Tag: new (page 63 of 127)

Have Aliens Left The Universe? Theory Predicts We’ll Follow

Excerpt from robertlanza.com

In Star Wars, the bars are bustling with all types of alien creatures. And then, of course, there’s Yoda and Chewbacca. Recently, renowned scientist Stephen Hawking stated that he too believes aliens exist: “To my mathematical brain, the numbers alone make thinking about aliens perfectly rational.”

Hawking thinks we should be cautious about interacting with aliens — that they might raid Earth’s resources, take our ores, and then move on like pirates. “I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.”
But where are they all anyhow?

For years, NASA and others have been searching for extraterrestrial intelligence. The universe is 13.7 billion years old and contains some 10 billion trillion stars. Surely, in this lapse of suns, advanced life would have evolved if it were possible. Yet despite half a century of scanning the sky, astronomers have failed to find any evidence of life or to pick up any of the interstellar radio signals that our great antennas should be able to easily detect.

Some scientists point to the “Fermi Paradox,” noting that extraterrestrials should have had plenty of time to colonize the entire galaxy but that perhaps they’ve blown themselves up. It’s conceivable the problem is more fundamental and that the answer has to do with the evolutionary course of life itself.

Look at the plants in your backyard. What are they but a stem with roots and leaves bringing nutriments to the organism? After billions of years of evolution, it was inevitable life would acquire the ability to locomote, to hunt and see, to protect itself from competitors. 
Observe the ants in the woodpile — they can engage in combat just as resolutely as humans. Our guns and ICBM are merely the mandibles of a cleverer ant. The effort for self-preservation is vague and varied. But when we’ve overcome our struggles, what do we do next? Build taller and more splendid houses?

What happens after life completes its transition to perfection? Perhaps across space, more advanced intelligences have taken the next evolutionary step. Perhaps they’ve evolved beyond the three dimensions we vertebrates know. A new theory — Biocentrism — tells us that space and time aren’t physical matrices, but simply tools our mind uses to put everything together. These algorithms are the key to consciousness, and why space and time — indeed the properties of matter itself — are relative to the observer. More advanced civilizations would surely understand these algorithms well enough to create realities that we can’t even imagine, and to have expanded beyond our corporeal cage.

Like breathing, we take for granted how our mind puts everything together. I can recall a dream I had of a flying saucer landing in Times Square. It was so real it took awhile to convince myself that it was a dream (that I was actually at home in bed). I was standing in a crowd surrounded by skyscrapers when a massive spaceship appeared overhead. Everyone started running. My mind had somehow generated this spatio-temporal experience out of electrochemical information. I could feel the vibrations under my feet as the ship started to land, merging this 3D world with my inner thoughts and sensations.

Although I was in bed with my eyes closed, I was able to run and move my arms and fingers. My mind had created a fully functioning body and placed it in a virtual world (replete with clouds in the sky and the Sun) that was indistinguishable from the one I’m in right now. Life as we know it is defined by this spatial-temporal logic, which traps us in the universe of up and down. But like my dream, quantum theory confirms that the properties of particles in the “real” world are also observer-determined.

Other information systems surely exist that correspond to other physical realities, universes based on logic completely different from ours and not based on space and time as we know it. In fact, the simplest invertebrates may only experience existence in one dimension of space. Evolutionary biology suggests life has progressed from a one dimensional reality, to two dimensions to three dimensions, and there’s no scientific reason to think that the evolution of life stops there.

Advanced civilizations would certainly have changed the algorithms so that instead of being trapped in the linear dimensions we find ourselves in, their consciousness moves through the multiverse and beyond. Why would Aliens build massive ships and spend thousands of years to colonize planetary systems (most of which are probably useless and barren), when they could simply tinker with the algorithms and get whatever they want?

Life on Earth is just beginning to send its shoots upward into the heavens. We’ve even flung a piece of metal outside the solar system. Affixed to the spacecraft is a record with greetings in 60 languages. One can’t but wonder whether some civilization more advanced than ours will come upon it. Or will it just drift across the gulf of space? To me the answer is clear. But in case I’m wrong, I have a pitch fork guarding the ore in my backyard.

View Article Here   Read More

Neanderthals Turned Eagle Talons Into ‘Stunning’ Jewelry

Image: Talons
The eight eagle talons from Krapina were arranged with an eagle phalanx that was also found at the site.

Excerpt from nbcnews.com

Long before they shared the landscape with modern humans, Neanderthals in Europe developed a sharp sense of style, wearing eagle claws as jewelry, new evidence suggests. 

