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Size and flows : As Douglas Adams rightly said, Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. Lets take an example. The Milky way is our galaxy. When talking about space, a galaxy is well understood. It's made of millions of stars. The size? Around 100,000 light years in diameter. If we had a spaceship going at exactly light speed (if that was possible), we would not even be able to cross one-thousandth of the distance in a hundred years.

Now Scientists have theorized about the size and movement of the local galactic supercluster. How have they been able to estimate its movement? By means of a simulation of the gravity and flow and density which pulls over 100,000 galaxies together into what is called the 'Great Attractor.' The human mind can possibly not even comprehend the size. The boundaries of this supercluster are not very well defined, and the flows are quite fascinating to watch. It takes me back to a post I made on flows (http://goo.gl/uho3rW) . At some stage, all the superclusters will be clumped into one. Maybe we will have a true idea of our Universe then!

+Knut Torgersen asked me to make this post... and here it is for your consumption. Though much has been said about the Laniakea Supercluster, this looks into the flows and size.

Cosmic Speed : The team used a database that compiles the velocities of thousands of galaxies, calculated after subtracting the average rate of cosmic expansion. “All these deviations are due to the gravitational pull galaxies feel around them, which comes from mass,” says Tully. The researchers used an algorithm to translate these velocities into a three-dimensional field of galaxy flow and density.

How did Brent Tully and his team do it? : If galaxies are clumped together closely in space they’ll orbit each other, or at least their mutual gravity will affect their motion. This in turn affects the redshift for each galaxy on top of the cosmic expansion. We know pretty well how the Universe is expanding on local scales, so if you subtract that part away, what’s left is the local motion of the galaxies. That can be used to map how gravity of other nearby galaxies is affecting them. This let them make a map of the density and movement of galaxies in space.

Size : The colossal supercluster is shown in the above computer-generated visualization, where green areas are rich with white-dot galaxies and white lines indicate motion towards the supercluster center. Galaxies flow into other galactic concentrations. The Laniakea Supercluster spans about 500 million light years and contains about 100,000 times the mass of our Milky Way Galaxy. The discoverers of Laniakea gave it a name that means "immense heaven" in Hawaiian.

Source Slate: http://www.slate.com/blogs/bad_astronomy/2014/09/04/laniakea_our_local_supercluster.html

Nature Source: http://www.nature.com/news/earth-s-new-address-solar-system-milky-way-laniakea-1.15819

Research paper: http://arxiv.org/abs/1409.0880

APOD source: http://apod.nasa.gov/apod/ap140910.html

Wikipedia reference: http://en.wikipedia.org/wiki/Laniakea_Supercluster

Video Link: Laniakea: Our home supercluster
 
Pics courtesy : http://goo.gl/Bsx20Q and http://goo.gl/y2MhAA

#laniakea #supercluster  
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The Expanding Universe.. and some embarrassing calculations! : This is a beautifully written article in Ars Technica, which explains the role of the cosmological constant, and more particularly how physicists are at a loss to explain absurd results when taking this as a constant. More particularly, it's a really excellent exposition on the basics.

Article Extract: The vacuum of space isn't actually "empty"; it teems with particles that pop in and out of existence, giving the vacuum an energy of its own. But here's an embarrassing fact about that energy: it predicts that the cosmological constant (which provides a measure of the rate of the expansion of the Universe) should be 10^120 times larger than we think it actually is.

When Einstein was first formulating a new theory of gravity, his solutions predicted that the Universe was expanding. At the time, the Universe was widely regarded to be static, so Einstein added a constant that counteracted the expansion and kept the Universe unchanging. Everyone rejoiced—electromagnetism, space, time, and gravity could all live together in harmony. Later, Edwin Hubble took advantage of a new generation of telescopes to measure the speed at which distant galaxies were moving. He found that the further away a galaxy was, the faster away from us it was moving. The conclusion was inescapable: the Universe was expanding. Everyone chuckled over Einstein's big goof.

