Researcher shows that black holes do not exist

This artist's concept depicts a supermassive black hole at the center of a galaxy. 

The blue colour here represents radiation pouring out from material very close to the black hole. 

The grayish structure surrounding the black hole, called a torus, is made up of gas and dust. 

Credit: NASA/JPL-Caltech

Black holes have long captured the public imagination and been the subject of popular culture, from Star Trek to Hollywood.

They are the ultimate unknown, the blackest and most dense objects in the universe that do not even let light escape, and as if they weren't bizarre enough to begin with, now add this to the mix: they don't exist.

By merging two seemingly conflicting theories, Laura Mersini-Houghton, a physics professor at UNC-Chapel Hill in the College of Arts and Sciences, has proven, mathematically, that black holes can never come into being in the first place.

The work not only forces scientists to reimagine the fabric of space-time, but also rethink the origins of the universe.

"I'm still not over the shock," said Mersini-Houghton. "We've been studying this problem for a more than 50 years and this solution gives us a lot to think about."

For decades, black holes were thought to form when a massive star collapses under its own gravity to a single point in space, imagine the Earth being squished into a ball the size of a peanut, called a singularity.

So the story went, an invisible membrane known as the event horizon surrounds the singularity and crossing this horizon means that you could never cross back.

It's the point where a black hole's gravitational pull is so strong that nothing can escape it.

The reason black holes are so bizarre is that it pits two fundamental theories of the universe against each other.

Einstein's theory of gravity predicts the formation of black holes but a fundamental law of quantum theory states that no information from the universe can ever disappear.

Efforts to combine these two theories lead to mathematical nonsense, and became known as the information loss paradox.

In 1974, Stephen Hawking used quantum mechanics to show that black holes emit radiation.

Since then, scientists have detected fingerprints in the cosmos that are consistent with this radiation, identifying an ever-increasing list of the universe's black holes.

But now Mersini-Houghton describes an entirely new scenario. She and Hawking both agree that as a star collapses under its own gravity, it produces Hawking radiation.

However, in her new work, Mersini-Houghton shows that by giving off this radiation, the star also sheds mass. So much so that as it shrinks it no longer has the density to become a black hole.

Before a black hole can form, the dying star swells one last time and then explodes. A singularity never forms and neither does an event horizon.

The take home message of her work is clear: there is no such thing as a black hole.

The paper, which was recently submitted to ArXiv, an online repository of physics papers that is not peer-reviewed, offers exact numerical solutions to this problem and was done in collaboration with Harald Peiffer, an expert on numerical relativity at the University of Toronto.

An earlier paper, by Mersini-Houghton, originally submitted to ArXiv in June, was published in the journal Physics Letters B, and offers approximate solutions to the problem.

Experimental evidence may one day provide physical proof as to whether or not black holes exist in the universe, but for now, Mersini-Houghton says the mathematics are conclusive.

Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang.

However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened.

"Physicists have been trying to merge these two theories, Einstein's theory of gravity and quantum mechanics, for decades, but this scenario brings these two theories together, into harmony," said Mersini-Houghton. "And that's a big deal."

More information: Mersini-Houghton's ArXiv papers: Approximate solutions: arxiv.org/abs/arXiv:1406.1525 Exact solutions: arxiv.org/abs/arXiv:1409.1837

NASA Gravity Probe B: Results of Epic Space-Time Experiment Announced

An artist's concept of GP-B measuring the curved spacetime around Earth.

Einstein was right again. There is a space-time vortex around Earth, and its shape precisely matches the predictions of Einstein's theory of gravity.

Researchers confirmed these points at a press conference today at NASA headquarters where they announced the long-awaited results of Gravity Probe B (GP-B).

"The space-time around Earth appears to be distorted just as general relativity predicts," says Stanford University physicist Francis Everitt, principal investigator of the Gravity Probe B mission.

"This is an epic result," adds Clifford Will of Washington University in St. Louis. An expert in Einstein's theories, Will chairs an independent panel of the National Research Council set up by NASA in 1998 to monitor and review the results of Gravity Probe B.

"One day," he predicts, "this will be written up in textbooks as one of the classic experiments in the history of physics."


Time and space, according to Einstein's theories of relativity, are woven together, forming a four-dimensional fabric called "space-time."

The mass of Earth dimples this fabric, much like a heavy person sitting in the middle of a trampoline. Gravity, says Einstein, is simply the motion of objects following the curvaceous lines of the dimple.

If Earth were stationary, that would be the end of the story. But Earth is not stationary. Our planet spins, and the spin should twist the dimple, slightly, pulling it around into a 4-dimensional swirl. This is what GP-B went to space in 2004 to check.

