Why Our Universe Must Have Been Born Inside a Black Hole

From Technology Review:

“Accordingly, our own Universe may be the interior of a black hole existing in another universe.” So concludes Nikodem Poplawski at Indiana University in a remarkable paper about the nature of space and the origin of time.

The idea that new universes can be created inside black holes and that our own may have originated in this way has been the raw fodder of science fiction for many years. But a proper scientific derivation of the notion has never emerged.

Today Poplawski provides such a derivation. He says the idea that black holes are the cosmic mothers of new universes is a natural consequence of a simple new assumption about the nature of spacetime.

Poplawski points out that the standard derivation of general relativity takes no account of the intrinsic momentum of spin half particles. However there is another version of the theory, called the Einstein-Cartan-Kibble-Sciama theory of gravity, which does.

This predicts that particles with half integer spin should interact, generating a tiny repulsive force called torsion. In ordinary circumstances, torsion is too small to have any effect. But when densities become much higher than those in nuclear matter, it becomes significant. In particular, says Poplawski, torsion prevents the formation of singularities inside a black hole.

That’s interesting for a number of reasons. First, it has important implications for the way the Universe must have grown when it was close to its minimum size.

Astrophysicists have long known that our universe is so big that it could not have reached its current size given the rate of expansion we see now. Instead, they believe it grew by many orders of magnitude in a fraction of a second after the Big Bang, a process known as inflation.

The problem with inflation is that it needs an additional theory to explain why it occurs and that’s ugly. Poplawski’s approach immediately solves this problem. He says that torsion caused this rapid inflation.

That means the universe as we see it today can be explained by a single theory of gravity without any additional assumptions about inflation.

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Revised theory of gravity doesn’t predict a Big Bang

Lisa Zyga in PHYSORG:

The Big Bang theory has formed the basis of our understanding of the universe’s origins since it was first proposed in 1927 by Georges Lemaitre. And for good reason: the theory is supported by scientists’ latest observations and experiments, and is based on Einstein’s widely accepted theory of general relativity. But scientists are always on the lookout for any evidence that might suggest an alternative to the Big Bang. The latest in this area of research comes from astrophysicists Maximo Banados and Pedro Ferreira, who have resurrected a theory of gravity from the early 20th century and discovered that a modified version of the theory may hold some surprises.

In a recent study published in , Banados and Ferreira have reconsidered the theory of gravity proposed by Arthur Eddington, a contemporary of Einstein. Eddington is perhaps best known for his trip to the Island of Principe on the west coast of Africa in 1919, where during a solar eclipse he observed that the Sun’s gravity does indeed bend starlight, providing one of the earliest confirmations of general relativity.

Although Eddington played a significant role in developing general relativity, during the following decades he became more interested in finding a theory to unify gravity and  – a task that is still being studied today. In 1924, Eddington proposed a new “gravitational action” as an alternative to the Einstein-Hilbert action, which could serve as an alternative starting point to general relativity. In astrophysics, a gravitational action is the mechanism that describes how gravity can emerge from space-time being curved by matter and energy. However, Eddington’s theory of gravity only worked for empty space and didn’t include any source of energy such as matter, making it an incomplete theory.

Since Eddington’s proposal, scientists have attempted various ways of including matter into the theory, although they have run into problems. In this study, Banados and Ferreira have tried a new way to extend the theory to include matter by using a gravitational action called the Born-Infeld action.

In their analysis, the scientists found that a key characteristic of Eddington’s revised  is that it reproduces Einstein gravity precisely in the vacuum conditions (with no matter), but it produces new effects when matter is added. Due to this characteristic, the revised theory has implications especially for high-density regions, such as in the very early Universe or within a black hole. For instance, the theory predicts a maximum density of homogeneous and isotropic space-time, which could have implications for black hole formation.

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How facts backfire

Joe Keohane in The Boston Globe:

It’s one of the great assumptions underlying modern democracy that an informed citizenry is preferable to an uninformed one. “Whenever the people are well-informed, they can be trusted with their own government,” Thomas Jefferson wrote in 1789. This notion, carried down through the years, underlies everything from humble political pamphlets to presidential debates to the very notion of a free press. Mankind may be crooked timber, as Kant put it, uniquely susceptible to ignorance and misinformation, but it’s an article of faith that knowledge is the best remedy. If people are furnished with the facts, they will be clearer thinkers and better citizens. If they are ignorant, facts will enlighten them. If they are mistaken, facts will set them straight.

