Friday, September 23, 2011

CERN: Light Speed May Have Been Exceeded By Subatomic Particle

GENEVA — One of the very pillars of physics and Einstein's theory of relativity – that nothing can go faster than the speed of light – was rocked Thursday by new findings from one of the world's foremost laboratories.
European researchers said they clocked an oddball type of subatomic particle called a neutrino going faster than the 186,282 miles per second that has long been considered the cosmic speed limit.
The claim was met with skepticism, with one outside physicist calling it the equivalent of saying you have a flying carpet. In fact, the researchers themselves are not ready to proclaim a discovery and are asking other physicists to independently try to verify their findings.
"The feeling that most people have is this can't be right, this can't be real," said James Gillies, a spokesman for the European Organization for Nuclear Research, or CERN, which provided the particle accelerator that sent neutrinos on their breakneck 454-mile trip underground from Geneva to Italy.
Going faster than light is something that is just not supposed to happen according to Einstein's 1905 special theory of relativity – the one made famous by the equation E equals mc2. But no one is rushing out to rewrite the science books just yet.
It is "a revolutionary discovery if confirmed," said Indiana University theoretical physicist Alan Kostelecky, who has worked on this concept for a quarter of a century.
Stephen Parke, who is head theoretician at the Fermilab near Chicago and was not part of the research, said: "It's a shock. It's going to cause us problems, no doubt about that – if it's true."
Even if these results are confirmed, they won't change at all the way we live or the way the world works. After all, these particles have presumably been speed demons for billions of years. But the finding will fundamentally alter our understanding of how the universe operates, physicists said.
Einstein's special relativity theory, which says that energy equals mass times the speed of light squared, underlies "pretty much everything in modern physics," said John Ellis, a theoretical physicist at CERN who was not involved in the experiment. "It has worked perfectly up until now." France's National Institute for Nuclear and Particle Physics Research collaborated with Italy's Gran Sasso National Laboratory on the experiment at CERN.
CERN reported that a neutrino beam fired from a particle accelerator near Geneva to a lab 454 miles (730 kilometers) away in Italy traveled 60 nanoseconds faster than the speed of light. Scientists calculated the margin of error at just 10 nanoseconds. (A nanosecond is one-billionth of a second.)
Given the enormous implications of the find, the researchers spent months checking and rechecking their results to make sure there were no flaws in the experiment.
A team at Fermilab had similar faster-than-light results in 2007, but a large margin of error undercut its scientific significance.
If anything is going to throw a cosmic twist into Einstein's theories, it's not surprising that it's the strange particles known as neutrinos. These are odd slivers of an atom that have confounded physicists for about 80 years.
The neutrino has almost no mass, comes in three different "flavors," may have its own antiparticle and has been seen shifting from one flavor to another while shooting out from our sun, said physicist Phillip Schewe, communications director at the Joint Quantum Institute in Maryland.
Columbia University physicist Brian Greene, author of the book "Fabric of the Cosmos," said neutrinos theoretically can travel at different speeds depending on how much energy they have. And some mysterious particles whose existence is still only theorized could be similarly speedy, he said.
Fermilab team spokeswoman Jenny Thomas, a physics professor at the University College of London, said there must be a "more mundane explanation" for the European findings. She said Fermilab's experience showed how hard it is to measure accurately the distance, time and angles required for such a claim.
Nevertheless, Fermilab, which shoots neutrinos from Chicago to Minnesota, has already begun working to try to verify or knock down the new findings.
And that's exactly what the team in Geneva wants.
Gillies told The Associated Press that the readings have so astounded researchers that "they are inviting the broader physics community to look at what they've done and really scrutinize it in great detail, and ideally for someone elsewhere in the world to repeat the measurements."
Only two labs elsewhere in the world can try to replicate the work: Fermilab and a Japanese installation that has been slowed by the tsunami and earthquake. And Fermilab's measuring systems aren't nearly as precise as the Europeans' and won't be upgraded for a while, said Fermilab scientist Rob Plunkett.
Drew Baden, chairman of the physics department at the University of Maryland, said it is far more likely that the CERN findings are the result of measurement errors or some kind of fluke. Tracking neutrinos is very difficult, he said.
"This is ridiculous what they're putting out," Baden said. "Until this is verified by another group, it's flying carpets. It's cool, but ..."
So if the neutrinos are pulling this fast one on Einstein, how can it happen?
Parke said there could be a cosmic shortcut through another dimension – physics theory is full of unseen dimensions – that allows the neutrinos to beat the speed of light.
Indiana's Kostelecky theorizes that there are situations when the background is different in the universe, not perfectly symmetrical as Einstein says. Those changes in background may alter both the speed of light and the speed of neutrinos.
But that doesn't mean Einstein's theory is ready for the trash heap, he said.
"I don't think you're going to ever kill Einstein's theory. You can't. It works," Kostelecky said. There are just times when an additional explanation is needed, he said.
If the European findings are correct, "this would change the idea of how the universe is put together," Columbia's Greene said. But he added: "I would bet just about everything I hold dear that this won't hold up to scrutiny."