The idea behind the experiment is simple:

Put a spinning gyroscope into orbit around the Earth, with the spin axis pointed toward some distant star as a fixed reference point.

Free from external forces, the gyroscope's axis should continue pointing at the star--forever. But if space is twisted, the direction of the gyroscope's axis should drift over time.

By noting this change in direction relative to the star, the twists of space-time could be measured.

In practice, the experiment is tremendously difficult.

One of the super-spherical gyroscopes of Gravity Probe B.

The four gyroscopes in GP-B are the most perfect spheres ever made by humans.

These ping pong-sized balls of fused quartz and silicon are 1.5 inches across and never vary from a perfect sphere by more than 40 atomic layers.

If the gyroscopes weren't so spherical, their spin axes would wobble even without the effects of relativity.

According to calculations, the twisted space-time around Earth should cause the axes of the gyros to drift merely 0.041 arcseconds over a year. An arcsecond is 1/3600th of a degree.

To measure this angle reasonably well, GP-B needed a fantastic precision of 0.0005 arcseconds. It's like measuring the thickness of a sheet of paper held edge-on 100 miles away.

"GP-B researchers had to invent whole new technologies to make this possible," notes Will.

“Logic will get you from A to B. Imagination will take you Everywhere!"

Inspirational poster for NASA’s One Hundred Year Starship Program, in the vein of Einstein’s famous thoughts on rationality vs. intuition. 

Albert Einstein Lives On - Robotics

Through the science of robotics, researchers in California have created a lifelike bust of Albert Einstein to teach others, and themselves, about the breakthroughs made with robots.

Edited and shot by: Alex Matthews

Read more at Smithsonian.com

ESA Edoardo Amaldi: ATV-3 and ATV-4 mission logo available

The ATV-3 Edoardo Amaldi mission logo is also available, styled in a cool green.

The ATV-4 Albert Einstein logo has arrived, fresh in from the designers. The ATV-4 logo sticks to the existing ATV logo theme, but sports nice red colours.

Einstein Ring Hubble Image: Cosmic Horseshoe seems to surround Red galaxy

A fortuitous alignment of celestial mechanics has given the Hubble Space Telescope an amazing view of some distant galaxies.

Here, one interesting red galaxy is encircled by a hazy blue horseshoe shape and contains about 10 times the mass of our Milky Way galaxy.

It's actually the blue horsehoe shape that has astronomers talking about this photo.

The horseshoe is actually a distant galaxy that has been magnified and warped into a nearly complete ring by the strong gravitational pull of the massive red galaxy in the foreground.

To see such a so-called Einstein Ring required the fortunate alignment of the foreground and background galaxies, making this object’s nickname "the Cosmic Horseshoe" particularly apt, NASA says.

Second Experiment Confirms Faster-Than-Light Neutrinos - Einstein's Theory questioned

A new experiment appears to provide further evidence that neutrinos can travel faster than light, contradicting Einstein's theory of relativity that underpins modern thinking of how the universe works.

Albert Einstein published his theory of relativity in 1905 and asserted that nothing - no matter how small - can travel faster than the speed of light, which is approximately 186,000 miles per second.

The experiment, which is the second of its kind this year, took place at the Gran Sasso laboratory in Italy and used a neutrino beam from CERN in Switzerland 450 miles away.

Scientists at the Italian Institute for Nuclear Physics (INFN) said in a statement that their new tests aimed to exclude one potential systematic effect that might have affected the original measurement.

"A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny," said Fernando Ferroni, president of the INFN.

Scientists were shocked in September when a similar experiment found that neutrinos had travelled faster than light and - in theory - arrived at their destination before they set off.

Reuters reports that physicists involved said they had checked and rechecked anything that could have produced a misreading before announcing what they had found.

In an attempt to rule out any margin for error, the beams sent by CERN in this latest experiment were a few nanoseconds shorter than those sent in the September experiment, with larger gaps of 524 nanoseconds between them, resulting in more accurate timing.

"In this way, compared to the previous measurement, the neutrinos bunches are narrower and more spaced from each other," the scientists said. "This permits to make a more accurate measure of their velocity at the price of a much lower beam intensity."

Although errors can still not be completely ruled out, this evidence does further suggest that Einstein's theory of relativity was incorrect, forcing a major rethinking about how the cosmos works. It may even mean that sending information back in time could be made possible.

CERN: Speed of light broken

Prof Jenny Thomas, of University College London, says the claims, if proven true, would call into question our very understanding of physics and the universe.

She said: "It would turn everything on its head. It is too awful to think about.