Researchers identified eight talons from white-tailed eagles — including four that had distinct notches and cut marks — from a 130,000-year-old Neanderthal cave in Croatia. They suspect the claws were once strung together as part of a necklace or bracelet.

"It really is absolutely stunning," study author David Frayer, an anthropology professor at the University of Kansas, told LiveScience. "It fits in with this general picture that's emerging that Neanderthals were much more modern in their behavior." 
The talons were first excavated more than 100 years ago at a famous sandstone rock-shelter site called Krapina in Croatia. 
There, archaeologists found more than 900 Neanderthal bones dating back to a relatively warm, interglacial period about 120,000 to 130,000 years ago. They also found Mousterian stone tools (a telltale sign of Neanderthal occupation), a hearth, and the bones of rhinos and cave bears — but no signs of modern human occupation. Homo sapiens didn't spread into Europe until about 40,000 years ago. 
The eagle talons were all found in the same archaeological layer, Frayer said, and they had been studied a few times before. But no one noticed the cut marks until last year, when Davorka Radovcic, curator of the Croatian Natural History Museum, was reassessing some of the Krapina objects in the collection. 
The researchers don't know exactly how the talons would have been assembled into jewelry. But Frayer said some facets on the claws look quite polished — perhaps made smooth from being wrapped in some kind of fiber, or from rubbing against the surface of the other talons. There were also nicks in three of the talons that wouldn't have been created during an eagle's life, Frayer said.
The findings were published March 11 in the journal PLOS ONE.

View Article Here   Read More

Confirmed: Jupiter’s moon Ganymede has a salt water ocean

GanymedeExcerpt from latimes.comAstronomers have found the most conclusive evidence yet that a large watery ocean lies beneath the surface of Jupiter's moon Ganymede.Scientists have suspected for decades that a subterranean ocean ...

View Article Here   Read More

Milky Way Galaxy May Be 50 Percent Bigger Than We Thought

 Excerpt from cbsnews.com Rings of stars thought to surround the Milky Way are actually part of it, according to new research, meaning the galaxy is bigger than previously believed.The findings extend the known width of the Milk...

View Article Here   Read More

Earth’s address within a massive supercluster of 100,000 galaxies ~ Video

Excerpt from cnet.com

Astronomers have mapped the Milky Way's position to the outskirts of a supercluster of galaxies, newly dubbed Laniakea, meaning "Immense Heaven".

The distribution of galaxies throughout the universe is not more-or-less even; instead, galaxies tend to cluster together, bound together by the pull of each other's gravity. These groups can be a variety of sizes. The Milky Way Galaxy, for instance, is part of what is called the Local Group, which contains upwards of 54 galaxies, covering a diameter of 10 megalight-years (10 million light-years).

Click to zoom

But this Local Group is just a small part of a much, much bigger structure, which researchers at the University of Hawai'i Mānoa have now mapped in detail. Coming in at over 100,000 galaxies, the massive supercluster has been given the name Laniakea -- "immense heaven" in Hawaiian.
The new 3D map was created by examining the positions and movements of the 8000 closest galaxies to the Milky Way. After calculating which galaxies were being pulled away from us and which were being pulled towards us -- accounting for the universe's expansion -- the team, led by astronomer R. Brent Tully, was able to map the paths of galactic migration -- and define the boundaries of Laniakea.

Traditionally, the borders of galactic superclusters have been difficult to map, but studying the gravitational force acting on our neighbouring galaxies has provided some important clues. All objects inside Laniakea are being slowly but surely drawn to a single point -- a force known as the Great Attractor, a gravitational anomaly with a mass tens of thousands of times the mass of the Milky Way.

Everything that is being pulled towards the Great Attractor is part of Laniakea -- although it's possible that Laniakea itself might in turn be part of a structure that is larger still.

"We probably need to measure to another factor of three in distance to explain our local motion," Tully said. "We might find that we have to come up with another name for something larger than we're a part of -- we're entertaining that as a real possibility."

The full paper, "The Laniakea supercluster of galaxies", can be read online in the journal Nature.

View Article Here   Read More

Our new neighbours: Rare dwarf galaxies found orbiting the Milky Way

The Large and Small Magellanic Clouds, near which the satellites were found. Excerpt from cnet.com Researchers have found rare satellite dwarf galaxies and candidate dwarf galaxies in orbit around our Milky Way, the largest number of such...

