Archive for the ‘cosmology’ category: Page 98
Sep 3, 2023
Dead Stars Could Hold the Secrets of Dark Matter
Posted by Genevieve Klien in category: cosmology
If you want to find something that’s invisible except for its gravitational effects, look down the steepest gravity wells in the universe.
Sep 2, 2023
A new image from NASA’s James Webb Space Telescope blows past Hubble again, revealing an iconic supernova in unprecedented detail
Posted by Genevieve Klien in category: cosmology
The supernova, which was first discovered in 1987, has a keyhole-like formation, full of clumpy gas and dust, at its center.
Aug 31, 2023
Earth has been hit by an ‘impossible’ blast of light. Scientists now know how
Posted by Arthur Brown in category: cosmology
Scientists believe they have found an explanation for an “impossible” blast of energy that hit Earth.
Last year, scientists reported that they had seen evidence that gamma-ray bursts could come out of mergers between neutron stars and another compact object, in the form of a neutron star or black hole. That was previously thought not to be possible.
Scientists had initially thought that the 50-second blast came when a massive star collapsed, but further work looking at the afterglow of the emission showed that it was in fact a “kilonova”, which happens when neutron stars merge with other compact objects. Previously, it was thought that only a supernova could make a long gamma-ray burst of that kind.
Aug 31, 2023
Challenging Einstein — New Study Suggests That Dark Matter Interacts With Gravity in a Non-Local Way
Posted by Paul Battista in categories: cosmology, quantum physics
Isaac Newton described his theory of gravity as a force that acts instantaneously across space: a planet immediately senses the effects of another astronomical object, regardless of the separation between them. This aspect inspired Einstein to create the renowned theory of general relativity, where gravity becomes a local deformation of spacetime.
The principle of locality states that an object is directly influenced only by its surrounding environment: distant objects cannot communicate instantaneously, only what is here right now matters. However, in the past century, with the birth and development of quantum mechanics, physicists discovered that non-local phenomena not only exist but are fundamental to understanding the nature of reality.
Now, a new study from SISSA – Scuola Internazionale Superiore di Studi Avanzati, recently published in The Astrophysical Journal.
Aug 29, 2023
Pulsars Detected the Background Gravitational Hum of the Universe. Now Can They Detect Single Mergers?
Posted by Shubham Ghosh Roy in categories: cosmology, physics
After over a decade of observations of pulsars, astronomers could finally tease out the gravitational wave background of the Universe, the combined signal from merging supermassive black holes. But it was just the general presence of mergers, not specific events. A new paper proposes that the same pulsars could next be used to detect the gravitational waves from individual merging supermassive black holes. The more nearby pulsars astronomers can find, the more accurate their measurements will become.
A black hole created by the collision of two parent bodies can rebound at a speed of more than 28,000 kilometres per second.
Aug 28, 2023
Scientists spot edge of supermassive black hole accidentally
Posted by Quinn Sena in category: cosmology
Supermassive black holes sit at the center of many galaxies and are often surrounded by accretion disks that they feed on. Scientists observed a previously unexplored region near one – by accident.
Aug 26, 2023
Researchers define the ‘speed limit’ of black holes, suggesting new laws of physics
Posted by Shubham Ghosh Roy in categories: cosmology, physics
When supermassive black holes barrel toward collision, they can reach speeds of up to 1/10th the speed of light, new research suggests.