Free Republic

Is it a message from far beyond out own galaxy? A brief mysterious pulse detected by Arecibo telescope has baffled boffins. The discovery of a split-second burst of radio waves by scientists using the Arecibo radio telescope in Puerto Rico raises major new questions over what caused it. The finding by an international team of astronomers, published July 10 in The Astrophysical Journal, marks the first time that a so-called 'fast radio burst' has been detected using an instrument other than the Parkes radio telescope in Australia.

~snip~ In 1967 British astronomer Jocelyn Bell Burnell was left stunned by mysterious pulsing signals she detected coming from outside the solar system. For months she suggested the signals could be of an extraterrestrial intelligent origin, but they were later proven to be rapidly spinning stars known as pulsars. However, a new series of mysterious signals, known as Fast Radio Bursts (FRBs), has again got astronomers scratching their heads and wondering if, maybe, we’re picking up alien messages...

Based on the latest evidence and theories our galaxy could be a huge wormhole (or space-time tunnel, have you seen the movie "Interstellar?") and, if that were true, it would be "stable and navigable." This is the hypothesis put forward in a study published in Annals of Physics and conducted with the participation of SISSA in Trieste. The paper, the result of a collaboration between Indian, Italian and North American researchers, prompts scientists to re-think dark matter. "If we combine the map of the dark matter in the Milky Way with the most recent Big Bang model to explain the...

The test rig for the Dark Energy Camera (DECam) at Fermilab. I picked this image today because it kinda sorta looks like the wormhole-making machine from the film version of Contact. [Credit: moi]A lot of science fiction plot devices are devoted to getting around the speed of light. In the real Universe, nothing with mass can travel faster than light, which means we can’t travel to distant stars without taking decades, centuries, or longer in transit. So, sci-fi draws from teleportation, hyperdrive, warp drive, and the ultimate cosmic short-cut: wormholes.[1] In some cases, the source of a science fiction...

Some simple observations about the universe seem to contradict basic physics. Solving these paradoxes could change the way we think about the cosmos Revolutions in science often come from the study of seemingly unresolvable paradoxes. An intense focus on these paradoxes, and their eventual resolution, is a process that has leads to many important breakthroughs. So an interesting exercise is to list the paradoxes associated with current ideas in science. It’s just possible that these paradoxes will lead to the next generation of ideas about the universe. Today, Yurij Baryshev at St Petersburg State University in Russia does just this...

The Chameleon in the Vacuum Chamber A new proposal for an experiment that could test the presence of a fifth force with unprecedented precision. It still amazes me that everything I see is made up of only some few dozen particles and four interactions. For all we know. But maybe this isn’t all there is? Physicists have been speculating for a while now that our universe needs a fifth fundamental force, one responsible for the phenomenon of dark energy, to maintain the observed expansion rate. Although this idea has been around for more than a decade, it has turned...

A star mystery solved? These newfound stars could help solve the so-called "photon underproduction crisis," which suggests that an extraordinary amount of ultraviolet light appears to be missing from the universe. The intergalactic stars could also help address what is known as the "missing baryon problem." Baryons are a class of subatomic particles that includes the protons and neutrons that make up the hearts of atoms inside normal matter. Theories of the formation and evolution of the universe predict there should be far more baryons than scientists currently see. The baryons that astronomers have accounted for in the local cosmic...

BRUSSELS, BELGIUM - The International Space Nomenclature Council today adopted the term 'emplacements de hauts gravité super' - or 'super high gravity locations' - as the official replacement name for black holes. Originally named in reference to the fact that light cannot escape their intense gravity, the term 'black hole' was increasingly criticized as being insensitive to African-Americans and African-Europeans. "We're glad the council finally took action on this issue." said Isaiah Herman, Chairman of the National African-American Coalition of People. "The unimaginable destructive power of these super high gravity locations was giving the word 'black' a negative connotation throughout...

There is a "missing light crisis" taking place in the universe with a huge deficit on what there should be and what there actually is, astronomers have said. In a statement, experts from the Carnegie Institution for Science said "something is amiss in the universe" with 80% of the light missing. Lead author of the study Juna Kollmeier said: "It's as if you're in a big, brightly-lit room, but you look around and see only a few 40-watt lightbulbs. Where is all that light coming from? It's missing from our census." Published in Astrophysical Journal Letters, scientists found that the...

Explanation: What is creating the gamma rays at the center of our Galaxy? Excitement is building that one answer is elusive dark matter. Over the past few years the orbiting Fermi Gamma-ray Space Telescope has been imaging our Galaxy's center in gamma-rays. Repeated detailed analyses indicate that the region surrounding the Galactic center seems too bright to be accounted by known gamma-ray sources. A raw image of the Galactic Center region in gamma-rays is shown above on the left, while the image on the right has all known sources subtracted -- leaving an unexpected excess. An exciting hypothetical model that...

