Primordial black holes older than the big bang could rewrite cosmology by providing evidence for a previous universe. It’s a wild idea, but some physicists think we’ve got a chance of finding them.
By Bernard Carr
Category: cosmology – Page 162
Computronium universe
Posted in cosmology, Ray Kurzweil
I read enough to realize it’s in depth enough to make it worthwhile. I’ll finish tomorrow as it’s 10:35 pm and I’m beat. I need to rest for my mother’s cardiac rehab tomorrow. She had a heart attack about a month ago.
Ray Kurzweil discusses having a universe filled with Computronium.
He discusses this happening within 200 years if wormholes or some other means allow faster than light travel.
Although neutrinos are produced abundantly in collisions at the Large Hadron Collider (LHC), until now no neutrinos produced in such a way had been detected. Within just nine months of the start of LHC Run 3 and the beginning of its measurement campaign, the FASER collaboration changed this picture by announcing its first observation of collider neutrinos at this year’s electroweak session of the Rencontres de Moriond. In particular, FASER observed muon neutrinos and candidate events of electron neutrinos. “Our statistical significance is roughly 16 sigma, far exceeding 5 sigma, the threshold for a discovery in particle physics,” explains FASER’s co-spokesperson Jamie Boyd.
In addition to its observation of neutrinos at a particle collider, FASER presented results on searches for dark photons. With a null result, the collaboration was able to set limits on previously unexplored parameter space and began to exclude regions motivated by dark matter. FASER aims to collect up to ten times more data over the coming years, allowing more searches and neutrino measurements.
FASER is one of two new experiments situated at either side of the ATLAS cavern to detect neutrinos produced in proton collisions in ATLAS. The complementary experiment, SND@LHC, also reported its first results at Moriond, showing eight muon neutrino candidate events. “We are still working on the assessment of the systematic uncertainties to the background. As a very preliminary result, our observation can be claimed at the level of 5 sigma,” adds SND@LHC spokesperson Giovanni De Lellis. The SND@LHC detector was installed in the LHC tunnel just in time for the start of LHC Run 3.
This is a galactic-sized problem. Scientists revealed Tuesday that galaxy PBC J2333.9–2343 has been reclassified after discovering a supermassive black hole that is currently facing our solar system, reports Royal Astronomical Society. Alien-hunting physicist on mission to prove meteorite that hit Earth is extraterrestrial probe Asteroid that could wipe out a city is near.
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Astronomers finally figure out what it’s like inside an actual, spinning black hole — and where exactly it’d kill you.
We don’t want to alarm you, but there’s a black hole pointing Earth squarely in the face.
Scientists have reclassified a galaxy after finding that the supermassive black hole in its centre has changed direction and it is now aiming right at us.
A white dwarf star can explode as a supernova when its mass exceeds the limit of about 1.4 solar masses. A team led by the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching and involving the University of Bonn has now found a binary star system in which matter flows onto the white dwarf from its companion.
The system was found due to bright, so-called super-soft X-rays, which originate in the nuclear fusion of the overflowed gas near the surface of the white dwarf. The unusual thing about this source is that it is helium and not hydrogen that overflows and burns. The measured luminosity suggests that the mass of the white dwarf is growing more slowly than previously thought possible, which may help to understand the number of supernovae caused by exploding white dwarfs. The results have been published in the journal Nature.
Exploding white dwarfs are not only considered the main source of iron in the universe, they are also an important tool for cosmology. As so-called Type Ia supernovae (SN Ia), they all become roughly equally bright, allowing astrophysics a precise determination of the distance of their host galaxies.
A probe going through a wormhole should be able to send messages home before such a tunnel forever closes, a new computer model finds.
With a bigger, better, and more sensitive detector than ever before, the XENON collaboration leaves little wiggle room for WIMP dark matter.
Just a couple of years earlier, in 1963, New Zealand mathematician Roy Kerr found a solution to Einstein’s equation for a rotating black hole. This was a “game changer for black holes,” Giorgi noted in a public lecture given at the virtual 2022 International Congress of Mathematicians. Rotating black holes were much more realistic astrophysical objects than the non-spinning black holes that Karl Schwarzschild had solved the equations for.
“Physicists really had believed for decades that the black hole region was an artifact of symmetry that was appearing in the mathematical construction of this object but not in the real world,” Giorgi said in the talk. Kerr’s solution helped establish the existence of black holes.
In a nearly 1,000-page paper, Giorgi and colleagues used a type of “proof by contradiction” to show that Kerr black holes that rotate slowly (meaning they have a small angular momentum relative to their mass) are mathematically stable. The technique entails assuming the opposite of the statement to be proved, then discovering an inconsistency. That shows that the assumption is false. The work is currently undergoing peer review. “It’s a long paper, so it’s going to take some time,” Giorgi says.