Astronomer Fred Hoyle supposedly coined the catchy term to ridicule the theory of the Universe’s origins — 75 years on, it’s time to set the record straight.
Category: cosmology – Page 85
A UCL-led research team has used artificial intelligence (AI) techniques to infer the influence and properties of dark energy more precisely from a map of dark and visible matter in the universe covering the last 7 billion years.
The study, submitted to the Monthly Notices of the Royal Astronomical Society and available on the arXiv preprint server, was carried out by the Dark Energy Survey collaboration. The researchers doubled the precision at which key characteristics of the universe, including the overall density of dark energy, could be inferred from the map.
This increased precision allows researchers to rule out models of the universe that might previously have been conceivable.
An international piece of research, led by the Instituto de Astrofísica de Canarias (IAC) has found clues to the nature of some of the brightest and hottest stars in our universe, called blue supergiants. Although these stars are commonly observed, their origin has been an old puzzle that has been debated for several decades.
In the 1920s, Edwin Hubble and Georges Lemaitre made a startling discovery that forever changed our perception of the Universe. Upon observing galaxies beyond the Milky Way and measuring their spectra, they determined that the Universe was expanding. By the 1990s, with the help of the Hubble Space Telescope, scientists took the deepest images of the Universe to date and made another startling discovery: the rate of expansion is speeding up! This parameter, denoted by Lambda, is integral to the accepted model of cosmology, known as the Lambda Cold Dark Matter (LCDM) model.
Since then, attempts to measure distances have produced a discrepancy known as the “Hubble Tension.” While it was hoped that the James Webb Space Telescope (JWST) would resolve this “crisis in cosmology,” its observations have only deepened the mystery. This has led to several proposed resolutions, including the idea that there was an “Early Dark Energy” shortly after the Big Bang. In a recent paper, an international team of astrophysicists proposed a new solution based on an alternate theory of gravity that states that our galaxy is in the center of an “under-density.”
The study was led by Sergij Mazurenko, an undergraduate physics student at the University of Bonn. He was joined by Indranil Banik, a Research Fellow with the Scottish Universities Physics Alliance at the University of Saint Andrews; Pavel Kroupa, an astrophysicist professor with The Stellar Populations and Dynamics Research Group at the University of Bonn and the Astronomical Institute at Charles University, and Moritz Haslbauer, a Ph.D. student at the Max Planck Institute for Radioastronomy (MPIfR). The paper that describes their findings recently appeared in the Monthly Notices of the Royal Astronomical Society (MNRAS).
Neutron star mergers are a treasure trove for new physics signals, with implications for determining the true nature of dark matter, according to research from Washington University in St. Louis.
On Aug. 17, 2017, the Laser Interferometer Gravitational-wave Observatory (LIGO), in the United States, and Virgo, a detector in Italy, detected gravitational waves from the collision of two neutron stars. For the first time, this astronomical event was not only heard in gravitational waves but also seen in light by dozens of telescopes on the ground and in space.
Physicist Bhupal Dev in Arts & Sciences used observations from this neutron star merger — an event identified in astronomical circles as GW170817 — to derive new constraints on axion-like particles. These hypothetical particles have not been directly observed, but they appear in many extensions of the standard model of physics.
A team of scientists has successfully mimicked black hole conditions by creating a quantum vortex in superfluid helium, shedding light on gravitational interactions and quantum field theories in curved spacetimes.
Scientists have for the first time created a giant quantum vortex to mimic a black hole in superfluid helium that has allowed them to see in greater detail how analog black holes behave and interact with their surroundings.
Research led by the University of Nottingham, in collaboration with King’s College London and Newcastle University, has created a novel experimental platform: a quantum tornado. They have created a giant swirling vortex within superfluid helium that is chilled to the lowest possible temperatures. Through the observation of minute wave dynamics on the superfluid’s surface, the research team has shown that these quantum tornados mimic gravitational conditions near rotating black holes. The research has been published today in Nature.
When it comes to the cosmic conundrum of how early galaxies grew to become so massive so quickly Gz9p3 could be a real puzzle. Not only is it more massive than expected, but it is around 10 times more massive than other galaxies the JWST has seen in similar eras of the universe’s history.
Related: James Webb Space Telescope complicates expanding universe paradox by checking Hubble’s work
“Just a couple of years ago, Gz9p3 appeared as a single point of light through the Hubble Space Telescope,” Kit Boyett, team member and a scientist at the University of Melbourne, wrote for the institute’s Pursuit publication. “But by using the JWST we could observe this object as it was 510 million years after the Big Bang, around 13 billion years ago.”
It is with sadness — and deep appreciation of my friend and colleague — that I must report the passing of Vernor Vinge.
The technological singularity —or simply the singularity[1] —is a hypothetical future point in time at which technological growth becomes uncontrollable and irreversible, resulting in unforeseeable consequences for human civilization.[2][3] According to the most popular version of the singularity hypothesis, I. J. Good’s intelligence explosion model, an upgradable intelligent agent will eventually enter a “runaway reaction” of self-improvement cycles, each new and more intelligent generation appearing more and more rapidly, causing an “explosion” in intelligence and resulting in a powerful superintelligence that qualitatively far surpasses all human intelligence.[4]
The first person to use the concept of a “singularity” in the technological context was the 20th-century Hungarian-American mathematician John von Neumann.[5] Stanislaw Ulam reports in 1958 an earlier discussion with von Neumann “centered on the accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue”.[6] Subsequent authors have echoed this viewpoint.[3][7]
Everyone loves a two-for-one deal—even physicists looking to tackle unanswered questions about the cosmos. Now, scientists at the Department of Energy’s SLAC National Accelerator Laboratory are getting just such a twofer: Particle detectors originally developed to look for dark matter are now in a position to be included aboard the Line Emission Mapper (LEM), a space-based X-ray probe mission proposed for the 2030s.
We don’t live in a universe where matter floats around in empty space… we live in a universe of energy fields that spread throughout the universe and interact with one another, creating everything we see in the process.