View Article Here   Read More

Surface of Venus revealed by new radio telescope data


Excerpt from smnweekly.com
By David M. DeMar

New radio telescope data from the National Radio Astronomy Observatory has revealed for the first time ever just what Venus has under its thick veil of clouds that otherwise occlude its surface from view.
25 million miles distant from us, Venus looks to the naked eye – or through a light telescope – much like a cloudy marble, thanks to the thick cloudbanks of carbon dioxide ringing the planet. However, the surface underneath, long a mystery to planetary scientists, has been laid bare thanks to the work of Puerto Rico’s Arecibo Observatory radio transmitter and the Green Bank Telescope, a radio telescope located in West Virginia and operated by the National Science Foundation.
The two facilities worked together with the NRAO in order to uncover the hidden surface of Mars. Arecibo sent radar signals to Venus, where they penetrated the thick atmosphere and bounced off the ground. The returning radio signals were picked up by the GBT in West Virginia in a process known as bistatic radar; the result is a radar image that shows craters and mountains strewn across the surface of Venus at a surprisingly high resolution.
The image is bisected by a dark line, representing areas where it’s particularly difficult to receive useful image data through the use of bistatic radar. However, scientists are intending to compare multiple images as time goes by in order to identify any active geologic processes on the surface of Venus such as volcanic activity.
It’s no particularly easy task to compare radar images in search of evidence of any change in this manner says Smithsonian senior scientist Bruce Campbell, but the work will continue. Campbell, who works at the National Air and Space Museum in the nation’s capital and is associated with the center for Earth and Planetary Studies, added that combining images from the latest NRAO endeavor and others will yield large amounts of data on how the surface of Venus might be altered by other processes.
The radar data, and a scientific paper based on it, will be published in April in Icarus, the scientific journal dedicated to studies of the solar system.

View Article Here   Read More

Billionaire teams up with NASA to mine the moon

Excerpt from cnbc.com
By Susan Caminiti

Moon Express, a Mountain View, California-based company that's aiming to send the first commercial robotic spacecraft to the moon next year, just took another step closer toward that lofty goal. 

Earlier this year, it became the first company to successfully test a prototype of a lunar lander at the Kennedy Space Center in Florida. The success of this test—and a series of others that will take place later this year—paves the way for Moon Express to send its lander to the moon in 2016, said company co-founder and chairman Naveen Jain.

Moon Express conducted its tests with the support of NASA engineers, who are sharing with the company their deep well of lunar know-how. The NASA lunar initiative—known as Catalyst—is designed to spur new commercial U.S. capabilities to reach the moon and tap into its considerable resources.In addition to Moon Express, NASA is also working with Astrobotic Technologies of Pittsburgh, Pennsylvania, and Masten Space Systems of Mojave, California, to develop commercial robotic spacecrafts. 

Jain said Moon Express also recently signed an agreement to take over Space Launch Complex 36 at Cape Canaveral. The historic launchpad will be used for Moon Express's lander development and flight-test operations. Before it was decommissioned, the launchpad was home to NASA's Atlas-Centaur rocket program and its Surveyor moon landers.

"Clearly, NASA has an amazing amount of expertise when it comes to getting to the moon, and it wants to pass that knowledge on to a company like ours that has the best chance of being successful," said Jain, a serial entrepreneur who also founded Internet companies Infospace and Intelius. He believes that the moon holds precious metals and rare minerals that can be brought back to help address Earth's energy, health and resource challenges. 

Among the moon's vast riches: gold, cobalt, iron, palladium, platinum, tungsten and Helium-3, a gas that can be used in future fusion reactors to provide nuclear power without radioactive waste. "We went to the moon 50 years ago, yet today we have more computing power with our iPhones than the computers that sent men into space," Jain said. "That type of exponential technological growth is allowing things to happen that was never possible before."

An eye on the Google prize

Source: MoonExpress

Helping to drive this newfound interest in privately funded space exploration is the Google Lunar X Prize. It's a competition organized by the X Prize Foundation and sponsored by Google that will award $30 million to the first company that lands a commercial spacecraft on the moon, travels 500 meters across its surface and sends high-definition images and video back to Earth—all before the end of 2016.

Moon Express is already at the front of the pack. In January it was awarded a $1 million milestone prize from Google for being the only company in the competition so far to test a prototype of its lander. "Winning the X prize would be a great thing," said Jain. "But building a great company is the ultimate goal with us." When it comes to space exploration, he added, "it's clear that the baton has been passed from the government to the private sector."