Scientists now can measure the rate at which the Universe expands. Turns out it's not a constant; every day, the Universe expands a bit faster than it did the day before. Inflation, it seems, is a physical as well as an economic universal, and Einstein's cosmological constant was back (albeit in altered form).

Funnily enough, it wouldn't have mattered whether the new cosmological constant was positive, negative, or zero—problems were going to arise. This is because Einstein's work had also established that mass and energy are two sides of the same coin. Since mass causes space and time to warp, so too should energy. So why doesn't the vacuum energy bend space and time? When physicists bolt the quantum vacuum energy on to general relativity, they get absurd results unless some kind of correction factor (to the tune of 10^120) is carefully added to counteract the vacuum. This fine-tuning bothers people because there is simply no way to obtain these numbers naturally.

Enter the new work by Nemanja Kaloper (UC-Davis) and Antonio Padilla (University of Nottingham), who have proposed a modification to general relativity that naturally generates a small cosmological constant. According to the researchers, the cosmological constant should be treated as the average of the vacuum contribution over all space and time. When this happens, the local vacuum energy contributions appear twice in the equations with opposite signs. No matter what energy the vacuum has right now, it can't bend space and time—think of it as pushing with one hand and pulling with the other.

Article Link: http://arstechnica.com/science/2014/03/getting-the-math-of-the-universe-to-cancel-out/

Research paper: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.091304

More about Vacuum state: http://en.wikipedia.org/wiki/Vacuum_state

The cosmological constant: http://www.space.com/9593-einstein-biggest-blunder-turns.html

Wikipedia link on the Cosmological constant: http://en.wikipedia.org/wiki/Cosmological_constant

NASA link: http://map.gsfc.nasa.gov/universe/uni_accel.html

Pics courtesy and detail: Pic on right: from http://complex.elte.hu/astro.html ( The best 3 dimensional map of the Universe. The above animation is based on the cca. 5 million galaxies in the SDSS Early Data Release. There is no visible structure in the distribution of the most distant quasars (white dots) but galaxies (yellow and green dots) are clustered on a foam-like structure. The slices are not physical, they are caused by the survey geometry ) Pic on left: From main article in http://arstechnica.com (Jim Brau, University of Oregon).

#science #sciencesunday #scienceeveryday #inflation  
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Dark Matter : “What makes the universe so hard to comprehend is that there’s nothing to compare it with.” -Anonymous. Such is the theory of Dark matter. What is it? As Dr. Amanda Peet said "It's not visible, so we called it Dark ". There is a large amount of mass which is missing and unaccounted for - which has a gravitational effect on visible matter. It was first postulated by Jan Oort in 1932 to account for the orbital velocities of stars in the Milky Way and by Fritz Zwicky in 1933 to account for evidence of "missing mass" in the orbital velocities of galaxies in clusters.

Article Extract : Why Dark Matter : We start with a hot, dense, nearly uniform Universe that’s expanding, and it unequivocally follows the following steps: It expands and cools down, It forms the light elements, Matter starts to collapse under its own gravity, while radiation (like photons) push back against it, Neutral atoms form, leaving a snapshot of the Universe at that time (the CMB), and Gravity pulls the neutral matter together into stars and planets, galaxies, galaxy clusters and superclusters.

The big distinction, of course, is that radiation doesn’t push back against dark matter, but does against normal matter (i.e., protons, neutrons, and electrons). It means that when we look out at the temperature fluctuations in the Cosmic Microwave Background (above), we can figure out whether our Universe is full of normal matter, dark matter, or both, and how much of each of them. You want a Universe without dark matter, and — at the very least — you have to throw out General Relativity. (From Scienceblogs http://goo.gl/EA6X4t)

Recent UCLA physics symposium : "Because dark matter makes up the bulk of the mass of galaxies and is fundamental in the formation of galaxies and stars, it is essential to the origin of life in the universe and on Earth," Cline said. One search technique involves using the vast amount of dark matter in our galaxy. The NASA Fermi Satellite Telescope, an international collaboration involving NASA, the Goddard Space Flight Center and the SLAC National Accelerator Laboratory, searches for gamma rays — very high-energy light particles — from this dark matter.
 
