A British-Dutch project aiming to send an
unmanned mission to Mars by 2018 announced Friday that the shareholders
of a Swiss financial services company have agreed a takeover bid.
"The acquisition is now
only pending approval by the board of Mars One Ventures," the company
said in a joint statement with InFin Innovative Finance AG, adding
approval from the Mars board would come "as soon as possible."
"The takeover provides a solid path to funding the next steps of Mars
One's mission to establish a permanent human settlement on Mars," the
statement added.
Mars One consists of two entities: the Dutch not-for-profit Mars One
Foundation and a British public limited company Mars One Ventures.
Mars One aims to establish a permanent human settlement on the Red
Planet, and is currently "in the early mission concept phase," the
company says, adding securing funding is one of its major challenges.
Some 200,000 hopefuls from 140 countries initially signed up for the
Mars One project, which is to be partly funded by a television reality
show about the endeavour.
Those have now been whittled down to just 100, out of which 24 will
be selected for one-way trips to Mars due to start in 2026 after several
unmanned missions have been completed.
"Once this deal is completed, we'll be in a much stronger financial
position as we begin the next phase of our mission. Very exciting
times," said Mars One chief executive Bas Lansdorp.
NASA is currently working on three Mars missions with the European
Space Agency and plans to send another rover to Mars in 2020.
But NASA has no plans for a manned mission to Mars until the 2030s.
This artist’s view shows how the light coming from the surface
of a strongly magnetic neutron star (left) becomes linearly polarised as
it travels through the vacuum of space close to the star on its way to
the observer on Earth (right). …more
By
studying the light emitted from an extraordinarily dense and strongly
magnetized neutron star using ESO's Very Large Telescope, astronomers
may have found the first observational indications of a strange quantum
effect, first predicted in the 1930s. The polarization of the observed
light suggests that the empty space around the neutron star is subject
to a quantum effect known as vacuum birefringence.
A team led by
Roberto Mignani from INAF Milan (Italy) and from the University of
Zielona Gora (Poland), used ESO's Very Large Telescope (VLT) at the
Paranal Observatory in Chile to observe the neutron star RX
J1856.5-3754, about 400 light-years from Earth.
Despite being amongst the closest neutron stars,
its extreme dimness meant the astronomers could only observe the star
with visible light using the FORS2 instrument on the VLT, at the limits
of current telescope technology.
Neutron stars are the very dense remnant cores of massive stars—at
least 10 times more massive than our Sun—that have exploded as
supernovae at the ends of their lives. They also have extreme magnetic
fields, billions of times stronger than that of the Sun, that permeate
their outer surface and surroundings.
These fields are so strong that they even affect the properties of the empty space around the star. Normally a vacuum
is thought of as completely empty, and light can travel through it
without being changed. But in quantum electrodynamics (QED), the quantum
theory describing the interaction between photons and charged particles
such as electrons, space is full of virtual particles that appear and
vanish all the time. Very strong magnetic fields can modify this space so that it affects the polarisation of light passing through it.
Mignani explains: "According to QED, a highly magnetised vacuum
behaves as a prism for the propagation of light, an effect known as
vacuum birefringence."
Among the many predictions of QED, however, vacuum birefringence so
far lacked a direct experimental demonstration. Attempts to detect it in
the laboratory have not yet succeeded in the 80 years since it was
predicted in a paper by Werner Heisenberg (of uncertainty principle
fame) and Hans Heinrich Euler.
This wide field image shows the sky around the very faint
neutron star RX J1856.5-3754 in the southern constellation of Corona
Australis. This part of the sky also contains interesting regions of
dark and bright nebulosity surrounding the …more
"This
effect can be detected only in the presence of enormously strong
magnetic fields, such as those around neutron stars. This shows, once
more, that neutron stars are invaluable laboratories in which to study
the fundamental laws of nature." says Roberto Turolla (University of
Padua, Italy).
