Gamma Ray Delay May Be Sign of 'New Physics'

Oct 01, 2007

Delayed gamma rays from deep space may provide the first evidence for physics beyond current theories.

The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescope found that high-energy photons of gamma radiation from a distant galaxy arrived at Earth four minutes after lower-energy photons, although they were apparently emitted at the same time. If correct, that would contradict Einstein's theory of relativity, which says that all photons (particles of light) must move at the speed of light.

"Everybody's very excited," about this result, said Daniel Ferenc, a physics professor at UC Davis and a member of the MAGIC collaboration. Ferenc cautioned that the results need to be repeated with other gamma-ray sources and that a simpler explanation had not been ruled out. But, "it shows that such measurements are possible," he said.

The researchers propose that the delay could be caused by photons interacting with "quantum foam," a type of structure of space itself. Quantum foam is predicted by quantum gravity theory, an attempt to unite quantum physics and relativity at cosmic scales.

The astronomers pointed the telescope at Markarian 501, a galaxy half a billion light-years away that contains a "blazar" -- a massive black hole that gives off bursts of gamma rays. Some of the material falling toward the black hole gets squeezed into jets that burst from the poles of the object at close to the speed of light. These jets fire off flares of gamma rays a few minutes long.

The researchers sorted high- and low-energy gamma-ray photons coming from the object with each flare. Joined by a group of theoretical physicists led by John Ellis from CERN, the MAGIC team showed that the high- and low-energy photons appeared to have been emitted at the same time. But the high-energy photons arrived four minutes late after traveling through space for about 500 million years.

The work has been submitted for publication in Physics Review Letters.

Source: UC Davis

Explore further: Imaging turns a corner

add to favorites email to friend print save as pdf

Related Stories

Spacetime: A smoother brew than we knew

Jan 09, 2013

Spacetime may be less like foamy quantum beer and more like smooth Einsteinian whiskey, according to research led by physicist Robert Nemiroff of Michigan Technological University being presented today at the 221st American ...

Revolutionary theory of dark matter

Jan 23, 2013

The universe abounds with dark matter. Nobody knows what it consists of. University of Oslo physicists have now launched a very hard mathematical explanation that could solve the mystery once and for all.

Strict limit on CPT violation from gamma-ray bursts

Dec 07, 2012

Kenji Toma (Osaka Univ.), Shinji Mukohyama (Kavli IPMU, Univ. of Tokyo), Daisuke Yonetoku (Kanazawa Univ.) and their colleagues have used the photon polarization in three distant gamma-ray bursts detected ...

Recommended for you

Using antineutrinos to monitor nuclear reactors

19 hours ago

When monitoring nuclear reactors, the International Atomic Energy Agency has to rely on input given by the operators. In the future, antineutrino detectors may provide an additional option for monitoring. ...

Imaging turns a corner

23 hours ago

(Phys.org) —Scientists have developed a new microscope which enables a dramatically improved view of biological cells.

Mapping the road to quantum gravity

Apr 23, 2014

The road uniting quantum field theory and general relativity – the two great theories of modern physics – has been impassable for 80 years. Could a tool from condensed matter physics finally help map ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

BaRbArIaN
not rated yet Oct 03, 2007
I've always wondered if higher energy photons were affected by gravity more than lower energy ones. After all the equivalent masses of their energies differ (via E=mc**2) by the same amount as their energies. While the effect of gravitation may not be much on such small equivalent masses, its conceivable that the difference of 4 minutes out of 500 million years is reasonable.
Sonhouse
not rated yet Mar 18, 2009
If there was some interaction with gravity, it would produce doppler effects also. Don't know if any such effect was noticed, maybe too small to be measured.
Sonhouse
not rated yet Mar 18, 2009
Maybe a development of new detectors like this will help in that search:
http://www.physor...753.html
smiffy
not rated yet Mar 19, 2009
Is this effect not to be expected from standard theory? I mean that photons of a higher frequency should travel more slowly in any given medium. Interstellar space is not a vacuum. It is a medium, albeit a very thin one.

More news stories

Phase transiting to a new quantum universe

(Phys.org) —Recent insight and discovery of a new class of quantum transition opens the way for a whole new subfield of materials physics and quantum technologies.

How do liquid foams block sound?

Liquid foams have a remarkable property: they completely block the transmission of sound over a wide range of frequencies. CNRS physicists working in collaboration with teams from Paris Diderot and Rennes ...

A 'quantum leap' in encryption technology

Toshiba Research Europe, BT, ADVA Optical Networking and the National Physical Laboratory (NPL), the UK's National Measurement Institute, today announced the first successful trial of Quantum Key Distribution ...

Google+ boss leaving the company

The executive credited with bringing the Google+ social network to life is leaving the Internet colossus after playing a key role there for nearly eight years.