„Dark energy is one of the great scientific mysteries of our time, so it isn’t surprising that so many researchers question its existence. But now, according to a team of astronomers at the University of Portsmouth and LMU University Munich, led by Tommaso Giannantonio and Robert Crittenden, the scientists the likelihood of the existence of dark matter stands at 99.996 per cent.
„But with our new work we’re more confident than ever that this exotic component of the Universe is real – even if we still have no idea what it consists of,“ said Bob Nichol, a member of the Portsmouth team.
Over a decade ago, astronomers observing the brightness of distant supernovae realised that the expansion of the Universe appeared to be accelerating. The acceleration is attributed to the repulsive force associated with dark energy now thought to make up 73 per cent of the content of the cosmos. The researchers who made this discovery received the Nobel Prize for Physics in 2011, but the existence of dark energy remains a topic of hot debate. Many other techniques have been used to confirm the reality of dark energy but they are either indirect probes of the accelerating Universe or susceptible to their own uncertainties.
One of the most fascinating discoveries of our new century may be imminent if the Large Hadron Collider outside Geneva produces nano-blackholes. According to the best current physics, such nano blackholes could not be produced with the energy levels the LHC can generate, but could only come into being if a parallel universe were providing extra gravitational input. Versions of multiverse theory suggest that there is at least one other universe very close to our own, perhaps only a millimeter away. This makes it possible that some of the effects, especially gravity, „leak through,“ which could be responsible for the production of dark energy and dark matter that make up 96% of the universe.
New results from NASA’s Galaxy Evolution Explorer and the Anglo-Australian Telescope atop Siding Spring Mountain in Australia confirm that dark energy is a smooth, uniform force that now dominates over the effects of gravity. The observations follow from careful measurements of the separations between pairs of galaxies.
But what causes that „smooth, uniform force“ that rules over gravity? Astronomers have known for years that something unknown apears to be „pulling“ our Milky Way and tens of thousands of other galaxies toward itself at a breakneck 22 million kilometers (14 million miles) per hour. But they couldn’t pinpoint exactly what, or where it is.
An exciting new theory says that antimatter could exist in the voids between galaxy clusters and superclusters and that some kind of repulsive gravity –- antigravity –- is pushing the Universe apart. The new theory is a direct challenge to the accepted theory for the Universe expanding at an accelerating rate: the presence of an unidentified X Factor labeled „dark energy,“ although several other possibilities have been proposed.
As a new study shows, general relativity predicts that the gravitational interaction between matter and antimatter is mutually repulsive, and could potentially explain the observed expansion of the Universe without the need for positing an elusive dark energy.
Some scientists believe that about 7 billion years ago, the still unknown repulsive force called dark energy „turned on“ to speed the expansion of the universe that continues to this day. University of California, Berkeley astronomers have won approval for a telescope project that will reach back in time more than 10 billion years to probe the role of mysterious dark energy in speeding the early expansion, and allow scientists to map the entire universe in greater detail than ever before.
Astronomer David Schlegel of the Lawrence Berkeley National Laboratory said it will involve 35 science institutions around the globe and will result in the biggest map of the universe ever created.
„This is a project that people have been screaming to do for years,“ Schlegel said Tuesday. „The universe itself is really unmapped today.“
The planet’s biggest -570-megapixel- camera the size of a smart car is being built at Fermilab by an international team of particle physicists and astronomers, to help solve one of the great mysteries of the cosmos: what is dark energy -the ubiquitous, invisible matter believed to make up 70 percent of the universe and the hidden force behind the acceleration of the universe.
When completed it will be shipped to the Cerro Tololo Inter-American Observatory in Chile, where it will be placed atop a four-meter telescope called the Blanco sometime in 2011. The mega gadget will take pictures of the universe not only as we see it today but back through time, closer to when the universe began, capturing images of roughly 300 million galaxies.
The Dark Energy Camera will peer deeper into the sky and unveil more galaxies at greater distances than any previous project, including the epic Sloan Digital Sky Survey that has transformed our knowledge of the universe. It will collect data on the distances of supernovae from Earth, the large-scale clustering of galaxies, the abundance of massive galaxy clusters, and the bending of light caused by galaxies and clusters of galaxies.
“If all four measures show the same result, it means that our current ideas about dark energy are correct; if they differ, there is either a problem in our understanding of gravity or some other explanation,” said Brenna Flaugher, who is spearheading the camera’s construction in an interview with Symmetry.com .
Confirming the existence of dark energy and understanding its origin would have profound implications for our understanding of the universe. But an even more radical outcome would emerge if scientists discovered that dark energy does not exist. Instead, some theoretical models suggest that an extra spatial dimension causes the universe to expand ever more rapidly, unraveling Einstein’s general theory of relativity. The Dark Energy Survey, scheduled to be up and running in 2011, might reveal which explanation is correct.