"The basic thing it that would be questioned is that there is an absolute speed limit which is the basis of special relativity and that is a huge building block of modern physics.

"It permeates everything to do with how we have modelled the universe and everything. It would be very hard to predict what the effects would be."

UPDATE: The ‘discovery’ was made by the OPERA experiment while the neutrinos were beamed from Geneva to a lab in Gran Sasso in Italy. The pre-print of the report, prepared by CERN and published today (23rd September) can be found here: http://arxiv.org/abs/1109.4897

Special relativity is integral to the understanding of particle accelerators and the creation of particle beams, which are of crucial importance in fields like medicine and engineering, she said.

It could even be that the most famous equation of all time, E=mc2, turns out to be incorrect because it is based on the law of special relativity, Prof Thomas said.

Before any conclusions can be drawn, the CERN team's results will be checked by scientists across the globe including at Fermilab near Chicago, where a similar experiment known as Minos is based.

Prof Thomas – the co-spokesperson for the Minos project – said the team had thrown up similar results several years ago but had discounted them because the possible margin of error was too high.

She said: "Our errors were rather large so we dismissed it. Nothing is further from your belief than that the results might be correct.

CERN Press Release by CMS: http://www.interactions.org/cms/?pid=1031063

"When I heard about the Cern results my first thought was that they must be wrong, there must be something they have not taken into account."

Potential errors could occur in the measurement of distance between the point the particle was created and where it was detected; the time it took to travel from one point to the other; or in the structure of the accelerator which the whole measurement relies upon.

Prof Thomas added: "I think everyone is sceptical. The scientists themselves have admitted they are sceptical but they cannot see what they have done wrong.

"We will repeat our experiment with higher precision, hopefully in the next six months."

The Fermilab team will then begin a second stage of their experiment, called Minos Plus, which is even more similar to the Cern trial and will deliver results accurate to one nanosecond, she said.

ESA Integral: Challenges physics beyond Einstein

Integral’s IBIS instrument captured the gamma-ray burst (GRB) of 19 December 2004 that Philippe Laurent and colleagues have now analysed in detail.

It was so bright that Integral could also measure its polarisation, allowing Laurent and colleagues to look for differences in the signal from different energies.

The GRB shown here, on 25 November 2002, was the first captured using such a powerful gamma-ray camera as Integral’s. When they occur, GRBs shine as brightly as hundreds of galaxies each containing billions of stars.

Credits: ESA/SPI Team/ECF

NASA's Gravity Probe B Confirms Two Einstein Space-Time Theories

NASA's Gravity Probe B (GP-B) mission has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test.

The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates.

GP-B determined both effects with unprecedented precision by pointing at a single star, IM Pegasi, while in a polar orbit around Earth. If gravity did not affect space and time, GP-B's gyroscopes would point in the same direction forever while in orbit. But in confirmation of Einstein's theories, the gyroscopes experienced measurable, minute changes in the direction of their spin, while Earth's gravity pulled at them.

The findings are online in the journal Physical Review Letters.

"Imagine the Earth as if it were immersed in honey. As the planet rotates, the honey around it would swirl, and it's the same with space and time," said Francis Everitt, GP-B principal investigator at Stanford University.

"GP-B confirmed two of the most profound predictions of Einstein's universe, having far-reaching implications across astrophysics research. Likewise, the decades of technological innovation behind the mission will have a lasting legacy on Earth and in space."

GP-B is one of the longest running projects in NASA history, with agency involvement starting in the fall of 1963 with initial funding to develop a relativity gyroscope experiment.

Subsequent decades of development led to groundbreaking technologies to control environmental disturbances on spacecraft, such as aerodynamic drag, magnetic fields and thermal variations. The mission's star tracker and gyroscopes were the most precise ever designed and produced.

GP-B completed its data collection operations and was decommissioned in December 2010.

More info here

Einstein and the end of space-time

Physicists struggling to reconcile gravity with quantum mechanics have hailed a theory – inspired by pencil lead – that could make it all very simple

IT WAS a speech that changed the way we think of space and time. The year was 1908, and the German mathematician Hermann Minkowski had been trying to make sense of Albert Einstein's hot new idea - what we now know as special relativity - describing how things shrink as they move faster and time becomes distorted.

"Henceforth space by itself and time by itself are doomed to fade into the mere shadows," Minkowski proclaimed, "and only a union of the two will preserve an independent reality."

And so space-time - the malleable fabric whose geometry can be changed by the gravity of stars, planets and matter - was born. It is a concept that has served us well, but if physicist Petr Horava is right, it may be no more than a mirage.

