Unix creator Dennis Ritchie dies aged 70

Pioneering computer scientist Dennis Ritchie has died after a long illness.

Mr Ritchie was one of the creators of the hugely influential Unix operating system and the equally pioneering C programming language.
A vast number of modern technologies depend on the work he and fellow programmers did on Unix and C in the early days of the computer revolution.
Those paying respects said he was a "titan" of the industry whose influence was largely unknown.
The first news of Mr Ritchie's death came via Rob Pike, a former colleague who worked with him at Bell Labs. Mr Ritchie's passing was then confirmed in a statement from Alcatel Lucent which now owns Bell Labs.
Jeong Kim, president of Alcatel-Lucent Bell Labs, said Mr Ritchie would be "greatly missed".

"He was truly an inspiration to all of us, not just for his many accomplishments, but because of who he was as a friend, an inventor, and a humble and gracious man," said Mr Kim.
Along with Ken Thompson, Brian Kernighan, Douglas McIlroy, and Joe Ossanna, Mr Ritchie was one of the key creators of the Unix operating system at Bell Labs during the 1960s and 70s.
Unix's influence has been felt in many ways. It established many software engineering principles that persist until today; it was the OS of choice for the internet; it kicked off the open source movement and has been translated to run on many different types of hardware.
It was also at Bell that Mr Ritchie created C, one of the most widely used programming languages in the world. It is familiar to almost every modern-day developer.
In 1999, Mr Ritchie's influence and accomplishments won official notice when he was awarded the US National Medal of Technology - the highest honour America can bestow on a technologist.
Mr Pike said that with his passing, the world had lost a "truly great mind."
Paying tribute on his blog, Google programmer Tim Bray said it was impossible to overstate the debt his profession owed to Dennis Ritchie.
"I've been living in a world he helped invent for over thirty years," he wrote.

Dead NASA satellite to crash-land Friday

WASHINGTON: Fragments from an old six-ton NASA satellite hurtled toward Earth on Friday, while the exact site of the crash-landing remained a mystery into the final hours.
The US space agency has stressed that the risk is "extremely small" of any of the 26 chunks expected to survive the fiery re-entry into Earth's atmosphere hitting one of the planet's seven billion people - a one in 3,200 chance.
"Re-entry is possible sometime during the afternoon or early evening of Sept. 23, Eastern Daylight Time," NASA said on its website Thursday night.
"It is still too early to predict the time and location of re-entry with any more certainty, but predictions will become more refined in the next 24 hours."
The Upper Atmosphere Research Satellite (UARS) was not expected to fall over North America, NASA added.
The influence of solar flares and the tumbling motion of the satellite make narrowing down the landing a particularly difficult task, experts said as the Internet lit up with rumors of where and when it would fall.
The US Department of Defense and NASA were busy tracking the debris and keeping all federal disaster agencies informed, a NASA spokeswoman said.
The Federal Aviation Administration issued a notice Thursday to pilots and flight crews of the potential hazard and urged them to "report any observed falling space debris to the appropriate (air traffic control) facility and include position, altitude, time and direction of debris observed," CNN said.
Orbital debris experts say space junk of this size from broken-down satellites and spent rockets tends to fall back to Earth about once a year, though this is the biggest NASA satellite to fall in three decades.
NASA's Skylab crashed into western Australia in 1979.
The surviving chunks of the tour-bus sized UARS, which launched in 1991, will include titanium fuel tanks, beryllium housing and stainless steel batteries and wheel rims.
The parts may weigh as little as two pounds (one kilogram) or as much as 350 pounds (158 kilograms), NASA said.
Orbital debris scientists say the pieces will fall somewhere between 57 north latitude and 57 south latitude, which covers most of the populated world.
The debris field is expected to span 500 miles (800 kilometers).
NASA has also said that in 50 years of space exploration no one has ever been confirmed injured by falling space junk.
The craft contains no fuel and so is not expected to explode on impact.
"No consideration ever was given to shooting it down," NASA spokeswoman Beth Dickey said.
NASA has warned anyone who comes across what they believe may be UARS debris not to touch it but to contact authorities for assistance.
Space law professor Frans von der Dunk from the University of Nebraska-Lincoln's College of Law told AFP that the United States will likely have to pay damages to any country where the debris falls.
"The damage to be compensated is essentially without limit," von der Dunk said, referring to the 1972 Liability Convention to which the United States is one of 80 state signatories."Damage here concerns 'loss of life, personal injury or other impairment of health; or loss of or damage to property of States or of persons, natural or juridical, or property of international intergovernmental organizations,'" he said, reading from the agreement.
However, the issue could get thornier if the debris causes damage in a country that is not part of the convention.
"The number of countries so far theoretically at risk is rather large, so there may be an issue if damage would be caused to a state not being party to the Liability Convention," he said. (AFP)