But not any more. The Van Gogh museum in Amsterdam has developed high-quality 3D reproductions of some of its finest paintings, with what it describes as the most advanced copying technique ever seen. Axel Rüger, the museum's director, said: "It really is the next generation of reproductions because they go into the third dimension. If you're a layman, they are pretty indistinguishable [from the originals]. Of course, if you're a connoisseur and you look more closely, you can see the difference."

Each reproduction is priced £22,000 – somewhat more than the cost of a postcard or poster. But the museum is hoping to increase access to pictures which, if they were sold, would go for tens of millions of pounds to Russian oligarchs or American billionaires.

The 3D scanning technique has so far reproduced Almond Blossom (1890), Sunflowers (1889), The Harvest (1888), Wheatfield under Thunderclouds (1890) and Boulevard de Clichy (1887). Further ventures into Van Gogh's back catalogue are planned.

Other museums are taking a close interest in the commercial potential of 3D, given that the Van Gogh museum expects to raise substantial funds from sales. The revenue will go towards planned renovations, as well as the preservation of a collection of 200 paintings, drawings and letters. Rüger said: "It is really fascinating to start an ambitious and commercial product of this kind. For museums, the financial situation is such that we all need to think about new products, new income streams, new business ideas to secure our finances."

The replicas, called Relievos, are being created by the museum in partnership with Fujifilm, with which it has had an exclusive deal for three years. Such is the complexity of the technology, known as Reliefography, that it has taken more than seven years to develop and only three a day can be made. It combines a 3D scan of the painting with a high-resolution print. The "super-accurate" reproduction even extends to the frame and the back of the painting. Every Relievo is numbered and approved by a museum curator. There is a limited edition of 260 copies per painting.

But Ballmer wasn’t completely blameless. He does seem to have been hobbled by a limited understanding of the technological revolution that was destroying his empire. In 2010, Ballmer and Steve Jobs appeared at an All Things D conference hosted by Walt Mossberg.

At that conference, held a few months after the introduction of the iPad, Jobs told Mossberg that he expected the PC to decline as people increasingly shifted to tablets. Mossberg asked Ballmer for his reaction.

“I think people are going to be using PCs in greater and greater numbers for many years to come,” Ballmer said. “I think PCs are going to continue to shift in form factor. The real question is: What’s a PC?”

Ballmer allowed that there’s a “fundamental difference” between devices that are “small enough to be in a pocket” and those that are not. But, he said, “nothing people do on a PC today is going to get less relevant tomorrow.” He predicted that “there will exist a general purpose device that does everything you want,” because most households can’t afford to own “five devices per person.”

This was more than a semantic disagreement. Jobs thought tablets and smartphones represented a fundamentally new kind of computing platform, and he had his engineers design a new user interface from scratch optimized for small, cheap touchscreen devices. Ballmer saw the tablet as just another kind of PC, and so he built a single OS designed to work both on tablets and on desktop PCs.

Today, the results speak for themselves. Apple sold 14 million iPads in its most recent quarter. In contrast, estimates suggest that only about 2 million Windows-based tablets were sold last quarter.

Obviously, the causes of the iPad’s success and Surface’s failure are complex. But the philosophical disagreement between Jobs and Ballmer surely played a role in their products’ divergent fortunes. Ballmer tried to build a device that could be all things for all people. That philosophy was echoed in May by Microsoft founder Bill Gates, who said that “a lot of [iPad] users are frustrated, they can’t type, they can’t create documents. They don’t have Office there.”

They are covered in a patina of 11,268 photovoltaic cells, which look dark blue in the grey predawn. The four 10-horsepower propellers they power now start to spin silently. Bertrand Piccard, a 55-year-old explorer and psychiatrist, dons his helmet and oxygen mask and completes his final checks. The Solar Impulse quietly taxies forwards.