Testing in stages

Jain said Moon Express has been putting its lunar lander through a series of tests at the space center. The successful outing earlier this year involved tethering the vehicle—which is the size of a coffee table—to a crane in order to safely test its control systems. "The reason we tethered it to the crane is because the last thing we wanted was the aircraft to go completely haywire and hurt someone," he said. 

At the end of March, the company will conduct a completely free flight test with no tethering. The lander will take off from the pad, go up and sideways, then land back at the launchpad. "This is to test that the vehicle knows where to go and how to get back to the launchpad safely," Jain explained.

Once all these tests are successfully completed, Jain said the lander—called MX-1—will be ready to travel to the moon. The most likely scenario is that it will be attached to a satellite that will take the lander into a low orbit over the Earth. From there the MX-1 will fire its own rocket, powered by hydrogen peroxide, and launch from that orbit to complete its travel to the moon's surface. 

The lander's first mission is a one-way trip, meaning that it's not designed to travel back to the Earth, said Jain. "The purpose is to show that for the first time, a company has developed the technology to land softly on the moon," he said. "Landing on the moon is not the hard part. Landing softly is the hard part." 

That's because even though the gravity of the moon is one-sixth that of the Earth's, the lander will still be traveling down to the surface of the moon "like a bullet," Jain explained. Without the right calculations to indicate when its rockets have to fire in order to slow it down, the lander would hit the surface of the moon and break into millions of pieces. "Unlike here on Earth, there's no GPS on the moon to tell us this, so we have to do all these calculations first," he said. 

Looking ahead 15 or 20 years, Jain said he envisions a day when the moon is used as a sort of way station enabling easier travel for exploration to other planets. In the meantime, he said the lander's second and third missions could likely involve bringing precious metals, minerals and even moon rocks back to Earth. "Today, people look at diamonds as this rare thing on Earth," Jain said.
He added, "Imagine telling someone you love her by giving her the moon."

View Article Here   Read More

Great Fuel Economy For Less: 5 Affordable Used Cars That are Surprisingly Good on Gas

Excerpt from autotrader.com By Josh Sadlier   Seems like the only thing automakers want to talk about these days is how their cars suddenly get great fuel economy. Given this relentless chatter, it's tempting to conclude that mos...

View Article Here   Read More

Dawn Enters Orbit Around Dwarf Planet Ceres ~ Video

Ceres Dawn

Dwarf Planet Ceres

Excerpt from spacenews.com

NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.  In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.  “We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”

Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.  The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres. 

Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.

Click to zoom
Dawn will gradually spiral down to its initial science orbit, 13,500 kilometers above Ceres, by April. Later in its mission Dawn will move gradually closer to the surface, eventually moving into an orbit of 375 kilometers.
The Dawn spacecraft, built by Orbital ATK, launched on a United Launch Alliance Delta 2 rocket in September 2007. After making a gravity assist flyby of Mars in February 2009, it entered orbit around the large main-belt asteroid Vesta in July 2011. It remained there for more than a year, using its ion thrusters to leave orbit in September 2012 to head to Ceres.
Ceres, the largest object in the main asteroid belt between the orbits of Mars and Jupiter, was the first asteroid discovered by astronomers, in 1801. The International Astronomical Union designated Ceres a “dwarf planet” in 2006, a new category of objects that also includes the former planet Pluto.
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf
WASINGTON — NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres March 6, completing a journey of nearly seven and a half years and five billion kilometers.
In a statement, NASA’s Jet Propulsion Laboratory said Dawn entered orbit about 61,000 kilometers above Ceres at 7:39 am EST March 6, sending a signal to Earth about an hour later confirming it was in orbit and in good health.
“We feel exhilarated,” Dawn principal investigator Chris Russell said in the statement. “We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives.”
- See more at: http://spacenews.com/dawn-enters-orbit-around-ceres/#sthash.yoclEQI4.dpuf

View Article Here   Read More

Habitable’ Super-Earth Might Exist After All

Artist's impression of Gliese 581d, a controversial exoplanet that may exist only 20 light-years from Earth.

Excerpt from news.discovery.com

Despite having discovered nearly 2,000 alien worlds beyond our solar system, the profound search for exoplanets — a quest focused on finding a true Earth analog — is still in its infancy. It is therefore not surprising that some exoplanet discoveries aren’t discoveries at all; they are in fact just noise in astronomical data sets.

