Dark energy: It was Einstein’s idea 80 yrs ago

PTI | Dec 12, 2012, 07.25 AM IST
READ MORE Erwin Schrodinger|Einstein|dark energy
LONDON: Physicist Albert Einstein was the first to come across the concept of 'dark energy' , much before the idea became popular and the genius regretted it as "the biggest mistake of my life" , researchers claim. A dialogue between Einstein and Austrian physicist Erwin Schrodinger suggests the pair stumbled upon the idea of dark energy 80 years before its time, while toying with what they thought was an ugly fudge factor.

In 1917, Einstein's novel equations of spacetime had geometric terms on the left and energy on the right. A constant on the left kept the universe steady, suiting observations at the time.

However, in 1929, it became clear that the universe is expanding and Einstein dubbed the constant "the biggest mistake of my life" , the 'New Scientist' reported. Historian Alex Harvey of New York University re-analysed papers from the physicists, published in 1918. In one Schrodinger toyed with Einstein's equations, moving the constant from the left to the right.

The simple move transformed the constant from part of the geometry of space-time to a source of energy for the universe. "While mathematically it doesn't make any difference, physically it does," says Harvey.

Einstein responded, rather cheekily, that the properties of this new energy term were either nothing or demand a "non-observable negative density in interstellar spaces" . "That turns out to be dark energy," Harvey says — which only emerged again in 1998 to explain the universe's accelerating expansion.
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Traffic robocops’ to guide driverless cars

PTI | Dec 10, 2012, 05.51 AM IST
READ MORE rakha|Driverless Cars|‘Traffic robocops
WASHINGTON: Engineers have developed a new robotic 'traffic cop' to help automated driverless cars in future to cruise through intersections faster with more safety.

Researchers said because such smart intersections would minimize human error, they would be safer than intersections are now.

Intelligent crossroads would also save every car an average of 35 seconds of wait time per stoplight, the Discovery News reported.

Hesham Rakha, a Virginia Tech engineering professor, and his doctoral student, Ismail Zohdy , in their calculations, assumed that everyone will be using robotic cars in the near future.

"You will not be driving your car anymore; you will be driven by your car," Zohdy said. "We are not talking about the distant future," Rakha said.

Robotic cars are closer to reality than many may think, Rakha and Zohdy said about their smart traffic signal. They cited some driverless cars under development now, including Google-made cars and research vehicles from Stanford University.

While other researchers have written programmes for how driverless cars should act at intersections, Rakha and Zohdy say their controller takes into account more variables than other systems do. For example, it calculates different cars' engine capacities.

In the futuristic intersections that Rakha and Zohdy imagined, cars coming up to the intersection would send data about their location and speed to a central controller . The controller would gather information about the weather, the speed limit at the intersection and how many lanes the intersection has. Once a car gets close enough, the controller would direct the car along paths that it has calculated are the swiftest, while remaining safe.

The result is an intersection where cars don't need to pause as often or as long as human-driven vehicles need to.

"The proposed intersection controller, which allows vehicles to keep moving, reduces the delay for each vehicle compared to traditional intersection control. Keeping vehicles moving is also more fuel efficient and reduces emissions," Rakha said.
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Tech that: Your next boss could be a computer!

PTI | Dec 10, 2012, 05.43 AM IST
READ MORE tech|computer|boss
LONDON: The first fully automatic computer system that can delegate tasks to human workers has been developed by a US-based scientist. Daniel Barowy, a computer scientist at the University of Massachusetts, Amherst has created 'AutoMan' that delegates tricky problems to human workers through crowd-sourcing platforms such as Amazon's Mechanical Turk.

"I'd rather have a computer as my boss than a jerk," says Barowy.

Artificial intelligence is improving all the time, but computers still struggle to complete certain tasks that are easy for us, such as quickly reading a car's license plate or translating a joke, the New Scientist reported. To get round this, people can post such tasks on platforms like Mechanical Turk for others to complete. Barowy wanted to automate this process — and 'Auto-Man' was born.

"We think of it as a new kind of computing. It changes the kind of things you can do," he said. Auto-Man was designed to send out jobs, manage workers, accept or reject work and make payments. The quality guarantee is the most important contribution of the work, says Barowy. "You're replacing people's bosses with a computer. Without a mechanism for addressing the quality of worker output, full automation is not possible," he said.
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