Nav: Home

Integral challenges physics beyond Einstein

June 30, 2011

ESA's Integral gamma-ray observatory has provided results that will dramatically affect the search for physics beyond Einstein. It has shown that any underlying quantum 'graininess' of space must be at much smaller scales than previously predicted.

Einstein's General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach.

One of the great concerns of modern physics is to marry these two concepts into a single theory of quantum gravity.

Now, Integral has placed stringent new limits on the size of these quantum 'grains' in space, showing them to be much smaller than some quantum gravity ideas would suggest.

According to calculations, the tiny grains would affect the way that gamma rays travel through space. The grains should 'twist' the light rays, changing the direction in which they oscillate, a property called polarisation.

High-energy gamma rays should be twisted more than the lower energy ones, and the difference in the polarisation can be used to estimate the size of the grains.

Philippe Laurent of CEA Saclay and his collaborators used data from Integral's IBIS instrument to search for the difference in polarisation between high- and low-energy gamma rays emitted during one of the most powerful gamma-ray bursts (GRBs) ever seen.

GRBs come from some of the most energetic explosions known in the Universe. Most are thought to occur when very massive stars collapse into neutron stars or black holes during a supernova, leading to a huge pulse of gamma rays lasting just seconds or minutes, but briefly outshining entire galaxies.

GRB 041219A took place on 19 December 2004 and was immediately recognised as being in the top 1% of GRBs for brightness. It was so bright that Integral was able to measure the polarisation of its gamma rays accurately.

Dr Laurent and colleagues searched for differences in the polarisation at different energies, but found none to the accuracy limits of the data.

Some theories suggest that the quantum nature of space should manifest itself at the 'Planck scale': the minuscule 10 E-35 of a metre, where a millimetre is 10 E-3 m.

However, Integral's observations are about 10 000 times more accurate than any previous and show that any quantum graininess must be at a level of 10 E-48 m or smaller.

"This is a very important result in fundamental physics and will rule out some string theories and quantum loop gravity theories," says Dr Laurent.

Integral made a similar observation in 2006, when it detected polarised emission from the Crab Nebula, the remnant of a supernova explosion just 6500 light years from Earth in our own galaxy.

This new observation is much more stringent, however, because GRB 041219A was at a distance estimated to be at least 300 million light years.

In principle, the tiny twisting effect due to the quantum grains should have accumulated over the very large distance into a detectable signal. Because nothing was seen, the grains must be even smaller than previously suspected.

"Fundamental physics is a less obvious application for the gamma-ray observatory, Integral," notes Christoph Winkler, ESA's Integral Project Scientist. "Nevertheless, it has allowed us to take a big step forward in investigating the nature of space itself."

Now it's over to the theoreticians, who must re-examine their theories in the light of this new result.
Notes for editors

Constraints on Lorentz Invariance Violation using INTEGRAL/IBIS observations of GRB041219A by P. Laurent, D. Götz, P. Binetruy, S. Covino, A. Fernandez-Soto is published online at Physical Review D June, 28th 2011, Vol. 83, issue 12 at

European Space Agency

Related Quantum Articles:

Quantum nanoscope
Researchers have studied how light can be used to 'see' the quantum nature of an electronic material.
'Quantum leap' for Liverpool
Physicists from the University of Liverpool have made a huge step forwards towards building a novel experiment to probe the 'dark contents' of the vacuum.
Testing quantum field theory in a quantum simulator
Quantum field theories are often hard to verify in experiments.
Quantum reservoir for microwaves
EPFL researchers use a mechanical micrometer-size drum cooled close to the quantum ground state to amplify microwaves in a superconducting circuit.
Looking for the quantum frontier
Researchers have developed a new theoretical framework to identify computations that occupy the 'quantum frontier' -- the boundary at which problems become impossible for today's computers and can only be solved by a quantum computer.
Quantum mechanics are complex enough, for now...
Physicists have searched for deviations from standard quantum mechanics, testing whether quantum mechanics requires a more complex set of mathematical rules.
Seeing the quantum future... literally
Sydney scientists have demonstrated the ability to 'see' the future of quantum systems and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.
The sound of quantum vacuum
Quantum mechanics dictates sensitivity limits in the measurements of displacement, velocity and acceleration.
New quantum states for better quantum memories
How can quantum information be stored as long as possible?
Watching quantum jumps
When a quantum system changes its state, this is called a quantum jump.

Related Quantum Reading:

Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality
by Manjit Kumar (Author)

“A lucid account of quantum theory (and why you should care) combined with a gripping narrative.”―San Francisco Chronicle

Quantum theory is weird. As Niels Bohr said, if you weren’t shocked by quantum theory, you didn’t really understand it. For most people, quantum theory is synonymous with mysterious, impenetrable science. And in fact for many years it was equally baffling for scientists themselves. In this tour de force of science history, Manjit Kumar gives a dramatic and superbly written account of this fundamental scientific revolution,... View Details

What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics
by Adam Becker (Author)

The untold story of the heretical thinkers who dared to question the nature of our quantum universe
Every physicist agrees quantum mechanics is among humanity's finest scientific achievements. But ask what it means, and the result will be a brawl. For a century, most physicists have followed Niels Bohr's Copenhagen interpretation and dismissed questions about the reality underlying quantum physics as meaningless. A mishmash of solipsism and poor reasoning, Copenhagen endured, as Bohr's students vigorously protected his legacy, and the physics community favored practical experiments... View Details

