SpaceX "optimistic" after space capsule mishap

WASHINGTON: SpaceX said it was "optimistic" Friday after a thruster outage delayed the latest resupply mission of its unmanned Dragon capsule en route to the International Space Station.

SpaceX and NASA officials said the cargo resupply mission was still on track, but the technical mishap could fuel concerns about the US agency's ambitious plans to cut costs by privatizing elements of the space program.

SpaceX's billionaire founder Elon Musk said the failure of three out of four thruster pods to fire up was a "little frightening" but that two pods were back online within a few hours and the others should be working again shortly.

"I'm optimistic that we will be able to turn all four thruster pods on and restore full control," he told reporters.

Musk later tweeted: "Thruster pods one through four are now operating nominally. Preparing to raise orbit. All systems green."

SpaceX and NASA officials said once the pods are back online, they would carry out a number of checks before clearing the vessel to dock at the space station in the coming days, perhaps as early as Sunday.

The original rendezvous had been planned for 1130 GMT Saturday, but Mike Suffredini, NASA program manager for the International Space Station, said there was "quite a bit of flexibility" in the berthing date.

He also praised the handling of the mishap, saying "it was a pleasure to watch the SpaceX team in action" as they worked through "anomalies."

The malfunction occurred shortly after the capsule achieved orbit and separated from the Falcon 9 rocket after a near-perfect launch earlier in the day from Cape Canaveral, Florida.

Musk said it was unclear what caused the problem, but suggested a valve leading to the oxidation tanks may have been blocked.

"I don't think it's a major concern. This is the first time we've seen this type of issue," he said. "I think it's an anomaly."

The Dragon vehicle is carrying 1,200 pounds (544 kilograms) of supplies on the firm's second resupply mission to the ISS. The two missions were preceded by a nearly flawless test flight.

The first resupply mission in October was a milestone in US efforts to cut costs by privatizing space exploration. The current mission is the second of 12 planned trips in NASA's $1.6 billion contract with SpaceX.

"This unique vehicle has become a very integral part of how we operate and use the space station," Suffredini said on Thursday, as he described plans for the 25-day mission.

The cargo includes equipment for 160 experiments to be conducted by the space station crew, which currently consists of two Americans, three Russians and a Canadian.

On the return flight, Dragon -- the only spacecraft able to bring cargo back to Earth for now -- will be loaded with just over a ton of materials, including results of medical research.

Before the thruster outage, the capsule had been scheduled for a splashdown landing off the coast of California on March 25.

NASA has bet on SpaceX and other commercial ventures to take over for its retired fleet of space shuttles, which last flew in July 2011.

Before SpaceX's successful mission in October, NASA had been relying on Russian spacecraft -- but the Soyuz craft does not have room for cargo on the return flight.

SpaceX says it has 50 launches planned -- both NASA missions and commercial flights -- representing about $4 billion in contracts.

So far, SpaceX has only sent unmanned flights into orbit, but the company aims to send a manned flight within the next three or four years. It is under a separate contract with NASA to refine the capsule so that it can carry a crew.

NASA also has a $1.9 billion resupply contract for the station with Orbital Sciences Corporation, which will launch the first test flight of its Antares rocket from a base in Virginia in the coming weeks.

-AFP/ac

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Scientists link rats to real-world 'Matrix' via the Internet

These guys are, like, totally on the same wavelength.

(Credit:
Screenshot by Eric Mack/CNET)

There is officially a Wachowski Brothers-style "Matrix" for rodents.

Scientists in North Carolina and Brazil have connected the brains of two rats using "brain-to-brain interfaces" that can connect directly or via the Internet. These allow the rodents to share sensory information, collaborate on tasks to earn rewards, and fight back against the shadowy and cyber-apocalyptic forces that have enslaved them.

There's actually no evidence of the latter, but I'd still suggest researchers watch out for any rats that start displaying a propensity for martial arts.

Hollywood franchises aside for a moment, the experiment was conducted by basically training one "encoder" rat in a lab to press a certain lever (represented by a certain color) to earn a food pellet as a reward. A copy of the brain activity behind that behavioral decision was then translated into a pattern of electrical stimulation that could be transported directly to another "decoder" rat's brain. That decoder rat was then able to press the same correct lever and receive its reward 70 percent of the time without undergoing the same training or receiving any other visual cues about which lever to select.

