“Is there such a thing as antigravity? Based on free-fall tests so far, we can’t say yes or no, ” says Joel Fajans of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “This is the first word, however, not the last.” These questions have long intrigued physicists, says Fajans, because “in the unlikely event that antimatter falls upwards, we’d have to fundamentally revise our view of physics and rethink how the universe works.”
Continue reading "Is Antigravity Real? --"If Antimatter Falls Upward We Need to Rethink How the Universe Works"" »
Cosmological natural selection – an idea first put forward in the 1990s to explain the apparent 'fine-tuning' of the universe’s basic parameters to allow for the existence of atoms, galaxies, and life itself- proposes that, if new universes are born inside black holes, a 'multiverse' of many possible universes could be shaped by a process similar to natural selection so that successive generations of universes evolve to become better at making black holes.
Continue reading ""Universes Evolve Inside Black Holes" --Radical Theories from ESO and Oxford " »
Among the unsolved mysteries confronting 21st century physics from gravitational waves to dark energy, neutrinos -the "ghosts of the cosmos"- are near the top of the list. These awesomely low-mass subatomic particles, less than a millionth of the mass of electrons, play a key role in weak interactions and come three flavors: electron, muon, and tau. Stars actively flood the universe with new neutrinos along with ancient particles created some two seconds after the Big Bang.
Continue reading "The Search for "Ghosts of the Universe" in Antarctica" »
Gravity is responsible for the long-range order of the universe. Using Einstein's general relativity, we now think of gravity as the geometrical curvature of the four-dimensional fabric of space-time. Extreme cosmological events such as the merging of neutron stars or black holes induce ripples in the fabric of space-time, but these ripples, or gravitational waves, are extremely weak, and their detection has remained elusive.
Continue reading ""Hearing Gravity Waves" --Scientists Launch World-Wide Search" »
NASA's Wide-field Infrared Survey Explorer (WISE) has discovered a pair of stars that has taken over the title for the third-closest star system to the sun. The duo is the closest star system discovered since 1916. Both stars in the new binary system are "brown dwarfs," which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun.
Continue reading "Closest Star System Found in a Century --Now Receiving TV Transmissions from 2006" »
Answering the observation that the dark matter particle might not be detectable at a colloquium organized by the Kavli Institute for Cosmological Physics at the University of Chicago, Michael Turner, a theoretical cosmologist trained in both particle physics and astrophysics who coined the term “dark energy,” said that for 20 to 30 years, this idea that dark matter is part of a unified theory has been our Holy Grail and has led to the WIMP hypothesis and the belief that the dark matter particle is detectable. "But there’s a new generation of physicists that is saying, 'Well, there's an alternative view. Dark matter is actually just the tip of an iceberg of another world that is unrelated to our world. And I cannot even tell you about that world. There are no rules for that other world, at least that we know of yet.
Continue reading "Dark Matter --"The Tip of an Iceberg of Another World Unrelated to Ours" " »
Ten years ago when the WMAP data on the cosmic microwave background (CMB) became available, John Cramer, Professor Emeritus of Physics at the University of Washington, completed a Mathematica calculation to produce "the sound of the Big Bang." Cramer decided to do the same thing with the new data from the ESA's Planck Mission analysis of the CMB, which analyzes the temperature variations of the cosmic microwave background into angular frequency components or multipoles. The new frequency spectrum goes to much higher frequencies than did the WMAP analysis, and therefore offers a more "high-fidelity" rendition of the Sound of the Big Bang.
Continue reading ""Voice of the Big Bang" --Sounds of the Universe 760,000 Years After (AUDIO)" »
When a massive star exhausts its fuel, it collapses under its own gravity and produces a black hole, an object so dense that not even light can escape its gravitational grip. According to a new analysis by an astrophysicist at the California Institute of Technology (Caltech), just before the black hole forms, the dying star may generate a distinct burst of light that will allow astronomers to witness the birth of a new black hole for the first time.
Continue reading "Cosmic Flashes May Signal Birth of Black Holes" »
Researchers working with data from NASA's Cassini spacecraft have discovered one way the bubble of charged particles around Saturn -- known as the magnetosphere -- changes with the planet's seasons. The finding provides an important clue for solving a riddle about the planet's naturally occurring radio signal. The results might also help scientists better understand variations in Earth's magnetosphere and Van Allen radiation belts, which affect a variety of activities at Earth, ranging from space flight safety to satellite and cell phone communications.
Continue reading "Saturn's Naturally Occurring Radio Signal --New Insights" »