Tag: ways (page 4 of 32)

8 Health Benefits of Dandelions

Meme - To many, dandelions are weeds with lovely yellow flowers that turn into white fluffy balls that will spread seeds and overtake your yard and garden. But dandelions are more than weeds; they are a gift from nature loaded with fiber, vitamins and minerals essential for the body.Dandelion root can be purchased as a supplement or tea; its leaves make a great salad when young; and dandelion milk is especially good for treating skin diseases while the jui [...]

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Could Google’s Project Fi be cable’s answer to wireless?

 Excerpt from cnet.com Google's Project Fi wireless service has the potential to turn the mobile industry on its head. But not in the way you might expect. Last week, Google announce...

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This revolutionary discovery could help scientists see black holes for the first time


supermassive black hole
Artist's concept of the black hole.



Excerpt from finance.yahoo.com
Of all the bizarre quirks of nature, supermassive black holes are some of the most mysterious because they're completely invisible.
But that could soon change.
Black holes are deep wells in the fabric of space-time that eternally trap anything that dares too close, and supermassive black holes have the deepest wells of all. These hollows are generated by extremely dense objects thousands to billions of times more massive than our sun.
Not even light can escape black holes, which means they're invisible to any of the instruments astrophysicists currently use. Although they don't emit light, black holes will, under the right conditions, emit large amounts of gravitational waves — ripples in spacetime that propagate through the universe like ripples across a pond's surface.
And although no one has ever detected a gravitational wave, there are a handful of instruments around the world waiting to catch one.

Game-changing gravitational waves



.
black hole
This illustration shows two spiral galaxies - each with supermassive black holes at their center - as they are about to collide. 

Albert Einstein first predicted the existence of gravitational waves in 1916. According to his theory of general relativity, black holes will emit these waves when they accelerate to high speeds, which happens when two black holes encounter one another in the universe.  

As two galaxies collide, for example, the supermassive black holes at their centers will also collide. But first, they enter into a deadly cosmic dance where the smaller black hole spirals into the larger black hole, moving increasingly faster as it inches toward it's inevitable doom. As it accelerates, it emits gravitational waves.
Astrophysicists are out to observe these waves generated by two merging black holes with instruments like the Laser Interferometer Gravitational-Wave Observatory.
"The detection of gravitational waves would be a game changer for astronomers in the field," Clifford Will, a distinguished profess of physics at the University of Florida who studied under famed astrophysicist Kip Thorne told Business Insider. "We would be able to test aspects of general relativity that have not been tested."
Because these waves have never been detected, astrophysicists are still trying to figure out how to find them. To do this, they build computer simulations to predict what kinds of gravitational waves a black hole merger will produce. 

Learn by listening

In the simulation below, made by Steve Drasco at California Polytechnic State University (also known as Cal Poly), a black hole gets consumed by a supermassive black hole about 30,000 times as heavy.
You'll want to turn up the volume.
What you're seeing and hearing are two different things.
The black lines you're seeing are the orbits of the tiny black hole traced out as it falls into the supermassive black hole. What you're hearing are gravitational waves.
"The motion makes gravitational waves, and you are hearing the waves," Drasco wrote in a blog post describing his work.
Of course, there is no real sound in space, so if you somehow managed to encounter this rare cataclysmic event, you would not likely hear anything. However, what Drasco has done will help astrophysicists track down these illusive waves.

Just a little fine tuning 

Gravitational waves are similar to radio waves in that both have specific frequencies. On the radio, for example, the number corresponding to the station you're listening to represents the frequency at which that station transmits.


.
gwaves
3D visualization of gravitational waves produced by 2 orbiting black holes. Right now, astrophysicists only have an idea of what frequencies two merging black holes transmit because they’re rare and hard to find. In fact, the first ever detection of an event of this kind was only announced this month. 

Therefore, astrophysicists are basically toying with their instruments like you sometimes toy with your radio to find the right station, except they don’t know what station will give them the signal they’re looking for.
What Drasco has done in his simulation is estimate the frequency at which an event like this would produce and then see how that frequency changes, so astrophysicists have a better idea of how to fine tune their instruments to search for these waves.
Detecting gravitational waves would revolutionize the field of astronomy because it would give observers an entirely new way to see the universe. Armed with this new tool, they will be able to test general relativity in ways never before made possible.