In the end, truth will out. Won’t it?

Maybe not. Recently, a few political scientists have begun to discover a human tendency deeply discouraging to anyone with faith in the power of information. It’s this: Facts don’t necessarily have the power to change our minds. In fact, quite the opposite. In a series of studies in 2005 and 2006, researchers at the University of Michigan found that when misinformed people, particularly political partisans, were exposed to corrected facts in news stories, they rarely changed their minds. In fact, they often became even more strongly set in their beliefs. Facts, they found, were not curing misinformation. Like an underpowered antibiotic, facts could actually make misinformation even stronger.

This bodes ill for a democracy, because most voters — the people making decisions about how the country runs — aren’t blank slates. They already have beliefs, and a set of facts lodged in their minds. The problem is that sometimes the things they think they know are objectively, provably false. And in the presence of the correct information, such people react very, very differently than the merely uninformed. Instead of changing their minds to reflect the correct information, they can entrench themselves even deeper.

“The general idea is that it’s absolutely threatening to admit you’re wrong,” says political scientist Brendan Nyhan, the lead researcher on the Michigan study. The phenomenon — known as “backfire” — is “a natural defense mechanism to avoid that cognitive dissonance.”

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A Scientist Takes On Gravity

Dennis Overbye in The New York Times:

It’s hard to imagine a more fundamental and ubiquitous aspect of life on the Earth than gravity, from the moment you first took a step and fell on your diapered bottom to the slow terminal sagging of flesh and dreams.

But what if it’s all an illusion, a sort of cosmic frill, or a side effect of something else going on at deeper levels of reality?

So says Erik Verlinde, 48, a respected string theorist and professor of physics at the University of Amsterdam, whose contention that gravity is indeed an illusion has caused a continuing ruckus among physicists, or at least among those who profess to understand it. Reversing the logic of 300 years of science, he argued in a recent paper, titled “On the Origin of Gravity and the Laws of Newton,”that gravity is a consequence of the venerable laws of thermodynamics, which describe the behavior of heat and gases.

“For me gravity doesn’t exist,” said Dr. Verlinde, who was recently in the United States to explain himself. Not that he can’t fall down, but Dr. Verlinde is among a number of physicists who say that science has been looking at gravity the wrong way and that there is something more basic, from which gravity “emerges,” the way stock markets emerge from the collective behavior of individual investors or that elasticity emerges from the mechanics of atoms.

Looking at gravity from this angle, they say, could shed light on some of the vexing cosmic issues of the day, like the dark energy, a kind of anti-gravity that seems to be speeding up the expansion of the universe, or the dark matter that is supposedly needed to hold galaxies together.

Dr. Verlinde’s argument turns on something you could call the “bad hair day” theory of gravity.

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The World Turned Upside Down

From Neuroskeptic:

This map is not “upside down”. It looks that way to us; the sense that north is up is a deeply ingrained one. It’s grim up north, Dixie is away down south. Yet this is pure convention. The earth is a sphere in space. It has a north and a south, but no up and down.

There’s a famous experiment involving four guys and a door. An unsuspecting test subject is lured into a conversation with a stranger, actually a psychologist. After a few moments, two people appear carrying a large door, and they walk right between the subject and the experimenter.

Behind the door, the experimenter swaps places with one of the door carriers, who may be quite different in voice and appearance. Most subjects don’t notice the swap. Perception is lazy: whenever it can get away with it, it merely tells us that things are as we expect, rather than actually showing us stuff. We often do not really perceive things at all. Did the subject really see the first guy? The second? Either?

The inverted map makes us actually see the Earth’s geography, rather than just showing us the expected “countries” and “continents”. I was struck by how parochial Europe is – the whole place is little more than a frayed end of the vast Eurasian landmass, no more impressive than the one at the other end, Russia’s Chukotski. Africa dominates the scene: it can no longer be written off as that poor place at the bottom.

