Open links in new window


Interesting Findings And World Unfolding Through My Eyes.

Wednesday, June 20, 2007

Top20 Magic Tricks

See,learn and enjoy.

Posted by Ajay :: 5:30 PM :: 0 comments

Post a Comment

Is Internet Ruining Our Culture?

Andrew Keen wants to start an argument. And his new book “The Cult of the Amateur: How Today’s Internet is Killing Our Culture” shows that he knows how to do it. A relentless attack on the beloved Web 2.0 touchstones of user generated content and “the wisdom of crowds,” Keen’s brief polemic is a strident one-sided, archly conservative view of how Internet culture is evolving — or, in his view, degenerating. Even as it hits stores it has already been smartly dissected and thoroughly condemned by blogosphere luminaries ranging from Dan Gillmor and Jeff Jarvis to Lawrence Lessig.

After such a drubbing, clearly no sensible Internet columnist should touch this book with a 10-foot pole. Yet it deserves a look for several reasons: Keen knows the technology and doesn’t make the purely technical blunders that usually discredit other doom-saying commentators. Keen is a fearless writer willing to take conservative positions in a field that’s overwhelmingly liberal. And finally, while Keen’s arguments are extreme and biased, they will also be heard — because they reflect real public concerns about the impact of the Internet, too often downplayed by the reigning digerati.

Keen’s original subtitle, simplified before publication, sums up his argument: How the democratization of the digital world is assaulting our economy, our culture and our values. He looks at the various user-centered Web activities that epitomize Web 2.0 — YouTube, MySpace, Wikipedia, blogs, file-sharing and so forth — and ties these, variously, to loss of accuracy in news and information, the declining quality of music and video, the troubled economics of the content industries and even an erosion of original thinking (as students use Google to create “cut-and-paste” term papers).

Keen’s central thesis is that user-generated content and the disaggregation of information by search engines — reducing books, magazines and newspapers to mere collections of facts — damages both economics and quality. His economic warning is the strongest element of the book: Keen worries that traditional media companies may be done in by the “cult of amateurs.” While probably not due to “amateurs,” it is indeed the case that virtually all of the old-line content producers, from encyclopedias and record companies to television, newspapers and now even pornographers, are experiencing painful business pressures as the Internet absorbs and reorders media.

Internet pundits often gleefully say that pampered Big Media is getting what it deserves, but the long-term social consequences may not be so humorous. Keen points out that in the time it takes for the economics to work out many traditional media companies may lose important assets — such as their staff — or close down altogether. And it’s not at all clear what would replace them.

Posted by Ajay :: 9:49 AM :: 0 comments

Post a Comment

Do Black Holes Exist?

Black holes might not exist – or at least not as scientists have imagined, cloaked by an impenetrable "event horizon". A controversial new calculation could abolish the horizon, and so solve a troubling paradox in physics.

The event horizon is supposed to mark a boundary beyond which nothing can escape a black hole's gravity. According to the general theory of relativity, even light is trapped inside the horizon, and no information about what fell into the hole can ever escape. Information seems to have fallen out of the universe.

That contradicts the equations of quantum mechanics, which always preserve information. How to resolve this conflict?

One possibility researchers have proposed in the past is that the information does leak back out again slowly. It may be encoded in a hypothetical flow of particles called Hawking radiation, which is thought to result from the black holes' event horizons messing with the quantum froth that is ever-present in space.

But other researchers argue the information may never have been cut off in the first place. Tanmay Vachaspati and his colleagues at Case Western Reserve University in Cleveland, Ohio, US, have tried to calculate what happens as a black hole is forming. Using an unusual mathematical approach called the functional Schrodinger equation, they follow a sphere of stuff as it collapses inwards, and predict what a distant observer would see.

They find that the gravity of the collapsing mass starts to disrupt the quantum vacuum, generating what they call "pre-Hawking" radiation. Losing that radiation reduces the total mass-energy of the object – so that it never gets dense enough to form an event horizon and a true black hole. "There are no such things", Vachaspati told New Scientist. "There are only stars going toward being a black hole but not getting there."

Dark and dense
These so-called "black stars" would look very much like black holes, says Vachaswati. From the point of view of a distant observer, gravity distorts the apparent flow of time so that matter falling inwards slows down. As it gets close to where the horizon would be, the matter fades, its light stretched to such long wavelengths by the dark object's gravity that it would be nearly impossible to detect.