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The Secret To A Meaningful Life In Just 7 ‘Magic’ Words

Excerpt from huffingtonpost.com Sometimes, it's the most fantastical, fictional characters that do the best job of teaching us about reality.New York Times bestselling author T.A. Barron spent decades creating the magical image of Merlin the wiza...

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8 Myths About Emotions That Are Holding Us Back

Excerpt from huffingtonpost.comAs a society, we don't talk much about emotions. Conversations tend to focus more on what we're doing or what we're thinking. In fact, most people find it easier to start sentences with, "I think..." instead of "I feel...

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Tombs Filled with Dozens of Mummies Discovered in Peru

A burial of a young woman found in the middle of a tomb. Analysis of her skeletal remains reveal that she suffered dental problems, including tooth loss. At one point in her life she suffered an internal hemorrhage in the meninges of her cranium. ...

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Why the U.S. Gave Up on the Moon

Moon nearside



Excerpt from spacenews.com


Recently, several space advocacy groups joined forces to form the Alliance for Space Development. Their published objectives include a mention of obvious near-term goals such as supporting the commercial crew program, transitioning from use of the International Space Station to future private space stations and finding ways to reduce the cost of access to space.  What is notably missing from these objectives and those of many other space agencies, companies and advocacy groups is any mention of building a permanent settlement on the moon. It’s as if the lunar surface has become our crazy uncle that we all acknowledge exists but we’d prefer not to mention (or visit).  What made the next logical step in mankind’s progression beyond the bounds of Earth such a taboo subject?  If, as the Alliance for Space Development suggests, our nation wishes to move toward a path of permanent space settlements, the most logical step is our own planet’s satellite.

Lunar base conception
A 2006 NASA conception of a lunar base. Credit: NASA


A base on the lunar surface is a better place to study space settlement than a space station or Mars for many reasons. Unlike a space station, the base does not have to contend with aerodynamic drag, attitude control issues or contamination and impingement from its own thrusters. Unlike a space station, which exists in a total vacuum and resource void, a lunar base has access to at least some surface resources in the forms of minerals, albeit fewer than might be available on Mars.  Many people naturally want to go directly to Mars as our next step. Even SpaceX has publicly stated this as its ultimate goal, with SpaceX President Gwynne Shotwell noting that “we’re not moon people.” However, Mars makes sense only if we think the technology is ready to safely support humans on another surface for long periods of time. Furthermore, budget restrictions make an ambitious goal like going immediately to Mars an unlikely prospect. Why are we afraid to take the seemingly necessary baby steps of developing the technology for a long-term base on a surface that can be reached in mere days instead of months?  The tendency to want to skip a lunar settlement is not a new phenomenon. Even before the first landing on the moon, U.S. and NASA political leadership was contemplating the future of manned space, and few of the visions involved a lunar base. The early space program was driven by Cold War competition with Moscow, and the kinds of ideas that circulated at the time involved milestones that seemed novel such as reusable spaceplanes, nuclear-powered rockets, space stations and missions to Mars. 

When the United States was on the verge of a series of landings on the moon, building a permanent base just didn’t seem like much of a new giant leap. NASA's ConstellationNASA’s Constellation program, featuring the Orion manned capsule set atop the Ares 1 launch vehicle, was meant to send astronauts back to the moon. Credit: NASA  The idea of a lunar landing mission was not reintroduced seriously until the George W. Bush administration and the introduction of the Constellation program. This program came at a complex time for NASA: The space shuttle was recovering from the Columbia disaster, the space station was in the midst of construction and the United States found itself with large budget deficits. However, despite its budgetary and schedule problems, which are common in any serious aerospace development project from space programs to jumbo-jet development, it provided NASA with a vision and a goal that were reasonable and sensible as next steps toward a long-term future of exploration beyond Earth. 

Constellation was nevertheless canceled, and we have since returned to a most uncommon sense.  The decision to avoid any sort of lunar activity in current space policy may have been biased by the Obama administration’s desire to move as far away as possible from the policies of the previous administration. 

