Physics
Getting
the Better of Einstein-For Once
Researchers
at the NIST Boulder Laboratories have convincingly demonstrated
one of the basic tenets of quantum mechanics (referred to as QM)
and, in the process, refuted a concept embraced by Albert Einstein.
The
NIST experiment—reported in Nature on Feb. 15, 2001—measured
correlations between two massive entangled particles (singly ionized
beryllium atoms).
QM
holds that many properties of particles are not determined until
they are measured or observed in some fashion, and also that two
particles can be put into a condition whereby an observation of
one of them is instantly transmitted (faster than the speed of
light) to affect the other.
Einstein, along with his colleagues Boris Podolsky and Nathan
Rosen, believed that the quantum mechanical view of the universe
was “incomplete” and proposed that there were “hidden
variables” of some unknown nature that could explain the
puzzling QM phenomena.
Previous
tests of the hidden variable theory have been limited by two loopholes.
One has to do with the possibility of an unknown signal passing
between parts of the apparatus and contaminating results (called
the “lightcone” or “locality” loophole), and
the other with assumptions made about whether the measured results
of an experiment were representative of all the results of that
experiment (the “detection” or “fair sampling”
loophole). In the NIST experiment, a measurement outcome was recorded
for every run of the experiment, so that no assumptions had to
be made about fair sampling, thus firmly closing the detection
loophole.
Previous
experiments by others eliminated the lightcone loophole but not
the detection loophole.
Media
Contact:
Collier
Smith, (303) 497-3198
Preservation
Students
Help Renovate a Part of WWII-and NIST-History
A
forerunner of today’s “smart weapons,” the Bat
of World War II was the first totally automated guided missile
employed by the United States. Like its namesake which uses
sonar (sound waves) for locating objects, the Bat emitted radar
(radio waves) pulses that reflected off an enemy ship or other
offshore object to target its path. The National Institute of
Standards and Technology, then known as the National Bureau
of Standards, was a major contributor in the missile’s
development during the 1940s.
During
the summer of 2000, the remains of a Bat missile were discovered
in a NIST Gaithersburg, Md., warehouse. The 4-meter (12-foot)
long, 3-meter (10-foot) wingspan flying bomb was tattered and
worn after more than 50 years in storage, yet its fuselage,
wings and tail assembly were still intact (the interior mechanisms
including the warhead had been discarded years ago). NIST’s
Office of Information Services, curator of the history museum
at the agency’s Maryland headquarters, decided to add the
Bat to its collection. But first, a renovation of the missile
was in order.
Fortunately
for NIST, a local academic institution, Frederick Community
College, runs an aviation maintenance program that provided
the needed expertise for the job. Students from FCC have been
working with NIST staff since January to repair, clean, paint
and reassemble the Bat. Completion of the project is expected
by the first week in March.
XCALIBIR
Cuts a Path to Advanced Microchips
To
build smaller and smaller microchips, one part of the semiconductor
industry has to get larger. Silicon wafers—the high-tech
canvases upon which multiple integrated circuits are printed—which
predominately run about 200 millimeters (8 inches) in diameter,
are beginning to appear in a 300-millimeter (12-inch) disk. A
300-millimeter disk means more than twice the number of chips
can be built at a single time.
However, larger wafers demand exceedingly accurate measurements
of flatness and thickness, while advanced lithography (printing)
systems require accurate assessments of the curvature of the specialized
lenses and mirrors used. And to make things even more difficult,
the readings have to be consistently within 0.25 nanometer (10
billionths of an inch), equivalent to the diameter of one or two
atoms.
Like
its namesake, the fabled sword that won England for King Arthur,
a National Institute of Standards and Technology-developed device
called XCALIBIR (for X-Ray Optics CALIBration InterferometeR)
may help the United States meet these needs and continue its leadership
in the world's microelectronics realm.
Like the optician whose tools provide accurate data on lens thickness
and curvature, XCALIBIR's operators hope to provide American semiconductor
manufacturers with atomic-level measurements of their “eyeglasses”—the
optics by which circuit patterns are affixed to silicon wafers.
Achieving such precise measurements requires XCALIBIR to be housed
in an enclosure that controls the temperature to within 0.05 degree
Celsius. It also must sit atop a 15-metric ton (16-ton) granite
table that suppresses measurement-upsetting vibrations.
The instrument currently is undergoing performance testing.
Media
Contact:
John
Blair, (301) 975-4261
MEP
Centers
Can Help Small Manufacturers Save Energy, Dollars
Anyone
who has opened an energy bill lately knows that the cost of energy,
especially natural gas, is soaring. Manufacturers consume more
than a quarter of the natural gas used in the United States and
have been especially hard hit. Small manufacturers can find ways
to reduce energy costs with help from the National Institute of
Standards and Technology’s Manufacturing Extension Partnership.
Here
are two examples:
The
Maine Manufacturing Extension Partnership, a NIST MEP affiliate,
helped Naturally Potatoes improve the energy efficiency of its
state-of-the-art processing facility in Mars Hill, Maine. Naturally
Potatoes is a small producer of mashed, sliced, diced and whole
potatoes for the institutional and retail markets. As a result
of an energy audit conducted by MMEP, Naturally Potatoes is saving
nearly $365,000 annually.