One of the most common observations in psychotherapy of people with depression or anxiety is that they hold themselves to impossibly high standards, although they have a perfectly sensible evaluation of everyone else. Their own failures are catastrophic; other people’s are minor setbacks. Other people’s successes are well-deserved triumphs; their own are never good enough, flukes, they don’t count.

The first step in challenging these unhelpful patterns of thought is to simply point out the double-standard: why are you such a perfectionist about yourself, when you’re not when it comes to other people? The idea being to help people to think about themselves in more like healthy way they already think about others. Turn the map of yourself upside down – what do you actually see?

Who is responsible?

Sana Saleem in Dawn:

Lahore is often known as the heart of Pakistan; the hub of culture and arts, the centre of education, the city of gardens, with the prominent aspect of the city being its ancient history and its deep-rooted connection to Sufism. Living in a city steeped in heritage and culture, Lahoris are known for their fun-loving spirit. This very spirit was attacked on July 1, when two suicide bombers attacked Data Darbar, shrine of the patron saint of Lahore.

The attack killed 45 people and left more than 175 injured.

This is not the first time a shrine has been attacked, previously the shrines of Rahman Baba and Mian Umer Baba in Khyber Pakhtunkhwa have also been attacked.

Attacking Data Darbar on a Thursday night was an obvious target – that is the night when the shrine is teeming with worshippers as well as those seeking shelter and food from all walks of life. There is no question that the attack was well-planned – CCTV footage showed scenes of carnage and the bombers just moments before they blew themselves up. The footage showed a security guard chasing after one of the bombers shortly before the bomb went off – body parts and blood splattered everywhere as the survivors fled in all directions.

The most common reactions after the attack are that of denial, with many pointing fingers at foreign involvement. Statements such as “these terrorists can neither be Muslims nor Pakistanis” echoed from the common man to those in authority. Despite a history of intolerance towards Sufism, the notorious TTP has also declined any involvement in the attack claiming they do not attack ‘public places Usman, 16, who was identified as the alleged suicide bomber by the authorities, was later reported to be a victim of the attack.

I was asked a similar question : What does the attack on the Ahmedis and on Data Darbar mean? Is this sectarian violence or do terrorists not have a religion? According to The Pakistan Security Report there have been over 249 terrorist attacks across the country, killing around 1182 and leaving over 995 injured. Not a single so-called ‘foreign’ terrorist has been arrested so far, clearly ruling out the possibility of foreign and/or non-muslin suicide bombers at work. As for the possibility of a conspiracy that foreign agencies could be involved, we must understand that the nature of such involvement is opportunistic.

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Brutally Hard Math Is Its Own Reward

Jordan Ellenberg in Slate:

The New York Times recently reported that reclusive Russian geometer Grigory Perelman has apparently proved the century-old Poincaré conjecture. The Times calls Poincaré “a landmark not just of mathematics, but of human thought.” But just whyit’s so significant is left a bit hazy. Big mathematical advances often generate the same kind of lofty but content-free rhetoric found in political speeches about “the family.” Like the family, math is a subject everyone agrees is very important without being able to specify exactly why.

I’m here to help. (With the Poincaré conjecture. As for the family, you’re on your own.)

Poincaré conjectured that three-dimensional shapes that share certain easy-to-check properties with spheres actually arespheres. What are these properties? My fellow geometer Christina Sormani describes the setup as follows:

The Poincaré Conjecture says, Hey, you’ve got this alien blob that can ooze its way out of the hold of any lasso you tie around it? Then that blob is just an out-of-shape ball. [Grigory] Perelman and [Columbia University’s Richard] Hamilton proved this fact by heating the blob up, making it sing, stretching it like hot mozzarella, and chopping it into a million pieces. In short, the alien ain’t no bagel you can swing around with a string through his hole.

That’s zingier than anything theTimes will run, but may still leave you without a clear picture of Perelman’s theorem. Indeed, it’s pretty hard to give an elementary account of the statement that Poincaré conjectured and that Perelman seems to have confirmed. (If that’s what you’re after, Sormani’s home page links to a variety of expositions, including one in the form of a short story.) Instead, I’ll try to explain why Perelman’s theorem matters without explaining what it is.

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