But because the pre-Hawking radiation prevents the formation of a black hole with a true event horizon, the matter never quite fades entirely. As nothing is cut off from the rest of the universe, there is no information paradox.

The idea faces firm opposition from other theoretical physicists, however. "I strongly disagree," says Nobel laureate Gerard 't Hooft of Utrecht University in the Netherlands. "The process he describes can in no way produce enough radiation to make a black hole disappear as quickly as he is suggesting." The horizon forms long before the hole can evaporate, 't Hooft told New Scientist.

Lab test
Steve Giddings of the University of California in Santa Barbara, US, is also sceptical. "Well-understood findings apparently conflict with their picture," he told New Scientist. "To my knowledge, there hasn't been an attempt to understand how they are getting results that differ from these calculations, which would be an important step to understanding if this is a solid result."

There could be a way to test the new theory. The Large Hadron Collider being constructed at CERN in Geneva might just be capable of making microscopic black holes – or, if Vachaspati is right, black stars. Unlike the large, long-lived black holes in space, these microscopic objects would evaporate fast. The spread of energies in their radiation might reveal whether or not an event horizon forms.

Alternatively, colliding black stars in space might reveal themselves, as Vachaspati says they would churn out not only gravitational waves (like colliding black holes) but also gamma rays. He suggests that they could be responsible for some of the gamma-ray bursts seen by astronomers.

Posted by Ajay :: 9:47 AM :: 0 comments

Post a Comment

Imagine Earth Without People!

It’s a common fantasy to imagine that you’re the last person left alive on earth. But what if all human beings were suddenly whisked off the planet? That premise is the starting point for The World without Us, a new book by science writer Alan Weisman, an associate professor of journalism at the University of Arizona. In this extended thought experiment, Weisman does not specify exactly what finishes off Homo sapiens; instead he simply assumes the abrupt disappearance of our species and projects the sequence of events that would most likely occur in the years, decades and centuries afterward.

According to Weisman, large parts of our physical infrastructure would begin to crumble almost immediately. Without street cleaners and road crews, our grand boulevards and superhighways would start to crack and buckle in a matter of months. Over the following decades many houses and office buildings would collapse, but some ordinary items would resist decay for an extraordinarily long time. Stainless-steel pots, for example, could last for millennia, especially if they were buried in the weed-covered mounds that used to be our kitchens. And certain common plastics might remain intact for hundreds of thousands of years; they would not break down until microbes evolved the ability to consume them.

Scientific American editor Steve Mirsky recently interviewed Weisman to find out why he wrote the book and what lessons can be drawn from his research. Some excerpts from that interview appear on the following pages.

The Interviewee

Alan Weisman is author of five books, including the forthcoming The World without Us (St. Martin’s Press, 2007). Q&A With Alan Weisman

If human beings were to disappear tomorrow, the magnificent skyline of Manhattan would not long survive them. Weisman describes how the concrete jungle of New York City would revert to a real forest.

“What would happen to all of our stuff if we weren’t here anymore? Could nature wipe out all of our traces? Are there some things that we’ve made that are indestructible or indelible? Could nature, for example, take New York City back to the forest that was there when Henry Hudson first saw it in 1609?

“I had a fascinating time talking to engineers and maintenance people in New York City about what it takes to hold off nature. I discovered that our huge, imposing, overwhelming infrastructures that seem so monumental and indestructible are actually these fairly fragile concepts that continue to function and exist thanks to a few human beings on whom all of us really depend. The name ‘Manhattan’ comes from an Indian term referring to hills. It used to be a very hilly island. Of course, the region was eventually flattened to have a grid of streets imposed on it. Around those hills there used to flow about 40 different streams, and there were numerous springs all over Manhattan island. What happened to all that water? There’s still just as much rainfall as ever on Manhattan, but the water has now been suppressed. It’s underground. Some of it runs through the sewage system, but a sewage system is never as efficient as nature in wicking away water. So there is a lot of groundwater rushing around underneath, trying to get out. Even on a clear, sunny day, the people who keep the subway going have to pump 13 million gallons of water away. Otherwise the tunnels will start to flood.
More at:

Posted by Ajay :: 9:42 AM :: 0 comments

Post a Comment



http:// googlea0b0123eb86e02a9.html