A little over two weeks after leaving his show “Dark Matter” on SiriusXM satellite radio, Art Bell has confirmed (on bellgab.com) that the company plans on enforcing the non compete clause in his contract. If not challenged and overturned this will prevent Art Bell from appearing on radio for two years.
Archive for dark matter
After only six weeks on the air, radio talk show host Art Bell’s new show for SiriusXM has abruptly ended its run. The reason? Here’s what he had to say:
Dark Matter is a mysterious, unobservable form of matter that some scientists believe fills our universe. Some thought they’d found evidence of its existence in mysterious peaks of radiation emanating from the center of our galaxy.
But now Science Daily is reporting on a study which disproves that theory:
The recent study has found that the ‘positrons’ fueling the radiation are not produced from dark matter but from an entirely different, and much less mysterious, source: massive stars explode and leave behind radioactive elements that decay into lighter particles, including positrons, the antimatter counterparts of electrons.
We wonder if Dark Matter isn’t here is it possible that it isn’t anywhere?
Although Dark Matter remains a popular explanation of observable gravitational anomalies, some critics argue this may simply come from our incomplete understanding of gravity. While others suggest even more exotic explanations, such as the gravitational pull from other dimensions.
Clearly, the study here doesn’t disprove the exist of Dark Matter. But it gives more ammunition to those who doubt its existence.
From Yahoo News:
PARIS (AFP) – European astronomers said on Wednesday that an anomalous energy signal detected by an orbiting satellite could be a telltale of the enigmatic substance known as.
The researchers, in a study appearing in the British journal Nature, say the hunch is that they picked up a signature of this strange phenomenon, but more work is needed.
Some years ago, astrophysicists calculating the amount of matter in the Universe arrived at the startling discovery that ordinary material — atoms — comprises perhaps as little as five percent of the stuff in the cosmos.
The rest, they believe, comes from the “dark” sector: matter and energy that appear to be pervasive but whose nature remains a puzzle.
Dark matter, which believes to account for 23 percent of the Universe, has been detected only indirectly, through the gravitational pull it exerts on visible matter.
What it is has ignited huge debate, including the hypothesis that dark matter is a new dimension of the Universe.
Another theory is 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. WIMPS (Weakly Interacting Massive Particles) are among the candidates for this.
Another idea is that dark matter is linked to “supersymmetric” particles, or partners to known sub-atomic particles.
A team led by Piergiorgio Picozza of the University of Rome Tor Vergata 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.
“Some scientists [in the team] think this is dark matter, while others think we have to study contributions” from other positron sources, Picozza told AFP.
These include positrons that are produced by pulsars, or magnetised that emitted regular pulses of radiation, he said.
“We need much more verification, which can come from other observations,” he said.
Around 72 percent of cosmic matter is expansion of the Universe., which could be responsible for the accelerating
From New Scientist:
FOR most of us the universe is unimaginably vast. But not for cosmologists. They feel decidedly hemmed in. No matter how big they build their telescopes, they can only see so far before hitting a wall. Approximately 45 billion light years away lies the cosmic horizon, the ultimate barrier because light beyond it has not had time to reach us.
So here we are, stuck inside our patch of universe, wondering what lies beyond and resigned to that fact we may never know. The best we can hope for, through some combination of luck and vigilance, is to spot a crack in the structure of things, a possible window to that hidden place beyond the edge of the universe. Now Sasha Kashlinsky believes he has stumbled upon such a window.
Kashlinsky, a senior staff scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has been studying how rebellious clusters of galaxies move against the backdrop of expanding space. He and colleagues have clocked galaxy clusters racing at up to 1000 kilometres per second – far faster than our best understanding of cosmology allows. Stranger still, every cluster seems to be rushing toward a small patch of sky between the constellations of Centaurus and Vela.
Kashlinsky and his team claim that their observation represents the first clues to what lies beyond the cosmic horizon. Finding out could tell us how the universe looked immediately after the big bang or if our universe is one of many. Others aren’t so sure. One rival interpretation is that it is nothing to do with alien universes but the result of a flaw in one of the cornerstones of cosmology, the idea that the universe should look the same in all directions. That is, if the observations withstand close scrutiny.
All the same colleagues are sitting up and taking notice. “This discovery adds to our pile of puzzles about cosmology,” says Laura Mersini-Houghton of the University of North Carolina, Chapel Hill. Heaped in that pile is 95 per cent of the universe’s contents, including the invisible dark matter that appears to hold the galaxies together, and the mysterious dark energy that is accelerating the universe’s expansion. Accordingly, Kashlinsky named this new puzzle the “dark flow”.
Kashlinsky measures how fast galaxy clusters up to 5 billion light years away are travelling by looking for signs of their motion in the cosmic microwave background, the heat left over from the big bang. Photons in the CMB generally stream uninterrupted through billions of light years of interstellar space, but when they pass through a galaxy cluster they encounter hot ionised gas in the spaces between the galaxies. Photons scattered by this gas show up as a tiny distortion in the temperature of the CMB, and if the cluster happens to be moving, the distortion will also register a Doppler shift.
In any individual cluster, this shift is far too small to detect, which is why no one had ever bothered looking for it. However, Kashlinsky realised if he combined measurements from a large enough number of clusters, the signal would be amplified to a measurable level.
Read the rest of the article here.