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2011′s top Physics and Astronomy Stories

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Einstein Wronged?

One of the physics stories this year that made it’s way significantly into the
media was that from the OPERA collaboration which observed Neutrinos travelling
faster than the speed of light. When this report broke back in September it was
met with a certain amount of trepidation from both the scientists involved and
the scientific community with the possibility that if confirmed it is a result
that would put ends to the underpinning concept of general relativity that
nothing can travel faster than the speed of light! In the months up to now the
scientists involved have been running the experiment again with the same results
and offering the challenge to other scientist to try and see what is wrong with
their experiment/result.

Currently although it hasn’t been able to be disproved the likelihood of this
being correct is low, one only has to apply the apparent difference in neutrino
and light speeds to the supernova of 1987. Under the OPERA speeds we should have
detected neutrinos from supernova 1987a 4 years before the light arrived, this
however wasn’t the case and they more or less arrived at the same time. The jury
is still out on this one and it’ll be interesting to see what experiments are
devised in 2012 to test these results.

Hints of Higgs.

In December CERN held a press conference regarding the Higgs Boson with much
excitement surrounding it. The rumours and speculations as to what results were
to be announced seemed to mirror most people’s hopes of the conference, that the
Higgs had finally been found at the LHC, this however was not necessarily the
case. Scientists at CERN couldn’t specifically say they had found the Higgs
Boson with significant certainty, however two experiments (ATLAS and CMS) had
seen hints of what was believed to be a Higgs signal around 125
gigaelectronvolts.

Although from experiments it cannot be stated if the Higgs exists or if the
signal observed is true 2012 holds hopes for the scientists involved. When the
LHC gets back up and running after the Christmas break scientists will be
hunting and acquiring as much data as possible to identify with significant
certainty where the Higgs signature lies. Expect by the end of 2012 to have an
answer as to whether the Higgs Boson exists!

The end of the Shuttle Program.

July brought the end of NASA’s 30 year shuttle program with the successful
launch and return of shuttle Atlantis. Funding strains and austerity measures
introduced by NASA grounded the fleet after 135 missions which brought massive
rewards into space research and technology developments. Sadly however measures
put into action in the period after the Columbia shuttle tragedy has seen NASA
aiming to shift it’s regular space travel to that of private investors to save
the limited amount of money already received from the US government. 2012 is
expected to see the first private companies staking claims in space exploration
with private space craft making the launch into space in the coming months.

Fukushima Fallout

It was hard to miss coverage of the events that took place on the East coast of
Japan back in March where a country best prepared for a tsunami was overwhelmed
by the result or 9.0 magnitude Earthquake.Luckily most of the nuclear fallout
was carried out to sea by winds although this didn’t stop mandatory evacuation
zones around the reactors. It took 9 months from the initial reactor meltdowns
to ensure that the reactors were safely in cold fusion and accordingly shut down
although the clean up of the site will take decades still at high cost.

The fukushima meltdown had significant effects on research and energy policy in
some nations. Compared to the Chernobyl disaster (occurring 25 years previously)
researchers could assess how a release of radioactive material effected the
environment and occupants in a wealthier nation such as Japan. The research also
aided the Japanese people with the lessons learnt previously from Chernobyl
being applied to prevent conditions caused by radiation. The disaster also had
an impact on policy with (understandably) Japan, Germany, Switzerland and Italy
taking an abrupt turn away from nuclear, Germany proposing to shut down all
reactors by 2020s. The coming years will be interesting to see if other
technologies come through for energy production or if these nations resume their
faith in nuclear energy.

The growing Universe

This years Nobel prize in Physics was awarded in October to Saul Perlmutter,
Brian Schmidt and Adam Reiss for their work on using supernovae to chart the
expansion of the universe. By using distant supernovae with standard intensity
the team were able to chart from their light how far away and how fast the
points were moving away from us on Earth. From this deductions and calculations
of the universe’s expansion could be ascertained as well as inferences made for
the effects of dark energy on matter in the universe. This year’s Nobel prize in
Physics was an odd one as the lauretes were relatively young compared to many
that have come before indicating potential shifts in those taking up scientific
research.

New Earths

2011 was an extraordinary year for NASA’s Keplar mission encompassing ground and
space based telescopes in a search for extrasolar planets. Although there was no
sign of Earth’s twin exactly, over 700 planets have been identified with some
strong candidates that may contain life. The mission identifies planets by
looking at stars. Measurements map out the light intensity observed from these
stars, periodic reductions in this intensity are sometime observed and it is
this which indicates that there is a body orbiting with a defined orbit. This
can data can also be applied in such ways to calculate the size of planets and
other properties.