But when disproving the existence of extrasolar planets that have some characteristics similar to Earth, we need to take more care during the analyses of these data, argue astronomers from Queen Mary, University of London and the University of Hertfordshire.

In a paper published by the journal Science last week, the researchers focus on the first exoplanet discovered to orbit a nearby star within its habitable zone.

Revealed in 2009, Gliese 581d hit the headlines as a “super-Earth” that had the potential to support liquid water on its possibly rocky surface. With a mass of around 7 times that of Earth, Gliese 581d would be twice as big with a surface gravity around twice that of Earth. Though extreme, it’s not such a stretch of the imagination that such a world, if it is proven to possess an atmosphere and liquid ocean, that life could take hold.

And the hunt for life-giving alien worlds is, of course, the central motivation for exoplanetary studies.

But the exoplanet signal has been called into doubt.
Gliese 581d’s star, Gliese 581, is a small red dwarf around 20 light-years away. Red dwarfs are known to be tempestuous little stars, often generating violent flaring outbursts and peppered in dark features called starspots. To detect the exoplanet, astronomers measured the very slight frequency shift (Doppler shift) of light from the star — as the world orbits, it exerts a tiny gravitational “tug”, causing the star to wobble. When this periodic wobble is detected, through an astronomical technique known as the “radial velocity method,” a planet may be revealed.

Last year, however, in a publication headed by astronomers at The Pennsylvania State University, astronomers pointed to the star’s activity as an interfering factor that may have imitated the signal from an orbiting planet when in fact, it was just noisy data.

But this conclusion was premature, argues Guillem Anglada-Escudé, of Queen Mary, saying that “one needs to be more careful with these kind of claims.”

“The existence, or not, of GJ 581d is significant because it was the first Earth-like planet discovered in the ‘Goldilocks’-zone around another star and it is a benchmark case for the Doppler technique,” said Anglada-Escudé in a university press release. “There are always discussions among scientists about the ways we interpret data but I’m confident that GJ 581d has been in orbit around Gliese 581 all along. In any case, the strength of their statement was way too strong. If the way to treat the data had been right, then some planet search projects at several ground-based observatories would need to be significantly revised as they are all aiming to detect even smaller planets.”

The upshot is that this new paper challenges the statistical technique used in 2014 to account for the signal being stellar noise — focusing around the presence of starspots in Gliese 581′s photosphere.

Gliese 581d isn’t the only possible exoplanet that exists around that star — controversy has also been created by another, potentially habitable exoplanet called Gliese 581g. Also originally detected through the wobble of the star, this 3-4 Earth mass world was found to also be in orbit within the habitable zone. But its existence has been the focus of several studies supporting and discounting its presence. Gliese 581 is also home to 3 other confirmed exoplanets, Gliese 581e, b and c.

Currently, observational data suggests Gliese 581g was just noise, but as the continuing debate about Gliese 581d is proving, this is one controversy that will likely keep on rumbling in the scientific journals for some time.

View Article Here   Read More

Far Flung Star Cluster Found at Milky Way’s Edge

Astronomers in Brazil have discovered a cluster of stars forming at the edge of the Milky Way, according to a press release from the Royal Astronomical Society.

Excerpt from  news.discovery.com

This is unusual because it was believed that stars generally take form closer to the center of our spiral-shaped galaxy, rather than from its swirling, spiral arms, which are thousands of light-years away. These two clusters of stars — named Camargo 438 and 439 — were seen in a cloud at the galaxy’s outskirts.

Denilso Camargo, an astronomer at the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, led a team that analyzed data from NASA’s orbiting Wide-Field Infrared Survey Explorer (WISE) observatory. They zeroed in on dense clumps of gas in so-called giant molecular clouds(GMCs) that are known to generate stars. GMCs are mainly located in the inner part of the galactic disc.

The new star clusters lie about 16,000 light-years away from the main disk of the Milky Way galaxy. How did they form there? The scientists aren’t yet sure but Camargo theorizes that one of two scenarios could have led to the stars’ formation.

In the first scenario, called the “chimney model,” supernovas could have flung the gas and dust that formed the cloud out of the Milky Way. Another explanation is the material could have drifted in from outside the galaxy.

“Our work shows that the space around the Galaxy is a lot less empty that we thought,” said Camargo. “The new clusters of stars are truly exotic.”

