Lima and Vanzella joined with George Matsas of São Paulo State University in their latest work to examine a model of the highly-curved spacetime that appears during formation of an ultradense neutron star. For some reasonable values of the mass and size of the star, they predict that the vacuum energy will grow within milliseconds for some values of the coupling parameter. At this point the vacuum energy would begin to induce additional gravitational effects, which they haven't yet calculated, so they don't know how the star would be affected. If further research shows such a neutron star to be unstable, the existence of stable neutron stars of particular sizes could rule out the existence fields of the type they modeled.
Group items tagged
Obama's dream of Mars at risk from radiation - physicsworld.com - 0 views
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Schwabe cycle
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Schwabe cycle, where sunspot numbers reach a peak roughly once every 11 years
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the intensity of each solar maximum is also thought to oscillate over a period, called the Gleissberg cycle
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If you're going to do good science, release the computer code too!!! - 3 views
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Les Hatton, an international expert in software testing resident in the Universities of Kent and Kingston, carried out an extensive analysis of several million lines of scientific code. He showed that the software had an unacceptably high level of detectable inconsistencies.
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haha. this guy won't have any new friends with this article! I kind of agree but making your code public doesn't mean you are doing good science...and inversely! He takes experimental physics as a counter example but even there, some teams keep their little secrets on the details of the experiment to have a bit of advance on other labs. Research is competitive in its current state, and I think only collaborations can overcome this fact. - ...1 more comment...
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My view is that the only proper way to do scientific communication is full transparency: methodologies, tests, codes, etc. Everything else should be unacceptable. This should hold both for publicly funded science (for which there is the additional moral requirement to give back to the public domain what was produced with taxpayers' money) and privately-funded science (where the need to turn a profit should be of lesser importance than the proper application of the scientifc method). -
Same battle we are fighting since a few years....
Physics - Outsmarting decoherence in a trapped ion quantum computer - 0 views
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This is the first ion trap demonstration of a set of logical gates that are universal for quantum computation
Official Google Blog: Announcing Google's Focused Research Awards - 0 views
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Today, we're announcing the first-ever round of Google Focused Research Awards — funding research in areas of study that are of key interest to Google as well as the research community. These awards, totaling $5.7 million, cover four areas: machine learning, the use of mobile phones as data collection devices for public health and environment monitoring, energy efficiency in computing, and privacy.
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Might be of some interest to Christos?
New pulsars could net gravitational waves - 0 views
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One of the physicists working on interferometers, Jim Hough of the University of Glasgow, agrees that pulsar timing is a good way to search for gravity waves at extremely low frequencies. He believes that if astronomers observe 20 pulsars with a timing precision of better than 100 nanoseconds for five years then they would "have a very good possibility of observing gravitational-wave signals."
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Again an article about the gravitational waves detected with pulsars. However its a bit fast conclusion, cause i don't know any serious article that draw this conclusion for sure...
Algae Show a Knack for Quantum Mechanics -- Berardelli 2010 (203): 3 -- ScienceNOW - 1 views
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the discovery will open up a new field of research, and it could lead to a new generation of superefficient light-sensitive devices.
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the experiments showed that the electron vibrations resulting from the photons striking the antennas persisted at full strength four times longer than expected. The reason, the researchers report this week in Nature, is that quantum mechanics controls the energy. "It was an utter surprise," says physical chemist and co-author Gregory Scholes of the University of Toronto in Canada. For the results to have occurred, he explains, a property called quantum coherence must have been operating.
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the research "will open an entirely new area of biophysics." And that effort should have "huge implications," he says, "not only for how we think about biophysics, but also light harvesting and light-sensitive devices."
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Very interesting work, showing that apparently algae mastered quantum coherence a few years before us... Inspiring for a new type of light-sensitive devices, and perhaps other applications...
What Should We Teach New Software Developers? Why? | January 2010 | Communications of t... - 3 views
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Industry wants to rely on tried-and-true tools and techniques, but is also addicted to dreams of "silver bullets," "transformative breakthroughs," "killer apps," and so forth.
