Science News- Faster Than Light; UARS Satellite Update; Move Over, "Total Recall"

Beam me up, Scotty!


"Faster than light" particles may be physics revolution

(Reuters) - Scientists around the world said on Friday the discovery of sub-atomic particles apparently traveling faster than light could force a major rethink of theories on the makeup of the cosmos, but the findings would first have to be independently confirmed.

"Extraordinary claims require extraordinary evidence, and this is an extraordinary claim," eminent cosmologist and astrophysicist Martin Rees told Reuters.

The CERN research institute near Geneva said measurements over three years had shown neutrinos pumped to a receiver in Gran Sasso, Italy, had arrived 60 nanoseconds sooner than light would have done -- a tiny difference that could nonetheless undermine Albert Einstein's 1905 special theory of relativity.

"It is premature to comment on this," Professor Stephen Hawking, the world's most well-known physicist, told Reuters. "Further experiments and clarifications are needed."

Professor Jenny Thomas, who works on neutrinos at CERN's friendly rival Fermilab near Chicago in the United States, commented: "The impact of this measurement, were it to be correct, would be huge."
Professor Geoffrey Hall of London's Imperial College, who has worked with CERN, said the

implications of the results were profound, possibly challenging "a fundamental part of our science culture."
CERN's own research director Sergio Bertolucci said if the findings were confirmed -- and at least two separate laboratories are likely to start work on this in the near future -- "it might change our view of physics."

The high level of caution is normal in science where anything that could be a breakthrough discovery, especially overturning well-established thinking, is in principle always checked and rechecked by other researchers.

The discovery would force a rethink of fundamental theories of physics and of the nature of the universe. It would herald a revolution in physics comparable to that caused by Einstein's publication of his Special Theory of Relativity.

In a comment issued by CERN, the world's leading laboratory for particle research on the edge of Geneva, Bertolucci underscored this principle.

"When an experiment finds an apparently unbelievable result and can find no artefact of the measurement to account for it, it is normal to invite broader scrutiny....it is good scientific practice," he said.

The experiment, whose measurements were posted on the scientific website arxiv.org/abs/1109.4897 overnight, found the long enigmatic neutrinos consistently traveling at an average of 60 nanoseconds faster than light.

GHOST PARTICLES

The team, working in an experiment dubbed OPERA, pumped neutrinos -- often called ghost particles because they pass through matter, and human bodies, unnoticed -- from CERN 730 kms (500 miles) to Gran Sasso south of Rome.

Over three years, and from 15,000 neutrino "events," a huge detector at the Italian center deep under mountain rock recorded what OPERA spokesman Antonio Ereditato described as the "startling" findings.
He said his team had high confidence they had measured correctly and excluded any possibility of some outside influence, or artefact, affecting the outcome. "My dream is now that other colleagues find we are right," he added.

In Einstein's Special Theory of Relativity, which underpins the current view of how the universe works, nothing can travel faster than light -- 300,000 kms, or 186,000 miles, per second -- because its mass would become impossibly infinite.

Einstein's theory has been tested thousands of times over the past 106 years and only recently have there been just slight hints that the behavior of some elementary particles of matter might not fit into it.

These hints were detected last year in Fermilab's MINOS experiment with neutrinos, but -- unlike those of OPERA -- were found to be within a normal margin of error.

Fermilab's Thomas, who is likely to be involved in MINOS experiments to check the CERN-Gran Sasso measurements, said if they were correct "it would overturn everything we thought we understood about relativity and the speed of light."

Ereditato, a physicist who also works at the Einstein Institute in the University of Berne, said the potential impact on science "is too large to draw any immediate conclusions or attempt physics interpretations."

SURPRISING WITH MYSTERIES

Also declining to claim a genuine scientific discovery before other researchers had confirmed them, he said the neutrino, whose existence was first confirmed in 1934, "is still surprising us with its mysteries."

Scientific bloggers on the Internet said the particle might be slipping into and out of dimensions, other than the known four of length, breadth, depth and time, as predicted by the controversial "string theory" of how the cosmos works.

