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    Science News

    Evening star goes black in rare celestial event
    Astronomers position themselves to capture crucial measurements as Venus passes across the face of the sun

    By Nadia Drake
    Web edition : Tuesday, May 22nd, 2012

    On June 5, skywatchers will have their last chance to glimpse a rare celestial spectacle, a “transit of Venus,” in which the planet passes directly between Earth and the sun. Venus will take six hours to march across the star’s face, appearing as an inky black dot in silhouette against the looming solar disk.

    After that, the sun-shadowed Venusian outline will disappear until 2117. Because the planet’s orbit is slightly off-kilter, its solar transits come in pairs spaced eight years apart, with more than 100 years between pairs.

    During the most recent transit pair of 1874 and 1882, observers around the world focused on triangulating the Earth-sun distance. They tried to time precisely when Venus entered and exited the sun’s disk, so they could calculate the size of the sun (a complicated endeavour, it turns out, since an optical effect that blurred the boundary between planet and sun muddied the timing measurements). The most recent transit happened in 2004 — only the sixth such performance seen through telescopes — and it revealed that large portions of the Venusian atmosphere are visible to Earthly observers.

    Now, scientists are hoping not only to study Venus itself during the transit, but are using the crossing to inform observations of far-off exoplanets that similarly betray their presence by passing between their star and Earth. “Over 100 years ago, astronomers couldn’t have anticipated this transit question,” says astronomer Jay Pasachoff of Williams College in Williamstown, Mass., who will observe the transit from Hawaii.

    Pasachoff and his colleagues are also deploying nine instruments to locations including Japan, Kazakhstan, and Norway, to study the sunlight filtered through Venus’ toxic clouds.

    During the transit the sun will act as a giant light bulb, illuminating Venus’ upper atmosphere and providing information about temperature and aerosols across the planet. The orbiting Venus Express spacecraft can gather data only about isolated portions of the swirling sulfuric acid clouds, begging the question of how the shroud behaves globally. “As temperatures and winds are closely linked, those measurements will be fed into models that aim to explain the exotic dynamics of the Venusian atmosphere,” says astronomer Thomas Widemann of the Paris Observatory, who will join Venus Express team members in Svalbard, Norway to observe the transit against the midnight sun.

    When Earth’s little sister passes before the solar backdrop, its planetprint produces the type of dimming that occurs when exoplanets periodically block their stars’ light. Astronomers have been able to study the atmospheres of Jupiter-sized exoplanets, but similar observations of terrestrial planets are still a thing of the future.

    Gathering data about a known planet – Venus – will help ground those future observations, says astronomer Paolo Tanga at the Cote d’Azur Observatory in Nice, France. “Maybe one day we will be able to measure the same light that is filtered from the atmospheres of exoplanets – exo-Venuses and exo-Earths,” says Tanga, who will be in Arizona for the transit.

    But such observations aren’t so simple. “Big mirrors and sensitive detectors are not good things to point at the sun,” explains planetary astronomer Heather Knutson of Caltech. Instead astronomers will use the Hubble Space Telescope to capture sunlight reflected off the face of the moon during the transit. In that light are signatures of chemical compounds in the Venusian atmosphere, Knutson says. “It’s the first time we can make this measurement for a truly terrestrial planet.”


    The shadow of Venus last passed across the sun in June 2004. After another transit by the planet this June 5 and 6, the spectacle will not recur until 2117. Credit: Andjelko Gilvar/ VT-2004 programme; ESO
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    Re: Science News

    I have my solar shades eagerly anticipating staring at the sun. Hopefully the skies will be clear here unlike when the eclipse happened.
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    Re: Science News

    Nice Master trigggl. I hope you can see all that you wish. Now more news from science.


    Blue light tells plants when to flower
    Protein that marks day length also coordinates blooming genes

    By Rebecca Cheung
    Web edition : Friday, May 25th, 2012

    As the days become longer in spring, plants know to bloom thanks to an interaction between several crucial proteins and blue light, scientists report in the May 25 Science. The new work describes the molecular mechanics that enables a light-sensitive protein to help switch on a suite of genes that control flowering. Understanding the biology of how plants regulate flowering could be useful for tweaking crops to start producing food earlier in the year.