As if that wasn't freaky enough, the brain-to-brain communication between the two rats was two-way and the encoder rat didn't get its full treat if the decoder rat made the wrong choice. This twist led the rats to actually work together.

"We saw that when the decoder rat committed an error, the encoder basically changed both its brain function and behavior to make it easier for its partner to get it right," Duke University Medical Center neurobiologist Miguel Nicolelis said in a statement.

"The encoder improved the signal to-noise ratio of its brain activity that represented the decision, so the signal became cleaner and easier to detect. And it made a quicker, cleaner decision to choose the correct lever to press. Invariably, when the encoder made those adaptations, the decoder got the right decision more often, so they both got a better reward."

Just to prove that rats don't use some sort of whisker-based sonar that we haven't yet decoded, a similar experiment was conducted with two rats attached to brain-to-brain interfaces, but separated by thousands of miles. The brain-to-brain connection in this case was held together by sending data over the Internet. The researchers found that even with the associated noisy transmission and signal delays, the distant rats were still able to work together to get fed.

This is what rodent cooperation looks like.

(Credit:
Duke University)

Turns out, there is a point to all this beyond just playing Dr. Frankenstein.

"These experiments (PDF) showed that we have established a sophisticated, direct communication linkage between brains, and that the decoder brain is working as a pattern-recognition device. So basically, we are creating what I call an organic computer," Nicolelis explains.

So now that we have created telepathic rats, what's next? Why, networked brains, of course!

Nicolelis believes it could be possible to connect more than just two brains together to form what he calls a "brain-net."

And you thought the "Matrix" reference was just link bait.

"We cannot even predict what kinds of emergent properties would appear when animals begin interacting as part of a 'brain-net'," Nicolelis said. "In theory, you could imagine that a combination of brains could provide solutions that individual brains cannot achieve by themselves."

This stuff isn't quite in the realm of totally nutso-mad-scientist fodder, however. Some of the possible practical applications include helping us to better understand the social interactions between animals, and recording networked brain signals could also be beneficial to current research aimed at restoring motor control to paralyzed people.

But I still think it's a good idea to keep Bruce Lee flicks out of the view of any brain-networked animal.

The researchers have published their findings in Scientific Reports. Nicolelis describes the experiments in the video below.

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Stinkbug Threat Has Farmers Worried

Part of our weekly "In Focus" series—stepping back, looking closer.

Maryland farmer Nathan Milburn recalls his first encounter.

It was before dawn one morning in summer 2010, and he was at a gas station near his farm, fueling up for the day. Glancing at the light above the pump, something caught his eye.

"Thousands of something," Milburn remembers.

Though he'd never actually seen a brown marmorated stinkbug, Milburn knew exactly what he was looking at. He'd heard the stories.

This was a swarm of them—the invasive bugs from Asia that had been devouring local crops.

"My heart sank to my stomach," Milburn says.

Nearly three years later, the Asian stinkbug, commonly called the brown marmorated stinkbug, has become a serious threat to many mid-Atlantic farmers' livelihoods.

The bugs have also become a nuisance to many Americans who simply have warm homes—favored retreats of the bugs during cold months, when they go into a dormant state known as overwintering.

The worst summer for the bugs so far in the U.S. was 2010, but 2013 could be shaping up to be another bad year. Scientists estimate that 60 percent more stinkbugs are hunkered down indoors and in the natural landscape now than they were at this time last year in the mid-Atlantic region.

Once temperatures begin to rise, they'll head outside in search of mates and food. This is what farmers are dreading, as the Asian stinkbug is notorious for gorging on more than a half dozen North American crops, from peaches to peppers.

Intruder Alert

The first stinkbugs probably arrived in the U.S. by hitching a ride with a shipment of imported products from Asia in the late 1990s. Not long after that, they were spotted in Allentown, Pennsylvania. Since then, they've been identified in 39 other states. Effective monitoring tools are being developed to help researchers detect regional patterns.

There are two main reasons to fear this invader, whose popular name comes from the pungent odor it releases when squashed. It can be distinguished from the native stinkbug by white stripes on its antennae and a mottled appearance on its abdomen. (The native stinkbug can also cause damage but its population number is too low for it to have a significant impact.)

For one thing, Asian stinkbugs have an insatiable appetite for fruits and vegetables, latching onto them with a needlelike probe before breaking down their flesh and sucking out juice until all that's left is a mangled mess.

