Tag Archive: Universe

The largest ever three dimensional map of galaxies and black holes was released by astronomers today.  It will help explain the mysterious dark matter and dark energy that they know makes up 96 percent of the universe.

The map is the creation of the Sloan Digital Sky Survey III (SDSS-III) an international project mapping the Milky Way in which a team from the University of Portsmouth is the only UK institution.  Early last year, the SDSS-III released the largest-ever image of the sky and astronomers have used new data to expand this image into a full three-dimensional map.

Data Release 9 (DR9) includes images of 200 million galaxies and spectra of 1.35 million galaxies, including 540,000 spectra of new galaxies from when the universe was half its present age. Spectra show how much light a galaxy gives off at different wavelengths. Because this light is shifted to longer redder wavelengths as the Universe expands, spectra allow scientists to work out how much the Universe has expanded since the light left each galaxy.

It will allow better estimates of how much of the universe is made up of dark matter – matter that can’t be seen directly see because it doesn’t emit or absorb light – and dark energy, the even more mysterious force that drives the accelerating expansion of the universe.

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Seeing is believing, except when you don’t believe what you see.

This is according to veteran radio astronomer Gerrit Verschuur, of the University of Memphis, who has an outrageously unorthodox theory that if true, would turn modern cosmology upside down.

He proposes that at least some of the fine structure seen in the all-sky plot of the universe’s cosmic microwave background is really the imprint of our local interstellar neighborhood. It has nothing to do with how the universe looked 380,000 years after the Big Bang, but how nearby clouds of cold hydrogen looked a few hundred years ago.

The idea is so unbelievable that it’s little wonder that cosmologists have largely ignored his work that has been published over the last few years.

“Science is supposed to be about the excitement of making new discoveries. But this discovery terrifies me,” he told reporters at the recent meeting of the American Astronomical Society in Anchorage, Alaska.

Verschuur’s radio maps of hydrogen surrounding our local stellar neighborhood out to a few hundred light-years appear to have an uncanny match-up to the mottled structure of the cosmic microwave background that is 13.7 billion light-years away.

NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) mapped the CMB in exquisite detail in 2003. The data show the slight temperature fluctuations in the early universe that are believed to be the seeds of galaxy formation. It is a landmark observation that is considered the “blueprint” for the subsequent evolution of the universe.

Verschuur is quick to applaud the WMAP team for a “brilliant experiment” to attempt to resolve the structure of the primeval universe as encoded in ancient microwave radiation. But he suggests that the team failed to subtract all the foreground radio phenomena that may have contaminated the data.

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Our universe may exist inside a black hole. This may sound strange, but it could actually be the best explanation of how the universe began, and what we observe today. It’s a theory that has been explored over the past few decades by a small group of physicists including myself.

Successful as it is, there are notable unsolved questions with the standard big bang theory, which suggests that the universe began as a seemingly impossible “singularity,” an infinitely small point containing an infinitely high concentration of matter, expanding in size to what we observe today. The theory of inflation, a super-fast expansion of space proposed in recent decades, fills in many important details, such as why slight lumps in the concentration of matter in the early universe coalesced into large celestial bodies such as galaxies and clusters of galaxies.

But these theories leave major questions unresolved. For example: What started the big bang? What caused inflation to end? What is the source of the mysterious dark energy that is apparently causing the universe to speed up its expansion?

The idea that our universe is entirely contained within a black hole provides answers to these problems and many more. It eliminates the notion of physically impossible singularities in our universe. And it draws upon two central theories in physics.

The first is general relativity, the modern theory of gravity. It describes the universe at the largest scales. Any event in the universe occurs as a point in space and time, or spacetime. A massive object such as the Sun distorts or “curves” spacetime, like a bowling ball sitting on a canvas. The Sun’s gravitational dent alters the motion of Earth and the other planets orbiting it. The sun’s pull of the planets appears to us as the force of gravity.

The second is quantum mechanics, which describes the universe at the smallest scales, such as the level of the atom. However, quantum mechanics and general relativity are currently separate theories; physicists have been striving to combine the two successfully into a single theory of “quantum gravity” to adequately describe important phenomena, including the behavior of subatomic particles in black holes.