Camargo’s team published their results in the journal Monthly

View Article Here   Read More

Warp in spacetime lets astronomers watch the same star explode four times

Excerpt from csmonitor.com

Thanks to a phenomenon known as gravitational lensing, the Hubble Space Telescope has captured four images of the same supernova explosion.

For the first time, a cosmic magnifying glass has allowed scientists to see the same star explosion four times, possibly offering a revealing glimpse into these explosive stellar deaths and the nature of the accelerating universe.

Astronomers using the Hubble Space Telescope have captured four images of a supernova explosion in deep space thanks to a galaxy located between Earth and the massive star explosion. You can see how Hubble saw the supernova in this NASA video. The galaxy cluster warped the fabric of space and time around it — like a bowling ball placed on a bed sheet — allowing scientists to see the supernova in four images.

"It was predicted 50 years ago that a supernova could be gravitationally lensed like this, but it's taken a long time for someone to find an example," lead study author Patrick Kelly, an astronomer at the University of California, Berkeley told Space.com. "It's fun to have been able to find the first one." 

The supernova, which was discovered on Nov. 11, 2014, is located about 9.3 billion light-years away from Earth, near the edge of the observable universe. The researchers have named the distant supernova SN Refsdal in honor of the late Norwegian astrophysicist Sjur Refsdal, a pioneer of gravitational lensing studies. Due to gravitational lensing, "the supernova appears 20 times brighter than its normal brightness," study co-author Jens Hjorth, head of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said in a statement.
The lensing galaxy, which is about 5 billion light-years from Earth, is part of a large cluster of galaxies known MACS J1149.6+2223. In 2009, astronomers discovered that this cluster was the source of the largest known image of a spiral galaxy ever seen through a gravitational lens.

The four images of the supernova each appeared separately over the course of a few weeks. This is because light can take various paths around and through a gravitational lens, arriving at Earth at different times.

Using gravity as a lens

Gravity is created when matter warps the fabric of reality. The greater the mass of an object, the more space-time curves around that object and the stronger its gravitational pull, the discovery enshrined in Einstein's theory of general relativity, which celebrates its centennial this year.

As a result, gravity can also bend light like a lens, meaning objects see n behind powerful gravitational fields, such as those of massive galaxies, are magnified. Gravitational lensing was first discovered in 1979, and today gravitational lenses can help astronomers see features otherwise too distant and faint to detect with even the largest telescopes.

"These gravitational lenses are like a natural magnifying glass. It's like having a much bigger telescope," Kelly said in a statement. "We can get magnifications of up to 100 times by looking through these galaxy clusters."

When light is far from a gravitationally lensing mass, or if the gravitationally lensing mass is not especially large, only "weak lensing" occurs, barely distorting the light. However, when the light comes from almost exactly behind the gravitationally lensing mass, "strong lensing" can happen. 

When a strongly lensed object occupies a large patch of space — for instance, if it's a galaxy — it can get smeared into an "Einstein ring" surrounding a gravitationally lensing mass. However, strong lensing of small, pointlike items — for instance, super-bright objects known as quasars — often produces multiple images surrounding the gravitationally lensing mass, resulting in a so-called "Einstein cross."

The observations of SN Refsdal mark the first time astronomers on Earth have witnessed strong lensing of a  supernova, with four images of an exploding star arrayed as an Einstein cross.

An expanding universe

These new findings could help scientists measure the accelerating rate at which the universe is expanding, researchers say.

A computer model of the lensing cluster suggests the scientists missed chances to see the lensed supernova 50 and 10 years ago. However, the model also suggests more images of the explosion will repeat again within the next 10 years.

The timing of when all these images of the supernova arrive depends on the gravitational pull of the matter generating the gravitational lens. So, by measuring those times, the researchers hope to map how visible normal matter and invisible dark matter is distributed in the lensing galaxy.

Dark matter is currently one of the greatest mysteries in science, a poorly understood substance thought to make up five-sixths of all matter in the universe. A better understanding of how dark matter is behaving in this gravitationally lensing cluster might help shed light on the material's nature, Kelly said.

Analyzing when the images arrive could also help scientists pinpoint the rate at which the universe is expanding. Although there are already several ways to measure the cosmic expansion rate, "there has been a lot of heated debate between different methods, so it'd be interesting to see how this new technique might affect the area," Kelly said. "It's always nice to have completely independent measurements of the same quantity."

The scientists detailed their findings in the March 6 issue of the journal Science.

View Article Here   Read More

Older posts Newer posts

Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0
International License
unless otherwise marked.

Terms of Use | Privacy Policy

Up ↑