The OPERA team is due to formally present its findings to the scientific community later on Friday at CERN, home to the Large Hadron Collider, or LHC, which is smashing particles together in research on how the universe began.

Source

[Note: Warp Speed, anyone?]

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You may not have to duck after all.

UARS satellite return expected later

(BBC News)- US officials now say the fall to Earth of Nasa's six-tonne UARS satellite could occur early on Saturday (GMT).

Estimates of where debris might fall will be narrowed hours before impact.

And a UK team studying the trajectory says the most likely time for re-entry could be after 23:00 GMT Friday, and as late as 03:00 GMT on Saturday.

Most of the decommissioned and now unpowered spacecraft should simply burn up, but modelling work suggests perhaps 500kg could survive to the surface.

UARS is the largest American space agency satellite to return uncontrolled into the atmosphere in about 30 years.

As of 15:30 GMT on Friday, the satellite was orbiting at an altitude between 160km and 170km (100 miles by 105 miles).

If the estimates for its re-entry are correct, it means the spacecraft will not come in over North America.

"The spacecraft orbits the Earth in 90 minutes, so even if we're off by a few minutes in the prediction - that's thousands of kilometres down range," said Mark Matney, an orbital debris scientist from Nasa's Johnson Space Center.

"We'll be able to know generally a few hours before, but we'll only get a final report after it re-enters. Even then, we won't know where the pieces fall because they'll be scattered over a 500-mile path," he told BBC News.

The Upper Atmosphere Research Satellite (UARS) will start to tumble rapidly when it engages the top of the atmosphere, about 80km up.

Mechanical forces will rip off less robust structures such as the solar array and antennas.

The heating that the satellite then experiences as it plunges deeper into the atmosphere will start to deform and melt low-temperature materials and then vaporise them.

Components expected to survive are made from high-temperature metals such as stainless steel, titanium and beryllium.

Some 26 items have been suggested as impactors. The largest is one of UARS' instrument tables and weighs over 150kg.
With more than 70% of the Earth's surface covered by water, the chances are that any debris will fall into the ocean.

But if the re-entry does occur over populated areas of land, it should make for a spectacular streak across the sky, even in daylight.

The British Kettering Group of amateur satellite observers has been running predictions based on orbital data released by US authorities.

The group's latest estimates put a re-entry somewhere between 23:00 GMT and 15:00 GMT (00:00-16:00 BST).

"Statistically speaking, the most likely epitaph for the satellite is UARS R.I.P. (Remains In Pacific)," said group member Dr Stuart Eves.

"But there is still a chance that observers in the UK with clear skies could be treated to a 'fireball' display moving generally from north-west to south-east across the sky."

The UARS satellite was deployed in 1991 from the space shuttle Discovery on a mission to study the Earth's upper atmosphere.

It contributed important new understanding on subjects such as the chemistry of the protective ozone layer and the cooling effect volcanoes can exert on the global climate.

Liability question
 
Nasa has warned members of the public not to touch any pieces of the spacecraft that may survive the re-entry, urging them to contact local law enforcement authorities.

"I've seen some things that have re-entered and they tend to have sharp edges, so there's a little concern that they might hurt themselves if they try to pick them up," said Dr Matney.

Experts have calculated the probability of anyone anywhere on Earth being injured by a falling UARS component as 1 in 3,200.

Under the terms of the Outer Space Treaty of 1967, the US government retains ownership of the debris and could, if it so wished, seek to take possession of any items found on the ground.

With those ownership rights also comes absolute liability if a piece of UARS were to damage property or injure someone.

"There is something called international responsibility; they're internationally liable," explained Joanne Wheeler of law firm CMS Cameron McKenna, and an expert representative for the UK on the UN Subcommittee for the Peaceful Uses of Outer Space.

"The Americans have to retain jurisdiction and control, and that pretty much can be interpreted as ownership. So they own it up there, they own it if it comes down to Earth and they're liable if it crashes into something."
Tracking stations will typically witness the uncontrolled return of at least one piece of space debris every day; and on average, one intact defunct spacecraft or old rocket body will come back into the atmosphere every week.