    “We might be able to grow three times or twice as much in a season,” says study coauthor Takato Imaizumi, a molecular biologist at the University of Washington in Seattle.

    Generally, plants need to start blooming around the time when most pollinating insects will be buzzing around — such as in early spring — to maximize their chances of reproducing.Scientists have known that plants have higher levels of the blue-light sensitive protein FKF1 toward the end of the day and that the protein is important for tracking day length. It’s also been shown that another protein, called CO, plays a key role in turning on flowering genes.

    In the new work, Imaizumi and his team looked at the flowering plant Arabidopsis thaliana. The researchers show that FKF1 helps stabilize the CO protein long enough to turn on flowering. Blue light — a particular wavelength of visible light that is common in sunlight that shines down at the end of a spring day, around the same time there is more FKF1 — enhances the interaction. FKF1 also lowers levels of a protein that normally serves as a brake on blooming.


    Day length helps plants determine when to bloom and is sensed by proteins tuned to blue-light wavelengths in the leaves of Arabidopisis thaliana. These proteins, in turn, help switch on genes that trigger flowering in springtime, a new study reveals. A. thaliana tissues where proteins that measure day length reside are shown stained in blue. Credit: © Science/AAAS
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    Climate Change Led to Collapse of Ancient Indus Civilization, Study Finds


    ScienceDaily (May 28, 2012) — A new study combining the latest archaeological evidence with state-of-the-art geoscience technologies provides evidence that climate change was a key ingredient in the collapse of the great Indus or Harappan Civilization almost 4000 years ago. The study also resolves a long-standing debate over the source and fate of the Sarasvati, the sacred river of Hindu mythology.

    Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest -- but least known -- of the first great urban cultures that also included Egypt and Mesopotamia. Like their contemporaries, the Harappans, named for one of their largest cities, lived next to rivers owing their livelihoods to the fertility of annually watered lands.

    "We reconstructed the dynamic landscape of the plain where the Indus civilization developed 5200 years ago, built its cities, and slowly disintegrated between 3900 and 3000 years ago," said Liviu Giosan, a geologist with Woods Hole Oceanographic Institution (WHOI) and lead author of the study published the week of May 28 in the Proceedings of the National Academy of Sciences. "Until now, speculations abounded about the links between this mysterious ancient culture and its life-giving mighty rivers."

    Today, numerous remains of the Harappan settlements are located in a vast desert region far from any flowing river. In contrast to Egypt and Mesopotamia, which have long been part of the Western classical canon, this amazingly complex culture in South Asia with a population that at its peak may have reached 10 percent of the world's inhabitants, was completely forgotten until 1920's. Since then, a flurry of archaeological research in Pakistan and India has uncovered a sophisticated urban culture with myriad internal trade routes and well-established sea links with Mesopotamia, standards for building construction, sanitation systems, arts and crafts, and a yet-to-be deciphered writing system.

    "We considered that it is high time for a team of interdisciplinary scientists to contribute to the debate about the enigmatic fate of these people," added Giosan.

    The research was conducted between 2003 and 2008 in Pakistan, from the coast of the Arabian Sea into the fertile irrigated valleys of Punjab and the northern Thar Desert. The international team included scientists from the U.S., U.K., Pakistan, India, and Romania with specialties in geology, geomorphology, archaeology, and mathematics. By combining satellite photos and topographic data collected by the Shuttle Radar Topography Mission (SRTM), the researchers prepared and analyzed digital maps of landforms constructed by the Indus and neighboring rivers, which were then probed in the field by drilling, coring, and even manually-dug trenches. Collected samples were used to determine the sediments' origins, whether brought in and shaped by rivers or wind, and their age, in order to develop a chronology of landscape changes.

    "Once we had this new information on the geological history, we could re-examine what we know about settlements, what crops people were planting and when, and how both agriculture and settlement patterns changed," said co-author Dorian Fuller, an archaeologist with University College London. "This brought new insights into the process of eastward population shift, the change towards many more small farming communities, and the decline of cities during late Harappan times."