After careful analysis of the VLT data, Mignani and his team detected
linear polarisation—at a significant degree of around 16%—that they say
is likely due to the boosting effect of vacuum birefringence occurring
in the area of empty space (some of us already know that empty space don't exist) surrounding RX J1856.5-3754.
Vincenzo Testa (INAF, Rome, Italy) comments: "This is the faintest
object for which polarisation has ever been measured. It required one of
the largest and most efficient telescopes in the world, the VLT, and
accurate data analysis techniques to enhance the signal from such a
faint star."
"The high linear polarisation that we measured with the VLT can't be
easily explained by our models unless the vacuum birefringence effects
predicted by QED are included," adds Mignani.
"This VLT study is the very first observational support for
predictions of these kinds of QED effects arising in extremely strong
magnetic fields," remarks Silvia Zane (UCL/MSSL, UK).
Mignani is excited about further improvements to this area of study
that could come about with more advanced telescopes: "Polarisation
measurements with the next generation of telescopes, such as ESO's
European Extremely Large Telescope, could play a crucial role in testing
QED predictions of vacuum birefringence effects around many more
neutron stars."
"This measurement, made for the first time now in visible light, also
paves the way to similar measurements to be carried out at X-ray
wavelengths," adds Kinwah Wu (UCL/MSSL, UK).
This research was presented in the paper entitled "Evidence for
vacuum birefringence from the first optical polarimetry measurement of
the isolated neutron star RX J1856.5−3754", by R. Mignani et al., to
appear in Monthly Notices of the Royal Astronomical Society.
In a light harvesting quantum photocell, particles of light
(photons) can efficiently generate electrons. When two absorbing
channels are used, solar power entering the system through the two
absorbers (a and b) efficiently generates power …more
A
University of California, Riverside assistant professor has combined
photosynthesis and physics to make a key discovery that could help make
solar cells more efficient. The findings were recently published in the
journal Nano Letters.
Nathan Gabor
is focused on experimental condensed matter physics, and uses light to
probe the fundamental laws of quantum mechanics. But, he got interested
in photosynthesis when a question popped into his head in 2010: Why are
plants green? He soon discovered that no one really knows.
During the past six years, he sought to help change that by combining his background in physics with a deep dive into biology.
He set out to re-think solar energy conversion
by asking the question: can we make materials for solar cells that more
efficiently absorb the fluctuating amount of energy from the sun.
Plants have evolved to do this, but current affordable solar cells -
which are at best 20 percent efficient - do not control these sudden
changes in solar power, Gabor said. That results in a lot of wasted
energy and helps prevent wide-scale adoption of solar cells as an energy
source.
Gabor, and several other UC Riverside physicists, addressed the problem by designing a new type of quantum heat engine photocell, which helps manipulate the flow of energy in solar cells.
The design incorporates a heat engine photocell that absorbs photons
from the sun and converts the photon energy into electricity.
Surprisingly, the researchers found that the quantum heat engine
photocell could regulate solar power conversion without requiring active
feedback or adaptive control mechanisms. In conventional photovoltaic
technology, which is used on rooftops and solar farms today,
fluctuations in solar power must be suppressed by voltage converters and
feedback controllers, which dramatically reduce the overall efficiency.
Nathan Gabor's Laboratory of Quantum Materials Optoelectronics
utilizes infrared laser spectroscopy techniques to explore natural
regulation in quantum photocells composed of two-dimensional
semiconductors. Credit: Max Grossnickle and QMO Lab
The goal of the UC Riverside teams was to
design the simplest photocell that matches the amount of solar power
from the sun as close as possible to the average power demand and to
suppress energy fluctuations to avoid the accumulation of excess energy.
The researchers compared the two simplest quantum mechanical
photocell systems: one in which the photocell absorbed only a single
color of light, and the other in which the photocell absorbed two
colors. They found that by simply incorporating two photon-absorbing
channels, rather than only one, the regulation of energy flow emerges
naturally within the photocell.
The basic operating principle is that one channel absorbs at a
wavelength for which the average input power is high, while the other
absorbs at low power. The photocell switches between high and low power
to convert varying levels of solar power into a steady-state output.
