Dark matter may be an illusion caused by the quantum vacuum

(PhysOrg.com) -- One of the biggest unsolved problems in astrophysics is that galaxies and galaxy clusters rotate faster than expected, given the amount of existing baryonic (normal) matter. The fast orbits require a larger central mass than the nearby stars, dust, and other baryonic objects can provide, leading scientists to propose that every galaxy resides in a halo of (as yet undetectable) dark matter made of non-baryonic particles. As one of many scientists who have become somewhat skeptical of dark matter, CERN physicist Dragan Slavkov Hajdukovic has proposed that the illusion of dark matter may be caused by the gravitational polarization of the quantum vacuum.

Ten mind-blowing solar views from the SDO: photos

Check out Ten Mind-Blowing Solar Views from the SDO: Photos

A star is torn

A University of Sydney researcher was part of an international team of astronomers that has observed an incredibly rare event that occurs once every 10,000 years per galaxy.

Researchers prove existence of antiproton radiation belt around Earth

Italian researchers using data from the satellite PAMELA have proven that theories showing there ought to be a ring of antiprotons encircling the Earth due to cosmic rays colliding with nuclei in the upper atmosphere are correct. Piergiorgio Picozza from the University of Rome, Tor Vergata, and a host of colleagues have published the results of their findings in arXiv.

Ninety-six star clusters discovered hidden behind dust of Milky Way

  • 4 Aug 2011

Astronomers have discovered 96 new open star clusters hidden by the dust in the Milky Way. These tiny and faint objects were invisible to previous surveys, but they could not escape the sensitive infrared detectors of the world

First opal-like crystals discovered in meteorite

Scientists have found opal-like crystals in the Tagish Lake meteorite, which fell to Earth in Canada in 2000. This is the first extraterrestrial discovery of these unusual crystals, which may have formed in the primordial cloud of dust that produced the sun and planets of our solar system 4.6 billion years ago.

First observational test of the 'multiverse'

The theory that our universe is contained inside a bubble, and that multiple alternative universes exist inside their own bubbles – making up the

Fundamental matter-antimatter symmetry confirmed

International collaboration including MPQ scientists sets a new value for the antiproton mass relative to the electron with unprecedented precision.

Study: Earth shares its orbit with tiny asteroid

(AP) -- Like a poodle on a leash, a tiny asteroid runs ahead of Earth on the planet

A cosmic superbubble

ESO’s Very Large Telescope captured this striking view of the nebula around the star cluster NGC 1929 within the Large Magellanic Cloud, a satellite galaxy of our own Milky Way. A colossal example of what astronomers call a superbubble dominates this stellar nursery. It is being carved by the winds from bright young stars and the shockwaves from supernova explosions.

Could the Big Bang have been a quick conversion of antimatter into matter?

(PhysOrg.com) -- Suppose at some point the universe ceases to expand, and instead begins collapsing in on itself (as in the “Big Crunch” scenario), and eventually becomes a supermassive black hole. The black hole’s extreme mass produces an extremely strong gravitational field. Through a gravitational version of the so-called Schwinger mechanism, this gravitational field converts virtual particle-antiparticle pairs from the surrounding quantum vacuum into real particle-antiparticle pairs. If the black hole is made from matter (antimatter), it could violently repel billions and billions of antiparticles (particles) out into space in a fraction of a second, creating an ejection event that would look quite similar to a Big Bang.

New planet discovered in Trinary star system

Until recently, astronomers were highly skeptical of whether or not planets should be possible in multiple star systems. It was expected that the constantly varying gravitational force would eventually tug the planet out of orbit. But despite doubts, astronomers have found several planets in just such star systems. Recently, astronomers announced another, this time in the trinary star HD 132563.