What Have You Done With Your Playstation 3?

From Space.com:

When black holes are perturbed, they vibrate somewhat like a ringing bell. Now astronomers have narrowed down the rotational speed at which that vibration should stop.

As is typical, they did it out by running a simulation. But instead of a supercomputer, they used a batch of Sony Playstation 3 gaming consoles wired together.

The so-called PS3 Gravity Grid, a network of 16 Playstation 3 consoles grouped together in a cluster capable of running simulations that rival a dedicated supercomputer at a much lower cost.

"You can get a supercomputer's capability with relatively little money," said Lior Burko of the University of Alabama, Huntsville, who led the black hole study, in an interview.

Rather than renting computer time on a supercomputer that could cost $5,000 per simulation, Burko and his colleagues used the PS3 Gravity Grid built by Gaurav Khanna, a physics professor at the University of Massachusetts, Dartmouth.

The cluster can be built for around $6,000, and allows simulations to be repeated at no extra cost. The system is tailored to simulations that require massive amounts of computations, but relatively little RAM memory.

Burko and Khanna used the PS3 Gravity Grid to run simulations that resolved an ongoing dispute over the speed at which spinning black holes stop vibrating just after forming or being perturbed by an outside object. One theory held that the black holes go silent at relatively fast speeds, while another theory contended they went quiet at slower speeds.

According to the new simulations, the gravity wave vibrations from a spinning black hole that's been perturbed would settle out according to the faster of the two theories, though the actual speed will vary, Burko said.

"It depends on the mass of the black hole," he added. "Let's say you're in a spaceship orbiting the black hole and the black hole is perturbed. Then you need to wait a shorter time for the vibrations to settle to a certain amplitude."

The phenomena, Burko said, can be compared to a ringing bell.

"A bell rings, but eventually it gets quiet. The energy that goes out with the sound waves is energy that the bell is losing," Burko described in a statement. "A black hole does exactly that in gravitational waves instead of sound waves. A black hole that is wobbling is emitting gravitational waves. When those vibrations die down you get a quiet black hole."

Gravitational waves are predicted by Einstein's theory of general relativity to emanate from neutron stars and black holes, but astronomers have not yet detected any directly.

The research is detailed in the Jan. 7 issue of the science journal Classical and Quantum Gravity.

While the PS3 Gravity Grid may not be useful for all types of research, for those requiring little RAM but massive computations it can prove a cost-cutting tool, said Khanna, who built a smaller cluster before stringing together the 16-machine grid.

"Science budgets have been significantly dropping over the last decade," said Khanna, who describes how to build a PS3 computer cluster on his Web site. "Here's a way that people can do science projects less expensively."

New Currency for Space Travelers

Be prepared. They may not take travelers checks.Scientists have come up with a new currency designed to be used by inter-planetary travelers. It is called the Quasi Universal Intergalactic Denomination, or Quid.

It is designed to withstand the stresses of space travel and has no sharp edges or chemicals that could hurt space tourists. Quids are made of the polymer best-known for its use in non-stick pans.

"None of the existing payment systems we use on earth - like cash, credit or debit cards - could be used in space," said Professor George Fraser from the University of Leicester. "Anything with sharp edges, like coins, would be a risk to astronauts while the chips and magnetic strips used in our cards on Earth would be damaged beyond repair by cosmic radiation," he added.

Using any sort of technology that involved sending and receiving information from Earth would also be impractical because of the distances involved.

It was designed for the foreign exchange company Travelex by scientists from the National Space Centre and the University of Leicester. Travelex is currently quoting the currency at £6.25 ($12.5) to the Quid.

Source: BBC and Spluch

University Of Minnesota Astronomers Find Gaping Hole In The Universe

Once again, I am a day late and a dollar short.


University of Minnesota astronomers have found an enormous hole in the Universe, nearly a billion light-years across, empty of both normal matter such as stars, galaxies and gas, as well as the mysterious, unseen "dark matter." While earlier studies have shown holes, or voids, in the large-scale structure of the Universe, this new discovery dwarfs them all.

more at Space Daily

From Astronomy Picture of the Day:

What has created this huge empty volume in the universe? No one is yet sure, and even the extent of the estimated billion-light year void is being researched. The void is not a hole in space like a black hole, but rather a vast region of the universe that appears to be mostly devoid of normal matter and even dark matter. The void is still thought to contain dark energy, though, and is clearly traversable by light. The void's existence is being postulated following scientific curiosity about how unusually cold spots came to appear on WMAP's map of cosmic microwave background (CMB) radiation. One possibility was that this CMB region was not actually very cold but light from the spot somehow became less cosmologically redshifted than normal along the way. Other voids in the universe are known to exist, but this void appears to have an unusually large gravitational effect, and so might possibly be the largest in our entire visible universe. Investigating this, a recent study found an unusually low number of cosmic radio sources between Earth and the CMB cold spot, which led to the inference of this giant void.

First sign of water on planet outside our system

Astronomers have detected water in the atmosphere of a planet outside our solar system for the first time.

The discovery, announced today, means one of the most crucial elements for life as we know it can exist around planets orbiting other stars.

“We know that water vapor exists in the atmospheres of one extrasolar planet and there is good reason to believe that other extrasolar planets contain water vapor,” said Travis Barman, an astronomer at the Lowell Observatory in Arizona who made the discovery.

HD209458b is a world well-known among planet hunters. In 1999, it became the first planet to be directly observed around a normal star outside our solar system and, a few years later, was the first exoplanet confirmed to have oxygen and carbon in its atmosphere.

Space.com