Notable mentions of planets discovered by the Keplar mission are ‘Keplar 22-b’
which was the first planet observed which was inside of the habitable zone, a
region around a star where life may exist. Another one was a planet orbiting two
suns which was aptly named Tatooine.

To boldly go…

In November 6 men returned to Earth from a mission to Mars, however they never
actually left the Earth. The simulated mission that took place in a Russian
warehouse came to an and proved to a point that the human body could at least
cope with the mental strain of isolation and close quarter living that would be
encountered on a manned mission to Mars. Whilst locked away in a mock space
craft the astronauts practised space walks, experiments on mars and simulated
repairs necessary to keep the craft going. This paved the way for future space
exploration and although a Mars mission won’t occur just yet it’s a tantalising
glimpse into what may be possible in regards to the human body.

Goodnight Tevatron.

As the LHC was colliding particles and obtaining data to probe into the origins
of the universe and evidence for the Higgs Boson, an older particle accelerator
came to the end of it’s functioning life. With over 25 years colliding particles
Fermilab’s Tevatron particle accelerator closed in September with most of the
scientists using it packing up to move to the bigger and more powerful LHC.
Although not as powerful, Tevatron was actively hunting for the Higg’s Boson and
helping to eliminate some of the mass energy ranges that it could reside in.
Flurries of particles were identified and greater understanding into the
standard model governing particle physics came with the experimental
observations for the predictions that it made. With the LHC going strong
hopefully the work conducted at Tevatron shalln’t be forgotten and who knows
what the last scraps of data will hold.

Biolaser.

A report in June in the journal Nature photonics reported and experiment where
biological components were turned into lasers. Fluorescent proteins from
jellyfish were inserted into the genome of mammalian cells which were suspended
between two mirrors. The effect of the living cells suspended between saw an
amplification of an inserted photon inducing a lasing process. The significance
of this was that the cell and the proteins survived which is often not observed
when fluorescent proteins undergo continuous light excitation. With the
development of this technique the biological lasers may be seen in future in
nanotechnology and other more familiar regions as CD/DVD players. In regards to
these biological systems it is very much watch this space.

James Webb Space telescope vs politics.

More delays and issues arose in regards to the Hubble telescopes successor this
year, the James Webb Telescope. The telescope which when complete will reside in
a region 1.5 million kilometres away from Earth far away from any communication
disturbances, it will also comprise of a set of mirrors exceeding the size of
Hubble allowing for far higher resolution. The telescope however has come under
fire due to spiralling costs of $8.7 billion and rising. With the rising costs
the House appropriations committee in the US have declared that given the chance
they would prefer to cancel the project rather than provide more funding to
sustain it until launch in 2018. Some members of the senate have come out in
support of the telescope and NASA have also hit back saying it could be made
cheaper with more money spent now to have it readied prior to the current
estimated completion date. 2012 will tell whether the project survives and if
the completion date changes at all.

And to commemorate the Shuttle here’s an awesome video by Nature with Sheffield’s finest 65daysofstatic providing the music.

http://www.youtube.com/watch?v=II7QBLt36xo

Goldilocks planet suggests life may be abundant in our galaxy

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Steve Sadler

A team of American planet hunters announced the discovery last week of an Earth-like planet in orbit around the nearby red dwarf star Gliese 581. The planet has got the astrobiology community excited because it fulfils several criteria thought necessary for a world to be hospitable to extraterrestrial life.

Weighing in at just 3.1 earth masses, the planet, unimaginatively named Gl581g, is the third lightest planet discovered orbiting a star other than our Sun. It is outdone only by one of its five sister planets, Gl581e, which orbits so close to their parent star that any atmosphere it might once have had has now boiled off into space, and a tiny irradiated rock in orbit around the pulsar PSR 1257+12.

Gl581g’s low mass makes it highly likely that it is a rocky, Earth-like body rather than a gas giant like Jupiter, Saturn and the majority of other extrasolar planets discovered to date. Whilst the mass is low, it is still high enough to allow the world to retain an atmosphere, which is another prerequisite for habitability. Furthermore, the team put the orbital distance of the new planet at 0.146 AU (where 1 AU is the orbital distance of the Earth around the Sun), which is slap-bang in the middle of the star’s so called ‘habitable zone’, defined as the range of orbital radii within which the moderate temperature allows water to exist in liquid form. As well as this stellar habitable zone, there is also a galactic habitable zone, which places limits on the position of a potentially habitable planet’s parent star in the galaxy. Too near the centre, and any planets that form will be sterilised by the flux of high energy radiation from the galactic centre. Too far away, and there are insufficient heavy elements to form the complex molecules that make up life as we know it, not to mention the rocky planets themselves. Until now, only one planet in the Universe was known to have all these factors ‘just right’ to support life, but this new discovery, if confirmed, would bring that figure up to two.

