Physicists May Be Closer To Understanding Dark Matter
An orbiting satellite has detected an anomalous energy signal that European astronomers say could be a sign of dark matter, the AFP reported.
The researchers said they may have picked up a signature of this strange phenomenon, but more work is needed.
Ordinary material such as atoms comprise perhaps as little as five percent of what makes up the cosmos, according to previous studies by astrophysicists calculating the amount of matter in the Universe.
Data suggests the remainder originates from the "dark" sector, where matter and energy appear to be pervasive.
Experts believe dark matter accounts for around 23 percent of the Universe, yet it has been detected only indirectly, through the gravitational pull it exerts on visible matter.
Some astronomers even suggest that dark matter is a new dimension of the Universe.
Other theories suggest that dark matter must be a new particle, or particles, that interact so weakly with ordinary matter that it does not produce light-emitting reactions.
They say WIMPS (Weakly Interacting Massive Particles) are among the candidates for this.
Dark matter could also be linked to "supersymmetric" particles, or partners to known sub-atomic particles.
The study appearing in the British journal Nature looked over data sent back by a European satellite called PAMELA between July 2006 and February 2008 and found a unusual abundance of positrons, the counterpart to the electron, in cosmic rays at a high part of the energy spectrum.
Piergiorgio Picozza of the University of Rome Tor Vergata told AFP that some of his colleagues believe it to be dark matter, while others think “we have to study contributions" from other positron sources.
He said these include positrons that are produced by pulsars, or magnetized neutron stars that emitted regular pulses of radiation.
"We need much more verification, which can come from other observations," Picozza said.
Experts believe at least 72 percent of cosmic matter is dark energy, which could be responsible for the accelerating expansion of the Universe.
Some astronomers suggest that the particles thought to constitute dark matter could be reproduced in the Large Hadron Collider (LHC) in Switzerland.
Picozza said if the new signal does not match the data collected from pulsars, and if experiments in the LHC back-up the dark matter theoreticians, "then we could then say we have discovered dark matter".
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