EVENTS, ADVANCES, AND NEWS
■ BY JEFF ECKERT
TRACTOR BEAMS BECOMING A REALITY?
Photo courtesy of Dr. Paul Stysley.
No, we're not talking about the headlights on a John Deere. As anyone who has ever watched Star Trek knows, any decent
starship will be fitted with a device — known as a tractor beam — that
produces a gravity-like attraction field capable of dragging in pretty
much any object, regardless of its mass and inertia. Although the
concept appears seriously impractical for any type of large objects, it
has been known for some time that certain types of lasers can move
small, solid items. For example, last year, scientists at the Australian
National University moved some tiny particles 1.5 m through the air
using a Laguerre-Gaussian beam. Now, NASA's Office of the Chief
Technologist is getting into the act and has awarded $100,000 to a
group of laser experts at the Goddard Space Flight Center (
www.nasa.gov/centers/goddard/) to study three different
approaches for creating the laser equivalent of a DustBuster®.
The first technique involves the "optical tweezers" concept in which two counterpropagating light beams generate a
ring-like geometry that traps particles in the dark core of the overlapping beams. Varying one of the beams' intensities
heats the air around the trapped particle and thereby moves it along the center of the ring. The drawback here is that
the system requires an atmosphere, which isn't exactly omnipresent in space.
The second employs "optical solenoid beams" which were introduced in a 2010 issue of Optics Express and
described as "diffractionless solutions of the Helmholtz equation whose diffraction-limited in-plane intensity peak spirals
around the optical axis, and whose wavefronts carry an independent helical pitch." Here, the particles are drawn back
along the entire light beam, and no atmosphere is required.
The remaining technique has never been demonstrated, but it involves the use of a Bessel beam in which rings of
light surround a central point. In theory, the beam could induce electric and magnetic fields in an object's path and use
the spray of forward-scattered light to pull it backward, against the beam itself. Whichever method — if any — proves
practical, it is expected to be useful not only for extraterrestrial particulate matter but also for single molecules, viruses,
RNA, and even functioning cells on Earth. ▲
■ Concept image of a Mars rover equipped
with a tractor beam device.
COMPUTERS AND NETWORKING
NEW ULTRABOOK UNDER $1,000
The Ultrabook category of computing has been defined by Intel as basically a notebook computer that fills the
gap between tablets and
lightweight laptops — sort of like a
netbook with everything
upgraded. They are configured
with low voltage, high powered
processors, fast power-up,
extended battery life, and fast
storage, typically in the form of
SSDs. Late last year, Acer
introduced its first Ultrabook: the
Aspire S3 series. Going with the
trend toward lean and mean, it's
only 0.51 to 0.68 in thick and weighs in at just under 3 lb.
The operating system is stored in a 20 GB SSD, allowing it
to resume from sleep mode in as little as 2 sec. A battery
charge is said to last up to 50 days
if unused, and you get about 6 hr
of continuous computing time.
Other features include a second-generation Core i5 processor, a
320 GB hard drive, and 4 GB of
memory. The S3-951 includes
Dolby® Home Theater v4. The
display is a 13. 3 in HD backlit
LED with 1366 by 788 maximum
resolution. Prices start at $899.
For details, visit
■ The Acer Aspire
starts at $899.