Galaxy clusters back general relativity - 0 views
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The Copenhagen group discovered that the redshifts agreed with the predictions of both general relativity and f(R) gravity, the theory that tries to avoid dark energy. However, the error bars on the redshifts excluded MOND and TeVeS, the theories that try to avoid dark matter.
Huge stellar nursery found in dusty corner of our galaxy - space - 23 June 2009 - New S... - 0 views
Galaxy Zoo Mergers - 0 views
Dark Matter or Black Hole Propulsion? - 1 views
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Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... http://arxiv.org/abs/0908.1429v1 http://arxiv.org/abs/0908.1803
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One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.
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well then I agree, how the fu.. they want to collect them !!!
Breakthrough Initiatives - 2 views
Amateur planet hunters find a world with a four star rating | Bad Astronomy | Discover ... - 4 views
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One more reason why we should be much more open about all these EO data we have .... The two citizen scientists, Kian Jek and Robert Gagliano, are listed as authors on the scientific paper recently published. I love this: the digital nature of these data make it far, far easier to analyze the science than it was in the past, and also easier to get the data out to people. Because of this, we have an explosive growth in these kinds of projects. Planet Hunters is great, but then so is Galaxy Zoo, Moon Mappers, Ice Hunters, and so many others. You can find several of these collected at the CosmoQuest website.
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Wiktor is also collecting these science games in the ACT-wiki. You should have a look at: http://sophia.estec.esa.int/actwiki/index.php/On-line_Games_4_Science
Mapping Dark Matter Case Study - Kaggle - 3 views
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Mapping Dark Matter competition to encourage the development of new algorithms that can measure the way dark matter causes tiny distortions in images of galaxies by changing their ellipticity, or how their shapes are stretched.
NASA Brings Earth Science 'Big Data' to the Cloud with Amazon Web Services | NASA - 3 views
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NASA answer to the big data hype
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"The service encompasses selected NASA satellite and global change data sets -- including temperature, precipitation, and forest cover -- and data processing tools from the NASA Earth Exchange (NEX)" Very good marketing move for just three types of selected data (MODIS, Landsat products) plus four model runs (past/projection) for the the four greenhouse gas emissions scenarios of the IPCC. It looks as if they are making data available to adress a targeted question (crowdsourcing of science, as Paul mentioned last time, this time climate evolution), not at all the "free scrolling of the user around the database" to pick up what he thinks useful, mode. There is already more rich libraries out there when it comes to climate (http://icdc.zmaw.de/) Maybe simpler approach is the way to go: make available the big data sets categorized by study topic (climate evolution, solar system science, galaxies etc.) and not by instrument or mission, which is more technical, so that the amateur user can identify his point of interest easily.
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They are taking a good leap forward with it, but it definitely requires a lot of post processing of the data. Actually it seems they downsample everything to workable chunks. But I guess the power is really in the availability of the data in combination with Amazon's cloud computing platform. Who knows what will come out of it if hundreds of people start interacting with it.
NASA - NASA's Fermi Telescope Finds Giant Structure in our Galaxy - 5 views
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wow ....
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impressive! I'm sure it's connected to the black hole, at some point it must have been active. It shows how it's important to put all observations public !
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this is what they speculate ... the original image looks though much less impressive ...
Special relativity passes key test - 2 views
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Granot and colleagues studied the radiation from a gamma-ray burst – associated with a highly energetic explosion in a distant galaxy – that was spotted by NASA's Fermi Gamma-ray Space Telescope on 10 May this year. They analysed the radiation at different wavelengths to see whether there were any signs that photons with different energies arrived at Fermi's detectors at different times.
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According to Granot, these results "strongly disfavour" quantum-gravity theories in which the speed of light varies linearly with photon energy, which might include some variations of string theory or loop quantum gravity. "I would not use the term 'rule out'," he says, "as most models do not have exact predictions for the energy scale associated with this violation of Lorentz invariance. However, our observational requirement that such an energy scale would be well above the Planck energy makes such models unnatural."
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essentially they made an experiment that does not prove or disprove anything -big deal-... what is the scientific value of "strongly disfavour"??? I also like the sentence "most models do not have exact predictions for the energy scale associated with this violation of Lorentz invariance" ... but if this is true WHAT IS THE POINT OF THE EXPERIMENT!!!! God, physics is in trouble ....
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hum, null result experiments are not useless !!! there is always the hope of finding "something wrong", which would lead to a great discovery. For the state of theoretical physics (the "no exact predictions" quote), i totally agree that physics is in trouble... That's what happen when physicists don't care anymore about experiments...! All you can do now is drawing "nice"graph with upper bounds on some parameters of an all tunable weird theory !
Mysterious 'dark flow' at the edge of the universe - 1 views
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Cosmologists have already observed two distinct effects caused by invisible entities in the universe: dark matter is known to affect the rotation of galaxies and dark energy seems to be causing the expansion of the universe to accelerate. Dark flow is the latest addition to this shadowy family.
Mapping Turbulence in the Solar Wind - 0 views
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a team reports studying the turbulent flow of solar wind particles by monitoring the accompanying waves of magnetic field. The team used a cluster of satellites to measure the field in unprecedented spatial detail. They found that the waves aren't equally strong in all directions but are larger in certain preferred directions, as theorists had predicted. The observation will help astrophysicists better understand the consequences of the solar wind, including its effect on the transmission of cosmic rays, particles that arrive at Earth from elsewhere in our galaxy.
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