Dark matter and dark energy may not exist at all

Posted by Emma Woollacott

Everything we know about the composition of the universe may be wrong, according to physicists.

The University of Durham team examined observations from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite of the remnant heat from the Big Bang and found evidence of errors in the data.

Launched in 2001, WMAP measures differences in the Cosmic Microwave Background (CMB) radiation, the residual heat from the Big Bang.

The size of the ripples in the CMB led scientists to conclude that the cosmos is made up of four percent 'normal' matter, 22 percent 'dark' or invisible matter and 74 percent 'dark' energy.

But graduate student Utane Sawangwit and professor Tom Shanks used astronomical objects that appear as unresolved points in radio telescopes to test the way the WMAP telescope smoothes out its maps.

They find that the smoothing is much larger than previously believed, suggesting that its measurement of the size of the CMBR ripples is not as accurate as was thought. This could mean that the ripples are significantly smaller, implying that dark matter and dark energy are not present after all.

"If our results prove correct then it will become less likely that dark energy and exotic dark matter particles dominate the universe," says professor Shanks. "So the evidence that the universe has a ‘Dark Side’ will weaken."

And in another study, scientists found that observations from the Sloan Digital Sky Survey did not show the level of blueshifting that would be expected if  galaxies are accelerating away from each other because of dark energy.

Utane Sawangwit says, "If our result is repeated in new surveys of galaxies in the southern hemisphere, then this could mean real problems for the existence of dark energy."

Some physicists have long had a problem with the idea of dark matter and dark energy - not least because none has ever been detected. The theory is also problematic for current ideas about the birth of stars in galaxies.