Using
lean manufacturing techniques (where activities with no value
added are eliminated), the Chicago Manufacturing Center, a NIST
MEP affiliate, helped Allied Tube & Conduit in Harvey, Ill.,
find a way to reduce set-up time. Allied was producing five million
feet of steel tubing in its mill each day, but set-up time to
produce a different size tube was taking more than five hours.
The Chicago center helped Allied cut its set-up time in half and
reduce labor, energy and time costs by $2.5 million.
Companies
can get help in reducing their energy costs—or improving
their entire operation—by contacting the local NIST MEP affiliate.
To reach any of the affiliates in the network serving all 50 states
and Puerto Rico, call (800) MEP-4MFG (637-4634).
Media
Contact:
Jan
Kosko, (301) 975-2767
Fire
Safety
Firefighter
Rescue Devices Checked for PASSing Grade
Each
year hundreds of firefighters die or are seriously injured in
building fires. Often they are overcome by smoke or heat before
they can call for help. In an effort to locate trapped or incapacitated
firefighters, many fire departments have equipped firefighter
protective clothing with transistor radio-sized motion detectors
called Personal Alert Safety System devices.
Sensors on the devices, first introduced in the early 1980s, register
movement or lack of movement after a specific time period. A loud
alarm signals a fallen firefighter and guides rescuers to his
or her location. The PASS device’s usefulness should expand
as advances in miniaturization and sensor technology are incorporated
into the devices.
NIST Building and Fire Research Laboratory engineers, with the
support of the U.S. Fire Administration, are assessing the current
state-of-the-art in PASS technology and examining specific enhancements,
which include elimination of false alarms, improved accuracy,
linking to Global Positioning Systems and/or fire ground personnel
tracking systems, and incorporating additional sensors, such as
thermal sensors or toxic gas analyzers.
BFRL engineers are evaluating PASS devices from different vendors
in laboratory tests, as well as in a series of controlled townhouse
and apartment burns. Laboratory evaluations include controlled
exposure in ovens (thermal radiation) and using an apparatus that
shoots hot gases toward the device (convector heat). Controlled
field burns include inserting instrumented mannequins into furnished
rooms that are set afire.
Media
Contact:
John
Blair, (301) 975-4261
NIST
Centennial
The
National Institute of Standards and Technology's 100th year of
service to America began on March 3, 2000, and will culminate
with our centennial anniversary one year later. For each month
during this period, NIST Tech Beat will recall a significant
event that occurred in the past century.
1904
Baltimore Disaster Made Standards a Hot Issue
When
Congress created the National Bureau of Standards (now the National
Institute of Standards and Technology) in March 1901, it hoped
that the new agency would soon address the problem of divergent
measurements and standards (such as eight different definitions
of the gallon). Little did the legislators know that within three
years, a very different—and more dramatic—need for standardization
would provide the first test of the fledgling national laboratory’s
ability to make a difference.
On the morning of Feb. 7, 1904, a fire broke out in a warehouse
in the Baltimore harbor. As flames began spreading through the
central business district, the Baltimore fire chief called for
help from Washington, D.C. However, engine companies arriving
by special train from the capital found themselves helpless when
their hoses would not fit Baltimore hydrants. There was no standard
thread size at the time for coupling hoses to hydrants. The blaze
raged for a total of 30 hours and destroyed some 1,500 buildings
over a 70-block area, while one by one, firefighting units from
New York, Philadelphia, Annapolis, Wilmington, Atlantic City,
Chester, York, Altoona and Harrisburg all arrived to find their
efforts cursed by incompatible equipment.
Following the catastrophe, the Secretary of Commerce requested
that NBS study the coupling problem. Before the investigation
ended, more than 600 sizes and variations in fire-hose couplings
were documented across the country. The following year, the National
Fire Protection Association, with the assistance of the Bureau,
adopted a national coupling standard along with an interchangeable
device for non-standard couplings.
Media
Contact:
Michael
E. Newman, (301) 975-3025
The
modern era of U.S. aviation was launched with NIST's help. Before
World War I, U.S. military forces had only several dozen aircraft,
all obsolete by European standards. Aviation instruments were
sent to NIST for testing, and many were modified or overhauled
before being adopted by the military. NIST also produced the first
quantitative data on the power-producing qualities of fuels and
the first serious U.S. studies of the aerodynamics of flight.
Gas
lasers are among the inventions influenced by NIST research on
spectroscopy, a technique for identifying and characterizing substances
based on the characteristics of the emitted light, which depend
on the energy levels of the atoms. Laser pioneers used Atomic
Energy Levels, three volumes published by NIST between 1949 and
1958, which are still considered models of authenticated, verified
and consistent spectroscopic data.
A
sound ranging device developed by NIST was used toward the close
of World War I to locate enemy artillery emplacements. The instrument
timed the arrival of sound from each enemy firing at microphones
placed along the Allied trench lines. An oscillogram found in
1962 at NIST’s former Washington, D.C., facility shows gunfire
noise on Nov. 11, 1918, abruptly stopping as the Armistice went
into effect at 11 a.m. It is the only known graphical record of
the end of a war.