Ghostly Images of Satellite Falling to Earth

By J. DAVID GOODMAN
An amateur astronomer in France captured video of an American satellite as it tumbled through space toward an expected impact with Earth sometime on Friday, according to NASA’s latest projections.
The Frenchman, Thierry Legault, posted the footage to a personal Web site and said it had been shot last week from the northern town of Dunkerque using a specially modified telescope. The object, he said, was approximately 150 miles above ground.
The satellite, known as the Upper Atmosphere Research Satellite or U.A.R.S., appears as a ghostly white form, spreading and narrowing as it corkscrews down at an increasingly fast rate.

NASA puts the chance of this six-ton piece of defunct equipment hitting a human somewhere on the planet at 1 in 3,200, despite a trail of debris that will likely stretch to about 500 miles. As my colleague Kenneth Chang reported this week, there are no known cases of injury by falling satellite, not even from the much larger Skylab space station that plummeted out of orbit and into western Australia in 1979.
Despite the extremely long odds, NASA sought to reassure jittery Americans that there is nothing to worry about, noting early Thursday that their latest calculations do not include a collision with the United States.
#UARS update: Debris not expected to land in North America, based on latest predictions. http://t.co/jAvx87ogThu Sep 22 00:19:42 via web
Mr. Legault and his sky-watching partner, Emmanuel Rietsch, were the subject of a profile in Wired magazine earlier this year that marveled at their ability to capture American intelligence satellites that usually remain unseen.

Thursday, September 22, 2011

Huge Defunct Satellite Falling to Earth Faster Than Expected, NASA Says

An artist's concept of the Upper Atmosphere Research Satellite (UARS) satellite in space
An artist's concept of the Upper Atmosphere Research Satellite (UARS) satellite in space. The 6 1/2-ton satellite was deployed from space shuttle Discovery in 1991 and decommissioned in December 2005.



This story was updated at 3:30 p.m. ET.
NASA space junk experts have refined the forecast for the anticipated death plunge of a giant satellite, with the U.S. space agency now predicting the 6 1/2-ton climate probe will plummet to Earth around Sept. 23, a day earlier than previously reported.
The defunct bus-size spacecraft is NASA's Upper Atmospheric Research Satellite (UARS), which launched in 1991 and was shut down in 2005 after completing its mission. The satellite was expected to fall to Earth sometime this year, with experts initially pegging a weeks-long window between late September and early October, then narrowing it to the last week of this month.
That window, NASA now says, has been trimmed to just three days.
"Re-entry is expected Sept. 23, plus or minus a day. The re-entry of UARS is advancing because of a sharp increase in solar activity since the beginning of this week," NASA officials wrote in a status update today (Sept. 16). The projection is a day earlier than a previous forecast released by NASA yesterday.
NASA spokeswoman Beth Dickey confirmed with SPACE.com earlier today that the reason UARS is expected to fall early in its re-entry window is because of the sharp uptick in solar activity. Solar effects from the sun can create an extra drag on satellites in space because they can heat the Earth's atmosphere, causing it to expand, agency officials have said.

