18 SCIENCE & TECH
The Epoch Times
MARCH 14 – 20, 2012
Jumping antimatter reveals
“anti-atom fingerprint”
Internal structure of antiparticles glimpsed
for the first time by CERN scientists.
Antimatter is made up
of particles like ordinary
matter, but with opposite charges and magnetic
properties; for example,
antihydrogen atoms are
the opposite to hydrogen
atoms.
Based on the idea that the
universe was created during
the big bang 13.6 billion
years ago, there should be
equal amounts of matter
and antimatter present.
However, antimatter is rare
and has only been detected
briefly, for example, in
cosmic rays and some radioactive materials.
An international team
of scientists captured
antihydrogen atoms
using magnets and then
bombarded them with
microwaves, causing
them to vibrate. When the
antimatter reached a particular frequency of vibration
– its internal resonance – it
jumped out of the magnetic
trap.
The precise magnetic
field and radiation frequency required to do this
showed the researchers
hydrogen’s “anti-atomic
fingerprint”, giving them an
insight into the structure of
these mysterious particles.
“For decades, scientists have wanted to study
the intrinsic properties of
antimatter atoms in the
hope of finding clues that
might help answer fundamental questions about
our universe,” said study
lead author Mike Hayden
at Canada’s Simon Fraser
University (SFU), in a press
release.
“In the middle of the last
century, physicists were
developing and using microwave techniques to study
ordinary atoms like hydrogen,” he added. “Now, 60 or
70 years down the road, we
have just witnessed the firstever microwave interactions
with an anti-atom.”
With this highly sensitive
technique, the researchers
can begin to better understand antimatter’s inner
structure.
“This study demonstrates
the feasibility of applying
microwave spectroscopy to
fiendishly difficult-to-handle anti-atoms,” said study
co-author Walter Hardy
at Canada’s University of
British Columbia (UBC), in
the release.
ALPHA will shortly be
upgraded in its ability to
produce more details of
antimatter’s nature.
“Hydrogen is the most
abundant element in the
universe and we understand
its structure extremely
well,” said ALPHA collaboration spokesperson Jeffrey
Hangst at Denmark’s Aarhus
University, in the release.
Chukman So
An artist’s concept of the ALPHA antimatter trap. A swirling track at the centre
represents a trapped antihydrogen atom, while its annihilation on the trap wall
generates muons (trio of exiting tracks), which deposit energy on the silicon detectors,
from which the tracks and the annihilation location is reconstructed.
“Now, we can finally begin to
coax the truth out of antihydrogen.”
“Are they different?” he
Four-winged dinosaur
had iridescent plumage
Cassie Ryan
The pigeon-sized dinosaur
Microraptor had glossy
blue-black feathers and
probably used them for
social signalling, according
to new research published
in Science on March 9.
This non-avian reptile
had a wing on each limb
and lived about 130
million years ago during
the Cretaceous Period.
Despite looking anatomically similar to a bird, it is
classified as a dromaeosaur,
along with Velociraptor.
An international team
of scientists compared
the shape of fossilised
Microraptor melanosomes –
cell structures that contain
pigments in feathers – with
those of various birds to
determine the dinosaur’s
feather colour.
Melanosomes are typically round or cigar-shaped
with around 100 of these
structures spanning the
width of a human hair.
When stacked in layers,
they cause iridescence,
which is widespread in
modern birds and often
important in displays.
Microraptor is the earliest known creature to
have possessed iridescent
plumage.
“This study gives us an
unprecedented glimpse at
what this animal looked
like when it was alive,”
said study co-author
Mark Norell, chair of the
American Museum of
Natural History’s Division
of Palaeontology, in a press
release.
“There’s been a lot of
speculation about how the
feathers of Microraptor
were oriented and whether
they formed airfoils for
flight or whether they had
to do with sexual display,”
he added. “So while we’ve
nailed down what colour
this animal was, even more
importantly, we’ve determined that Microraptor, like
many modern birds, most
likely used its ornate feathering to give visual social
signals.”
As well as being used for
display for courtship and
deterring rivals, the feathers of modern birds have
other uses, including flight
and thermoregulation.
Microraptor was previously
thought to have been active
at night, but existing nocturnal birds do not have
dark, shiny feathers.
“With numerous fossil
discoveries of birds and
asked. “Today, we can confidently say ‘time will tell’.”
The findings were published in Nature on March 8.
David and
Goliath battle site
to be excavated
Chippy Yan
AMNH/M. Ellison
A fossilised Microraptor specimen from the Beijing
Museum of Natural History is shown. Microraptor was
a pigeon-sized, 4-winged dinosaur that lived about 130
million years ago.
flowered plants, we knew
that the Cretaceous was a
colourful world, but now
we’ve further enhanced
that view with Microraptor
as the first dinosaur to
show iridescent colour,”
said study co-author Ke-Qin
Gao at Peking University,
Beijing, in the release.
“Just a few years ago, it
would have been inconceivable for us to have imagined
doing a study like this.”
The team also studied
Microraptor’s tail fan, which
they believe was probably
not aerodynamic in function, but rather was used for
attracting mates and other
social displays.
“Most aspects of early
dinosaur feathering continue to be interpreted
as fundamentally aerodynamic, optimised for
some aspect of aerial
locomotion,” said study coauthor Julia Clarke at The
University of Texas in the
release.
“[...] But, as any birder
will tell you, feather colours
and shapes may also be tied
with complex behavioural
repertoires and, if anything,
may be costly in terms of
aerodynamics.”
To view a video explaining
how the team of physicists
create and trap antimatter,
see: epochtim.es/antimatter.
An international archaeological dig will begin this
summer at the city of Azekah
in Israel, the location of the
legendary battle between
David and Goliath.
This famous biblical
story describes a shepherd’s
youngest son, David, who
goes into battle for his Jewish
kingdom and miraculously
defeats the giant Philistine
warrior Goliath.
Through this excavation,
named the Lautenschläger
Azekah Expedition, the
archaeologists are aiming
for a deeper understanding
of the city to “shed light on
some of the most intriguing
riddles in its history throughout the second and first
millennia BCE”, according to
the project’s website.
Azekah was a prosperous
city and historically held a
strategic location, located
on the western border of
the ancient Jewish kingdom,
next to the Philistine lands.
It was conquered twice by
Middle Eastern groups and
now lies destroyed.
Although the collaboration is mainly between Israeli
and German universities,
numerous other universi-
ties around the world have
joined the project, such
as Duke University in the
United States. Students can
receive academic credit for
participating and even amateurs may participate in this
effort.
“In every square that we
are excavating, there will be
participants from all over
the world,” says Yuval Gadot
of Israel’s Tel Aviv University,
one of the dig leaders, according to a press release.
The first part of the dig
will last from July 15 to Aug
24.
Osmar Schindler
Archaeologists will
excavate the city of
Azekah in Israel, the
location of the legendary
battle between David and
Goliath.