    The new study suggests that the decline in monsoon rains led to weakened river dynamics, and played a critical role both in the development and the collapse of the Harappan culture, which relied on river floods to fuel their agricultural surpluses.

    From the new research, a compelling picture of 10,000 years of changing landscapes emerges. Before the plain was massively settled, the wild and forceful Indus and its tributaries flowing from the Himalaya cut valleys into their own deposits and left high "interfluvial" stretches of land between them. In the east, reliable monsoon rains sustained perennial rivers that crisscrossed the desert leaving behind their sedimentary deposits across a broad region.

    Among the most striking features the researchers identified is a mounded plain, 10 to 20 meters high, over 100 kilometers wide, and running almost 1000 kilometers along the Indus, they call the "Indus mega-ridge," built by the river as it purged itself of sediment along its lower course.

    "At this scale, nothing similar has ever been described in the geomorphological literature," said Giosan. "The mega-ridge is a surprising indicator of the stability of Indus plain landscape over the last four millennia. Remains of Harappan settlements still lie at the surface of the ridge, rather than being buried underground."

    Mapped on top of the vast Indo-Gangetic Plain, the archaeological and geological data shows instead that settlements bloomed along the Indus from the coast to the hills fronting the Himalayas, as weakened monsoons and reduced run-off from the mountains tamed the wild Indus and its Himalayan tributaries enough to enable agriculture along their banks.

    "The Harappans were an enterprising people taking advantage of a window of opportunity -- a kind of "Goldilocks civilization," said Giosan. "As monsoon drying subdued devastating floods, the land nearby the rivers -- still fed with water and rich silt -- was just right for agriculture. This lasted for almost 2,000 years, but continued aridification closed this favorable window in the end."

    In another major finding, the researchers believe they have settled a long controversy about the fate of a mythical river, the Sarasvati. The Vedas, ancient Indian scriptures composed in Sanskrit over 3000 years ago, describe the region west of the Ganges as "the land of seven rivers." Easily recognizable are the Indus and its current tributaries, but the Sarasvati, portrayed as "surpassing in majesty and might all other waters" and "pure in her course from mountains to the ocean," was lost. Based on scriptural descriptions, it was believed that the Sarasvati was fed by perennial glaciers in the Himalayas. Today, the Ghaggar, an intermittent river that flows only during strong monsoons and dissipates into the desert along the dried course of Hakra valley, is thought to best approximate the location of the mythic Sarasvati, but its Himalayan origin and whether it was active during Vedic times remain controversial.

    Archaeological evidence supports the Ghaggar-Hakra as the location of intensive settlement during Harappan times. The geological evidence -- sediments, topography -- shows that rivers were indeed sizable and highly active in this region, but most likely due to strong monsoons. There is no evidence of wide incised valleys like along the Indus and its tributaries and there is no cut-through, incised connections to either of the two nearby Himalayan-fed rivers of Sutlej and Yamuna. The new research argues that these crucial differences prove that the Sarasvati (Ghaggar-Hakra) was not Himalayan-fed, but a perennial monsoon-supported watercourse, and that aridification reduced it to short seasonal flows.

    By 3900 years ago, their rivers drying, the Harappans had an escape route to the east toward the Ganges basin, where monsoon rains remained reliable.

    "We can envision that this eastern shift involved a change to more localized forms of economy: smaller communities supported by local rain-fed farming and dwindling streams," said Fuller. "This may have produced smaller surpluses, and would not have supported large cities, but would have been reliable."

    Such a system was not favorable for the Indus civilization, which had been built on bumper crop surpluses along the Indus and the Ghaggar-Hakra rivers in the earlier wetter era. This dispersal of population meant that there was no longer a concentration of workforce to support urbanism. "Thus cities collapsed, but smaller agricultural communities were sustainable and flourished. Many of the urban arts, such as writing, faded away, but agriculture continued and actually diversified," said Fuller.