When Gabor's team applied these simple models to the measured solar
spectrum on Earth's surface, they discovered that the absorption of
green light, the most radiant portion of the solar power
spectrum per unit wavelength, provides no regulatory benefit and should
therefore be avoided. They systematically optimized the photocell
parameters to reduce solar energy fluctuations, and found that the
absorption spectrum looks nearly identical to the absorption spectrum
observed in photosynthetic green plants.
The findings led the researchers to propose that natural regulation
of energy they found in the quantum heat engine photocell may play a
critical role in the photosynthesis in plants, perhaps explaining the
predominance of green plants on Earth.
Other researchers have recently found that several molecular
structures in plants, including chlorophyll a and b molecules, could be
critical in preventing the accumulation of excess energy
in plants, which could kill them. The UC Riverside researchers found
that the molecular structure of the quantum heat engine photocell they
studied is very similar to the structure of photosynthetic molecules
that incorporate pairs of chlorophyll.
The hypothesis set out by Gabor and his team is the first to connect
quantum mechanical structure to the greenness of plants, and provides a
clear set of tests for researchers aiming to verify natural regulation.
Equally important, their design allows regulation without active input, a
process made possible by the photocell's quantum mechanical structure.
The paper is called "Natural Regulation of Energy Flow in a Green Quantum Photocell.
A breakthrough in solar power could make it cheaper and more
commercially viable, thanks to research at the University of Warwick.
In a paper published in Nature Energy,
Dr Ross Hatton, Professor Richard Walton and colleagues, explain how
solar cells could be produced with tin, making them more adaptable and
simpler to produce than their current counterparts.
Solar cells based on a class of semiconductors known as lead
perovskites are rapidly emerging as an efficient way to convert sunlight
directly into electricity. However, the reliance on lead is a serious
barrier to commercialisation, due to the well-known toxicity of lead.
Dr Ross Hatton and colleagues show that perovskites using tin in
place of lead are much more stable than previously thought, and so could
prove to be a viable alternative to lead perovskites for solar cells.
Lead-free cells could render solar power cheaper, safer and more commercially attractive - leading to it becoming a more prevalent source of energy in everyday life.
This could lead to a more widespread use of solar power, with
potential uses in products such as laptop computers, mobile phones and
cars.
The team have also shown how the device structure can be greatly
simplified without compromising performance, which offers the important
advantage of reduced fabrication cost.
Dr Hatton comments that there is an ever-pressing need to develop renewable sources of energy:
"It is hoped that this work will help to stimulate an intensive
international research effort into lead-free perovskite solar cells,
like that which has resulted in the astonishingly rapid advancement of lead perovskite solar cells.
"There is now an urgent need to tackle the threat of climate change
resulting from humanity's over reliance on fossil fuel, and the rapid
development of new solar technologies must be part of the plan."
Perovskite solar cells are lightweight and compatible with flexible
substrates, so could be applied more widely than the rigid flat plate
silicon solar cells that currently dominate the photovoltaics market, particularly in consumer electronics and transportation applications.
The paper, 'Enhanced Stability and Efficiency in Hole-Transport Layer Free CsSnI3 Perovskite Photovoltaics', is published in Nature Energy,
and is authored by Dr Ross Hatton, Professor Richard Walton and PhD
student Kenny Marshall in the Department of Chemistry, along with Dr
Marc Walker in the Department of Physics.
A microscopic image of 2.5 billion-year-old sulfur-oxidizing
bacterium. Credit: Andrew Czaja, UC assistant professor of geology
Somewhere between Earth's creation and
where we are today, scientists have demonstrated that some early life
forms existed just fine without any oxygen.
While
researchers proclaim the first half of our 4.5 billion-year-old planet's
life as an important time for the development and evolution of early
bacteria, evidence for these life forms remains sparse including how
they survived at a time when oxygen levels in the atmosphere were less
than one-thousandth of one percent of what they are today.