Much larger direct dark matter detectors are being planned in the U.S., Italy, Canada and China (including Xenon 3 Ton, LUX-ZEPLIN 7 Ton and DarkSide, which will weigh five tons). These larger detectors potentially could see a dark matter signal in the next few years, Cline said. (From the UCLA newsroom : http://goo.gl/YRz0Mu )

Elusive : Scientists have expressed increasing interest in the search for low-mass dark matter particles, with CDMS and three other experiments — DAMA, CoGeNT, and CRESST — all finding their data compatible with the existence of dark matter particles between 5 and 20 GeV. But such light dark-matter particles are hard to pin down. The lower the mass of the dark-matter particles, the less energy they leave in detectors, and the more likely it is that background noise will drown out any signals. ( From MIT : http://goo.gl/0a3SUc )

WIMPS : The presence of dark matter is inferred from its gravitational effects. Stars and gas clouds in galaxies and galaxies in clusters move faster than can be explained by the pull of visible matter alone. Light from distant objects may be distorted by the gravity of intervening dark material. The pattern of large-scale structures across the Universe is largely dictated by dark matter. In fact, about 85% of the Universe's mass is dark, accounting for about one-quarter of the total cosmic energy budget.  The main constituents are expected to be weakly interacting massive particles (WIMPs). These particles have masses a few tens to thousands of times that of the proton. WIMPs interact among themselves and with ordinary matter gravitationally and through the weak force, but not electromagnetically or through the strong nuclear force. To explain the way in which galaxies form and cluster, dark-matter particles should be relatively slow moving, or 'cold'. (From the Journal Nature : http://goo.gl/BdsQn0 )

A Simple explanation : Stars orbiting the centers of their galaxies travel so fast that they should be flung out into the cosmos, but they aren’t. Galaxies in clusters dance around one another, held in formation by something unseen. We study astronomical images, carefully accounting for the gravitational pull of everything we can see—stars, gas, dust, even black holes lit up by the matter they’re consuming—and it simply isn’t enough. There must be something else there, a ghostly cloud of invisible matter surrounding and enveloping each galaxy and cluster. At a loss as to what this invisible substance could be, we call it dark matter. What else do we know about dark matter? We know it doesn’t interact with electromagnetism in any significant way. It doesn’t absorb or emit light, and it doesn’t seem to experience friction or collisions with itself or other matter. It is probably passing through you right now, but without electromagnetic interactions, you won’t feel a thing. We know that it’s “cold,” in the sense that whatever makes it up is not moving at anything close to the speed of light. (Exactly how cold is still a matter of some debate—it could still be a little bit warm, or, perhaps, tepid.) We’re pretty sure dark matter is some kind of particle, but as far as we’ve seen, the only way dark matter particles interact with anything at all is through their gravity. Our theories (and our hopes!) depend on the possibility that dark matter can interact, if only rarely, via another kind of force: the weak force. (From Slate : http://goo.gl/f7uEAl )

+NASA  Link : http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/

+Wikipedia link : http://en.wikipedia.org/wiki/Dark_matter

CERN link: http://home.web.cern.ch/about/physics/dark-matter

Universe may be crashing though dark matter walls : http://goo.gl/WWrQap

The Hunt for dark matter : http://goo.gl/k5NuCn

Hunting for Dark matter at the Gran Sasso Lab (h/t +Knut Torgersen ) - http://goo.gl/qhWkRE

Welcome to the Darkside (h/t +Knut Torgersen ) : http://www.princeton.edu/cfr/news/archive/?id=12009

