Milky Way's black hole pulling in gas cloud

July 19, 2013, An ill-fated gas cloud has begun a close encounter with the monstrous black hole at the center of the Milky Way, a fresh set of observations reveals. Astronomers don’t expect the cloud to emerge intact, resulting in an unprecedented view of our galaxy’s largest black hole feasting on its prey.

In December 2011, astronomers identified the gas cloud, called G2, and found that its orbit would bring it perilously close to the Milky Way’s central black hole by mid-2013. Nineteen months ago, the immense gravity of the black hole, which weighs in at about 4.3 million times the mass of the sun, was already squeezing and stretching the gas cloud as if it were pasta dough.
Now images captured in April with the Very Large Telescope in Chile show that the leading edge of G2 has whipped around the black hole’s far side. “The line of sight is such that the gas cloud is falling away from us toward the black hole,” says Stefan Gillessen of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany. “Some material swung by the back side of the black hole and is now flying toward us.”
“If you think of the cloud as a roller coaster train, the first carriage has already swung by the black hole,” Gillessen says. “The main part of the train is still in approach.”
The gas cloud is whizzing through space at up to 3,000 kilometers per second, 100 times the speed at which Earth orbits the sun and a whopping 1 percent of the speed of light. In just a few months, the black hole has not only accelerated the cloud to those speeds, but reversed the motion of the front side a full 180 degrees. The findings will appear in an upcoming Astrophysical Journal.
Gillessen and his team also found that the black hole has stretched G2 to twice its length last year. As a result, the researchers predict that the bulk of the cloud won’t make its closest approach to the black hole until early next year. When that happens, telescopes around the world will point at the galactic center to capture the drama.
Dimitrios Giannios, an astrophysicist at Purdue University in West Lafayette, Ind., does not expect G2 to survive its encounter with the galaxy’s central black hole.  The cloud will probably fade from view in coming months as it continues to stretch out, he says. But its remnants might gradually get funneled into the black hole within a few decades, culminating in a rare bright display as they approach the point of no return. “It would be a last echo of the death of this cloud,” he says.

Source: http://www.sciencenews.org/view/generic/id/351747/description/Milky_Ways_black_hole_pulling_in_gas_cloud

Microchips That Mimic the Brain

 

July 22, 2013 — Novel microchips imitate the brain's information processing in real time. Neuroinformatics researchers from the University of Zurich and ETH Zurich together with colleagues from the EU and US demonstrate how complex cognitive abilities can be incorporated into electronic systems made with so-called neuromorphic chips: They show how to assemble and configure these electronic systems to function in a way similar to an actual brain.

No computer works as efficiently as the human brain -- so much so that building an artificial brain is the goal of many scientists. Neuroinformatics researchers from the University of Zurich and ETH Zurich have now made a breakthrough in this direction by understanding how to configure so-called neuromorphic chips to imitate the brain's information processing abilities in real-time. They demonstrated this by building an artificial sensory processing system that exhibits cognitive abilities.

New approach: simulating biological neurons
Most approaches in neuroinformatics are limited to the development of neural network models on conventional computers or aim to simulate complex nerve networks on supercomputers. Few pursue the Zurich researchers' approach to develop electronic circuits that are comparable to a real brain in terms of size, speed, and energy consumption. "Our goal is to emulate the properties of biological neurons and synapses directly on microchips," explains Giacomo Indiveri, a professor at the Institute of Neuroinformatics (INI), of the University of Zurich and ETH Zurich.
The major challenge was to configure networks made of artificial, i.e. neuromorphic, neurons in such a way that they can perform particular tasks, which the researchers have now succeeded in doing: They developed a neuromorphic system that can carry out complex sensorimotor tasks in real time. They demonstrate a task that requires a short-term memory and context-dependent decision-making -- typical traits that are necessary for cognitive tests. In doing so, the INI team combined neuromorphic neurons into networks that implemented neural processing modules equivalent to so-called "finite-state machines" -- a mathematical concept to describe logical processes or computer programs. Behavior can be formulated as a "finite-state machine" and thus transferred to the neuromorphic hardware in an automated manner. "The network connectivity patterns closely resemble structures that are also found in mammalian brains," says Indiveri.
Chips can be configured for any behavior modes
The scientists thus demonstrate for the first time how a real-time hardware neural-processing system where the user dictates the behavior can be constructed. "Thanks to our method, neuromorphic chips can be configured for a large class of behavior modes. Our results are pivotal for the development of new brain-inspired technologies," Indiveri sums up. One application, for instance, might be to combine the chips with sensory neuromorphic components, such as an artificial cochlea or retina, to create complex cognitive systems that interact with their surroundings in real time.

Source:http://www.sciencedaily.com/releases/2013/07/130722152705.htm