Recent geology research from the University of Cincinnati presents
new evidence for bacteria found fossilized in two separate locations in
the Northern Cape Province of South Africa.
"These are the oldest reported fossil sulfur bacteria to date," says
Andrew Czaja, UC assistant professor of geology. "And this discovery is
helping us reveal a diversity of life and ecosystems that existed just
prior to the Great Oxidation Event, a time of major atmospheric
evolution."
The 2.52 billion-year-old sulfur-oxidizing bacteria are described by
Czaja as exceptionally large, spherical-shaped, smooth-walled
microscopic structures much larger than most modern bacteria, but
similar to some modern single-celled organisms that live in deepwater
sulfur-rich ocean settings today, where even now there are almost no
traces of oxygen.
UC Professor Andrew Czaja indicates the layer of rock from which
fossil bacteria were collected on a 2014 field excursion near the town
of Kuruman in the Northern Cape Province of South Africa. Credit: Aaron
Satkoski, UWM postdoc on the excursion.
In his research published in the December issue of the journal Geology
of the Geological Society of America, Czaja and his colleagues Nicolas
Beukes from the University of Johannesburg and Jeffrey Osterhout, a
recently graduated master's student from UC's department of geology,
reveal samples of bacteria that were abundant in deep water areas of the
ocean in a geologic time known as the Neoarchean Eon (2.8 to 2.5
billion years ago).
"These fossils represent the oldest known organisms that lived in a
very dark, deep-water environment," says Czaja. "These bacteria existed
two billion years before plants and trees, which evolved about 450
million years ago. We discovered these microfossils preserved in a layer
of hard silica-rich rock called chert located within the Kaapvaal
craton of South Africa."
With an atmosphere of much less than one percent oxygen, scientists
have presumed that there were things living in deep water in the mud
that didn't need sunlight or oxygen, but Czaja says experts didn't have
any direct evidence for them until now.
Czaja argues that finding rocks this old is rare, so researchers'
understanding of the Neoarchean Eon are based on samples from only a
handful of geographic areas, such as this region of South Africa and
another in Western Australia.
According to Czaja, scientists through the years have theorized that
South Africa and Western Australia were once part of an ancient
supercontinent called Vaalbara, before a shifting and upending of
tectonic plates split them during a major change in the Earth's surface.
Based on radiometric dating and geochemical isotope analysis, Czaja
characterizes his fossils as having formed in this early Vaalbara
supercontinent in an ancient deep seabed containing sulfate from
continental rock. According to this dating, Czaja's fossil bacteria were
also thriving just before the era when other shallow-water bacteria
began creating more and more oxygen as a byproduct of photosynthesis.
"We refer to this period as the Great Oxidation Event that took place 2.4 to 2.2 billion years ago," says Czaja.
Microstructures here have physical characteristics consistent
with the remains of compressed coccodial (round) bacteria
microorganisms. Credit: Andrew Czaja, permission to publish by
Geological Society of America
Early recycling
Czaja's fossils show the Neoarchean bacteria in plentiful numbers
while living deep in the sediment. He contends that these early bacteria
were busy ingesting volcanic hydrogen sulfide—the molecule known to
give off a rotten egg smell—then emitting sulfate, a gas that has no
smell. He says this is the same process that goes on today as modern
bacteria recycle decaying organic matter into minerals and gases.
"The waste product from one [bacteria] was food for the other," adds Czaja.
"While I can't claim that these early bacteria are the same ones we
have today, we surmise that they may have been doing the same thing as
some of our current bacteria," says Czaja. "These early bacteria likely
consumed the molecules dissolved from sulfur-rich minerals that came
from land rocks that had eroded and washed out to sea, or from the
volcanic remains on the ocean's floor.
There is an ongoing debate about when sulfur-oxidizing bacteria arose
and how that fits into the earth's evolution of life, Czaja adds. "But
these fossils tell us that sulfur-oxidizing bacteria were there 2.52 billion years ago, and they were doing something remarkable."