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This leads to immense conservatism in the choice of basic tools (such as programming languages and operating systems) and a desire for monocultures (to minimize training and deployment costs).
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The idea of software development as an assembly line manned by semi-skilled interchangeable workers is fundamentally flawed and wasteful.
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Nice opinion piece by the creator of C++ Bjarne Stroustrup. Substitute "industry" with "science" and many considerations still apply :)
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"for many, "programming" has become a strange combination of unprincipled hacking and invoking other people's libraries (with only the vaguest idea of what's going on). The notions of "maintenance" and "code quality" are typically forgotten or poorly understood. " ... seen so many of those students :( and ad "My suggestion is to define a structure of CS education based on a core plus specializations and application areas", I am not saying the austrian university system is good, but e.g. the CS degrees in Vienna are done like this, there is a core which is the same for everybody 4-5 semester, and then you specialise in e.g. software engineering or computational mgmt and so forth, and then after 2 semester you specialize again into one of I think 7 or 8 master degrees ... It does not make it easy for industry to hire people, as I have noticed, they sometimes really have no clue what the difference between Software Engineering is compared to Computational Intelligence, at least in HR :/
RHIC nets strange antimatter - 0 views
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The antihypertriton – consisting of an antiproton, an antineutron and an antilambda particle – is the heaviest antinucleus yet produced and opens up a new realm of strange antinucluei. It could also shed light on a number of problems in astrophysics and cosmology, including the dominance of matter over antimatter in the universe.
Researcher Creates 'Facebook for Scientists' - 1 views
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tsk tsk typical ex-ACT criticism.. Maybe for me too from next week;P -
WRONG! You ignore the fact that I complained already while I was yet in the ACT!! Seriously: I clicked around in "ResearchGate" a little bit, couldn't find too many interesting things. Many scientists from India, Iran etc. desperately looking for contacts, retired engineers/scientists from industry that now remember that they were once at university and also quite a number of semi-crackpots. My honest conclusion: not a must. Btw: wish you a nice post-ACT depression! Keep a stiff upper lip, esp. in case you go back to Greece...
Hawking: Aliens are out there, likely to be Bad News * The Register - 3 views
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I think it's time to quote "Calvin & Hobbes" (yes, I'm still the guy who knows a C&H for any situation in life) "Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us." One should sue this idiot for racism against extraterrestrials!!
Dark matter 'no result' comes under fire - 3 views
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On Monday the XENON100 collaboration published an analysis of the first experimental results from its dark-matter detector. It reported no evidence of dark matter, the substance thought to constitute over 80% of mass in the universe. The experiment covered a similar parameter range as dark-matter searches DAMA and CoGeNT, which have previously claimed possible evidence for dark matter. As a result, the XENON100 team concluded that both the DAMA and CoGeNT evidence could be excluded. But now the DAMA and CoGeNT collaborations claim that the XENON100 researchers' analysis is flawed, and that their original evidence for dark matter should remain intact
Commercial quantum cryptography system hacked - 0 views
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quantum cryptography, according to some engineers, is not without its faults. In a preprint submitted late last week to arXiv, Hoi-Kwong Lo and colleagues at the University of Toronto, Canada, claim to have hacked into a commercial quantum cryptography system by exploiting a certain practical “loophole”.
Global Warning - a project of the National Security Journalism Initiative - 0 views
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"WASHINGTON, D.C. - In a three-month investigation, a team of Northwestern University student reporters has found that the US nation's security establishment is not adequately prepared for many of the environmental changes that are coming faster than predicted and that threaten to reshape demands made on the military and intelligence community. This is despite the fact that the Defense Department has called climate change a potential "accelerant of instability." The Medill School of Journalism graduate student team began publication on January 10 of its findings on the national security implications of climate change with a series of print, video and interactive stories."
Seminar: You and Your Research, Dr. Richard W. Hamming (March 7, 1986) - 10 views
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This talk centered on Hamming's observations and research on the question "Why do so few scientists make significant contributions and so many are forgotten in the long run?" From his more than forty years of experience, thirty of which were at Bell Laboratories, he has made a number of direct observations, asked very pointed questions of scientists about what, how, and why they did things, studied the lives of great scientists and great contributions, and has done introspection and studied theories of creativity. The talk is about what he has learned in terms of the properties of the individual scientists, their abilities, traits, working habits, attitudes, and philosophy.