Quantum Revelation: A Radical Synthesis of Science and Spirituality
by Paul Levy (Author), Jean Houston (Foreword)

"The Quantum Revelation is mind-blowing." ―Sting To say that quantum physics is the greatest scientific discovery of all time is not an exaggeration. In their discovery of the quantum realm, the physics community stumbled upon a genuine multifaceted revelation which can be likened to a profound spiritual treasure―a heretofore undreamed of creative power―hidden within our own mind. Quantum physics unequivocally points out that the study of the universe and the study of consciousness are inseparably linked, which is to say that ultimate progress in the one will be impossible... View Details

Quantum Mechanics: The Theoretical Minimum
by Leonard Susskind (Author), Art Friedman (Author)

From the bestselling author of The Theoretical Minimum, a DIY introduction to the math and science of quantum mechanics.
First he taught you classical mechanics. Now, physicist Leonard Susskind has teamed up with data engineer Art Friedman to present the theory and associated mathematics of the strange world of quantum mechanics.

In this follow-up to the New York Times best-selling The Theoretical Minimum, Susskind and Friedman provide a lively introduction to this famously difficult field, which attempts to understand the behavior of sub-atomic objects... View Details

The Quantum Labyrinth: How Richard Feynman and John Wheeler Revolutionized Time and Reality
by Paul Halpern (Author)

The story of the unlikely friendship between the two physicists who fundamentally recast the notion of time and history
In 1939, Richard Feynman, a brilliant graduate of MIT, arrived in John Wheeler's Princeton office to report for duty as his teaching assistant. A lifelong friendship and enormously productive collaboration was born, despite sharp differences in personality. The soft-spoken Wheeler, though conservative in appearance, was a raging nonconformist full of wild ideas about the universe. The boisterous Feynman was a cautious physicist who believed only what could be... View Details

Quantum Enigma: Physics Encounters Consciousness
by Bruce Rosenblum (Author), Fred Kuttner (Author)

In trying to understand the atom, physicists built quantum mechanics, the most successful theory in science and the basis of one-third of our economy. They found, to their embarrassment, that with their theory, physics encounters consciousness. Authors Bruce Rosenblum and Fred Kuttner explain all this in non-technical terms with help from some fanciful stories and anecdotes about the theory's developers. They present the quantum mystery honestly, emphasizing what is and what is not speculation. Quantum Enigma's description of the experimental quantum facts, and the quantum theory explaining... View Details

The Quantum Spy: A Thriller
by David Ignatius (Author)

From the best-selling author of The Director and Body of Lies comes a thrilling tale of global espionage, state-of-the-art technology, and unthinkable betrayal.

A hyper-fast quantum computer is the digital equivalent of a nuclear bomb; whoever possesses one will be able to shred any encryption and break any code in existence. The winner of the race to build the world’s first quantum machine will attain global dominance for generations to come. The question is, who will cross the finish line first: the U.S. or China?

In this gripping cyber... View Details

Baby University Four-Book Set
by Chris Ferrie (Author)

The perfect gift for your future genius!

Written by an expert, the Baby University series features colorful, simple introductions to scientific principles and are beloved by babies―and grownups!

Included in this Four-Book Set:
• Quantum Physics for Babies
• Rocket Science for Babies
• General Relativity for Babies
• Newtonian Physics for Babies This series is the perfect way to introduce basic scientific concepts to even the youngest scientist.

View Details

The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory
by Brian Greene (Author)

The international bestseller that inspired a major Nova special and sparked a new understanding of the universe, now with a new preface and epilogue.

Brian Greene, one of the world's leading string theorists, peels away layers of mystery to reveal a universe that consists of eleven dimensions, where the fabric of space tears and repairs itself, and all matter―from the smallest quarks to the most gargantuan supernovas―is generated by the vibrations of microscopically tiny loops of energy. The Elegant Universe makes some of the most sophisticated... View Details

Quantum Physics for Babies (Baby University)
by Chris Ferrie (Author)

Simple explanations of complex ideas for your future genius!

Written by an expert, Quantum Physics for Babies is a colorfully simple introduction to the principle that gives quantum physics its name. Babies (and grownups!) will discover that the wild world of atoms never comes to a standstill. With a tongue-in-cheek approach that adults will love, this installment of the Baby University board book series is the perfect way to introduce basic concepts to even the youngest scientists. After all, it’s never too early to become a quantum physicist!

View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Attention Please
In an age of constant information and infinite distractions, how can we pay more attention to our ... attention? This hour, TED speakers explore the battle for our awareness during the digital age. Guests include sociologist Zeynep Tufekci, podcast host Manoush Zomorodi, neuroscientist Amishi Jha, designer Tristan Harris, and computer scientist Jaron Lanier.
Now Playing: Science for the People

#475 Mother Nature is Trying to Kill You (Rebroadcast)
This week, we're learning how deadly and delightful our planet and its ecosystem can be. We're joined by biologist Dan Riskin, co-host of Discovery Canada's Daily Planet, to talk about his book "Mother Nature Is Trying to Kill You: a Lively Tour Through the Dark Side of the Natural World." And we'll talk to astronomer and author Phil Plait about Science Getaways, his company that offers educational vacation experiences for science lovers.