Nov 13, 2023 05:56 PM
(This post was last modified: Nov 13, 2023 06:24 PM by C C.)
‘Dark Big Bang’ theory argues a second cosmological origin event could help resolve dark matter mystery
https://thedebrief.org/dark-big-bang-the...r-mystery/
EXCERPT: . . . In a new preprint paper by authors Katherine Freese and Martin Wolfgang Winkler, the authors propose a second type of cosmological event, which they call the “Dark Big Bang,” could have been responsible for the creation of dark matter and possibly also dark radiation.
Occurring sometime after the original Big Bang, Freese and Winkler posit that the Dark Big Bang might have taken place at a much later time, and within a hypothetical region of the universe composed of dark matter and dark energy, aptly named the dark sector.
At some point, they argue, the dark sector may have undergone a phase transition that could have caused dark vacuum energy to be transformed into a plasma of dark particles that manifested at extremely high temperatures. This transitional stage, known as a first-order phase transition, describes the physical process where one state, such as solids or liquids, is converted into another.
According to Freese and Winkler’s preprint paper, dark matter might have originated during this Dark Big Bang in a variety of ways, which includes what they call “dark matter cannibalism,” where dark matter particles effectively consume each other. An additional possibility involves dark matter particle annihilation in pairs, after which they undergo a cooling phase called thermal freeze-out.
In another scenario, the formation of extremely heavy dark matter, which Freese and Winkler refer to as “dark-zilla”, might have originated as a result of the collision of bubbles during this hypothetical Dark Big Bang... (MORE - missing details)
Skywatchers have a new space object to train their sights on: a toolbag that is now floating through space around Earth.
https://www.theguardian.com/science/2023...-spacewalk
INTRO: The Nasa astronauts Jasmin Moghbeli and Loral O’Hara were conducting a rare all-female spacewalk outside the International Space Station (ISS) on 1 November when their toolbag gave them the slip, according to Nasa.
The astronauts, both on their first spacewalk, were making repairs on assemblies that allow the ISS solar arrays to track the sun continuously, reported SciTechDaily, which was documenting the spacewalk.
“During the activity, one tool bag was inadvertently lost. Flight controllers spotted the tool bag using external station cameras. The tools were not needed for the remainder of the spacewalk. Mission Control analyzed the bag’s trajectory and determined that risk of recontacting the station is low and that the onboard crew and space station are safe with no action required,” said Nasa on its blog.
The white, satchel-like bag is surprisingly bright, shining just below the limit of visibility to the naked eye, which means observers would be able to spot it using binoculars, according to EarthSky. Its visual magnitude is around a 6, making it slightly less bright than the ice giant Uranus.
To track the bag, observers need only to find the ISS, which is the third-brightest object in the night sky, according to Nasa, and can be located using the agency’s Spot the Station tool. The bag will be orbiting Earth two to four minutes ahead of the ISS.
The bag was spotted floating over Mount Fuji last week by the Japanese astronaut Satoshi Furukawa... (MORE - details)
https://thedebrief.org/dark-big-bang-the...r-mystery/
EXCERPT: . . . In a new preprint paper by authors Katherine Freese and Martin Wolfgang Winkler, the authors propose a second type of cosmological event, which they call the “Dark Big Bang,” could have been responsible for the creation of dark matter and possibly also dark radiation.
Occurring sometime after the original Big Bang, Freese and Winkler posit that the Dark Big Bang might have taken place at a much later time, and within a hypothetical region of the universe composed of dark matter and dark energy, aptly named the dark sector.
At some point, they argue, the dark sector may have undergone a phase transition that could have caused dark vacuum energy to be transformed into a plasma of dark particles that manifested at extremely high temperatures. This transitional stage, known as a first-order phase transition, describes the physical process where one state, such as solids or liquids, is converted into another.
According to Freese and Winkler’s preprint paper, dark matter might have originated during this Dark Big Bang in a variety of ways, which includes what they call “dark matter cannibalism,” where dark matter particles effectively consume each other. An additional possibility involves dark matter particle annihilation in pairs, after which they undergo a cooling phase called thermal freeze-out.
In another scenario, the formation of extremely heavy dark matter, which Freese and Winkler refer to as “dark-zilla”, might have originated as a result of the collision of bubbles during this hypothetical Dark Big Bang... (MORE - missing details)
Skywatchers have a new space object to train their sights on: a toolbag that is now floating through space around Earth.
https://www.theguardian.com/science/2023...-spacewalk
INTRO: The Nasa astronauts Jasmin Moghbeli and Loral O’Hara were conducting a rare all-female spacewalk outside the International Space Station (ISS) on 1 November when their toolbag gave them the slip, according to Nasa.
The astronauts, both on their first spacewalk, were making repairs on assemblies that allow the ISS solar arrays to track the sun continuously, reported SciTechDaily, which was documenting the spacewalk.
“During the activity, one tool bag was inadvertently lost. Flight controllers spotted the tool bag using external station cameras. The tools were not needed for the remainder of the spacewalk. Mission Control analyzed the bag’s trajectory and determined that risk of recontacting the station is low and that the onboard crew and space station are safe with no action required,” said Nasa on its blog.
The white, satchel-like bag is surprisingly bright, shining just below the limit of visibility to the naked eye, which means observers would be able to spot it using binoculars, according to EarthSky. Its visual magnitude is around a 6, making it slightly less bright than the ice giant Uranus.
To track the bag, observers need only to find the ISS, which is the third-brightest object in the night sky, according to Nasa, and can be located using the agency’s Spot the Station tool. The bag will be orbiting Earth two to four minutes ahead of the ISS.
The bag was spotted floating over Mount Fuji last week by the Japanese astronaut Satoshi Furukawa... (MORE - details)