Video link: The Search for Dark Matter

ESA link: http://www.esa.int/Our_Activities/Space_Science/Herschel/Herschel_finds_less_dark_matter_but_more_stars

Pics courtesy: From Sciblogs left and bottom right - http://goo.gl/EA6X4t . From Univ of chicago: http://goo.gl/gWRBXw

Additional link from Phys.org : http://phys.org/news/2014-03-tokai-j-parc-solar-neutrino-slightly.html#inlRlv

Additinal link on news from Gizmag : http://www.gizmag.com/dark-matter-observations-wimp-sterile-neutrino-esa-nasa/30997/

Additional link (plot of the week) : http://www.science20.com/quantum_diaries_survivor/plot_week_dark_matter_candidates_supercdms-130811

#science #sciencesunday #physics #darkmatter
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Critters in space : Right from the days where monkeys, dogs and other animals and bacteria have made it to space, the study of flora and fauna and their behavior is space has been quite interesting to scientists. Here is a partial list of some of the insects who have made it to space (via Popular Mechanics).

Article Extract: A fruit fly is a scientist's best friend being a model organism. As scientific exploration turned skyward, fruit flies were an obvious choice. In 1947 the United States strapped a few hapless flies to a V-2 rocket, launching them into the limelight as the first animals in space. In 2006 NASA sent 15 fruit flies into orbit on the space shuttle Discovery—which returned to Earth two weeks later with more than 3000 flies on board. When scientists discovered that microgravity had taken a serious toll on the flies' immune systems, NASA proposed a Fruit Fly Lab for the International Space Station, due to launch later this year.

Silkworm snacks : Silkworm eggs and larvae have traveled into orbit on NASA space shuttles and journeyed alongside astronauts for decades. But our relationship with these critters is sure to sour with the news that silkworms may soon shift from trusty sidekicks to tasty space snacks.

Honeybees in space : In an experiment clearly designed to terrify everyone on board, NASA sent 3500 honeybees into orbit in 1984. Researchers found that the bees were capable of building honeycombs in microgravity, and that their beehive structure was essentially the same as it would have been on Earth.

Orb-weaver astronauts : NASA's fascination with spiders culminated in a mission that sent two orb-weaver spiders to the International Space Station. The "arachnidnauts" fared so well aboard the ISS that NASA actually ordered another mission soon after.

Article Link: http://www.popularmechanics.com/science/space/nasa/bugs-in-space-5-unusual-astronauts#slide-5

Spiders in space from Smithsonian : _http://smithsonianeducation.org/students/secrets_of_the_smithsonian/spiders_in_space.html_

Article about bumblebees: http://gravitationalandspacebiology.org/index.php/journal/article/view/565

Fruitfly lab: http://www.nasa.gov/mission_pages/station/research/experiments/1201.html

Pics courtesy: NASA / Ames and smithsonianeducation.

#science #bugs #insects #space  
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Turbulence ahead : The interstellar wind has changed direction and is now blowing at a faster speed..

Article Extract: Interstellar space—the region between stars in our galaxy—is fairly empty. There are still enough atoms in that space to produce a measurable effect as the Sun orbits the galactic center, however. The flow of these atoms, known as the interstellar wind, provides a way to study interstellar gas, which moves independently of the Sun's motion.

A new analysis of 40 years of data showed that the interstellar wind has changed direction and speed over time, demonstrating that the environment surrounding the Solar System changes measurably as well. Priscilla Frisch and colleagues compared the results from several spacecraft, both in Earth orbit and interplanetary probes. The different positions and times in which these instruments operated revealed that the interstellar wind has increased slightly in speed. Additional measurements revealed that the flow of atoms has shifted somewhere between 4.4 degrees and 9.2 degrees. Both these results indicate that the Sun is traveling through a changing environment, perhaps one shaped by turbulence in interstellar space.