Horava, who is at the University of California, Berkeley, wants to rip this fabric apart and set time and space free from one another in order to come up with a unified theory that reconciles the disparate worlds of quantum mechanics and gravity - one the most pressing challenges to modern physics.

Since Horava published his work in January 2009, it has received an astonishing amount of attention. Already, more than 250 papers have been written about it. Some researchers have started using it to explain away the twin cosmological mysteries of dark matter and dark energy.

Others are finding that black holes might not behave as we thought. If Horava's idea is right, it could forever change our conception of space and time and lead us to a "theory of everything", applicable to all matter and the forces that act on it.

For decades now, physicists have been stymied in their efforts to reconcile Einstein's general theory of relativity, which describes gravity, and quantum mechanics, which describes particles and forces (except gravity) on the smallest scales.

The stumbling block lies with their conflicting views of space and time. As seen by quantum theory, space and time are a static backdrop against which particles move. In Einstein's theories, by contrast, not only are space and time inextricably linked, but the resulting space-time is moulded by the bodies within it.

Part of the motivation behind the quest to marry relativity and quantum theory - to produce a theory of quantum gravity - is an aesthetic desire to unite all the forces of nature. But there is much more to it than that.

We also need such a theory to understand what happened immediately after the big bang or what's going on near black holes, where the gravitational fields are immense.

One area where the conflict between quantum theory and relativity comes to the fore is in the gravitational constant, G, the quantity that describes the strength of gravity. On large scales - at the scale of the solar system or of the universe itself - the equations of general relativity yield a value of G that tallies with observed behaviour.

But when you zoom in to very small distances, general relativity cannot ignore quantum fluctuations of space-time. Take them into account and any calculation of G gives ridiculous answers, making predictions impossible.

To read the full article Click Here

Einstein's General Relativity Theory Fights Off Challengers

Two new and independent studies have put Einstein's General Theory of Relativity to the test like never before. These results, made using NASA's Chandra X-ray Observatory, show Einstein's theory is still the best game in town.

Each team of scientists took advantage of extensive Chandra observations of galaxy clusters, the largest objects in the Universe bound together by gravity. One result undercuts a rival gravity model to General Relativity, while the other shows that Einstein's theory works over a vast range of times and distances across the cosmos.

The first finding significantly weakens a competitor to General Relativity known as "f(R) gravity".

"If General Relativity were the heavyweight boxing champion, this other theory was hoping to be the upstart contender," said Fabian Schmidt of the California Institute of Technology in Pasadena, who led the study. "Our work shows that the chances of its upsetting the champ are very slim."

In recent years, physicists have turned their attention to competing theories to General Relativity as a possible explanation for the accelerated expansion of the universe. Currently, the most popular explanation for the acceleration is the so-called cosmological constant, which can be understood as energy that exists in empty space. This energy is referred to as dark energy to emphasize that it cannot be directly detected.

In the f(R) theory, the cosmic acceleration comes not from an exotic form of energy but from a modification of the gravitational force. The modified force also affects the rate at which small enhancements of matter can grow over the eons to become massive clusters of galaxies, opening up the possibility of a sensitive test of the theory.

Schmidt and colleagues used mass estimates of 49 galaxy clusters in the local universe from Chandra observations, compared them with theoretical model predictions and studies of supernovas, the cosmic microwave background, and the large-scale distribution of galaxies.

They found no evidence that gravity is different from General Relativity on scales larger than 130 million light years. This limit corresponds to a hundred-fold improvement on the bounds of the modified gravitational force's range that can be set without using the cluster data.

"This is the strongest ever constraint set on an alternative to General Relativity on such large distance scales," said Schmidt. "Our results show that we can probe gravity stringently on cosmological scales by using observations of galaxy clusters."

The reason for this dramatic improvement in constraints can be traced to the greatly enhanced gravitational forces acting in clusters as opposed to the universal background expansion of the universe. The cluster-growth technique also promises to be a good probe of other modified gravity scenarios, such as models motivated by higher- dimensional theories and string theory.

For the full article click here on this link to NASA

Chinese Scientists Seek Support For Dark Matter Mission In Space

Chinese Scientists Seek Support For Dark Matter Mission In Space

Chinese scientists are lobbying for greater government support for a groundbreaking project that would see the launch of a satellite to investigate mysterious dark matter in space.

The Center for Space Science and Applied Research (CSSAR) of the Chinese Academy of Sciences was focusing on developing China's first astronomical satellite to prove the existence of dark matter.

"This would be a major breakthrough in the field of basic science which has been dormant for decades since Einstein's Theory of Relativity," said center director Wu Ji.

Dark matter and dark energy represent the vast majority of the mass in the observable universe, but their presence is only inferred from their gravitational effects on visible matter. Dark matter is believed to play a central role in galaxy evolution and the formation of universe.

