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One of Stephen Hawking's most famous theories about dark matter — that this mysterious and invisible substance is made up of primordial black holes — recently suffered a huge blow. That conclusion comes from a massive telescope that captured an image of an entire galaxy in one shot. The findings don't completely rule out Stephen Hawking's famous notion. But they suggest that primordial black holes would have to be truly tiny to explain dark matter. Dark matter mystery Dark matter is the name given by physicists to explain a particularly mysterious phenomenon: Everything in the universe moves, orbits and rotates...

The laws of physics are such that one photon just passes by another with zero interaction. But in a new experiment inside the world's most powerful atom smasher, researchers got a glimpse of the impossible: photons bumping into each other. The answer lies in one of the most inscrutable and yet delicious aspects of modern physics, and it goes by the funky name of quantum electrodynamics. In this picture of the subatomic world, the photon isn't necessarily a photon. Well, at least, it's not always a photon. Particles like electrons and photons and all the other -ons continually flip back...

It takes 1 trillion times the age of the universe for a xenon-124 sample to shrink by half For the first time, researchers have directly observed an exotic type of radioactive decay called two-neutrino double electron capture.The decay, seen in xenon-124 atoms, happens so sparingly that it would take 18 sextillion years (18 followed by 21 zeros) for a sample of xenon-124 to shrink by half, making the decay extremely difficult to detect. The long-anticipated observation of two-neutrino double electron capture, reported in the April 25 Nature, lays the groundwork for researchers to glimpse a yet unseen, even rarer version...

The black hole is enormous, with a radius of roughly 9 billion miles... The concept of a black hole goes back to the 18th century, when the English astronomer-clergyman John Michell calculated that a sufficiently large star couldn't shine because light wouldn’t move fast enough to “lift off” and escape the star’s gravity. But Michell’s conjecture outran the physics of its time, which didn’t understand light, gravity or stars well enough to support it. The foundations for the modern understanding of black holes weren’t laid until the early 20th century, building on James Clerk Maxwell’s theory of electromagnetism and Albert...

One of the reasons why humans are handicapped in our understanding of reality is because of our reliance on the “scientific method”. It is a system based on observation. The problem with this method is that our understanding of reality is corrupted by the limits imposed by observation. Indeed, as well well know, it is the perception of the observer that changes our reality. This is a well understood rule. If you the reader, don’t “get it”, then you need to study quantum mechanics 101. For in the last two decades the entire foundation of our understanding of reality has...

Scientists improved the performance of electricity-harvesting crystals by adding the rare earth metal samarium. Photo by Wikimedia Commons ============================================================ April 19 (UPI) -- Researchers have discovered that the addition of a rare earth metal significantly improves the performance of piezoelectric crystals. Piezoelectric crystals are used in sensors, including underwater sonars and medical ultrasound imaging devices. These technologies use perovskite oxide crystals, or PMN-PT crystals. Scientists have also tried to use piezoelectric crystals, which convert mechanical oscillations into electricity, to power wearable electronics and other types of novel technologies. An international team of scientists from Australia, China and the United States...

Scientists believe that time is continuous, not discrete—roughly speaking, they believe that it does not progress in "chunks," but rather "flows," smoothly and continuously. So they often model the dynamics of physical systems as continuous-time "Markov processes," named after mathematician Andrey Markov. Indeed, scientists have used these processes to investigate a range of real-world processes from folding proteins, to evolving ecosystems, to shifting financial markets, with astonishing success. In a pair of papers, one appearing in this week's Nature Communications and one appearing recently in the New Journal of Physics, physicists at the Santa Fe Institute and MIT have shown...

Astronomers have captured the first image of a black hole, heralding a revolution in our understanding of the universe’s most enigmatic objects. The picture shows a halo of dust and gas, tracing the outline of a colossal black hole, at the heart of the Messier 87 galaxy, 55m light years from Earth.

The first image of a black hole has been captured by astronomers, heralding a revolution in our understanding of the universe’s most enigmatic objects. The picture shows a halo of dust and gas, tracing the outline of a colossal black hole, at the heart of the Messier 87 galaxy, 55 million light years from Earth. The black hole itself – a cosmic trapdoor from which neither light nor matter can escape – is unseeable. But the latest observations take astronomers right to its threshold for the first time, illuminating the event horizon beyond which all known physical laws break down.

https://www.cnn.com/2019/04/10/us/katie-bouman-mit-black-hole-algorithm-sci-trnd/index.html

Nearly 40 years after it was proposed, mathematicians have settled one of the most profound questions in the study of general relativity. In a paper posted online last fall, mathematicians Mihalis Dafermos and Jonathan Luk have proven that the strong cosmic censorship conjecture, which concerns the strange inner workings of black holes, is false.“I personally view this work as a tremendous achievement — a qualitative jump in our understanding of general relativity,” emailed Igor Rodnianski, a mathematician at Princeton University.The strong cosmic censorship conjecture was proposed in 1979 by the influential physicist Roger Penrose. It was meant as a...