The plane is travelling impossibly slowly – 30km an hour – when it gently noses up and leaves the ground. With air beneath them, the rangy wings seem to gain strength; the fuselage that on the ground seemed flimsy becomes elegant, like a crane vaunting in flight. It seems not to fly, though, so much as float. Piccard spends the day wheeling the solar-powered plane around the Matterhorn and lands 12 hours later, after sunset.

But the Solar Impulse is a plane that would fly for ever.

This summer, it limited itself to crossing the US. It took off from San Francisco in May and flew past the Statue of Liberty before landing at JFK in July, traversing the country in five stages, with Piccard and the other co-founder of the project, André Borschberg, a former fighter pilot in the Swiss air force, swapping places in the cockpit. The flight was a remarkable achievement: the Solar Impulse flew further than any solar-powered aircraft before.

The plane that crossed America is a prototype, with the name HB-SIA. Its successor, the HB-SIB, currently being built, will try to circumnavigate the world in 2015, using about as much power as a scooter does. With no rival, it will have the skies to itself, but on land and on sea, too, a new generation of solar-powered vehicles is making extraordinary journeys, around the world and across continents.

Solar power can seem the least exciting of clean energy sources: it just sits there, soaking up the sun. At least wind turbines turn. Now, though, a number of projects across the globe are pushing the boundaries of technical knowledge and coupling them to daring and demanding adventure. That the technology involved might also one day save the planet is a nice bonus.

Piccard started the Solar Impulse project because he had a problem with fossil fuels, a personal one – they had nearly cost him his life. In March 1999, along with British pilot Brian Jones, he made the first non-stop circumnavigation of the world by balloon, in Breitling Orbiter 3.

The team is to begin work on Monday. Activists say Syrian forces killed more than 300 people in several suburbs east and west of the capital on Wednesday.

A US official accused Damascus earlier of an "indiscriminate use of chemical weapons". He said the delay was meant to allow evidence to degrade.

Syria has blamed "terrorists".

State media have reported that chemical agents have been found in tunnels used by rebel fighters, and also that soldiers "suffered from cases of suffocation" when rebels used poison gas "as a last resort" after government forces made "big gains" in the suburb of Jobar.

State TV is meanwhile reporting that the governor of the central district of Hama, Anas Abdul-Razzaq Naem, has been killed in a car bomb attack.

'Degradation of evidence'

The Syrian foreign ministry statement broadcast on state television said an agreement to allow UN chemical weapons experts to "investigate allegations of chemical weapons use in Damascus province" had been concluded on Sunday with the UN's disarmament chief, Angela Kane.

The agreement was "effective immediately", the statement added.

A spokesperson for UN Secretary General Ban Ki-moon subsequently announced that the inspectors were "preparing to conduct on-site fact-finding activities", starting on Monday. A ceasefire will be observed at the affected locations, the statement said.

Russia, a key ally of Syria, welcomed the decision to allow UN inspectors in but warned the West against pre-empting the results.

Earlier, a senior US government official said "there is very little doubt at this point that a chemical weapon was used by the Syrian regime against civilians" and the authorities were intentionally delaying the UN probe.

"Any belated decision by the regime to grant access to the UN team would be considered too late to be credible, including because the evidence available has been significantly corrupted as a result of the regime's persistent shelling and other intentional actions over the last five days," the official told reporters in Washington.

Medecins Sans Frontieres (MSF) said on Saturday that three hospitals it supports in the Damascus area had treated about 3,600 patients with "neurotoxic symptoms" early on Wednesday morning, of whom 355 died.

Mr Mubarak is facing a retrial on charges of complicity in the killing of protesters during the 2011 uprising.

He sat in the defendants' cage along with his two sons, former interior minister, and six security chiefs.

Earlier, the separate trial of the Muslim Brotherhood's general guide and his two deputies was adjourned.

The court convened briefly and made its decision because Mohammed Badie, Khairat al-Shater and Rashad Bayoumi were absent for security reasons.

Their presence was requested for the trial's resumption on 29 October.