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10. There are 100,000 times as many stars in the universe as sounds and words ever uttered by all humans who have ever lived.

9. Humans are genetically connected with life on Earth, chemically connected with life on other star systems and atomically connected with all matter in the universe.

8. Dark matter and dark energy make up 94 percent of the universe. We can measure their existence, yet we have no idea what they are.

7. Beneath a thick layer of surface ice, Jupiter’s moon Europa likely harbors a liquid ocean kept warm by the gravitational stresses induced by Jupiter and by neighboring moons — a potential haven for life.

6. An asteroid the size of Mount Everest slammed into Earth 65 million years ago. The ensuing global climatic catastrophe left 70 percent of all the world’s species extinct, including the ferocious dinosaurs.

5. There are more molecules of water in a cup of water than cups of water in all the world’s oceans. This means that some molecules in every cup of water you drink passed through the kidneys of Genghis Khan, Napoleon, Abe Lincoln or any other historical person of your choosing. Same goes for air: There are more molecules of air in a single breath of air than there are breaths of air in Earth’s entire atmosphere. Therefore, some molecules of air you inhale passed through the lungs of Billy the Kid, Joan of Arc, Beethoven, Socrates or any other historical person of your choosing.

4. The laws of physics, as measured here on Earth, apply everywhere else in the universe — across space and time.

3. Since light takes time to travel from one place to another, the farther out in space you look, the farther back in time you see. With our most powerful telescopes, we can observe the universe all the way back to its earliest moments — all the way back to the Big Bang itself.

2. With Mars likely to have been wet and fertile before Earth in the early solar system; with known bacteria that can survive extremes of temperature, pressure and radiation; with asteroid impacts that can cast into space rocks that contain bacterial stowaways, allowing life to move between planets, it may be that life on Earth was seeded by life from Mars, making all of us descendants of Martians.

1.With chemical elements forged over 14 billion years in the fires of high-mass stars that exploded into space, and with these elements enriching subsequent generations of stars with carbon, oxygen, nitrogen and other basic ingredients of life itself, we are not just figuratively but literally made of stardust.

How would the sky look through infrared eyes? The scientists behind NASA’s Wide-field Infrared Survey Explorer mission have served up that kind of view with an all-sky map of infrared wavelengths, centered on the glowing Milky Way.

The map was unveiled this week to mark the completion of WISE’s infrared sky atlas, more than two years after the $320 million mission was launched. The telescope collected more than 2.7 million images in four infrared wavelengths and sent down more than 15 trillion bytes of data. The WISE spacecraft was shut down a year ago, after surveying the entire sky one and a half times, but scientists needed still more time to analyze and organize the data.

The images were combined into an atlas of more than 18,000 images. The atlas is accompanied by a catalog listing the infrared properties of more than 560 million individual objects, ranging from near-Earth asteroids to far-flung galaxies. Wednesday’s release of the catalog meets the fundamental objective of a mission that was conceived in 1998.

Source: MSNBC

Dark matter in the Universe is distributed as a network of gigantic dense (white) and empty (dark) regions, where the largest white regions are about the width of several Moons on the sky. Credit: Van Waerbeke, Heymans, and CFHTLenS collaboration.

We can’t see it, we can’t feel it, we can’t even interact with it… but dark matter may very well be one of the most fundamental physical components of our Universe. The sheer quantity of the stuff – whatever it is – is what physicists have suspected helps gives galaxies their mass, structure, and motion, and provides the “glue” that connects clusters of galaxies together in vast networks of cosmic webs.

Now, for the first time, this dark matter web has been directly observed.

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The Known Universe

An exotic planet that seems to be made of diamond racing around a tiny star in our galactic backyard in an undated image courtesy of Swinburne University of Technology in Melbourne. REUTERS/Handout

Astronomers have spotted an exotic planet that seems to be made of diamond racing around a tiny star in our galactic backyard.

The new planet is far denser than any other known so far and consists largely of carbon. Because it is so dense, scientists calculate the carbon must be crystalline, so a large part of this strange world will effectively be diamond.

“The evolutionary history and amazing density of the planet all suggest it is comprised of carbon — i.e. a massive diamond orbiting a neutron star every two hours in an orbit so tight it would fit inside our own Sun,” said Matthew Bailes of Swinburne University of Technology in Melbourne.