Regardless of the cause, discussion of returning to the moon is no longer on the table.  Without the moon, the only feasible mission that NASA could come up with that is within reach given the current technology and budget is the Asteroid Redirect Mission.  
Even planetary scientists have spoken out against the mission, finding that it will provide little scientific value. It will also provide limited engineering and technology value, if we assume that our long-term goal is to permanently settle space. The experience gained from this sort of flight has little applicability to planetary resource utilization, long-term life support or other technologies needed for settlement.  

If we are to have a program of manned space exploration, we must decide what the long-term goals of such a program should be, and we should align our actions with those goals. When resources such as funding are limited, space agencies and political leaders should not squander these limited resources on missions that make no sense. Instead, the limited funding should be used to continue toward our long-term goals, accepting a slower pace or slight scale-back in mission scope.  Establishing a permanent human settlement in space is a noble goal, one that will eventually redefine humanity. Like explorers before us, it is also not a goal that will be achieved in a short period of time. We would be wise to keep our eyes on that goal and the road needed to get us there. And the next likely stop on that road is a permanent home just above our heads, on the surface of the brightest light in the night sky.  

Paul Brower is an aerospace systems engineer on the operations team for the O3b Networks satellite fleet. He previously worked in mission control at NASA for 10 years.
Recently, several space advocacy groups joined forces to form the Alliance for Space Development. Their published objectives include a mention of obvious near-term goals such as supporting the commercial crew program, transitioning from use of the International Space Station to future private space stations and finding ways to reduce the cost of access to space.
What is notably missing from these objectives and those of many other space agencies, companies and advocacy groups is any mention of building a permanent settlement on the moon. It’s as if the lunar surface has become our crazy uncle that we all acknowledge exists but we’d prefer not to mention (or visit).
What made the next logical step in mankind’s progression beyond the bounds of Earth such a taboo subject?
If, as the Alliance for Space Development suggests, our nation wishes to move toward a path of permanent space settlements, the most logical step is our own planet’s satellite.
Lunar base conception
A 2006 NASA conception of a lunar base. Credit: NASA
A base on the lunar surface is a better place to study space settlement than a space station or Mars for many reasons. Unlike a space station, the base does not have to contend with aerodynamic drag, attitude control issues or contamination and impingement from its own thrusters. Unlike a space station, which exists in a total vacuum and resource void, a lunar base has access to at least some surface resources in the forms of minerals, albeit fewer than might be available on Mars.
Many people naturally want to go directly to Mars as our next step. Even SpaceX has publicly stated this as its ultimate goal, with SpaceX President Gwynne Shotwell noting that “we’re not moon people.” However, Mars makes sense only if we think the technology is ready to safely support humans on another surface for long periods of time. Furthermore, budget restrictions make an ambitious goal like going immediately to Mars an unlikely prospect. Why are we afraid to take the seemingly necessary baby steps of developing the technology for a long-term base on a surface that can be reached in mere days instead of months?
The tendency to want to skip a lunar settlement is not a new phenomenon. Even before the first landing on the moon, U.S. and NASA political leadership was contemplating the future of manned space, and few of the visions involved a lunar base. The early space program was driven by Cold War competition with Moscow, and the kinds of ideas that circulated at the time involved milestones that seemed novel such as reusable spaceplanes, nuclear-powered rockets, space stations and missions to Mars. When the United States was on the verge of a series of landings on the moon, building a permanent base just didn’t seem like much of a new giant leap.
NASA's Constellation
NASA’s Constellation program, featuring the Orion manned capsule set atop the Ares 1 launch vehicle, was meant to send astronauts back to the moon. Credit: NASA
The idea of a lunar landing mission was not reintroduced seriously until the George W. Bush administration and the introduction of the Constellation program. This program came at a complex time for NASA: The space shuttle was recovering from the Columbia disaster, the space station was in the midst of construction and the United States found itself with large budget deficits. However, despite its budgetary and schedule problems, which are common in any serious aerospace development project from space programs to jumbo-jet development, it provided NASA with a vision and a goal that were reasonable and sensible as next steps toward a long-term future of exploration beyond Earth.
Constellation was nevertheless canceled, and we have since returned to a most uncommon sense.
The decision to avoid any sort of lunar activity in current space policy may have been biased by the Obama administration’s desire to move as far away as possible from the policies of the previous administration. Regardless of the cause, discussion of returning to the moon is no longer on the table.
Without the moon, the only feasible mission that NASA could come up with that is within reach given the current technology and budget is the Asteroid Redirect Mission.
Even planetary scientists have spoken out against the mission, finding that it will provide little scientific value. It will also provide limited engineering and technology value, if we assume that our long-term goal is to permanently settle space. The experience gained from this sort of flight has little applicability to planetary resource utilization, long-term life support or other technologies needed for settlement.
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If we are to have a program of manned space exploration, we must decide what the long-term goals of such a program should be, and we should align our actions with those goals. When resources such as funding are limited, space agencies and political leaders should not squander these limited resources on missions that make no sense. Instead, the limited funding should be used to continue toward our long-term goals, accepting a slower pace or slight scale-back in mission scope.
Establishing a permanent human settlement in space is a noble goal, one that will eventually redefine humanity. Like explorers before us, it is also not a goal that will be achieved in a short period of time. We would be wise to keep our eyes on that goal and the road needed to get us there. And the next likely stop on that road is a permanent home just above our heads, on the surface of the brightest light in the night sky.