Chaos Theory Moves on: What about Entanglement?

At the level of atoms, our definition of chaos has run into a problem.

Chaos is usually defined by a system’s movement: Set a pendulum swinging, track exactly where it goes, and its motion will reveal whether it is chaotic. Atoms, however, are governed by the uncertainty principle, which means that their location cannot be known precisely. What’s more, the laws of quantum mechanics say that hypersensitivity to initial conditions, which is considered the primary characteristic of a chaotic system, is physically impossible for atoms—at least in the way it’s understood at the classical level.

This presents a serious quandary because quantum mechanics is considered the most basic set of universal laws. Chaos must have some connection with the quantum level, but how it manifests itself, or how to quantify it, has thus far eluded physicists. Work published recently in Nature helps shed light on this problem as researchers working with cooled atoms searched for what they call signatures of chaos.

If such hypersensitivity to initial conditions cannot happen in a quantum system, other red flags of classical chaos might still be detectable. This could indicate that chaos in some form could exist at the level of atoms, or, at the very least, would imply a connection between quantum events and classical chaos. “Though you will never be able to find hypersensitivity to initial conditions in the quantum system, you are able to tell if the outward signs produced by classical chaotic systems are the same in quantum systems,” says Poul Jessen of Arizona State University, the lead researcher on the Nature paper.

In order to see these signatures, physicists have taken the conditions that cause chaotic behavior in human-scale systems and applied them on the atomic level. Jessen and his collaborators recently succeeded in making a quantum “kicked top” out of cesium atoms for the first time.

Kicked tops are an excellent example of chaotic systems when it comes to classic physics. You start an object twirling—say, a gyroscope—and then give it a series of kicks and twists as it spins. The initial condition that decides whether a gyroscope moves stably or chaotically is the direction of its axis when it starts spinning.

In order to visualize the gyroscope’s behaviour, the different values of its angular momentum are plotted on the surface of a globe. Some initial orientations of its axis cause the momentum to swerve in a “chaotic sea,” covering most of the surface of the globe. But other orientations cause the spin to settle into stable, regular motion in one of three main “islands” in the sea.

In their experiment, researchers substituted atoms for gyroscopes and looked at how angular momenta affected the atoms’ quantum states. What they found was intriguing: Some spins of the quantum top locked the atoms into a stable set of islands, while other values let the atoms’ quantum states wander erratically.

The number and location of the islands, when plotted, corresponded eerily to the classical model. So while the atoms’ behavior could not technically be called chaotic because they cannot show hypersensitivity, they mimicked the evolution of the classical, chaotic system almost exactly. Other measurements indicated that the system might have some sensitivity to disturbances, another interesting link to chaotic behaviour.

These observations alone provided good evidence that something related to chaos was happening. But the most fascinating result was that one of the strangest properties of atoms, entanglement, shot up in areas corresponding to the chaotic sea. When two quantum-scale objects, like atoms or nuclei, are entangled, performing an action on one instantaneously affects the other even if vast distances separate the entangled objects. Einstein famously called entanglement “spooky action at a distance,” and it forms the basis of modern attempts to built quantum computers.

Could entanglement be a signature of chaos?

Read the full article in Seed magazine ..............

Galaxies Missing in Space: Can Weak Gravity be the Culprit

LIKE moths about a flame, thousands of tiny satellite galaxies flutter about our Milky Way. For astronomers this is a dream scenario, fitting perfectly with the established models of how our galaxy's cosmic neighbourhood should be. Unfortunately, it's a dream in more ways than one and the reality could hardly be more different.

As far as we can tell, barely 25 straggly satellites loiter forlornly around the outskirts of the Milky Way. "We see only about 1 per cent of the predicted number of satellite galaxies," says Pavel Kroupa of the University of Bonn in Germany. "It is the cleanest case in which we can see there is something badly wrong with our standard picture of the origin of galaxies."

It isn't just the apparent dearth of galaxies that is causing consternation. At a conference earlier this year in the German town of Bad Honnef, Kroupa and his colleagues presented an analysis of the location and motion of the known satellite galaxies. They reported that most of those galaxies orbit the Milky Way in an unexpected manner and that, taken together, their results are at odds with mainstream cosmology. There is "only one way" to explain the results, says Kroupa: "Gravity has to be stronger than predicted by Newton."

Defying Gravity

If happy little blowflies can defy gravity then why, oh why, can't we? (Image: Simon Faithfull)

One man's attempt to defy Gravity! or maybe not, but it could be the answer to the 'office chair from space falls on car' mystery!

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