Something the size of UARS is seen perhaps once a year. Much larger objects such as space station cargo ships return from orbit several times a year, but they are equipped with thrusters capable of guiding their dive into a remote part of the Southern Ocean.

• UARS orbits the Earth between 57 degrees North and South
• Nasa calculates some 26 components may survive the fall to Earth
• The largest is a moveable instrument platform weighing almost 160kg
• In total, about half a tonne may make it all the way to the surface
• The risk of any one of 7bn people being hit is 1 in 3,200, Nasa says
  
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"Total Recall" not so far fetched?

Scientists Can (Almost) Read Your Mind, Turn Thoughts into Movies

(Techland.Time.com)- Mind, prepare to be blown—and scanned, by a device that can almost read thoughts, or at least digitize them into almost-identifiable images. No, it's not some artsy video project, it's for real: a system developed by University of California Berkeley scientists to capture visual activity in our brains and reassemble it as recognizable video data.

It sounds like science fiction, but it's not, and according to the scientists, it represents a "critical" step toward reconstructing everything from what we're thinking while awake to what's happening as we dream.

(MORE: Want to Scan Your Brain? There's an App for That!)

That's a video of the process up top. A test subject is undergoing an MRI while watching random video clips from Hollywood movies. On the left side, you see clips from what the subject viewed. On the right, you see the fMRI results of "quantitative modeling" using "a new motion-energy encoding model," essentially a matchup of brain activity with the viewed images. As you can see, at worst, it's capable of reconstructing what was viewed in terms of the video image's elemental geometry, e.g. broad shapes, lights and darks, etc. And at best, you can make out identifiable human forms and even vague facial features. (Interestingly, the human-related images seem the least abstruse, which, perhaps—wild speculation on my part here—says something about species-related bias in our recognition patterns.)

Here's the research team's "intuitive" description of the process:

As you move through the world or you watch a movie, a dynamic, ever-changing pattern of activity is evoked in the brain. The goal of movie reconstruction is to use the evoked activity to recreate the movie you observed. To do this, we create encoding models that describe how movies are transformed into brain activity, and then we use those models to decode brain activity and reconstruct the stimulus. 

"This is a major leap toward reconstructing internal imagery," said U.C. Berkeley neuroscientist Jack Gallant, a coauthor of the study published yesterday in the journal Current Biology (via U.C. Berkeley News Center). "We are opening a window into the movies in our minds."

How'd they do it? Volunteers remained still within the MRI scanner for several hours and watched two sets of Hollywood movie trailers. Blood flow through the visual cortex was measured and their brains divided into tiny three-dimensional cubes (no, not literally—on the computer!) called volumetric pixels...or as I first heard them described in gaming parlance decades ago, "voxels" (remember the Comanche attack helicopter series?).

Researchers created a computer model that describes how visual information translates as brain activity, then applied it to each "brain voxel." As volunteers watched the first set of movie clips, their brain activity was processed by the computer to "learn" to associate visual patterns in the clips with corresponding brain activity. 

Brain activity from viewing the second set of clips was then used to test the computer's reconstruction algorithm—the computer used 18 million seconds (5,000 hours) of random YouTube videos that didn't include the movies viewed by the test subjects to build a kind of "reference library," correlating the brain imagery with video clip imagery.

In the final step, the computer selected the 100 clips that were most like the ones the subjects had watched and combined them to form the movie you see above (the right-side feed)—an indirect way of going about it, to be sure, but astonishing for what it accomplishes.

We're probably a ways from science fiction movies like Strange Days, where "Superconducting Quantum Interference Devices" record events direct from a wearer's cerebral cortex and can translate them to others as if they were experiencing the same events firsthand—but with results like these, where computers can "learn" to accurately relate what was seen with how the brain recorded it, we're definitely getting closer.

Read more

[Note: Oh, now that is just scary! -SW]

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