“Our findings offer a very compelling case for a potentially habitable planet,” said Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz who led the team along with Paul Butler from the Carnegie Institute of Washington. “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”

Gl581g was discovered by the radial velocity or ‘RV’ method, which involves searching for the tiny forward-backward wobble of a star’s motion induced by the gravitational attraction of its daughter planets. The wobble manifests itself as a shifting of the dark absorption lines in the star’s spectrum, first to the blue (short wavelength) as the star is pulled towards us, then to the red (long wavelength) end as the star is pulled away. This phenomenon, ubiquitous in astronomy, is called Doppler shifting, and is the process responsible for the change in pitch of an ambulance siren as it speeds first towards and then away from an observer on the pavement. Vogt and Butler’s team studied the spectrum of the star over a period of 11 years, and by plotting the precise radial velocity implied by the star’s Doppler shift against time, they were able to infer the existence of the ‘Super-Earth’ and its five sisters.

The paper is due to be published in the Astrophysical Journal, and is available now as a preprint from arXiv.org, or from: http://www.nsf.gov//news/longurl.cfm?id=206. Gl581g data on the exoplanet encyclopedia: http://exoplanet.eu/planet.php?p1=Gl+581&p2=g.

How to build a ‘Black hole’

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Ben Robinson


Scientists from the Southeast University in Nanjing, China have produced a device that is capable of acting as an “Electromagnetic Black Hole”.

The device reported this month in the New journal of Physics, is capable of achieving a 99 per cent absorption rate for microwaves. This work has applications for the study of Black holes in the lab, harvesting Electromagnetic waves (light, microwaves, X-rays etc) or acting as a thermal heating source due to processes in it’s core.

Theoretical work by Prof. Evgenii Narimanov and Dr. Alexander Vildishev proposed that it would be possible to create an “Omnidirectional light Absorber”. Scientists, led by Dr. Qiang Cheng, have created such a device using metamaterials, artificially created structured materials that have an effect and can manipulate electromagnetic waves.

The device is comprised of two key regions, an outer shell that causes microwaves to spiral in to the second region, an absorptive core. Using the principle of refraction (changing the direction of light) the scientists could build an outer shell that directs incident microwaves into the core. This was achieved through an architecture of 60 concentric rings of metamaterials that had a varying degree of refraction, formed by variations in the size of the metamaterials’ structured patterns. This created a gradient where the angle that microwaves were guided to the core increased as they got closer.

Experimental data for the outer shell showed that no microwaves were scattered or “lost” and that all were directed into a core that absorbs them, converting the microwaves to heat.  The scientists collected further experimental data for microwaves at different incident angles. Results from these showed that regardless of angle, the core thus acting like a Black hole absorbed 99 per cent of microwaves.

Whereas this device doesn’t absorb matter like a black hole, it successfully mimics the spiralling motion that incoming matter takes as it is absorbed and traps light/electromagnetic waves, much like it’s far larger namesake. The team of scientists hope to take this work further and produce a similar absorber for visible light and different parts of the electromagnetic spectrum.

This work is published in New Journal of Physics.

Cheng, Q, Cui, T.J, Jiang, W.X and Cai, B.G. An omnidirectional electromagnetic absorber made of metamaterials. New Journal of Physics 12 (pp10-21)

 

Hubble Space Telescope Detects Wandering Supermassive Black Holes

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Kathryn Swindells


A supermassive black hole at the centre of our most massive local galaxy, M87, is not where researchers expected it to be. Using the Hubble Space Telescope, a team of researchers from the Rochester Institute of Technology in New York state, the Florida Institute of Technology and the University of Sussex have found that the supermassive black hole is actually located away from the centre of the galaxy. They believe that the most likely cause for this is a previous merger between two older, less massive black holes

.
The study of this galaxy located 55 million light years away was part of a wider Hubble Space Telescope project directed by Andrew Robinson, professor of physics at Rochester. He explains the significance of this discovery by saying, “What may well be the most interesting thing about this work is the possibility that what we found is a signpost of a black hole merger.” He goes on to explain that this is of specific interest “for people modelling these systems as a demonstration that black holes really do merge.”


Once displaced it may take many millions or even billions of years for the supermassive black hole to return to rest. Searching for these displacements in other galaxies may prove to be an effective way of studying the history of galaxy mergers.