The properties of the Solar System are dominated by the Sun's gravity, magnetic field, and the flow of charged particles outward from its surface. However, a small number of electrically neutral particles—mostly light atoms—pass through the Solar System. These particles are part of the local interstellar cloud (LIC), a relatively hot region of space governed by its internal processes.

Article Link: http://arstechnica.com/science/2013/09/turbulence-ahead-interstellar-wind-changes-direction-blows-faster/

Related research: http://www.sciencemag.org/content/341/6150/1080

Pic detail: Artist's conception of the Sun's motion through the Local Interstellar Cloud (LIC). The motion of gas in the cloud means that the motion of particles through the Solar System has changed over the last 40 years, as observed by a number of different spacecraft.
NASA /Goddard /Adler / University of Chicago/ Wesleyan University


#science #interstellarspace #space #wind  
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Starburst Jewel

Like a July 4 fireworks display, a young, glittering collection of stars looks like an aerial burst. The cluster is surrounded by clouds of interstellar gas and dust—the raw material for new star formation. The nebula, located 20,000 light-years away in the constellation Carina, contains a central cluster of huge, hot stars, called NGC 3603. This environment is not as peaceful as it looks. Ultraviolet radiation and violent stellar winds have blown out an enormous cavity in the gas and dust enveloping the cluster, providing an unobstructed view of the cluster.

Most of the stars in the cluster were born around the same time but differ in size, mass, temperature, and color. The course of a star's life is determined by its mass, so a cluster of a given age will contain stars in various stages of their lives, giving an opportunity for detailed analyses of stellar life cycles. NGC 3603 also contains some of the most massive stars known. These huge stars live fast and die young, burning through their hydrogen fuel quickly and ultimately ending their lives in supernova explosions.

Star clusters like NGC 3603 provide important clues to understanding the origin of massive star formation in the early, distant universe. Astronomers also use massive clusters to study distant starbursts that occur when galaxies collide, igniting a flurry of star formation. The proximity of NGC 3603 makes it an excellent lab for studying such distant and momentous events. This Hubble Space Telescope image was captured in August 2009 and December 2009 with the Wide Field Camera 3 in both visible and infrared light, which trace the glow of sulfur, hydrogen, and iron.

Article Link: http://www.wired.com/wiredscience/2013/01/space-photo-of-the-day-2/?pid=6842

Image: NASA, ESA, R. O'Connell (University of Virginia), F. Paresce (National Institute for Astrophysics, Bologna, Italy), E. Young (Universities Space Research Association/Ames Research Center), the WFC3 Science Oversight Committee, and the Hubble Heritage Team (STScI/AURA) [high-resolution]

#science #scienceeveryday #starburst #jewel #spaceoddity #space #galaxy  
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NASA buys blow-up habitat for space station astronauts

The US space agency has signed a $17.8-million contract with Bigelow Aerospace of Nevada to build an inflatable crew habitat for the ISS.

According to details released today at a press briefing , the Bigelow Expandable Activity Module, or BEAM, will launch in 2015. Astronauts on the ISS will test the module for safety and comfort.

BEAM will fly uninflated inside the trunk of a SpaceX Dragon capsule. Once docked and fully expanded, the module will be 4 metres long and 3 metres wide. For two years astronauts will monitor conditions inside, such as temperature and radiation levels.

The company has made progress, developing shielding that resists punctures from space debris and micrometeorites. BEAM's skin, for instance, is made from layers of material like Kevlar to protect occupants from high-speed impacts. The craft's skin has been tested in the lab alongside shielding used right now on the rest of the ISS, says Bigelow director Mike Gold.

"Our envelope will not only equal but be superior to what is flying on the ISS today. We have a strong and absolute focus on safety," he says.