The heart of every major galaxy is said to contain a supermassive black hole — a place where anything, including light, can be devoured to the point of no return. For years, scientists have struggled to capture one of these deadly masses on camera, since the absence of light renders them nearly impossible to see. Now, for the first time, a group of scientists from the international Event Horizon Telescope (EHT) project are expected to unveil a photograph of a black hole to the public.

There are ghostly shapes hidden in magnetic fields. They're not made of stuff in the way a lightning bolt or a beam of light is. A lighting bolt carries a fairly defined group of electrons from the sky all the way to the ground.... But magnetic fields contain things called skyrmions that are different from electrons and photons; a skyrmion is a knot of magnetic field lines looping around each other. As it drifts from one spot to the next, a skyrmion makes itself anew out of the magnetic field lines that are already there. The knot holds together because...

For more than a century, physicists have hunted for superconductivity in warmer materials.... In 1986, researchers uncovered ceramics that were superconductive at temperatures as high as 30 degrees above absolute zero, or minus 406 degrees Fahrenheit (minus 243 degrees Celsius). Later, in the 1990s, researchers first looked in earnest at very high pressures, to see if they might reveal new kinds of superconductors. The next big breakthrough came in 2001, when researchers showed that magnesium diboride (MgB2) was superconductive at 39 degrees above absolute zero, or minus 389 F (minus 234 C). Since then, the hunt for warm superconductors has...

Physicists who have been roaming the “landscape” of string theory—the space of zillions and zillions of mathematical solutions of the theory, where each solution provides the kinds of equations physicists need to describe reality—have stumbled upon a subset of such equations that have the same set of matter particles as exists in our universe. But this is no small subset: there are at least a quadrillion such solutions, making it the largest such set ever found in string theory.

To investigate Faraday waves, the team confined BECs to a linear one-dimensional waveguide, resulting in a cigar-shaped BEC. The researchers then shook the BECs using a weak, slowly oscillating magnetic field to modulate the strength of interactions between atoms in the 1D waveguide. The Faraday pattern emerged when the frequency of modulation was tuned near a collective mode resonance. But the team also noticed something unexpected: When the modulation was strong and the frequency was far below a Faraday resonance, the BEC broke into "grains" of varying size. Rice research scientist Jason Nguyen, lead co-author of the study, found the...

Atheism Is Inconsistent with the Scientific Method, Prizewinning Physicist Says In conversation, the 2019 Templeton Prize winner does not pull punches on the limits of science, the value of humility and the irrationality of nonbeliefLee Billings Marcelo Gleiser, a 60-year-old Brazil-born theoretical physicist at Dartmouth College and prolific science popularizer, has won this year’s Templeton Prize. Valued at just under $1.5 million, the award from the John Templeton Foundation annually recognizes an individual “who has made an exceptional contribution to affirming life’s spiritual dimension.” Its past recipients include scientific luminaries such as Sir Martin Rees and Freeman Dyson, as well...

Researchers there have developed a way to levitate and propel objects using only light, by adding specific nanoscale patterning to their surface. Scientists have the ability to move and manipulate tiny objects with the use of ‘optical tweezers.’ The tweezers move objects via the radiative pressure from a sharply focused beam of laser light. However, this impressive tool can only move small very small objects a very limited distance. The trick is to create very specific patterns on the object's surface. These nanoscale patterns interact with the light so that the object keeps ‘righting’ itself if disturbed so that it...

California scientists think they’ve found a way to make objects levitate using concentrated light — a theory that could even propel spacecraft farther than they’ve ever traveled before, according to a report. Researchers at the California Institute of Technology believe that by covering the surfaces of objects with microscopic nanoscale patterns specially designed to interact with beams of light, they could be propelled without fuel — and potentially by light sources millions of miles away, according to Phys.org.The findings, first detailed in the online science journal Nature Photonics, already have scientists salivating over the potentially out-of-this-world applications. One could be the...

Spacecraft already navigate our solar system using gravity wells as slingshots. The same basic principles operate in the intense gravity wells around black holes, which bend not only the paths of solid objects, but light itself. If a photon, or a light particle, enters a particular region in the vicinity of a black hole, it will do one partial circuit around the black hole and get flung back in exactly the same direction. Physicists call those regions "gravitational mirrors" and the photons they fling back "boomerang photons." Boomerang photons already move at the speed of light, so they don't pick...