than 50 feet, and the tallest measured 91 feet. But the
researchers say that the sensors may have missed the biggest waves, as
the instruments were off when the most powerful part of the storm
passed overhead. They estimate that some waves could have been 130
feet high.
The waves dissipated in the rough gulf waters before reaching shore.
But waves of such magnitude could easily destroy an oil platform, say,
or a fishing boat. The largest waves would have peak-to-peak lengths
of more than 600 feet, and a cargo ship or other large boat caught in
such a wave likely would break in two.
Moons of Saturn
The greatest moments of the Cassini mission to Saturn involved the
exploration of the moon Titan, which with its atmosphere and lakes of
methane lakes is one of the most fascinating bodies in the solar
system. But Cassini has spent time exploring Saturn's more mundane
reaches. The latest is the moon Mimas, which the spacecraft flew by
last week.
Images taken during the flyby show Mimas, which is about 250 miles in
diameter, to be deader than a doornail and heavily pockmarked with
craters. The images are available at
[4]nasa.gov/mission_pages/cassini/main.
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