Researchers in the US claim to have overturned our understanding of the way in which the visual process is initiated by light entering the eye. They suggest that the initial trigger is provided by electrical processes rather than structural changes in the retina, as has been believed for the past 50 years. The work was carried out by a team led by Kenneth Foster at Syracuse University in the US.

It is long established that the first stage in vision is when light arrives at the retina at the back of the eye and individual photons are absorbed by photoreceptor molecules. Biophysicists have noted that this absorption causes parts of these molecules known as chromophores to change shape. It was believed that this process, in turn, electrically polarizes the chromophores, thereby establishing an electric field that triggers further molecular chemical processes that result in a signal being sent to the brain.

But Foster and his colleagues had their doubts about this explanation and they wanted to determine whether this shape-changing - a process known as isomerization - is in fact the first process in vision. So, the researchers set out to suppress the chromophores to prevent them from changing shape to see what effect this had.

Ann Arbor, Michigan - Physicists and astronomers have long believed that the universe has mirror symmetry, like a basketball. But recent findings from the University of Michigan suggest that the shape of the Big Bang might be more complicated than previously thought, and that the early universe spun on an axis.

To test for the assumed mirror symmetry, physics professor Michael Longo and a team of five undergraduates catalogued the rotation direction of tens of thousands of spiral galaxies photographed in the Sloan Digital Sky Survey.

The mirror image of a counter-clockwise rotating galaxy would have clockwise rotation. More of one type than the other would be evidence for a breakdown of symmetry, or, in physics speak, a parity violation on cosmic scales, Longo said.

The researchers found evidence that galaxies tend to rotate in a preferred direction. They uncovered an excess of left-handed, or counter-clockwise rotating, spirals in the part of the sky toward the north pole of the Milky Way. The effect extended beyond 600 million light years away.

A study by USDA scientists finds that raising cows on grass, instead of in factory farms, produces fewer greenhouse-gas emissions and other pollutants.

Perhaps a study conducted by the U.S. Department of Agriculture (USDA), entitled "Putting Dairy Cows Out to Pasture - An Environmental Plus," won't put an end to the controversy over whether cows raised outdoors on grass are better for the environment than cows raised on grain in confinement. But the USDA's findings on the matter are all the more remarkable considering that it's only in recent years that the agency has acknowledged there's a type of agriculture besides industrial agriculture, and it's called sustainable.

The Details

Unknown to most of the general public, there have, in fact, been Ag Dept scientists toiling away at experiments that confirm the value of sustainable agriculture, producing reports like "Pecan Growers Boost Revenue by Growing Organically," and "Organic Cover Crops: More Seeds Means Fewer Weeds."

Still, the research conducted about dairy cows may be the USDA's most controversial yet. In fact, both sides continue to argue about which method of raising cattle is better for the environment.

C. Alan Rotz, PhD, an agricultural engineer for the USDA's Agricultural Research Service at University Park, Pennsylvania, and an adjunct professor at Penn State, was the lead researcher for the dairy cows study. And he says he is "tired of all the criticism" about cows raised on pasture. "There's a place for grass-fed cows. There's nothing wrong with grass-based systems, and from an environmental point of view there are a lot of benefits," he says.

According to the USDA's Agricultural Research magazine for May/June 2011, Rotz's peer-reviewed study, first published in a research journal in 2009, concludes that "a dairy cow living year-round in the great outdoors may leave a markedly smaller ecological hoofprint than her more sheltered sisters."

On Tuesday, July 12, 2011, the planet Neptune completes its first revolution around the sun since its discovery on September 23, 1846. Neptune finally reaches this milestone at 22:27 Universal Time today. It takes Neptune 164.79 Earth-years to go full circle through the constellations of the Zodiac, whereas the Earth goes full circle in just 365.256 days.

Neptune, the 8th planet outward from the sun, is presently the most distant planet in the solar system. That's because the International Astronomical Union reclassified Pluto as a "dwarf planet" in 2006. By the way, Neptune circles the sun three times for every two times that Pluto does.

You can see Neptune with good binoculars or a telescope, but you need to know right where to look. At this time of year, you have to stay up late or wake up early to see this world. Moreover, you'll probably need a detailed sky chart to find Neptune's place in the sky.