Paul Brower is an aerospace systems engineer on the operations team for the O3b Networks satellite fleet. He previously worked in mission control at NASA for 10 years.
- See more at: http://spacenews.com/op-ed-why-the-u-s-gave-up-on-the-moon/#sthash.czfTscvg.dpuf

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How Quantum Physics will change your life and amaze the world!

 Excerpt from educatinghumanity.com "Anyone not shocked by quantum mechanics has not yet understood it."Niels Bohr10 Ways Quantum Physics Will Change the WorldEver want to have a "life do over", teleport, time travel, have your computer wor...

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Is Titan submarine the most daring space mission yet?

The submersible could extract cores from the seabed to unlock a rich climatic historyExcerpt from bbc.comDropping a robotic lander on to the surface of a comet was arguably one of the most audacious space achievements of recent times. But one...

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This Alien Color Catalog May Help Us Spot Life on Other Planets






Excerpt from smithsonianmag.com


In the hunt for alien life, our first glimpse of extraterrestrials may be in the rainbow of colors seen coming from the surface of an exoplanet.

That's the deceptively simple idea behind a study led by Siddharth Hegde at the Max Planck Institute for Astronomy in Germany. Seen from light-years away, plants on Earth give our planet a distinctive hue in the near-infrared, a phenomenon called red edge. That's because the chlorophyll in plants absorbs most visible light waves but starts to become transparent to wavelengths on the redder end of the spectrum. An extraterrestrial looking at Earth through a telescope could match this reflected color with the presence of oxygen in our atmosphere and conclude there is life here.


exoplanets palette
Eight of the 137 microorganism samples used to measure biosignatures for the catalog of reflection signatures of Earth life forms. In each panel, the top is a regular photograph of the sample and the bottom is a micrograph, a version of the top image zoomed-in 400 times.



Plants, though, have only been around for 500 million years—a relative blip in our planet's 4.6-billion-year history. Microbes dominated the scene for some 2.5 billion years in the past, and some studies suggest they will rule the Earth again for much of its future. So Hegde and his team gathered 137 species of microorganisms that all have different pigments and that reflect light in specific ways. By building up a library of the microbes' reflectance spectra—the types of colors those microscopic critters reflect from a distance—scientists examining the light from habitable exoplanets can have a plethora of possible signals to search for, the team argues this week in the Proceedings of the National Academy of Sciences.

"No one had looked at the wide range of diverse life on Earth and asked how we could potentially spot such life on other planets, and include life from extreme environments on Earth that could be the 'norm' on other planets," Lisa Kaltenegger, a co-author on the study, says via email. "You can use it to model an Earth that is different and has different widespread biota and look how it would appear to our telescopes."

To make sure they got enough diversity, the researchers looked at temperate-dwelling microbes as well as creatures that live in extreme environments like deserts, mineral springs, hydrothermal vents or volcanically active areas.