Lying 4,000 light years away, or around an eighth of the way toward the center of the Milky Way from the Earth, the planet is probably the remnant of a once-massive star that has lost its outer layers to the so-called pulsar star it orbits.

Pulsars are tiny, dead neutron stars that are only around 20 kilometers (12.4 miles) in diameter and spin hundreds of times a second, emitting beams of radiation.

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Scientists have discovered the largest black holes yet, and they’re far bigger than researchers expected based on the galaxies in which they were found.

The discovery suggests we have much to learn about how monster black holes grow, scientists said.

All large galaxies are thought to harbor super-massive black holes at their hearts that contain millions to billions of times the mass of our sun. Until now, the largest black hole known was a mammoth dwelling in the giant elliptical galaxy Messier 87. This black hole has a mass 6.3 billion times that of the sun.

Now research suggests black holes in two nearby galaxies are even bigger.

The scientists used the Gemini and Keck observatories in Hawaii and the McDonald Observatory in Texas to monitor the velocities of stars orbiting around the centers of a pair of galaxies. These velocities reveal the strength of the gravitational pull on those stars, which in turn is linked with the masses of the black holes lurking there.

The new findings suggest that one galaxy, known as NGC 3842, the brightest galaxy in the Leo cluster of galaxies nearly 320 million light years distant, has a central black hole 9.7 billion solar masses large. The other, named NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass. Both encompass regions or “event horizons” about five times the distance from the sun to Pluto.

Image of the center of our Galaxy from laser-guide-star adaptive optics on the Keck Telescope. This is an HKL-band color mosaic, where H(1.8 microns) = blue, K(2.2 microns) = green, and L(3.8 microns) = red. More massive black holes have larger event horizons, the region within which even light cannot escape. If a 10 billion solar mass black hole resided at the Galactic center, its immense event horizon would be visible (illustrated by the central black disk). The actual black hole at the Galactic center is 2,500 times smaller.

“For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way galaxy, whose event horizon is one-fifth the orbit of Mercury,” said study lead author Nicholas McConnell at the University of California, Berkeley.

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What is a computer? Steve Jobs famously described the computer as “a bicycle for the mind” — a tool to help us remember, think, discover, and create. Computers are high-tech, universal tools; they’re so useful, in fact, that some of us spend all day in contact with some sort of digital device.

There’s another way, though, to think about what a computer is: not as a high-tech tool, but as a profound intellectual achievement. In a deep sense, the power of the computer is as much about ideas as it is about circuits. The incredible, open-ended flexibility that makes computers so powerful — and that lets us use them to figure out everything from climate modeling to “Jeopardy!” — is, in fact, the product of more than two thousand years of painstaking, hard-won intellectual progress in low-tech fields like mathematics, logic, and philosophy. Like the tide line on a beach, the computer marks the furthest we’ve progressed in a philosophical quest to understand, perfect, and extend the reach of reason.

The creation of the modern computer in the 1940s was a watershed moment in that quest; today’s super-fast computers are still essentially built on that achievement. Now, however, we’re poised to take another leap forward. That leap is the quantum computer — a computer built on an atomic scale. Though they’re still mostly theoretical, quantum computers would use individual atoms to do their computations, instead of circuits etched in silicon. Such a computer wouldn’t just be built differently — it would also think differently, using the uncertainty of particle physics instead of the rigid on/off circuitry of a modern computer.

Before the telescope was invented in 1608, our picture of the universe consisted of six planets, our moon, the sun and any stars we could see in the Milky Way galaxy. But as our light-gathering capabilities have grown, so too have the boundaries of the visible universe. Our interactive map shows how the known universe has grown from 1950 to 2011.

In the late 1700s, William Herschel, an English astronomer using a telescope with an 18.7-inch aperture, made the first systematic surveys of the skies, revealing more than 2,000 distant galaxies, nebulae and other objects invisible to the naked eye. Since then, increasingly powerful optical and radio telescopes have greatly expanded our store of knowledge.