Where will UARS fall?
But exactly where the UARS spacecraft will fall is still unknown.
NASA expects at least 26 large pieces of the massive satellite to survive the scorching temperatures of re-entry and reach Earth's surface. Titanium pieces and onboard tanks could be among that debris, but the UARS satellite carries no toxic propellant (NASA used up all the fuel in 2005).
The debris is expected to fall over a swath of Earth about 500 miles (804 kilometers) long, NASA officials said. [Video: Where Could UARS Satellite Debris Fall?]
There is a 1-in-3,200 chance of satellite debris hitting a person on the ground, odds that NASA says are extremely remote. Outside experts agree.
"Look at how much of Earth is covered with water," Victoria Samson, the Washington Office Director of the Secure World Foundation, an organization dedicated to the peaceful use of outer space, told SPACE.com this week. "There's a really good chance it's going to go straight into the ocean."
The Upper Atmosphere Research Satellite is in the grasp of the remote manipulator system end effector above the payload bay of the Earth-orbiting Discovery during STS-48 pre-deployment checkout procedures.
The Upper Atmosphere Research Satellite is in the grasp of the remote manipulator system end effector above the payload bay of the Earth-orbiting Discovery during STS-48 pre-deployment checkout procedures.
Constant satellite watch
NASA officials expect the UARS satellite to fall over a region somewhere between the latitudes of northern Canada and southern South America, which leaves a vast swath of the world open as a possible re-entry point. About 75 percent of the Earth's surface is covered in water, which makes an ocean splashdown likely, NASA and experts have said.
NASA and the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., are keeping a close watch on the falling satellite, but will only be able to pinpoint its actual crash zone to within about 6,000 miles (10,000 km) about two hours before re-entry.
As of Thursday, the UARS satellite was flying in an orbit of between 143 and 158 miles (230 to 255 km) above Earth. That orbit is dropping lower each day, NASA officials said.
NASA has advised the public not to touch any debris that may reach the surface, should it be discovered. Instead, the space agency says that anyone who finds satellite debris should contact their local law enforcement agency.
The $750 million UARS mission was designed to measure ozone and other chemical compounds found in Earth's ozone layer in order to better understand how the upper atmosphere affects our planet. It also recorded wind speeds and temperatures in the stratosphere, as well as the energy Earth received from the sun.

Thursday, September 8, 2011

Dead NASA Satellite Will Soon Fall To Earth



NASA says the 20-year-old satellite will probably fall sometime between late September and October. Pieces of it could land anywhere in the six inhabited continents in a worldwide swath from south of Juneau, Alaska, to just north of the tip of South America. NASA scientists estimate a 1-in-3,200 chance a satellite part could hit someone. Most of it will burn up after entering Earth's atmosphere.
The 6-ton Upper Atmosphere Research Satellite (UARS) ran out of fuel in 2005 and will fall uncontrolled out of orbit. Only about 1,200 pounds of metal should survive, NASA said.
This satellite is far smaller than the 135-ton Russian space station Mir, which fell to Earth in 2001 or the 100-ton Skylab that fell in 1979. Mir fell into the South Pacific, while Skylab hit the Indian Ocean and parts of sparsely populated western Australia. Because two-thirds of the Earth is ocean, space debris usually hits water
"Things have been re-entering ever since the dawn of the Space Age; to date nobody has been injured by anything that's re-entered," said NASA orbital debris chief Gene Stansbery. "That doesn't mean we're not concerned."
NASA now has a rule that the chance of any of its satellites hitting someone has to be more than 1 in 10,000. But UARS, which measured chemicals in the air, was launched in 1991 before that rule was adopted. The agency usually tries to put dead satellites into "a graveyard orbit" or steer them down to the ocean, Stansbery said. But there was not enough fuel in this one to fire engines that would move it to a higher orbit or steer it down safely.
The 1-in-3,200 odds of being hit pertain to any of the nearly 7 billion people on Earth. But any one individual's odds of being struck are about 1 in 21 trillion.
Space debris bigger than 5 tons doesn't often fall to Earth. But this will be the third time this year for something that big to reach Earth, according to Jonathan McDowell, a Harvard University astrophysicist who tracks objects in orbit.
The UARS satellite travels over a large band of Earth, avoiding only areas close to the poles. NASA calculates that when the satellite does fall it will scatter pieces over a 500-mile-wide region.Stansbery said the agency doesn't know exactly when and where those will fall because it depends on the orientation of the satellite in the atmosphere, solar storm activity and other variables.
There probably is no hazardous material left in the falling pieces, but people should not touch any fallen satellite parts just in case, he said.
NASA will be tracking the satellite on a weekly and later daily basis until it falls.
NASA's UARS satellite re-entry tracking site: http://www.nasa.gov/mission_pages/uars/index.html