There's nothing triangular about the Mount Teide volcano. From its base, it's the third largest volcano in the world but is pretty flat on top. So why does its shadow look like a perfect ghost pyramid rising over the horizon?

The answer is very simple: Perspective. This amazing photo was taken by Juan Carlos Casado from the top of the Teide. From his point of view, the perspective accentuates the shape of the volcano's shadow as it's projected by the Sun onto the sea, converting it into a triangle:

A key reason for the strange dark shape is that the observer is looking down the long corridor of a sunset (or sunrise) shadow that extends to the horizon. Even if the huge volcano was a perfect cube and the resulting shadow was a long rectangular box, that box would appear to taper off at its top as its shadow extended far into the distance, just as parallel train tracks do.

For decades, the mystery behind "hole punch" clouds have puzzled scientists and on-lookers as they continue to witness giant, open spaces in otherwise continuous cloud cover.

However, a new research paper published recently in the journal Science has revealed that the main culprit behind this unusual phenomenon is airplane.

"It appears to be a rather widespread effect for aircraft to inadvertently cause some measureable amount of rain or snow as they fly through certain clouds," stated lead author Andrew Heymsfield of the National Center for Atmospheric Research, Boulder, Co. "This is not necessarily enough precipitation to affect global climate, but it is likely to be noticeable around major airports in the midlatitudes."

Many reports in the past have even connected this phenomenon with UFOs and rocket launches. But, no one has been able to shed substantial light on the "mechanism of formation the physics of the development, duration."

Besides describing the physics of how planes form the holes in specific cloud types, the Science paper also looks at this "inadvertent" cloud seeding. The authors suggest that the effect is not large enough to have an impact on global climate, but that "regionally near major airports in midlatitudes during cool weather months it may lead to enhanced precipitation at the ground."

The research was partly funded by NASA grants and NASA Langley Research Center cloud specialist Patrick Minnis was one of the co-authors on the paper.

Check out the amazing 'Hole Punch' clouds visuals released by NASA below:

It's not known how many comets orbit the Sun in our solar system, but the number may be in the trillions. They spend a long, long time in the deep reaches of the outer solar system, only occasionally plunging toward us. If they pass near a planet their orbit can be changed, and some wind up on paths that take them so close to the Sun they burn up. These are called sungrazers.

That is what NASA's Solar Dynamic Observatory saw on the evening of July 5/6, 2011. This has been seen many times before, but this is the first time one has been seen streaking directly across the Sun's face!

Although it is known that a supernova, the violent explosion of a star, is one source of cosmic dust, the origin of the large amounts of dust needed to form planets and stars like the Sun has long been unclear.

Now, with the aid of the European Space Association's powerful Herschel Space Observatory, astronomers have been able to detect massive amounts of cosmic dust emitted from a supernova almost 25 years ago.

"We are looking at the sky at wavelengths that have never been observed before," said Mikako Matsuura, an astronomer at University College London and the study's lead author.

She and her colleagues report their findings in the journal Science.

It's been cleared to take to the skies for more than a year - but that's not much use when you're supposed to be able to drive it, too.

But now the flying car has at least been declared officially road legal.

It means the Terrafugia Transition could be in U.S. garages as early as next autumn, after two years of delays.

It may not be the world's first flying car, but its makers say it is the first to have wings that fold up automatically at the push of a button.

In a fresh blow to NASA's post-shuttle aspirations, key US lawmakers voted Thursday to kill off funding for the successor to the vastly successful space-gazing Hubble telescope.

The US House of Representatives Appropriations Subcommittee on Commerce, Justice, and Science approved by voice vote a yearly spending bill that includes no money for the James Webb Space Telescope (JWST).

The move -- spurred on by belt-tightening in cash-strapped Washington -- still requires the full committee's approval, the full House's approval, the Senate's approval, and ultimately President Barack Obama's signature.

But the relatively mild dissents in the committee, which said in a terse statement this week that the project "is billions of dollars over budget and plagued by poor management," suggests the JWST faces an uphill fight to survive.