Peaches, apples, peppers, soybeans, tomatoes, and grapes are among their favorite crops, said Tracy Leskey, a research entomologist leading a USDA-funded team dedicated to stinkbug management. She adds that in 2010, the insects caused $37 million in damage just to apple crops in the mid-Atlantic region.

Another fear factor: Although the stinkbug has some natural predators in the U.S., those predators can't keep up with the size of the stinkbug population, giving it the almost completely unchecked freedom to eat, reproduce, and flourish.

Almost completely unchecked. Leskey and her team have found that stinkbugs are attracted to blue, black, and white light, and to certain pheromones. Pheromone lures have been used with some success in stinkbug traps, but the method hasn't yet been evaluated for catching the bugs in large numbers.

So Milburn—who is on the stakeholders' advisory panel of Leskey's USDA-funded team—and other farmers have had to resort to using some chemical agents to protect against stinkbug sabotage.

It's a solution that Milburn isn't happy about. "We have to be careful—this is people's food. My family eats our apples, too," he says. "We have to engage and defeat with an environmentally safe and economically feasible solution."

Damage Control

Research Entomologist Kim Hoelmer agrees but knows that foregoing pesticides in the face of the stinkbug threat is easier said than done.

Hoelmer works on the USDA stinkbug management team's biological control program. For the past eight years, he's been monitoring the spread of the brown marmorated stinkbug with an eye toward containing it.

"We first looked to see if native natural enemies were going to provide sufficient levels of control," he says. "Once we decided that wasn't going to happen, we began to evaluate Asian natural enemies to help out."

Enter Trissolcus, a tiny, parasitic wasp from Asia that thrives on destroying brown marmorated stinkbugs and in its natural habitat has kept them from becoming the extreme pests they are in the U.S.

When a female wasp happens upon a cluster of stinkbug eggs, she will lay her own eggs inside them. As the larval wasp develops, it feeds on its host—the stinkbug egg—until there's nothing left. Most insects have natural enemies that prey upon or parasitize them in this way, said Hoelmer, calling it "part of the balance of nature."

In a quarantine lab in Newark, Delaware, Hoelmer has been evaluating the pros and cons of allowing Trissolcus out into the open in the U.S. It's certainly a cost-effective approach.

"Once introduced, the wasps will spread and reproduce all by themselves without the need to continually reintroduce them," he says.

And these wasps will not hurt humans. "Entomologists already know from extensive research worldwide that Trissolcus wasps only attack and develop in stinkbug eggs," Hoelmer says. "There is no possibility of them biting or stinging animals or humans or feeding on plants or otherwise becoming a pest themselves."

But there is a potential downside: the chance the wasp could go after one or more of North America's native stinkbugs and other insects.

"We do not want to cause harm to nontarget species," Hoelmer says. "That's why the host range of the Asian Trissolcus is being studied in the Newark laboratory before a request is made to release it."

Ultimately, the USDA's Animal and Plant Health Inspection Service will decide whether or not to introduce the wasp. If it does, the new natural enemy could be let loose as early as next year.

Do you have stinkbugs in your area? Have they invaded your home this winter? Or your garden last summer? How do you combat them? Share your sightings and stories in the comments.

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Sequester Begins But Govt. Shutdown Looks Unlikely

Mar 1, 2013 4:13pm

Andrew Harrer/Bloomberg/Getty Imag

It may not be readily obvious from the blizzard of news out there today on the “sequester,” but a government shutdown became significantly less likely today, even as the automatic budget cuts barreled ahead toward reality.

What happened? Both sides – Republicans and Democrats – basically seem to have agreed that as they will continue to fight out the $85 billion in automatic budget cuts starting to take effect today, they will not allow that disagreement to jeopardize full funding for the federal government. That funding is now scheduled to expire March 27.

RELATED: President Obama, Congressional Leaders Fail to Avert Sequester Cuts

After the White House meeting this morning, House Speaker John Boehner said he would have the House vote next week to fund the full government – what’s known as a “continuing resolution.”

Boehner: “I did lay out that the House is going to move a continuing resolution next week to fund the government past March 27th, and I’m hopeful that we won’t have to deal with the threat of a government shutdown while we’re dealing with the sequester at the same time. The House will act next week, and I hope the Senate will follow suit.”

READ MORE: 6 Questions (and Answers) About the Sequester

Boehner’s office provided this read-out of the meeting: “The president and leaders agreed legislation should be enacted this month to prevent a government shutdown while we continue to work on a solution to replace the president’s sequester.”

The president was asked at his mini-news conference whether he would definitely sign such a bill, even if it keeps government going at the new, lower spending levels as this fight is resolved (or not).

RELATED: 57 Terrible Consequences of the Sequester

Obama’s response: “With respect to the budget and keeping the government open – I’ll try for our viewing audience to make sure that we’re not talking in Washington gobbledygook. What’s called the continuing resolution, which is essentially just an extension of last year’s budget into this year’s budget to make sure that basic government functions continue, I think it’s the right thing to do to make sure that we don’t have a government shutdown. And that’s preventable.”

So even as we moved toward the brink of sequester, the nation’s leaders took a step back from another, much larger cliff.

SHOWS: World News

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Mystery ring of radiation briefly encircled Earth

What were you doing last September? The charged particles that dance around Earth were busy. Unbeknown to most earthlings, a previously unseen ring of radiation encircled our planet for nearly the whole month – before being destroyed by a powerful interplanetary shock wave.

We already knew that two, persistent belts of charged particles, called the Van Allen radiation belts, encircle Earth. The discovery of a third, middle ring by NASA's twin Van Allen probes, launched in August 2012, suggests that these belts, which have puzzled scientists for over 50 years, are even stranger than we thought. Working out what caused the third ring to develop could help protect spacecraft from damaging doses of radiation.

Charged particles get trapped by Earth's magnetic field into two distinct regions, forming the belts. The inner belt, which extends from an altitude of 1600 to 12,900 kilometres, is fairly stable. But the outer belt, spanning altitudes ranging from 19,000 to 40,000 kilometres, can vary wildly. Over the course of minutes or hours, its electrons can be accelerated to close to the speed of light, and it can grow to 100 times its usual size.

Mystery acceleration

No one is sure what causes these "acceleration events", although it seems to have something to do with solar activity interacting with the Earths' magnetic field.

"That's one of the key things the probes are in place to understand," says Dan Baker of the University of Colorado, Boulder. "How does this cosmic accelerator, operating just a few thousand miles above our head, accelerate electrons to such extraordinarily high energies?"

When the Van Allen probes started taking data on 1 September 2012, one of these mysterious events was already under way. "We came in the middle of the movie there," Baker says. But otherwise, he says, "What we expected was what we saw when we first turned on: two distinct belts, separated."

That changed a day later when, to the team's surprise, an extra ring developed between the inner and outer ones. "We watched it develop right before our eyes," Baker says. The new, middle ring was relatively narrow, and its electrons had energies between 4 and 7.5 megaelectronvolts - about the same as in the outer Van Allen belt during an acceleration event.

Although the outer ring displayed its characteristic inconstancy, the new middle ring barely budged for nearly four weeks. Then a shock wave, probably linked to a burst of solar activity, wiped it out in less than an hour on 1 October.

Spacecraft malfunctions

It's not clear where the middle ring came from, Baker says, although it was probably related to the acceleration event. The electrons could have been stripped from the outer Van Allen belt, funnelled back towards the Earth and got trapped in the middle on the way, or they could have been energised from closer to Earth and shot up to higher altitudes.

Figuring out what happened could be important to protecting spacecraft from radiation damage, says Yuri Shprits of the University of California in Los Angeles, who was not involved in the observations but is crafting a theoretical explanation that he hopes to publish soon. "It truly presents us with a very important question, and very important puzzles," he says.

There were no specific spacecraft malfunctions during September that can be directly linked to the new belt, says Shprits. However satellite operators will want to know if such belts are common and if they pose more of a risk.

With no other examples of a transient belt caught so far, it's too soon to answer all those questions, Baker says. "We only have one in captivity," he says. "We're still trying to figure out exactly how it works."

Journal reference: Science, DOI: 10.1126/science.1233518

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Groupon CEO "fired" after losses, stock slump

NEW YORK: Groupon said Thursday it was replacing chief executive Andrew Mason, who said he was "fired," following the struggling daily deals firm's share price plunge of 24 percent after bad quarterly results.

The company said executive chairman Eric Lefkofsky and vice chairman Ted Leonsis would take over the post of chief executive, effective immediately and that Groupon "will continue to invest in growth."

The board thanked Mason, a founder of Groupon, and said it has begun a search for a new chief executive.

"Andrew helped invent the daily deals space, leading Groupon to become one of the fastest growing companies in history," said Lefkofsky.

Leonsis said: "Groupon will continue to invest in growth, and we are confident that with our deep management team and market-leading position, the company is well positioned for the future."

Mason, in a letter to employees, said he was "fired" but remained upbeat about the company.

"I love Groupon, and I'm terribly proud of what we've created," Mason said.

"I'm OK with having failed at this part of the journey. If Groupon was Battletoads, it would be like I made it all the way to the Terra Tubes without dying on my first ever play through."

Sentiment has been souring on Groupon, which made a splash with its 2011 stock market debut but has been dogged by fears of "deal fatigue," and worries about its profitability as well as accounting questions.

"We believe uncertainties with Groupon remain due to staff turnover, competition, and increased investments," said a note earlier Thursday from Edward Woo at Ascendiant Capital Markets.

"In our view, the slowing growth and weak margins are likely to bolster continued skepticism as to Groupon's valuation, growth prospects, and profit potential."

Groupon's shares slumped to $4.53 at Thursday's close, a 77 percent drop from its public offering price of $20 in November 2011.

Scott Devitt at Morgan Stanley said Groupon's mission appears muddled now that it has moved into new services such as direct sales to consumers, and not just coupons for discounts with merchants.

"We continue to believe Groupon is a local ecommerce leader. However, we remain on the sidelines as the company experiments with myriad operating levers and strategies," the analyst said.

"We would become more constructive on the stock if we could better understand Groupon's ability to integrate the product companies it has acquired with the internally developed projects.

The Chicago-based firm reported a loss of $81 million in the fourth quarter, and a $67 million dollar deficit for the full year.

The loss translated to 12 cents per share in the quarter, compared with expectations of a profit of three cents a share.

With the daily deals sector fading fast, Groupon also offered a weak revenue outlook of $560 million to $610 million, well below market expectations of $650 million.

Groupon shares were listed on the Nasdaq in 2011 in a blockbuster public offering that raised a whopping $700 million and triggered fears that investors were overvaluing hot Internet startups.

The troubles at Groupon come amid ongoing woes at number two sector member LivingSocial, also losing money.

- AFP/ac

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Former Groupon CEO leaks outgoing memo: 'I was fired today'

Groupon CEO Andrew Mason

(Credit:
Dan Farber/CNET)

Not waiting for a leak, newly ousted Groupon CEO Andrew Mason made his departing memo public this afternoon.

In it, Mason claims responsibility for missing expectations and the company's stock price, and says that a "fresh CEO" earns the company a chance at a second chance.

Mason also shows a geeky, youthful spirit, making the comparison of running the company this far to the popular, though notoriously difficult 1991 video game Battletoads.

You can read the whole memo below, which Mason linked to in a Tweet:

(This is for Groupon employees, but I'm posting it publicly since it will leak anyway)

People of Groupon,

After four and a half intense and wonderful years as CEO of Groupon, I've decided that I'd like to spend more time with my family. Just kidding - I was fired today. If you're wondering why... you haven't been paying attention. From controversial metrics in our S1 to our material weakness to two quarters of missing our own expectations and a stock price that's hovering around one quarter of our listing price, the events of the last year and a half speak for themselves. As CEO, I am accountable.

You are doing amazing things at Groupon, and you deserve the outside world to give you a second chance. I'm getting in the way of that. A fresh CEO earns you that chance. The board is aligned behind the strategy we've shared over the last few months, and I've never seen you working together more effectively as a global company - it's time to give Groupon a relief valve from the public noise.

For those who are concerned about me, please don't be - I love Groupon, and I'm terribly proud of what we've created. I'm OK with having failed at this part of the journey. If Groupon was Battletoads, it would be like I made it all the way to the Terra Tubes without dying on my first ever play through. I am so lucky to have had the opportunity to take the company this far with all of you. I'll now take some time to decompress (FYI I'm looking for a good fat camp to lose my Groupon 40, if anyone has a suggestion), and then maybe I'll figure out how to channel this experience into something productive.

If there's one piece of wisdom that this simple pilgrim would like to impart upon you: have the courage to start with the customer. My biggest regrets are the moments that I let a lack of data override my intuition on what's best for our customers. This leadership change gives you some breathing room to break bad habits and deliver sustainable customer happiness - don't waste the opportunity!

I will miss you terribly.

Love,

Andrew

In a follow-up tweet, Mason joked that he was "good" on the fat camp recommendations:

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Pictures: Saving Sumatra's Orangutans

Photograph by Paul Hilton

A young boy shows off his illegally owned pet, a two-year-old orphaned orangutan that was later confiscated by SOCP and the local police, in April 2012.

When the team first discovered the ape, he'd been tied up to the back of the house in a village located on the outskirts of the Tripa peat forest.

A prompt health inspection by veterinarian Saraswati found that the young orphan was not in good health. "He's suffering from malnutrition, his skin is bad, and he has a wound from where he had been tied with a rope," she said in a statement.

Although trading and owning wildlife is illegal in Indonesia, the government does not impose strict penalties for those who are caught. Instead, they are only given a warning. (Watch video: "Grisly Wildlife Trade Exposed.")

According to Singleton, based on the number of cases reported to rescue centers since 1970 in Sumatra and neighboring Borneo, there have been at least 2,800 confiscations—only three of which he knows resulted in prosecution of the owners.

"People are not afraid of being arrested for it, and the only way to change that is to see more arrests and prosecutions," he said.

Published February 28, 2013

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Obama Admin to Urge End to Gay Marriage Ban

Solicitor General Donald B. Verrilli, plans to file a brief today with the Supreme Court in favor of challengers of Prop. 8, according to an administration source.

It would mark the first time that the Obama administration has come out in court against the California ballot initiative that defines marriage as between one man and one woman.

As far back as 2008, the president said that he thought Prop 8 was "divisive and discriminatory," but his Justice Department has never opined on its constitutionality. Because the DOJ is not a party to the case, it is not required to file a "friend of the court" brief, but the deadlines for briefs supporting the challengers to Prop 8 is tonight at midnight.

Justin Sullivan/Getty Images

Theodore Olson, one of the lead lawyers challenging Prop 8, told reporters last week that he hoped the DOJ lawyers would take the opportunity to set down a legal position.

In Depth: Obama's Prop 8 Decision

"However," Olson added, "whether they do or not, the president of the United States made it very clear in his inaugural address that we cannot rest in America until all civilians have equal rights under the law so, in a sense, the president has made that statement already."

Today, 39 states have laws restricting marriage to opposite-sex couples. This number includes voter-approved constitutional amendments in 30 states barring same sex marriage. Nine states allow gay marriage.

Related: Eric Holder Says Gay Marriage is the Next Civil Rights Issue

Related: Republican Moderates Join Legal Fight for Gay Marriage

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Quantum skyfall puts Einstein's gravity to the test

DIVIDING a falling cloud of frozen atoms sounds like an exotic weather experiment. In fact, it's the latest way to probe whether tiny objects obey Einstein's theory of general relativity, our leading explanation for gravity.

General relativity is based on the equivalence principle, which says that in free fall, all objects fall at the same rate, whatever their mass, provided the only force at work is gravity. That has been proven for large objects: legend has it that Galileo did it first by dropping various balls from the Tower of Pisa. Whether equivalence holds at quantum scales, where gravity's effects are not well understood, isn't clear. Figuring it out could help create a quantum theory of gravity, one of the biggest goals of modern physics.

Creating a quantum equivalent of Galileo's test isn't easy. In 2010 a team led by Ernst Rasel of the University of Hannover in Germany monitored a quantum object in free fall, by tossing a Bose-Einstein condensate (BEC) – a cloud of chilled atoms that behaves as a single quantum object and so is both particle and wave – down a 110-metre tall tower. Now they have split and recombined the wave – all before the BEC, made of rubidium atoms, reached the bottom. This produces an interference pattern that records the path of the falling atoms and can be used to calculate their acceleration (Physical Review Letters, doi.org/km6). The next step is to do the same experiment on a different kind of atom, with a different mass, to see if the equivalence principle holds.

The BEC can only be split for 100 milliseconds in the tower before hitting the bottom, so to allow tiny differences between the atom types to emerge, the work must be repeated in space, where the waves can be split for longer. By showing that a matter-wave can be split and recombined while falling, Rasel's result is a "major step" towards the space version, says Charles Wang of the University of Aberdeen, UK.

This article appeared in print under the headline "Quantum skyfall tests Einstein's gravity"

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

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