We've all seen
pictures of astronauts pirouetting weightlessly in space, floating
freely about, no longer tethered to the ground by gravity's pull.
And while it all looks like effortless fun, it seems that prolonged
exposure to weightlessness is no lightweight matter.
We need gravity
to give us the vertical cues to orient ourselves to our environment.
In short, it helps us keep our balance. And going without gravity
for long durations leaves us seriously disoriented. Astronauts who
spend lengthy periods in space often suffer myriad problems, like
"downs illusion"a sensation that occurs when they're
upside down and begin to sense that whatever is beneath their feet
is a floor, even though intellectually they know better.
induces nausea and sickness in two-thirds of astronauts. And those
who venture on space walks are also prone to sudden attacks of high
vertigo, leaving them with a terrifying feeling of plummeting into
space. Moreover, the aftereffects sometimes in the form of
disorienting flashbackscan last for days, weeks, even months.
"The longer you fly in space, the more time you need to recover
full balance function," explains Charles Oman, director of
the Massachusetts Institute of Technology's Manned-Vehicle Laboratory.
To help better understand and remedy the problems caused by a lack
of gravity, NASA's Johnson Space Center recently awarded $3.6 million
to MIT's Center for Space Research to develop experiments for a
virtual-reality system that will be installed in the International
Space Station now being assembled in orbit. Oman is the project's
that within two years the device will be used to help conduct a
series of 10 motion-related experiments, some as simple as having
people trying to catch tossed balls. The tests will be conducted
before, during and after long flights. Why use a virtual-reality
system to simulate weightlessness on people who are in a gravity-free
space station? "To have a controlled visual environment,"
Oman explains. For instance, the system should let researchers measure
the precise point at which astronauts begin to feel the onset of
Eventually, virtual-reality machines may be used to help train astronauts
in advance of long flights to cope with the debilitating effects
of weightlessness. It's also anticipated that the results will increase
understanding of human balance disorders on earth and lead to new
And those are potentially some heavy-duty benefits.
as hell because someone tried to pass off your work as his or hers?
A researcher at one of Down-Under's leading universities is fine-tuning
a way to beat this annoying problem.
a Ph.D. student at Monash University's School of Computer Science
and Software Engineering in Melbourne, has developed an advanced
algorithm to detect plagiarism. He hopes it will make would-be copycats
think twice before lifting other people's work and using it without
permission. "Because technology has made access to information
so readily available, there's a growing need to have better ways
of policing how original texts are used," Monostori says.
work uses what's known as a suffix tree to search vast numbers of
documents much more quickly and accurately than other available
methods. "'Suffix trees' have been used in many other areas,
such as file compression and DNA matching in molecular biology,"
Monostori says. "But algorithms so far haven't used suffix
trees for plagiarism detection. My method uses a two-stage approach,
with suffix trees used in the second stage to find the exact positions
and lengths of matching text."
Using his algorithm
to build a structure for a particular document, Monostori can then
compare it to others for overlapping content. While he says the
most obvious application will be to detect plagiarism in student
presentations and in research papers, Monostori believes it will
also be valuable for identifying documents placed on the Internet
without authorization. "The package I've developed will help
search for and identify such cases of copyright infringement,"
he says, adding that the research will also be useful in developing
more advanced search engines.
says that if an evaluation of the research confirms its merit, a
software product could be commercially available in about two years.
Look! Up in
the sky! It's a bird, it's a plane, it's, it's . . . it's a Microbat?
Yep. Palm-sized, weighing in at no more than 11 gramsabout
the same as two nickelsand with rapidly flapping wings, the
Microbat is a MEMS, or a microelectromechanical system.
developed at the California Institute of Technology's Micromachining
Laboratory, can be fitted with a tiny video camera to let the operatorwho
controls the craft with a joysticksee what it "sees."
There are now three Microbats, each taking six months to produce
since the project began a little more than 18 months ago.
technology is mainly for research. Flapping-wing aerodynamics is
at its very, very early stages," explains Yu-Chong Tai, a professor
of electrical engineering at Caltech. Tai and his team were put
to work on the Microbat by the Department of Defense, which is looking
to develop small, fast, highly maneuverable, unmanned, and mostly
silent reconnaissance aircraft.
aircraft have many advantages over the fixed-wing varietyat
least at the mini-level. They can turn and swoop more quickly, they
can hover like hummingbirds, and they're quieter. But Tai sees no
need to ever transfer the technology to full-sized jets. "Today's
fixed-wing passenger aircraft are really, really efficient,"
he says, and perfectly suited for open-space flight.
is constructed mainly of titanium, was fairly cheap to develop,
and could be inexpensive to make. That's because most of the technology
it uses is off-the-shelf. So far, Tai says, the DOD has spent only
$1.3 million on the project. In U.S. defense spending terms, that's
while the technology for the electronics and framework of the Microbat
is already available, as Tai has proven, the MEMS' power source
remains feeble. The current generation can fly for only 50 seconds,
at speeds nearing 50 mph. Once it loses power, the Microbat floats
to a soft landing, its wings still flickering a bit, "like
a wounded bird," Tai says. And therein lies the rub. He estimates
it may be another decade before more efficient lightweight batteries
are built, even though the Pentagon is spending millions upon millions
of tax dollars on battery development.
applications, Tai thinks the Microbat could prove useful as a rescue
tool, helping to find victims inside damaged or smoke-filled buildings,
or people lost in thick woods. But until someone invents a better
battery, this bat won't be making trips that go far from its home
cave anytime soon.
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