Article Link: http://www.newscientist.com/article/dn23083-nasa-buys-blowup-habitat-for-space-station-astronauts.html

Picture courtesy: Bigelow airspace

#science   #scienceeveryday   #bigelow   #nasa   #space   #ISS  
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The Woodward Effect

Space travel has always presented the same problem — the universe is big and mostly empty. This can make it extremely hard to provision any starship that needs to travel freely. Although technically, a spaceship can get up to speed and then jet through space on inertia alone, any change of speed or direction is going to require more fuel. If we really want to move in any direction, at will, around space, we're going to need a source of propulsion that can be accessed anywhere, without needing an outside source of matter or energy.

And then we have the Woodward Effect, which proposes that we can, essentially cycle a group of particles through a loop again and again, and they will change mass. We can pull on them when they're at a light point in their mass, and push them away when they're heavy. It will be like grabbing a balloon and pulling it towards you, only to have it change into a bowling ball as it reaches its nearest point and you push it away again. You'll feel an overall push outwards.

How likely is this? That depends on whether Mach's Principle actually works, practically speaking. Many scientists dismiss the very idea — and Einstein was one of them. Others are considering the utility of the idea, and looking into the practical benefits that we could get from it if it's true. The Woodward Effect has been tested multiple times. While some tests indicate it might be even greater than Woodward himself estimated, other tests are muddy and inconclusive. Still, its another potential avenue to the stars. We always like that.


Article Link: http://io9.com/5972727/the-woodward-effect-allows-for-endless-supplies-of-starship-fuel

#science #scienceeveryday #woodward #spaceexploration 
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Extremophiles in Space

The search of life in extreme environments on Earth is going to the edge of space. NASA scientists and engineers are planning to launch a balloon to the upper atmosphere to retrieve samples of microorganisms.

"This is really the last ecosystem on the planet to be explored. There's just not much known," said microbiologist David Smith, a recent University of Washington PhD graduate who will be joining NASA full-time in January.

Smith heads a project called Microorganisms in the Stratosphere, or MIST, designed to fly a balloon to the upper atmosphere to collect microorganisms. The goal of the mission is to determine the concentration of cells in the stratosphere and figure out what percentage are alive.

"There's very little doubt in my mind they’re there," Smith told Discovery News. "But can we detect them? Can we build instruments to detect things that are in such low concentrations? You're pretty much at the edge of space."

If microorganisms are detected, scientists would then want to know where they came from, how long they were they airborne and if the radioactive environment caused any DNA mutations.

Article Link: http://news.discovery.com/earth/stratosphere-search-for-extreme-life-121121.html

Pics courtesy: discovery.comsciencenewsforkids.org

#science   #scienceeveryday   #extremeophiles  
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Europe Eyes Funding for Miniature Robotic Space Plane

A European-built robot space plane could be soaring in orbit before the end of the decade if the program to develop it gains funding approval next month.

The Innovative Space Vehicle (ISV) would be Europe's civilian equivalent of the U.S. Air Force's unmanned X-37B Orbital Test Vehicle, a robotic miniature space shuttle that has flown on two missions since 2010. The unmanned space plane would be much smaller than the Air Force vehicle, however.

Its fate rests with the European Space Agency’s ministers, who are scheduled to meet Nov. 20-21 in Italy. The ESA ministerial meeting is conducted every three years to decide programs and funding for the period until the next meeting. PRIDE (the Program for Reusable In-orbit Demonstrator in Europe) will be seeking funding there for the ISV, which would be a follow-up to its Intermediate Experimental Vehicle (or IXV), currently being built after months of delays.

The PRIDE-ISV would carry modular payloads in its multipurpose cargo bay, operate in orbit as a test bed and return to Earth in the manner of a NASA space shuttle, landing on a runway. It could be used to monitor the Earth or to service satellites, its planners say. The vehicle would be "refurbished" in between launches. 

Full Article: http://www.space.com/18223-robot-mini-space-shuttle-europe-funding.html

Pic courtesy ESA: This concept graphic shows one possible configuration of the Innovative Space Vehicle and its various orbital flight mission phases.

#space   #esa   #robotics   #science   #scienceeveryday  
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