Archive for the ‘physics’ category: Page 246
Aug 18, 2018
The Universe as We Understand It May Be Impossible
Posted by Michael Lance in categories: physics, space
A new conjecture in physics challenges the leading “theory of everything.” (Via The Atlantic)
Aug 17, 2018
Another way for stellar-mass black holes to grow larger
Posted by Genevieve Klien in categories: cosmology, physics
A trio of researchers with The University of Hong Kong, Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Northwestern University in the U.S., has come up with an alternative theory to explain how some stellar-mass black holes can grow bigger than others. In their paper published in The Astrophysical Journal Letters, Shu-Xu Yi, K.S. Cheng and Ronald Taam describe their theory and how it might work.
Since the initial detection of gravitational waves three years ago, five more detections have been observed—and five of the total have been traced back to emissions created by two stellar-mass black holes merging. The sixth was attributed to neutron stars merging. As part of their studies of such detections, space researchers have been surprised by the size of the stellar-mass black holes producing the gravity waves—they were bigger than other stellar-mass black holes. Their larger size has thus far been explained by the theory that they grew larger because they began their lives as stars that contained very small amounts of metal—stars with traces of metals would retain most of their mass because they produce weaker solar winds. In this new effort, the researchers suggest another possible way for stellar-mass black holes to grow larger than normal.
The new theory starts out by noting that some supermassive black holes at the hearts of galaxies are surrounded by a disk of gas and dust. In such galaxies, there are often stars lying just outside the disk—stars that could evolve to become stellar-mass black holes. The researchers suggest that it is possible that sometimes, pairs of these stars wind up in the disk as they evolve into black holes. Such stellar-mass black holes would pull in material from the disk, causing them to grow larger. The researchers note that if such a scenario were to play out, it is also possible that the two merging stars could wind up with a synchronized spin resulting in a stellar-mass black hole that produces more gravity waves than if the spins had not been synchronized, making them easier for researchers to spot.
Aug 16, 2018
Settling Arguments About Hydrogen With 168 Giant Lasers
Posted by Genevieve Klien in categories: physics, space
With gentle pulses from gigantic lasers, scientists at Lawrence Livermore National Laboratory in California transformed hydrogen into droplets of shiny liquid metal.
Their research, reported on Thursday in the journal Science, could improve understanding of giant gas planets like Jupiter and Saturn whose interiors are believed to be awash with liquid metallic hydrogen.
The findings could also help settle some fractious debates over the physics of the lightest and most abundant element in the universe.
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Aug 8, 2018
New laser based on unusual physics phenomenon could improve telecommunications, computing
Posted by Klaus Baldauf in categories: computing, engineering, physics
Researchers at the University of California San Diego have demonstrated the world’s first laser based on an unconventional wave physics phenomenon called bound states in the continuum. The technology could revolutionize the development of surface lasers, making them more compact and energy-efficient for communications and computing applications. The new BIC lasers could also be developed as high-power lasers for industrial and defense applications.
“Lasers are ubiquitous in the present day world, from simple everyday laser pointers to complex laser interferometers used to detect gravitational waves. Our current research will impact many areas of laser applications,” said Ashok Kodigala, an electrical engineering Ph.D. student at UC San Diego and first author of the study.
“Because they are unconventional, BIC lasers offer unique and unprecedented properties that haven’t yet been realized with existing laser technologies,” said Boubacar Kanté, electrical engineering professor at the UC San Diego Jacobs School of Engineering who led the research.
Aug 7, 2018
Physicists find surprising distortions in high-temperature superconductors
Posted by Genevieve Klien in categories: materials, physics
There’s a literal disturbance in the force that alters what physicists have long thought of as a characteristic of superconductivity, according to Rice University scientists.
Rice physicists Pengcheng Dai and Andriy Nevidomskyy and their colleagues used simulations and neutron scattering experiments that show the atomic structure of materials to reveal tiny distortions of the crystal lattice in a so-called iron pnictide compound of sodium, iron, nickel and arsenic.
These local distortions were observed among the otherwise symmetrical atomic order in the material at ultracold temperatures near the point of optimal superconductivity. They indicate researchers may have some wiggle room as they work to increase the temperature at which iron pnictides become superconductors.
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Aug 6, 2018
Physicists Tied Laser Beams into Knots
Posted by Genevieve Klien in categories: futurism, physics
The technology could improve future precision light sources. But right now the biggest surprise is how many holes there are in a laser figure-eight.
Aug 4, 2018
Scientists Discover the Great Pyramid of Giza’s Design Can Concentrate Electromagnetic Energy
Posted by Genevieve Klien in categories: energy, physics
Researchers from St Petersburg’s ITMO University in Russia and Laser Zentrum Hannover in Germany have discovered a fascinating phenomenon regarding the design of the Great Pyramid of Giza.
A theoretical investigation published in the Journal of Applied Physics on July 20 2018 reveals the chambers within the Great Pyramid can “collect and concentrate electromagnetic energy.” Scientists looked at the “excitation of the pyramid’s electromagnetic dipole and quadrupole moments,” or the combinations of outgoing and incoming electromagnetic waves, to determine its capacity for electromagnetic focus. Using numerical simulations to deduce their findings, the research team found that under certain conditions, the pyramid’s internal chambers and the area under its base (where the third, unfinished chamber is located) can concentrate this energy.
Modern physics has provided unprecedented insight into the secrets of the pyramids, which were constructed around 2560 BC. For instance, cosmic ray-based imaging (also known as muon tomography) has been used to see further into the depths of these ancient structures, illuminating a previously unknown “large void” that humans haven’t encountered in several millennia.
Aug 3, 2018
New Physics Needed to Resolve Universe Expansion Debate?
Posted by Genevieve Klien in categories: computing, cosmology, physics
Next time you eat a blueberry (or chocolate chip) muffin consider what happened to the blueberries in the batter as it was baked. The blueberries started off all squished together, but as the muffin expanded they started to move away from each other. If you could sit on one blueberry you would see all the others moving away from you, but the same would be true for any blueberry you chose. In this sense galaxies are a lot like blueberries.
Since the Big Bang, the universe has been expanding. The strange fact is that there is no single place from which the universe is expanding, but rather all galaxies are (on average) moving away from all the others. From our perspective in the Milky Way galaxy, it seems as though most galaxies are moving away from us – as if we are the centre of our muffin-like universe. But it would look exactly the same from any other galaxy – everything is moving away from everything else.
To make matters even more confusing, new observations suggest that the rate of this expansion in the universe may be different depending on how far away you look back in time. This new data, published in the Astrophysical Journal, indicates that it may time to revise our understanding of the cosmos.
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