    "An amazing amount of archaeological work has been accumulating over the last decades, but it's never been linked properly to the evolution of the fluvial landscape. We now see landscape dynamics as the crucial link between climate change and people," said Giosan. "Today the Indus system feeds the largest irrigation scheme in the world, immobilizing the river in channels and behind dams. If the monsoon were to increase in a warming world, as some predict, catastrophic floods such as the humanitarian disaster of 2010, would turn the current irrigation system, designed for a tamer river, obsolete."


    Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Himalayas and the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest—but least known—of the first great urban cultures that also included Egypt and Mesopotamia. Named for one of their largest cities, the Harappans relied on river floods to fuel their agricultural surpluses. Today, numerous remains of the Harappan settlements are located in a vast desert region far from any flowing river. (Credit: Liviu Giosan, Woods Hole Oceanographic Institution; Stefan Constantinescu, University of Bucharest; James P.M. Syvitski, University of Colorado.)
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    Milky Way will be hit head-on
    Andromeda galaxy will smash directly into ours
    By Alexandra Witze
    Web edition : 4:26 pm

    The monstrous Andromeda galaxy and the Milky Way are destined to hit head-on, not in a glancing blow, new observations from the Hubble Space Telescope show.

    By precisely locating the same stars in Andromeda in 2002 and then again in 2010, astronomers at the Space Telescope Science Institute in Baltimore have calculated how the galaxy has moved against the background of deep space — confirming that the galaxy’s sideways motion is but a fraction of the speed at which it’s hurtling toward the Milky Way.

    Andromeda is 2.5 million light-years away and closing in on the Milky Way at 250,000 miles per hour. The cosmic collision will transform the heavens into a hallucinogenic swirl 4 billion years from now. Calculations suggest that the sun will be tossed out during this galactic mash-up, to drift erratically in the eventual single, large galaxy that will coalesce from the two.

    The work will appear in an upcoming Astrophysical Journal.


    Four billion years from now, a collision between the Milky Way (left) and Andromeda (right) galaxies will have ripped out streams of stars, warped the galactic shapes and turned Earth’s night sky into a dramatic swirl of starlight. Credit: NASA, ESA, Z. Levay and R. van der Marel/STScI, A. Mellinger
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    Re: Science News

    Quantum teleportation leaps forward
    Two teams improve long-distance transmission of information about particles
    By Alexandra Witze
    Web edition : Thursday, May 31st, 2012

    Quantum information has leapt through the air about 100 kilometers or more in two new experiments, farther and with greater fidelity than ever before. The research brings truly long-distance quantum communication networks, in which satellites could beam encrypted information around the globe, closer to reality.

    Both studies involve quantum teleportation, which transports the quantum state of one particle onto another. This Star Trek–like feat is possible because of a phenomenon called entanglement, in which pairs of particles become linked in such a way that measuring a certain property of one instantly determines the same property for the other, even if separated by large distances.

    In teleportation, two people — physicists call them Alice and Bob — share one each of a pair of entangled particles. Alice measures a property on her particle and sends Bob a note, through regular channels, about what she did. Bob then knows how to alter his own particle to match Alice’s. Bob’s particle then possesses the information that had been contained in Alice’s, which was obliterated by her measurement. Thus the information has been “teleported” from Alice’s lab to Bob’s.

    Physicists first teleported quantum information in 1997 using a single pair of entangled photons, or particles of light. Since then researchers have slowly upped the ante, teleporting with larger groups of photons, over longer distances and sometimes using atoms as the entangled particles.

    In 2007 Anton Zeilinger of the University of Vienna and his colleagues set a distance record by using a pair of entangled photons to transmit a piece of quantum information over 143 kilometers, between two of the Canary Islands. In new work, posted online May 17 at arXiv.org, the team reports a cleaner and more robust version of the same experiment using multiple entangled photons.

    This time around, the scientists added a phase shift into the laser beams that made the final measurement cleaner and easier to pick out from background signals. The technique, called “active feed-forward,” is “an essential ingredient in future applications such as communication between quantum computers,” Zeilinger and his colleagues wrote. Team members declined interviews because the paper is not yet published.