The Brotherhood leaders face charges of inciting the murder of protesters who stormed the Islamist movement's headquarters in Cairo on 30 June as millions took to the streets demanding the resignation of Mr Mubarak's democratically elected successor, Mohammed Morsi.

Mr Morsi was deposed by the military three days later.

He is is being detained while prosecutors investigate allegations related to his escape from prison during the uprising that forced Mr Mubarak from power, including that he conspired with the Palestinian militant group Hamas. Helicopter

On Sunday, Mr Mubarak appeared in the dock inside the high-security courtroom at the police academy on the eastern outskirts of Cairo sitting in a wheelchair, wearing a white tracksuit and dark sunglasses.

The 85-year-old was reportedly flown by helicopter to the court from a military hospital where he has been held under house arrest since his release from prison on Thursday. The hearing has been adjourned until 14 September.

Mr Mubarak was sentenced to life in prison in June 2012 after being found guilty of complicity in the killing of hundreds of protesters. His former interior minister, Habib al-Adly, also received a life sentence, but the security chiefs were acquitted.

The former president and his sons, Alaa and Gamal, were cleared of separate charges of corruption relating to a gas export deal at the same trial because of the statute of limitations.

In January 2013, the Court of Cassation accepted appeals against their convictions by Mr Mubarak and Mr Adly and ordered a retrial of all the defendants. Their supporters had noted that the original trial judge had said there was no evidence linking Mr Mubarak to the shooting of protesters.

Their retrial began in May but it has been repeatedly adjourned for various reasons, prompting claims from pro-democracy activists and representatives of the victims that the judges and defence team were dragging out proceedings to avoid a verdict.

The animal had extensive abnormalities around its head and was missing its brain.

The Zoo said that stillbirths in giant pandas are extremely rare.

Officials added that results from Saturday’s necropsy on the deceased cub won’t be known for several days.

The zoo also said that it was able to examine the cub that was born Friday and found the animal in excellent health. The cub weighed 4.8 ounces.

The giant panda cub born 5:32 p.m. Friday received an exam from animal care staff Saturday morning. Chief veterinarian Suzan Murray said the cub is robust, has a steady heartbeat and is nursing well.

A New York appeals court unanimously rejected every Argentine argument against the payout.

The decision is the latest twist in the long-running legal saga.

Argentina refuses to pay anything to investors who declined to participate in a previous debt reduction deal involving most of the nation's lenders.

"What the consequences predicted by Argentina have in common is that they are speculative, hyperbolic and almost entirely of the Republic's own making," the judges said in their decision.

But the appeals court held off forcing Argentina to pay pending an appeal to the Supreme Court - which is considered unlikely to hear the case, but puts off any decision to 2014, well after Argentina's congressional elections in October.

The appeal came after a Manhattan court ruled last February that Argentina had violated its contractual obligation to treat all creditors equally. That meant the country would have to pay the bondholders, led by NML Capital and Aurelius Capital Management.

Argentina defaulted on some $100bn of debts in 2002, and has since restructured its debt twice, cancelling around 75% of the nominal value of the bonds.

Almost 92% of the country's bondholders agreed to write off most of the amount owed to them.

NML Capital and Aurelius are demanding 100% repayment of the $1.3bn, plus interest.

In an interview with CNN's Chris Cuomo in May, Knox said she "didn't know" whether she'd return.

"It's a really complicated question," Knox said. "I mean, I'm afraid to go back there. I don't want to go back into prison."

Knox: Sometimes I can't stop crying

Amanda Knox: 'I'm afraid to go back'

Knox spent several years behind bars in Italy, after she was convicted in 2009 of murdering 21-year old British exchange student Meredith Kercher. Kercher was found stabbed to death in November 2007 in the villa she rented with Knox, then 20, in the central Italian university town of Perugia. The convictions of Knox and her ex-boyfriend, Raffaele Sollecito, were overturned in 2011 for "lack of evidence."

After her acquittal, Knox returned to her hometown of Seattle, Washington, where she has been living since. Italians ask: Can Americans get away with murder?

