The Hunt for Dark Energy. The Hunt for Dark Energy Peter Cameron, George Ellis, David Tong.
Sue Nelson hosts. Dark energy is supposed to make up two-thirds of the universe. But troublingly CERN has yet to find any evidence. A dark matter bridge in our cosmic neighborhood. By using the best available data to monitor galactic traffic in our neighborhood, Noam Libeskind from the Leibniz Institute for Astrophysics Potsdam (AIP) and his collaborators have built a detailed map of how nearby galaxies move.
In it, they have discovered a bridge of dark matter stretching from our Local Group all the way to the Virgo Cluster — a huge mass of some 2,000 galaxies roughly 50 million light-years away that is bound on either side by vast bubbles completely devoid of galaxies. This bridge and these voids help us understand a 40-year-old problem regarding the curious distribution of dwarf galaxies. These dwarf galaxies are often found swarming around larger hosts like our Milky Way. Since they are dim, they are hard to detect and are thus found almost exclusively in our cosmic neighborhood. One possibility is that these small galaxies echo the geometry of structure on much greater scales.
What is Dark Matter? This Hubble Space Telescope composite image shows a ghostly "ring" of dark matter in the galaxy cluster Cl 0024+17.Credit: NASA, ESA, M.J.
Jee and H. Ford (Johns Hopkins University) Roughly 80 percent of the mass of the universe is made up of material that scientists cannot directly observe. Known as dark matter, this bizarre ingredient does not emit light or energy. So why do scientists think it dominates? What could dark matter be? Although nearly a century has passed since an astronomer first used the term “dark matter” in the 1930s, the elusive substance still defies explanation.
Physicists can measure its effects on the movements of galaxies and other celestial objects, but what it’s made of remains a mystery. In order to solve it, physicists have come up with myriad possibilities, plus a unique way to find each one. Some ideas for dark matter particles arose out of attempts to solve other problems in physics. Others are pushing the boundaries of what we understand dark matter to be. “You don’t know which experiment is going to ultimately show it,” says Neal Weiner, a New York University physics professor. Artwork by Sandbox Studio, Chicago. The dark side of the universe – a primer. Over the past 40 years astronomers have realised that everything we can see – all the stars, planets and galaxies – make up less than 5% of the entire universe. What is the rest? The short answer is, we have no idea. What we do know is there are two gaping holes in our understanding of our universe. Dark Energy: No Answers but More Questions.
What is Dark Matter? Dark Matter: The Cosmos' Greatest Mystery Deepens. Like Hollywood legends Audrey Hepburn and Katharine Hepburn, dark energy and dark matter are completely unrelated, even though they share a name.
Dark-Matter Theory Questioned by Astronomers' New Findings. The theory of dark matter took decades to take hold in astronomy, and no wonder.
It's pretty tough to wrap your mind around the notion that some mysterious, invisible substance pervades the cosmos — and even tougher to accept that it outweighs ordinary matter by a factor of 6 to 1, at least. Evidence eventually trumped incredulity, though, and by the 1980s, the vast majority of scientists were on board with the idea, nutty though it might seem, and there they've remained ever since. But a new study out of the European Southern Observatory claims that this now established theory could be in trouble. Simulation shows that dark energy and matter can reproduce the Universe.
To the best of our ability to tell, the Universe is being shaped by things we can't directly detect: dark matter and dark energy.
That makes it somewhat challenging to determine if our understanding of these influences is roughly correct. It's simply hard to be confident that we haven't missed some other dark entity that's lurking beyond our abilities of detection. One of the ways we can have some confidence that we're not missing anything major is to run models of the Universe. If we've got the basic physics right, then you should be able to set these models loose at an early point in the Universe's history and end up with something that looks like the Universe we're living in. Curious signal hints at dark matter – first evidence of axions? Space scientists at the University of Leicester have detected a curious signal in the X-ray sky – one that provides a tantalising insight into the nature of mysterious 'dark matter'.
The Leicester team has found what appears to be a signature of 'axions', predicted dark matter particle candidates, something that has been a puzzle to science for years. In a study being published on 20 October in the journal Monthly Notices of the Royal Astronomical Society, the University of Leicester scientists describe their finding of a signal which has no conventional explanation. A sketch (not to scale) showing axions (blue) streaming out from the Sun, converting in the Earth's magnetic field (red) into X-rays (orange), which are then detected by the XMM-Newton observatory. Credit: University of Leicester. Click to enlarge.As first author Professor George Fraser, who sadly died in March of this year, wrote: "The direct detection of dark matter has preoccupied physics for over thirty years.
" Prof. Fermi telescope detects signal that could be annihilating dark matter. Researchers using data obtained by the orbiting Fermi Telescope may have found the first clear, direct evidence of dark matter in our own galaxy.
The signal comes in the form of an excess of gamma rays coming from an area surrounding the galactic core, and it appears to be exactly what we'd expect from a weakly interacting massive particle, or WIMP. Perhaps as significantly, however, there are no known astronomical features that can produce a signal like this. Could Mystery Signal be First Detection of Dark Matter? Through the analysis of light from distant galactic clusters, astronomers have detected a mysterious signal that they’re having a hard time explaining.
Although the signal is weak, could it be the much sought-after direct evidence for dark matter? Dark matter pervades the entire universe and makes up for the bulk of its mass, but what is it? We know it’s out there and oodles of indirect evidence for its presence, but seeing a direct signal has so far proven elusive. NEWS: Vast Web of Dark Matter Mapped When observing a galactic cluster, for example, we can gauge how much mass it contains by how much light is bent around the cluster. Four things you might not know about dark matter. Not long after physicists on experiments at the Large Hadron Collider at CERN laboratory discovered the Higgs boson, CERN Director-General Rolf Heuer was asked, “What’s next?” One of the top priorities he named: figuring out dark matter.
Dark matter is five times more prevalent than ordinary matter. It seems to exist in clumps around the universe, forming a kind of scaffolding on which visible matter coalesces into galaxies. Cosmic Mystery Solved? Possible Dark Matter Signal Spotted. Astronomers may finally have detected a signal of dark matter, the mysterious and elusive stuff thought to make up most of the material universe.
While poring over data collected by the European Space Agency's XMM-Newton spacecraft, a team of researchers spotted an odd spike in X-ray emissions coming from two different celestial objects — the Andromeda galaxy and the Perseus galaxy cluster. The signal corresponds to no known particle or atom and thus may have been produced by dark matter, researchers said. Dark Matter's New Wrinkle: It May Behave Like Wavy Fluid.