Maybe there is more to it than you think...

Multiverse  --- maybe we are only one of many universes




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1# > A < Posted 2011-8-4 10:18 Only show this user's posts Study hints at 'bubble universes



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2011-8-4 10:18



The team has located possible "bubble universe" evidence in WMAP data







The idea that other universes - as well as our own - lie within "bubbles" of space and time has received a boost.



Studies of the low-temperature glow left from the Big Bang suggest that several of these "bubble universes" may have left marks on our own.



This "multiverse" idea is popular in modern physics, but experimental tests have been hard to come by.



The preliminary work, to be published in Physical Review D, will be firmed up using data from the Planck telescope.



For now, the team has worked with seven years' worth of data from the Wilkinson Microwave Anisotropy Probe, which measures in minute detail the cosmic microwave background (CMB) - the faint glow left from our Universe's formation.



'Mind-blowing'



The theory that invokes these bubble universes - a theory formally called "eternal inflation" - holds that such universes are popping into and out of existence and colliding all the time, with the space between them rapidly expanding - meaning that they are forever out of reach of one another.



But Hiranya Peiris, a cosmologist at University College London, and her colleagues have now worked out that when these universes are created adjacent to our own, they may leave a characteristic pattern in the CMB.



"I'd heard about this 'multiverse' for years and years, and I never took it seriously because I thought it's not testable," Dr Peiris told BBC News. "I was just amazed by the idea that you can test for all these other universes out there - it's just mind-blowing."



Dr Peiris' team first proposed these disc-shaped signatures in the CMB in a paper published in Physical Review Letters, and the new work fleshes out the idea, putting numbers to how many bubble universes we may be able to see now.



Crucially, they used a computer program that looked for these discs automatically - reducing the chance that one of the collaborators would see the expected shape in the data when it was not in fact there.



The program found four particular areas that look likely to be signatures of the bubble universes - where the bubbles were 10 times more likely than the standard theory to explain the variations that the team saw in the CMB.





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Data from the Planck telescope should resolve the question once and for all





However, Dr Peiris stressed that the four regions were "not at a high statistical significance" - that more data would be needed to be assured of the existence of the "multiverse".



"Finding just four patches is not necessarily going to give you a good probability on the full sky," she explained to BBC News. "That's not statistically strong enough to either rule it out or to say that there is a collision."



Dr Peiris said that data from the Planck telescope - a next-generation space telescope designed to study the CMB with far greater sensitivity - would put the idea on a firmer footing, or refute it. However, the data from Planck cannot be discussed publicly before January 2013.





Data from the Planck telescope should resolve the question once and for all

George Efstathiou, director of the Kavli Institute of Cosmology at the University of Cambridge, called the work "the first serious attempt to search for something like this... from the methodology point of view it's interesting".



He noted that the theories that invoked the multiverse were fraught with problems, because they dealt in so many intangible or immeasurable quantities.



"My own personal view is that it will need new physics to solve this problem," he told BBC News. "But just because there are profound theory difficulties doesn't mean one shouldn't take the picture seriously."



Dr Peiris said that even if these bubble universes were confirmed, we could never learn anything further about them.



"It would be wonderful to be able to go outside our bubble, but it's not going to be possible," she explained.



"They're born close together - that's when the collision happens - and this same inflation happens between the bubbles. They're being hurled apart and space-time is expanding faster than light between them."



But Professor Efstathiou said the search was inherently worth it. He explained: "It would be a pretty amazing thing to show that we have actually made physical contact in another universe. It's a long shot, but it would by very profound for physics."







BBC

Aborted Dream of a Bad Night Sleeping

By Joseph E. Stiglitz





Just a few years ago, a powerful ideology – the belief in free and unfettered markets – brought the world to the brink of ruin. Even in its hey-day, from the early 1980’s until 2007, American-style deregulated capitalism brought greater material well-being only to the very richest in the richest country of the world. Indeed, over the course of this ideology’s 30-year ascendance, most Americans saw their incomes decline or stagnate year after year.





Moreover, output growth in the United States was not economically sustainable. With so much of US national income going to so few, growth could continue only through consumption financed by a mounting pile of debt.





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Joseph E. Stiglitz





I was among those who hoped that, somehow, the financial crisis would teach Americans (and others) a lesson about the need for greater equality, stronger regulation, and a better balance between the market and government. Alas, that has not been the case. On the contrary, a resurgence of right-wing economics, driven, as always, by ideology and special interests, once again threatens the global economy – or at least the economies of Europe and America, where these ideas continue to flourish.





In the US, this right-wing resurgence, whose adherents evidently seek to repeal the basic laws of math and economics, is threatening to force a default on the national debt. If Congress mandates expenditures that exceed revenues, there will be a deficit, and that deficit has to be financed. Rather than carefully balancing the benefits of each government expenditure program with the costs of raising taxes to finance those benefits, the right seeks to use a sledgehammer – not allowing the national debt to increase forces expenditures to be limited to taxes.





This leaves open the question of which expenditures get priority – and if expenditures to pay interest on the national debt do not, a default is inevitable. Moreover, to cut back expenditures now, in the midst of an ongoing crisis brought on by free-market ideology, would inevitably simply prolong the downturn.





A decade ago, in the midst of an economic boom, the US faced a surplus so large that it threatened to eliminate the national debt. Unaffordable tax cuts and wars, a major recession, and soaring health-care costs – fueled in part by the commitment of George W. Bush’s administration to giving drug companies free rein in setting prices, even with government money at stake – quickly transformed a huge surplus into record peacetime deficits.





The remedies to the US deficit follow immediately from this diagnosis: put America back to work by stimulating the economy; end the mindless wars; rein in military and drug costs; and raise taxes, at least on the very rich. But the right will have none of this, and instead is pushing for even more tax cuts for corporations and the wealthy, together with expenditure cuts in investments and social protection that put the future of the US economy in peril and that shred what remains of the social contract. Meanwhile, the US financial sector has been lobbying hard to free itself of regulations, so that it can return to its previous, disastrously carefree, ways.





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But matters are little better in Europe. As Greece and others face crises, the medicine du jour is simply timeworn austerity packages and privatization, which will merely leave the countries that embrace them poorer and more vulnerable. This medicine failed in East Asia, Latin America, and elsewhere, and it will fail in Europe this time around, too. Indeed, it has already failed in Ireland, Latvia, and Greece.





There is an alternative: an economic-growth strategy supported by the European Union and the International Monetary Fund. Growth would restore confidence that Greece could repay its debts, causing interest rates to fall and leaving more fiscal room for further growth-enhancing investments. Growth itself increases tax revenues and reduces the need for social expenditures, such as unemployment benefits. And the confidence that this engenders leads to still further growth.





Regrettably, the financial markets and right-wing economists have gotten the problem exactly backwards: they believe that austerity produces confidence, and that confidence will produce growth. But austerity undermines growth, worsening the government’s fiscal position, or at least yielding less improvement than austerity’s advocates promise. On both counts, confidence is undermined, and a downward spiral is set in motion.





Do we really need another costly experiment with ideas that have failed repeatedly? We shouldn’t, but increasingly it appears that we will have to endure another one nonetheless. A failure of either Europe or the US to return to robust growth would be bad for the global economy. A failure in both would be disastrous – even if the major emerging-market countries have attained self-sustaining growth. Unfortunately, unless wiser heads prevail, that is the way the world is heading.







Joseph E. Stiglitz is University Professor at Columbia University, a Nobel laureate in economics, and the author of Freefall: Free Markets and the Sinking of the Global Economy.