Italy's Supreme Court decided last year to retry the case, saying the jury that acquitted Knox didn't consider all the evidence, and that discrepancies in testimony needed to be answered.

The high court also said evidence could support prosecutors' initial argument -- that Kercher was killed in a twisted sex misadventure game, according to Italian news agency ANSA. Knox says such claims were "a bombardment of falsehood and fantasy."

"No one has ever claimed that I was ever taking part in deviant sexual activity. None of my roommates, none of my friends, none of the people who knew me there. This is simply coming out of the prosecution," she told CNN in May. "I was not strapping on leather and bearing a whip. I have never done that. I have never taken part in an orgy. Ever."

Knox and Sollecito's retrial, which is expected to start this fall, should examine discrepancies in testimony, the high court said. These include differing witness accounts of when screaming could be heard from the home, ANSA reported.

Ballmer, 57, a close friend and confidant of co-founder Bill Gates since the company's earliest days, took over as CEO in January 2000. During his tenure Microsoft's revenues tripled but he's long been a target of criticism from Wall Street and Silicon Valley as the company's share price stagnated and rivals Apple Inc and Google Inc led a mobile computing revolution that has upended the global technology industry.

Ballmer's planned exit comes just weeks after the company announced a major reorganization and delivered an earnings report that showed across-the-board weakness in the business, including dismal sales of the company's new Surface tablet and a lukewarm reaction to the crucial Windows 8 operating system.

Activist investing fund ValueAct Capital Management LP said in April that it had taken a stake in the company and shortly after began agitating for a change in strategy and a clear CEO succession plan.

There are no obvious candidates to succeed Ballmer at the company that has only had two CEOs in its 38-year history. Many promising executives have left or were pushed out by Ballmer, who had once indicated that he intended to stay at least until 2017.

The recent reorganization was aimed at reshaping Microsoft - once primarily a purveyor of packaged software - into a company focused on devices and services, essentially mimicking Apple. Most industry watchers felt it was too little, too late, though the company's statements on Friday said the strategy would remain intact for now.

"Since he took over in 2000, it is fair to say he missed a number of transitions: mobile, tablets, cloud," said Zeus Kerravala, an analyst at ZK Research. "Microsoft continues to live off traditional PC computing. Ballmer's strength is traditional PC computing. He was a great guy for his era but times have changed and a new leadership is needed. It's hard to say his tenure has been a success."

Microsoft's already-large profits doubled since Ballmer became CEO, but its share price has flatlined over the last decade, and has never come close to the split-adjusted high of $59.97 it reached in late 1999, before the tech stock bubble burst.

Microsoft shares were up 7 percent at $34.64 on Nasdaq on Friday.

At issue is how to ensure that Apple does not violate antitrust law, following a July 10 ruling by U.S. District Judge Denise Cote in Manhattan that it had conspired with five major publishers to undermine pricing by rivals including Amazon.com Inc, which dominates the market for electronic books.

Apple says the government is overreaching by insisting that it hire an external monitor, let e-book retailers add hyperlinks to their own websites in their e-book apps without charge, and face limits on how it negotiates for other content including movies, music and TV shows.

Cote must approved any injunction.

In a court filing, the U.S. Department of Justice, joined by 33 U.S. states and territories, suggested halving the length of its previously proposed injunction to five years from 10, with leave to seek as many as five one-year extensions if needed.

At Cote's suggestion, they also recommended that Apple hold staggered negotiations with the publishers starting in two years, hopefully minimizing the chance of future collusion, and removed previously proposed language that they said Apple had claimed would hurt its ability to run its popular App Store.

But in rejecting other changes that the company wanted, and while expressing a desire not to "unnecessarily harm Apple," the governments said the Cupertino, California-based company's continuing refusal to admit it did anything wrong warranted tough medicine.

"Quite simply, Apple wants to continue business as usual, regardless of the antitrust laws," the filing said. "This court should have no confidence that Apple on its own effectively can ensure that its illegal conduct will not be repeated. There must be significant oversight by someone not entrenched in Apple's culture of insensitivity to basic tenets of antitrust law."