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Here's the link related to one of the lunch time discussions. I recommend it to every single one of you. I promise it will be worth your time. If you're lazy, you have a summary here (good stuff also in the references, have a look at them): Erren TC, Cullen P, Erren M, Bourne PE (2007) Ten Simple Rules for Doing Your Best Research, According to Hamming. PLoS Comput Biol 3(10): e213.
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honestly I think that some of these rules actually make sense indeed ... but I am always curious to get a good book recommendation (which book of Copernic would you recommend?) btw Pacome: we are in Paris ... in case you have some time ... -
I warmly recommend this book, a bit old but fascinating: The sleepwalkers from Arthur Koestler. It shows that progress in science is not straight and do not obey any rule... It is not as rational as most of people seem to believe today. http://www.amazon.com/Sleepwalkers-History-Changing-Universe-Compass/dp/0140192468/ref=sr_1_1?ie=UTF8&qid=1294835558&sr=8-1 Otherwise yes I have some time ! my phone number: 0699428926 We live around Denfert-Rochereau and Montparnasse. We could go for a beer this evening ?
Invisibility cloaks shield the large and visible - physicsworld.com - 1 views
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Two independent groups of physicists have built invisibility cloaks that can shield large objects lying on a plane. These "carpet cloaks" are far closer to the intuitive idea of an invisibility cloak than devices previously built, they argue, because they hide objects that can be seen with the naked eye and do so at visible wavelengths. The cloaks are also relatively cheap and easy to make, being constructed from the natural material calcite.
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The team used a technique known as transformation optics to design their cloak.
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Tomas Tyc of Masaryk University in the Czech Republic, who was not a member of either group, thinks that the papers "describe important achievements in the area of experimental cloaking." But he maintains that a carpet cloak is quite different to a fully fledged Harry Potter-style invisibility cloak. He points out that a carpet cloak only really works when viewing an object – be it a rucksack or a sword on someone's back, for example – side on. Otherwise the object will appear flat but still be visible.
Nautilus X MMSEV Is More Outside-the-Box Space Thinking from NASA - 1 views
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Wonder what is the most creative: the system or the name! NAUTILUS-X = Non-Atmospheric Universal Transport Intended for Lengthy United States X-ploration http://spirit.as.utexas.edu/~fiso/telecon/Holderman-Henderson_1-26-11/Holderman_1-26-11.ppt
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dreaming ...
The Fallout of a Helium-3 Crisis : Discovery News - 3 views
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So short in fact, that last year when the looming crisis, which reporters had been covering for years, became official, the price of helium-3 went from $150 per liter to $5,000 per liter.
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The science, medical and security uses for helium-3 are so diverse that the crisis banded together a hodge-podge of universities, hospitals and government departments to try and find workable alternatives and engineer ways to recycle the gas they do have.
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So, which shall it be? Are we going to increase the production of hydrogen bombs, or can we finally go back to the Moon (http://en.wikipedia.org/wiki/Helium-3#Extraterrestrial_supplies) ?
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None of these. Either you recycle, or you take it from natural sources on Earth. Although most people don't know - there is plenty of natural He3 on Earth. It's just nonsens to use it for energy production (in fusion reactors) since the energy belance for getting the He3 from these source on Earth is just negative. Or you try to substitute He3.
Europe's Plan to Move An Asteroid - Technology Review - 3 views
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In 2002, the European Space Agency began a program called Don Quijote to find out how best to perform such a deflection.
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Now, Stephen Wolters at the Open University in the UK and a few friends have published a new analysis of the mission saying that measuring the change in orbit is not enough. Instead, the spacecraft needs to characterise the impact in detail, determining the density of the material near the asteroid's surface, the size of the surface grains as well as the mass and speed distribution of the impact ejecta.
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Ref: arxiv.org/abs/1107.4229: Measurement Requirements For A Near-Earth Asteroid Impact Mitigation Demonstration Mission
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