Explanation: What are black hole jets made of? Many black holes in stellar systems are surely surrounded by disks of gas and plasma gravitationally pulled from a close binary star companion. Some of this material, after approaching the black hole, ends up being expelled from the star system in powerful jets emanating from the poles of the spinning black hole. Recent evidence indicates that these jets are composed not only electrons and protons, but also the nuclei of heavy elements such as iron and nickel. The discovery was made in system 4U1630-47 using CSIRO’s Compact Array of radio telescopes in...

Scientists at the Homestake Gold Mine in South Dakota running the biggest, most sensitive dark matter detector yet released its first round of results yesterday -- and they found nothing. The Large Underground Xenon dark matter experiment, or LUX, consists of a vat of 368 kilograms of liquid xenon to minus 110 degrees Celsius, surrounded by a tank of water. LUX sits 4,850 feet underground at the old mine, shielded from cosmic rays. An international team of researchers watched for three months to see if any WIMPS -- weakly interacting massive particles -- would pass through the rock and reveal...

ANN ARBOR—Moonless nights outside the Cerro Tololo astronomical observatory in Chile are so dark that when you look down, you can't see your feet. "You can't see your hands," said David Gerdes, physics professor at the University of Michigan. "But you can hold them up to the sky and see a hand-shaped hole with no stars in it. It's really incredible." From this site in the Andes over the next five years, an international team will map one-eighth of the sky in unprecedented detail—aiming to make a time lapse of the past 8 billion years of a slice of the...

Credit: Phys. Rev. Lett. 110, 211302 (2013) (Phys.org) —A team of Harvard University physicists has proposed the possible existence of a type of dark matter not described by current physics models. In their paper published in the journal Physical Review Letters, the team suggests it's possible that not all dark matter is cold and collision-less. In the visible universe, galaxies form into a disk shape—the Milky Way is a good example. All of its members align roughly along a single plane, this due to the forces of gravity and spin. Objects form into masses which, over time, spread out...

Enlarge Left panel: Air molecules whiz around at a variety of speeds, and some are very fast. When they collide with both heavy and light elements - for example, xenon (purple) and silicon (orange) - these fast moving particles have enough momentum to affect both nuclei. Right panel: Dark matter particles are moving more slowly and are less able to affect the heavy xenon nucleus. As a result, detectors made from lighter materials like silicon may prove to be more effective at picking up signals of dark matter. Credit: Greg Stewart/SLAC National Accelerator Laboratory (Phys.org) —Now that it looks...

Try using the entire Earth to hunt for a new fundamental force of nature. So say Larry Hunter of Amherst College in Massachusetts, and colleagues. They have created a map of the spins of electrons deep within the Earth's mantle, which could be used to reveal the as-yet-unseen force as well as the strange particles – known as "unparticles" – that might carry it. We currently know of four fundamental forces: gravity, electromagnetism and the strong and weak nuclear forces. The hypothetical fifth force can be thought of as a version of magnetism that does not weaken as quickly with...

3D image shows ginormous filament of Big Bang batter Dark matter can't really be "seen" as such, it can only be detected by looking at the gravitational effects it has on the space around it. But by collating images from the Hubble Space telescope, the researchers now have a picture of dark matter (shown in blue above) extending 60 million light-years away from one of the most massive galaxy clusters astrophysicists know about – MACS J0717. Big Bang theories predict that when the universe was first created, dense matter condensed into a web of tangled dark matter filaments throughout the...

A re-analysis of radio telescope observations from three countries has yielded a surprising result: nearby galaxies harbour one-third more hydrogen than had previously been estimated. While nothing like enough matter to solve physics’ “dark matter” problem, the work by CSIRO astronomer Dr Robert Braun (chief scientist at the agency’s Astronomy and Space Science division in Sydney) also helps explain why the rate of star formation has slowed down. While there’s more hydrogen than astronomers had thought, its distribution makes star formation more difficult. Andromeda – the galaxy headed for a catastrophic collision with our own in about four billion years...

Analysis of data from the National Science Foundation-(NSF) funded 10-m South Pole Telescope (SPT) in Antarctica provides new support for the most widely accepted explanation of dark energy, the source of the mysterious force that is responsible for the accelerating expansion of the universe. The results begin to hone in on the tiny mass of the neutrinos, the most abundant particles in the universe, which until recently were thought to be without mass. The SPT data strongly support Albert Einstein's cosmological constant—the leading model for dark energy—even though researchers base the analysis on only a fraction of the SPT data...

Astronomers have measured the precise distance to over a quarter of a million galaxies to gain new insights into a key period in cosmic history. The 3D map of the sky allows scientists to probe the time six billion years ago when dark energy became the dominant influence on the Universe's expansion. No-one knows the true nature of this repulsive force, but the exquisite data in the international BOSS survey will help test various theories. The analysis appears in six papers. These have all been posted on the arXiv preprint server. "This is an incredibly exciting time to be working...