LETTER AND SPIRIT OF THE LAW

In a separate court filing, Apple said the proposal for an external monitor "exceeds the bounds of even criminal price-fixing cases," and reflects an effort "to use this civil injunction to inflict punishment, which is impermissible."

The company said its own proposed remedies are stringent enough, and enable it to remain "one of the world's most innovative companies, while acting consistently with both the letter and spirit of the antitrust laws."

Setting up shop in Los Angeles' Santa Monica and New York's Nolita brings Intel closer to the major TV networks and production studios that the world's biggest chipmaker must strike deals with to gather content for its live and on-demand service, Intel spokesman Jon Carvill said.

Opening the offices is a sign that Intel is committed to moving ahead with the venture even though progress making deals has been slow. Some industry insiders have expressed doubts about Intel's ability to successfully create a business to challenge traditional cable operators.

"It suggests that there's an ongoing level of interest, maybe an incremental positive to their commitment," said Cody Acree, an analyst at Williams Financial Group. "They have to continue down this path or there's no hope of being successful."

Intel plans to introduce the TV service, to be delivered through the Internet and a set-top box, this year in a phased rollout in regional markets, Carvill said.

In July, Intel Media hired Moe Khosravy, a cloud-computing expert who previously worked at Microsoft Corp and VMWare Inc, as head of software and user experiences. Intel has about 375 people working on the TV business, most of them based at Intel's headquarters in Santa Clara, California.

Doubts about Intel's commitment to the venture emerged in June after newly appointed Chief Executive Brian Krzanich warned he was taking a cautious approach to television, far from the company's core business of chip manufacturing.

Some content providers have agreed with Intel about how their content would be distributed, but as of June the chipmaker had yet to sign any deals despite offering to pay sizeable premiums over traditional cable rates.

Carvill declined to comment on Intel's negotiations.

Intel is not the only technology company trying to revolutionize the TV industry, where Comcast Corp, Time Warner Cable Inc and DirecTV are players and have much to lose from potential new entrants. Apple Inc, Google Inc and Amazon.com Inc are believed to be working on their own new TV services and products.

Media companies typically give better prices to operators with more viewers, such as large cable companies, and charge higher prices to smaller or newer entrants. Since Intel's TV service has yet to start, it can expect to pay a premium.

As opponents of Syrian President Bashar al-Assad braved the frontlines around Damascus to smuggle out tissue samples from victims of Wednesday's mass poisoning, Obama brushed over an interviewer's reminder that he once called chemical weapons a "red line" that could trigger U.S. action.

A White House spokesman reiterated Obama's position that he did not expect to have "boots on the ground" in Syria.

Obama's caution contrasted with calls for action from NATO allies, including France, Britain and Turkey, where leaders saw little doubt Assad's forces had staged pre-dawn missile strikes that rebels say killed between 500 and well over 1,000 people.

But two years into a civil war that has divided the Middle East along sectarian lines, a split between Western governments and Russia once again illustrated the international deadlock that has thwarted outside efforts to halt the killing.

While the West accused Assad of a cover-up by preventing the U.N. team from visiting the scene, Moscow said the rebels were impeding an investigation.

The United Nations released data showing that a million children were among refugees forced to flee Syria, calling it a "shameful milestone". And mosque bombings that left at least 42 dead and hundreds wounded in neighboring Lebanon were a reminder of how Syria's conflict has spread. But, for now, there seems little prospect of an end to the violence.

According to U.S. and European security sources, U.S. and allied intelligence agencies have made a preliminary assessment that Syrian government forces did use chemical weapons in the attack this week and that the act likely had high-level approval from President Bashar al-Assad's government.

Obama played down the chances of Assad cooperating with the U.N. experts who might provide conclusive evidence of what happened, if given access soon.

Noting budget constraints, problems of international law and a continuing U.S. casualty toll in Afghanistan, Obama told CNN: