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Issue no. 33, 2010
Published: Oct 22, 2010 |
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 Moon crash kicks up ice, silver and mercury | | UN urged to freeze climate geo-engineering projects | | Kitchen sink experiment simulates exotic white holes | | New method yields more rice with less water: Oxfam | | Planet hunters no longer blinded by the light | | Miniature batteries smaller than grains of salt |
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| Moon crash kicks up ice, silver and mercury |
A rocket sent crashing into the Moon last year kicked up several hundred
kilograms of water, silver, mercury and other surprising chemicals. The
US space agency NASA sent the rocket to the permanently shadowed moon
crater Cabeus last October to see what would, literally, pop up.
Several reports published in Science show some surprising findings,
including a large amount of water in the form of ice, carbon monoxide,
ammonia and the silvery metals.
During the mission, called LCROSS for Lunar Crater Observation and
Sensing Satellite, the rocket was sent crashing into the dark and
freezing crater and instruments on the satellite measured the spectra of
light in the dust kicked up.
Researchers at the NASA Ames Research Center estimated that 5.6% of the
total mass inside Cabeus crater is made up of frozen water. The rocket
impact created a crater about 25 to 30 metres wide, sending up an
estimated 4,000 to 6,000 kg of debris, dust and vapour.
The silver may just be tiny particles, not in a form that could be
mined, the researchers said, and the large amount of mercury was an
unpleasant surprise as its toxicity could present a challenge for human
exploration. |
| ABC News / Reuters
Oct 21, 2010 |
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| UN urged to freeze climate geo-engineering projects |
The UN should impose a moratorium on 'geo-engineering' projects such as
artificial volcanoes and vast cloud-seeding schemes to fight climate
change, green groups say, fearing they could harm nature and mankind.
The risks were too great because the impacts of manipulating nature on a
vast scale were not fully known, the groups said at a major UN meeting
in Nagoya, Japan aimed at combating increasing losses of plant and
animal species. An important cause for the rapid losses in nature is
climate change, the UN says, raising the urgency for the world to do
whatever it can to curb global warming and prevent extreme droughts,
floods and rising sea levels.
Some countries regard geo-engineering projects as a way to control
climate change by cutting the amount of sunlight hitting the earth or
soaking up excess greenhouse gas emissions, particularly CO2. But
critics say geo-engineering is a way for some governments and companies
to get out of taking steps to slash planet-warming emissions.
The UN climate panel says a review of geo-engineering will be part of
its next report in 2013. Some of the geo-engineering schemes proposed
include ocean fertilization, solar reflectors in space, artificial
volcanoes, and carbon capture and storage. |
| Reuters
Oct 21, 2010 |
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| Kitchen sink experiment simulates exotic white holes |
Expensive particle colliders are not the only way to explore far-out
physics. It seems that water gushing from a tap and hitting a sink
behaves like a white hole. A black hole is a dense concentration of mass
surrounded by an extremely powerful gravitational field. Nothing that
falls within a certain radius surrounding it, known as the event
horizon, escapes. A white hole is the opposite: its event horizon allows
things to escape but prevents anything from entering. However, so far
white holes only exist in theory, so cannot be studied observationally.
When water hits the bottom of a sink, it flows outwards in all
directions. At a certain distance from the point where the water hits
the sink, the outgoing liquid rapidly decelerates and piles up before
continuing its outward flow, creating a ring-like ridge. Physicists have
previously suspected that any ripples that might arise beyond the ridge
and travel towards it should not be able to get past the ridge. This is
because at the ridge the water flows outwards at the maximum speed that
ripples could travel inwards, so the ripples would make no forward
progress. This makes the ridge behave like a white hole event horizon.
Now this has been experimentally confirmed by researchers at the
University of Nice in France. The team let a stream of viscous oil hits
an empty aquarium. When they placed the tip of a needle in the path of
the oil as it spread out from the collision point, it generated a
v-shaped disturbance. The angle of the v depended on the relative speeds
of the fluid and any ripples on its surface. When the team measured it,
they found that the two speeds are indeed equal, preventing ripples
flowing in and creating something akin to a white hole event horizon.
They also found that between the collision point and the ridge, the oil
flowed faster than the ripple speed, causing any ripples arising there
to be swiftly carried outwards - just as things inside a white hole
should get spat out. |
| New Scientist / arxiv.org/abs/1010.1701
Oct 19, 2010 |
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| New method yields more rice with less water: Oxfam |
Rice farmers could boost their yields by 50% with a new method that uses
less water according to development group Oxfam, as climate change and
drought threaten the staple crop.
Growing rice - considered the major calorie source for around half the
world's population - is water-intensive, accounting for as much as
one-third of the planet's annual freshwater use. Rice farmers normally
rely on flooding their fields to keep seeds covered in water throughout
the growing season.
But the new method, known as the System of Rice Intensification, or SRI,
involves planting seedlings farther apart, keeping fields moist instead
of flooding them, transplanting seedlings to fields earlier and weeding
manually, Oxfam said in a report.
Farmers using SRI in parts of Africa, Southeast Asia and India have been
able to produce as much as 50% more rice with less water, and often with
less labour, said the report. Oxfam's goal is to encourage rice-
producing countries to convert 25% of rice cultivation to SRI by 2025. |
| Reuters
Oct 20, 2010 |
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| Planet hunters no longer blinded by the light |
Using new optics technology developed at the University of Arizona's
Steward Observatory, an international team of astronomers has obtained
images of a planet on a much closer orbit around its parent star than
any other extrasolar planet previously found.
The discovery is a result of an international collaboration among the
Steward Observatory, the Swiss Federal Institute of Technology Zurich,
the European Southern Observatory, Leiden University in the Netherlands
and Germany's Max-Planck-Institute for Astronomy.
Installed on the European Southern Observatory's Very Large Telescope,
or VLT, atop Paranal Mountain in Chile, the new technology enabled the
astronomers to confirm the existence and orbital movement of Beta
Pictoris b, a planet about seven to 10 times the mass of Jupiter, around
its parent star, Beta Pictoris, 63 light years away.
At the core of the system is a small piece of glass with a highly
complex pattern inscribed into its surface. Called an Apodizing Phase
Plate, or APP, the device blocks out the starlight in a very defined
way, allowing planets to show up in the image whose signals were
previously drowned out by the star's glare.
The breakthrough, which may allow observers to even block out starlight
completely with further refinements, was made possible through highly
complex mathematical modelling. |
| PhysOrg.com / Astrophysical Journal Letters
Oct 14, 2010 |
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| Miniature batteries smaller than grains of salt |
They may be as small as grains of salt, but new batteries being
developed by scientists from the University of California in Los Angeles
still pack the power of their larger kin.
The key to these tiny batteries, which could eventually power everything
from microrobots to medical implants, is their architecture. The
scientists start with a field of tiny nanowires. Then they deposited
layers of nano-sized lithium aluminosilicate to those nanowires,
creating a three-dimensional structure.
Most batteries today have a two-dimensional structure. Expanding up,
instead of just out, means the battery can hold more energy in a smaller
space. The textured surface also increases the surface area of the
battery, making it easier to pass power between the battery's components
and an electrolyte, the conductive material that allows current to flow.
Batteries that are the size of a grain of salt - or smaller - could
power sensors that detect viruses, chemicals and more. Eventually these
microscopic batteries will power microscopic robots as well. Although
the design is promising, the researchers have yet to construct this tiny
battery. The anode and the cathode of the battery have already been
built, but the pieces still need to be assembled and tested. |
| MSNBC / Discovery Channel
Oct 21, 2010 |
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