In 1948, astronomers erected the 200-inch Hale Telescope at Palomar Observatory in California, and now, large-scale projects such as the Sloan Digital Sky Survey and NASA’s Kepler mission use sensitive digital imaging and computational power to collect and analyze hundreds of terabytes of data on millions of galaxies billions of light-years from Earth. With each additional bit of data, the universe itself grows larger.

A spectrum from the Infrared Space Observatory superimposed on an image of the Orion Nebul...

A spectrum from the Infrared Space Observatory superimposed on an image of the Orion Nebula where the complex organics are found.

Researchers at the University of Hong Kong (HKU) claim to have solved the mystery of “Unidentified Infrared Emission features” that have been detected in stars, interstellar space, and galaxies. For over two decades, the most commonly accepted theory regarding this phenomenon was that these signatures come from polycyclic aromatic hydrocarbon (PAH) molecules – simple organic molecules made of carbon and hydrogen atoms. Now HKU researchers say the substances generating these signatures are actually complex organic compounds that are made naturally by stars and ejected into interstellar space.

The team of Prof. Sun Kwok and Dr. Yong Zhang used observations taken by the Infrared Space Observatory and the Spitzer Space Telescope of stardust formed in exploding stars called novae to show that the astronomical spectra contain a mixture of aromatic (ring-like) and aliphatic (chain-like) components that cannot be explained by PAH molecules.

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One of the most cherished principles in science – the constancy of physics – may not be true, according to research carried out at the University of New South Wales (UNSW), Swinburne University of Technology and the University ofCambridge.

The study found that one of the four known fundamental forces, electromagnetism – measured by the so-called fine-structure constant and denoted by the symbol ‘alpha’ – seems to vary across the Universe.

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One of the great mysteries of planetary science is how Earth got so wet. By the time our planet formed about 4.5 billion years ago, the Sun’s heat had driven most of the Solar System’s complement of water out toward the edges. Most of it is still there, frozen solid in, among other things, the rings of Saturn, Jupiter’s moon Europa, the bodies of Neptune and Uranus and billions upon billions of comets.

But the Earth has plenty of water as well, and scientists have wondered for years how it got here. One leading theory: it came from a fusillade of comets that came screaming back in toward the Sun a half-billion years or so after our planet formed. That idea got a big boost just last week with the discovery that some comets, at least, have the same chemical signature as the water found on Earth.

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Dark Matter Mystery Deepens

Like all galaxies, our Milky Way is home to a strange substance called dark matter. Dark matter is invisible, betraying its presence only through its gravitational pull. Without dark matter holding them together, our galaxy’s speedy stars would fly off in all directions. The nature of dark matter is a mystery — a mystery that a new study has only deepened.

“After completing this study, we know less about dark matter than we did before,” said lead author Matt Walker, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics.

The standard cosmological model describes a universe dominated by dark energy and dark matter. Most astronomers assume that dark matter consists of “cold” (i.e. slow-moving) exotic particles that clump together gravitationally. Over time these dark matter clumps grow and attract normal matter, forming the galaxies we see today.

Cosmologists use powerful computers to simulate this process. Their simulations show that dark matter should be densely packed in the centers of galaxies. Instead, new measurements of two dwarf galaxies show that they contain a smooth distribution of dark matter. This suggests that the standard cosmological model may be wrong.

“Our measurements contradict a basic prediction about the structure of cold dark matter in dwarf galaxies. Unless or until theorists can modify that prediction, cold dark matter is inconsistent with our observational data,” Walker stated.

Dwarf galaxies are composed of up to 99 percent dark matter and only one percent normal matter like stars. This disparity makes dwarf galaxies ideal targets for astronomers seeking to understand dark matter.

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Neuroscientist and best-selling author David Eagleman introduces the concept of Possibilianism, a new philosophy that simultaneously embraces a scientific toolbox while exploring new, unconsidered uncertainties about the world around us.

This fantastic interactive flythru really gives you a sense of The Scale of Things. Are you feeling small? More here.

Around the world, a new generation of astronomers are hunting for the most mysterious objects in the universe. Young stars, black holes, even other forms of life. They have created a dazzling new set of super-telescopes that promise to rewrite the story of the heavens.

This film follows the men and women who are pushing the limits of science and engineering in some of the most extreme environments on earth. But most strikingly of all, no-one really knows what they will find out there.

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