While it might seem that alien life could take a huge variety of forms—for instance, something like the silicon-based Horta from Star Trek—it's possible to narrow things down if we restrict the search to life as we know it. First, any life-form that is carbon-based and uses water as a solvent isn't going to like the short wavelengths of light far in the ultraviolet, because this high-energy UV can damage organic molecules. At the other end of the spectrum, any molecule that alien plants (or their analogues) use to photosynthesize won't be picking up light that's too far into the infrared, because there's not enough energy at those longer wavelengths.

In addition, far-infrared light is hard to see through an Earth-like atmosphere because the gases block a lot of these waves, and whatever heat the planet emits will drown out any signal from surface life. That means the researchers restricted their library to the reflected colors we can see when looking at wavelengths in the visible part of the spectrum, the longest wavelength UV and short-wave infrared.

The library won't be much use if we can't see the planets' surfaces in the first place, and that's where the next generation of telescopes comes in, Kaltenegger says. The James Webb Space Telescope, scheduled for launch in 2018, should be able to see the spectra of relatively small exoplanet atmospheres and help scientists work out their chemical compositions, but it won't be able to see any reflected spectra from material at the surface. Luckily, there are other planned telescopes that should be able to do the job. The European Extremely Large Telescope, a 40-meter instrument in Chile, will be complete by 2022. And NASA's Wide Field Infrared Survey Telescope, which is funded and in its design stages, should be up and running by the mid-2020s.

Another issue is whether natural geologic or chemical processes could look like life and create a false signal. So far the pigments from life-forms look a lot different from those reflected by minerals, but the team hasn't examined all the possibilities either, says Kaltenegger. They hope to do more testing in the future as they build up the digital library, which is now online and free for anyone to explore at biosignatures.astro.cornell.edu.

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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.

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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.

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What happens to your body when you give up sugar?





Excerpt from independent.co.uk
By Jordan Gaines Lewis


In neuroscience, food is something we call a “natural reward.” In order for us to survive as a species, things like eating, having sex and nurturing others must be pleasurable to the brain so that these behaviours are reinforced and repeated.
Evolution has resulted in the mesolimbic pathway, a brain system that deciphers these natural rewards for us. When we do something pleasurable, a bundle of neurons called the ventral tegmental area uses the neurotransmitter dopamine to signal to a part of the brain called the nucleus accumbens. The connection between the nucleus accumbens and our prefrontal cortex dictates our motor movement, such as deciding whether or not to taking another bite of that delicious chocolate cake. The prefrontal cortex also activates hormones that tell our body: “Hey, this cake is really good. And I’m going to remember that for the future.”
Not all foods are equally rewarding, of course. Most of us prefer sweets over sour and bitter foods because, evolutionarily, our mesolimbic pathway reinforces that sweet things provide a healthy source of carbohydrates for our bodies. When our ancestors went scavenging for berries, for example, sour meant “not yet ripe,” while bitter meant “alert – poison!”
Fruit is one thing, but modern diets have taken on a life of their own. A decade ago, it was estimated that the average American consumed 22 teaspoons of added sugar per day, amounting to an extra 350 calories; it may well have risen since then. A few months ago, one expert suggested that the average Briton consumes 238 teaspoons of sugar each week.
Today, with convenience more important than ever in our food selections, it’s almost impossible to come across processed and prepared foods that don’t have added sugars for flavour, preservation, or both.
These added sugars are sneaky – and unbeknown to many of us, we’ve become hooked. In ways that drugs of abuse – such as nicotine, cocaine and heroin – hijack the brain’s reward pathway and make users dependent, increasing neuro-chemical and behavioural evidence suggests that sugar is addictive in the same way, too.