    “Our experiment confirms the maturity and applicability of the involved technologies in real-world scenarios, and is a milestone towards future satellite-based quantum teleportation,” they wrote.

    In the second experiment, Chinese researchers entangled many photons together and teleported information 97 kilometers across a lake in China. That’s two orders of magnitude farther than any other multiphoton teleportation experiment, say Jian-Wei Pan of the University of Science and Technology of China in Shanghai and his colleagues. The work appeared online May 9 on arXiv.org.

    Pan’s team also developed a way to track moving teleportation signals more accurately, which again could help make the final result more robust. “Our results show that even with high-loss ground to satellite uplink channels, quantum teleportation can be realized,” the scientists wrote.

    Both Zeilinger and Pan next want to teleport information to a satellite in low-earth orbit. That distance is about three times that already accomplished in the Canary Islands, but because there are fewer air molecules to interfere with the signals at higher altitudes it may be easier to do.

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    Re: Science News

    New Hypothesis Explains Why We Sleep [Preview]

    During sleep, the brain weakens the connections among nerve cells, apparently conserving energy and, paradoxically, aiding memory
    By Giulio Tononi and Chiara Cirelli

    Every night, while we lie asleep, blind, dumb and almost paralyzed, our brains are hard at work. Neurons in the sleeping brain fire nearly as often as they do in a waking state, and they consume almost as much energy. What is the point of this unceasing activity at a time when we are supposedly resting? Why does the conscious mind disconnect so completely from the external environment while the brain keeps nattering on?

    See more on:
    http://www.scientificamerican.com/ar...T_EVO_20130722


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    Re: Science News

    How Pesticides Can Cause Parkinson's

    Foreign chemicals may prevent the brain from disposing of its own toxic waste

    By Melinda Wenner Moyer

    Many studies over the past decade have pointed to pesticides as a potential cause of Parkinson's disease, a neurodegenerative condition that impairs motor function and afflicts a million Americans. Yet scientists have not had a good idea of how these chemicals harm the brain. A recent study suggests a possible answer: pesticides may inhibit a biochemical pathway that normally protects dopaminergic neurons, the brain cells selectively attacked by the disease. Preliminary research also indicates that this pathway plays a role in Parkinson's even when pesticides are not involved, providing an exciting new target for drug development.



    More on: http://www.scientificamerican.com/ar...AT_MB_20130724
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    Re: Science News

    "may prevent"..."potential cause"..."suggests a possible answer"..."pesticides may inhibit"

    Science in the news is almost always junk. And when reporters use BS words like those, run away.

    Seriously everyone, think about this: Have you ever seen or read a news article about something you are actually intimately involved in? And if so, how much of the story has was accurate? My personal experience is that the news report is screwed up and wrong for almost all of the pertinent facts!

    The point: If they cannot get right the one thing thing that you do know something about, why do you think they are getting right all other the stuff that you are not an expert on?

    Have you ever seen a TV program, concerning a topic about which you were actually knowledgeable, spew forth anything other than total BS? I don't think I can recall one :-( It's scary! --Malcolm Hoar
    Edit: P.S. Duke, this is not a slam on you. You find interesting science stories and share them with us, and that's good! I am just being grumpy about the sloppy fourth estate.
    Last edited by zombie67; 07-25-13 at 01:52 AM.
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    Re: Science News

    Quote Originally Posted by zombie67 View Post
    "may prevent"..."potential cause"..."suggests a possible answer"..."pesticides may inhibit"
    I agree with you 100%. I've never heard facts being stated by a scientist, or anyone else, using words like "may, potential, suggests, possible, can...etc." Any single occurrence of any one of those words renders it not a fact, but a guess, hunch, hypothesis, or (more likely) propaganda. Never get science news from a non-scientific source*.

    *Back in the 80's, Scientific American was actually scientific. Now it's just commercialized garbage with a dash of paranoia, propaganda and fear-mongering with writers who hold no scientific degree in anything whatsoever.
    Last edited by John P. Myers; 07-25-13 at 04:03 AM.


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