There is also evidence to suggest that the M87 jet may have pushed the black hole away from the centre. This is a jet of matter which emerges from the core of M87 and is ejected 5000 light years into space. They are commonly found in a class of objects called Active Galactic Nuclei which is a compact region at the centre of the galaxy and produces more radiation than the galaxy as a whole. It is believed that the merger of two galaxies activates supermassive black holes and this finding could be linked to how active galaxies are born and how their jets form.


This work also leads to the interesting possibility that many more galaxies contain supermassive black holes which are not in the centre of their host galaxies. This would require more work utilising the Hubble Space Telescope to find these relatively subtle changes. Researchers will no longer be able to assume that all supermassive black holes reside at the centre of their galaxies.
One especially interesting aspect of this research is how it may relate to our own galaxy which is expected to merge with the Andromeda galaxy in about three billion years as noted by Eric Perlman, associate professor of physics and space sciences at Florida Tech. “The result of the merger will likely be an active elliptical galaxy, similar to M87…our results suggest that after the merger, the supermassive black hole may wander in the galaxy’s nucleus for billions of years.”


This work was published in The Astrophysical Journal Letters.

21.6 million seconds to mars

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Joey Shepherd


Next month, a multi-national crew of six including three Russians, two Europeans and one Chinese, will find out what it’s like to boldly go where no man has gone before. 

In a simulation of a mission to Mars, which will in fact see the participants remain sealed inside an isolation chamber in the distinctly un-outer space environment of Moscow, the crew will endure isolation, limited nutrition, and each other throughout the 520-day mission. For nearly two years, the participants will mimic a manned mission to the Red Planet as closely as possible, allowing 250 days for the outward journey, 30 days for exploration of the surface of Mars in a landing simulation module and 240 days for the trip home to Earth. 

The mission, MARS500, is jointly conducted by the European Space Agency and Russia’s Institute of Biomedical Problems. It will be the concluding experiment in a project which has already seen a 14-day simulation in 2007 and a successful 105-day test in 2009. Martin Zell, Head of ISS Utilisation Department in the ESA Directorate of human spaceflight, said of the previous work “The experiments during the 105 days were primarily on the medical effects on the men – that is in the psychological and physiological fields – stress linked with cardiovascular problems, effects on the immune system. Of course, the co-operation and co-existence of people and dietary aspects play a large role too”.

Evaluating the effects of isolation and confinement-related stress will be a major part of the current study. Away from family, friends and home comforts for over 500 days, insights into how the crew interact and cope with such psychological strains will be provided by cameras installed in each of the rooms of the chamber, allowing their mental and physical conditions to be constantly monitored. The project will also allow the team ‘back on Earth’ to see how the group adapts and organises itself over time, and how long periods of confinement affect the decision-making process. 

There will be several other studies running during the mission, including evaluating the effects of long term confinement-related stress on the immune response, the effectiveness of exercise and dietary supplements on performance and mood, the microbial ecology of the confined habitat and even the effect of the lighting on alertness and sleep/wake patterns. All of this data will be invaluable in planning future manned missions to space. Martin Zell said “Of course, we still need a lot of such studies: both on Earth and under different conditions – like on the ISS, which will in any case be the first step for manned space exploration, and which is an ideal environment for the preparation of such flights”.

Diego Urbina, a Columbian-born electronic engineer currently based in Turin, Italy, is one of the lucky six. The 26 year old, one of two Europeans selected by the ESA from 5600 applicants,  made it to the final pair through a rigorous selection process, akin to that for choosing astronauts, and will be joined by 31 year old French national Romain Charles. Urbina said of his motivation to take part in the mission: “I want to collaborate in this huge human endeavour of sending humans to Mars

which I really hold very important, and (finally) another motivation here is many of the experiments we’re doing here will actually help us here on Earth to improve our living conditions”. He is optimistic about being confined in the chamber, which will be split into four separate modules for storage, living, a medical module and the Mars landing module simulator, saying “I’ve met the guys here and I really get on well with them, and I think it’s going to be fun with them”.

Whilst sealed inside the isolation chamber, the six will not be in total seclusion; a voice link complete with built-in 20 minute delay to simulate Mars to Earth communication will be provided to talk to family, and they will be allowed to take in personal items such as books, movies and laptops. For their part, Diego and Romain will be taking a Nintendo Wii to help the team combat boredom. Although an arduous task is ahead of them, the ‘Mars500 Six’ can rest assured that they will be helping to pave the way for future manned space exploration. 


Follow Diego Urbina on twitter @DiegoU, and the mission @Mars_500