Sugar addiction is real

Anyone who knows me also knows that I have a huge sweet tooth. I always have. My friend and fellow graduate student Andrew is equally afflicted, and living in Hershey, Pennsylvania – the “Chocolate Capital of the World” – doesn’t help either of us. But Andrew is braver than I am. Last year, he gave up sweets for Lent. “The first few days are a little rough,” Andrew told me. “It almost feels like you’re detoxing from drugs. I found myself eating a lot of carbs to compensate for the lack of sugar.”
There are four major components of addiction: bingeing, withdrawal, craving, and cross-sensitisation (the notion that one addictive substance predisposes someone to becoming addicted to another). All of these components have been observed in animal models of addiction – for sugar, as well as drugs of abuse.
A typical experiment goes like this: rats are deprived of food for 12 hours each day, then given 12 hours of access to a sugary solution and regular chow. After a month of following this daily pattern, rats display behaviours similar to those on drugs of abuse. They’ll binge on the sugar solution in a short period of time, much more than their regular food. They also show signs of anxiety and depression during the food deprivation period. Many sugar-treated rats who are later exposed to drugs, such as cocaine and opiates, demonstrate dependent behaviours towards the drugs compared to rats who did not consume sugar beforehand.
Like drugs, sugar spikes dopamine release in the nucleus accumbens. Over the long term, regular sugar consumption actually changes the gene expression and availability of dopamine receptors in both the midbrain and frontal cortex. Specifically, sugar increases the concentration of a type of excitatory receptor called D1, but decreases another receptor type called D2, which is inhibitory. Regular sugar consumption also inhibits the action of the dopamine transporter, a protein which pumps dopamine out of the synapse and back into the neuron after firing.
In short, this means that repeated access to sugar over time leads to prolonged dopamine signalling, greater excitation of the brain’s reward pathways and a need for even more sugar to activate all of the midbrain dopamine receptors like before. The brain becomes tolerant to sugar – and more is needed to attain the same “sugar high.”

Sugar withdrawal is also real

Although these studies were conducted in rodents, it’s not far-fetched to say that the same primitive processes are occurring in the human brain, too. “The cravings never stopped, [but that was] probably psychological,” Andrew told me. “But it got easier after the first week or so.”
In a 2002 study by Carlo Colantuoni and colleagues of Princeton University, rats who had undergone a typical sugar dependence protocol then underwent “sugar withdrawal.” This was facilitated by either food deprivation or treatment with naloxone, a drug used for treating opiate addiction which binds to receptors in the brain’s reward system. Both withdrawal methods led to physical problems, including teeth chattering, paw tremors, and head shaking. Naloxone treatment also appeared to make the rats more anxious, as they spent less time on an elevated apparatus that lacked walls on either side.
Similar withdrawal experiments by others also report behaviour similar to depression in tasks such as the forced swim test. Rats in sugar withdrawal are more likely to show passive behaviours (like floating) than active behaviours (like trying to escape) when placed in water, suggesting feelings of helplessness.
A new study published by Victor Mangabeira and colleagues in this month’s Physiology & Behavior reports that sugar withdrawal is also linked to impulsive behaviour. Initially, rats were trained to receive water by pushing a lever. After training, the animals returned to their home cages and had access to a sugar solution and water, or just water alone. After 30 days, when rats were again given the opportunity to press a lever for water, those who had become dependent on sugar pressed the lever significantly more times than control animals, suggesting impulsive behaviour.
These are extreme experiments, of course. We humans aren’t depriving ourselves of food for 12 hours and then allowing ourselves to binge on soda and doughnuts at the end of the day. But these rodent studies certainly give us insight into the neuro-chemical underpinnings of sugar dependence, withdrawal, and behaviour.
Through decades of diet programmes and best-selling books, we’ve toyed with the notion of “sugar addiction” for a long time. There are accounts of those in “sugar withdrawal” describing food cravings, which can trigger relapse and impulsive eating. There are also countless articles and books about the boundless energy and new-found happiness in those who have sworn off sugar for good. But despite the ubiquity of sugar in our diets, the notion of sugar addiction is still a rather taboo topic.
Are you still motivated to give up sugar? You might wonder how long it will take until you’re free of cravings and side-effects, but there’s no answer – everyone is different and no human studies have been done on this. But after 40 days, it’s clear that Andrew had overcome the worst, likely even reversing some of his altered dopamine signalling. “I remember eating my first sweet and thinking it was too sweet,” he said. “I had to rebuild my tolerance.”
And as regulars of a local bakery in Hershey – I can assure you, readers, that he has done just that.
Jordan Gaines Lewis is a Neuroscience Doctoral Candidate at Penn State College of Medicine

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