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sabato 25 giugno 2022
# astro: eight new echoing black hole binaries (in Milky Way)
sabato 23 marzo 2024
# astro: black hole portraits will become more frequent
lunedì 19 settembre 2022
# astro: black holes (as Q-ball-type saturons) could admit multi-vortex dynamics
sabato 5 febbraio 2022
# astro: aprops of horrific encounters, how to survive inside a (virtual) black hole
mercoledì 5 agosto 2020
# astro: runaway cooling of intracluster gas during a silent black hole
venerdì 9 giugno 2023
# gst: another way for the evaporation of a black hole
martedì 20 luglio 2021
# life: some scientists hypothesize the possibility of (A) traveling faster than light, (B) visiting the interior of a black hole, (C) being already under observation by alien entities.
lunedì 8 febbraio 2021
# gst; apropos of hair that can be combed, some perturbation fields, along the event horizon of extreme black holes, seem to evolve in time indefinitely
martedì 22 febbraio 2022
# gst: apropos of a immaginary transition (with a tipping point), which simulates the chaotic interactions of three black holes.
venerdì 3 aprile 2020
# astro: apropos of elusive predators ... the mid-sized mass black hole
venerdì 26 agosto 2016
# s-phys: spontaneous oddities observed in a home-made black hole in sound
AA << observe spontaneous Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole in an atomic Bose–Einstein condensate. >>
Jeff Steinhauer. Observation of quantum Hawking radiation and its entanglement in an analogue black hole. Nature Physics (2016) doi:10.1038/nphys3863 Published online 15 Aug 2016
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3863.html
Davide Castelvecchi. Artificial black hole creates its own version of Hawking radiation. Result could be closest thing yet to an observation of the bizarre phenomenon. 15 Aug 2016.
Ron Cowen. One-man band: the solo physicist who models black holes in sound. Working alone, Jeff Steinhauer has created a sonic analogue of Hawking radiation. 15 Aug 2016.
http://www.nature.com/news/one-man-band-the-solo-physicist-who-models-black-holes-in-sound-1.20437
martedì 12 novembre 2019
# gst: marginally outer trapped surfaces (during a binary Black Hole merger)
mercoledì 10 aprile 2019
# astro: the first picture of a black hole at the heart of galaxy Messier 87.
<< We have taken the first picture of a black hole, (..) This is an extraordinary scientific feat accomplished by a team of more than 200 researchers. (..) We have achieved something presumed to be impossible just a generation ago, (..) Breakthroughs in technology, connections between the world's best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes and the event horizon. >> Sheperd S. Doeleman
<< This breakthrough was announced today in a series of six papers published in a special issue of The Astrophysical Journal Letters. >>
<< The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope Alfonso Serrano, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope. Petabytes of raw data from the telescopes were combined by highly specialised supercomputers hosted by the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory. >>
Astronomers Capture First Image of a Black Hole. An international collaboration presents paradigm-shifting observations of the gargantuan black hole at the heart of distant galaxy Messier 87. Apr 10, 2019.
https://eventhorizontelescope.org
The Event Horizon Telescope Collaboration et al. First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole. 2019 ApJL 875 L4
giovedì 26 luglio 2018
# phys: a holographic image of a black hole
<< by applying a magnetic field to a small, irregularly shaped graphene flake, the flake becomes a quantum hologram of a black hole. This means that the graphene flake recreates the spatial structure and characteristic properties of a black hole, but in a much smaller, lower-dimensional system. >>
<< The type of holographic duality illustrated by the SYK [Sachdev-Ye-Kitaev] model is particularly interesting because it exhibits some of the signature properties of black holes, such as non-zero residual entropy and quantum chaos propagation. >>
Lisa Zyga. Holographic image of a black hole proposed in a graphene flake. Phys.org. July 25, 2018.
https://m.phys.org/news/2018-07-holographic-image-black-hole-graphene.html
Anffany Chen, R. Ilan, F. de Juan, D. I. Pikulin, and M. Franz. Quantum Holography in a Graphene Flake with an Irregular Boundary. Phys. Rev. Lett. 121, 036403. July 18, 2018
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.036403
sabato 20 gennaio 2024
# gst: the fascinating possibility of two black holes masquerading as one.
lunedì 28 agosto 2017
# astro: the binary black hole spin distribution, a sort of cosmic estension of Mr. Jelly Roll
<< The direct detection of gravitational waves from merging binary black holes opens up a window into the environments in which binary black holes form. One signature of such environments is the angular distribution of the black hole spins >>
AA << report that, if the magnitudes of the black hole spins are allowed to extend to high values, the effective spins for these systems indicate a 0.015 odds ratio against an aligned angular distribution compared to an isotropic one [isotropic spin orientation: the spins of the black holes are randomly oriented with respect to the orbit of the binary system]. When considering the effect of ten additional detections, this odds ratio decreases to 2.9 × 10−7 against alignment >>
Will M. Farr, Simon Stevenson, et al. Distinguishing spin-aligned and isotropic black hole populations with gravitational waves. Nature 548, 426–429 Aug 24, 2017 doi: 10.1038/nature23453
http://www.nature.com/nature/journal/v548/n7668/full/nature23453.html
https://arxiv.org/abs/1706.01385
<< Amico, qualunque cosa suonerai . . . suonerai Jelly Roll >>
Jelly Roll Morton (opp. Mouton, alias di Ferdinand La Menthe, opp. La Mothe, New Orleans, 20 ott ~1885 - Los Angeles, 10 luglio 1941, ~56a). Ref: Alan Lomax. "Mister Jelly Roll". Duell, Sloan & Pearce, New York (1950); cit. in: Arrigo Polillo, "JAZZ". Oscar Saggi Mondadori. (1977):315,325.
mercoledì 29 agosto 2018
# astro: when an unlucky star ventures close enough to a black hole, it spaghettifies ...
<< To be disrupted, an unlucky star must venture close enough to a black hole that gravitational tides exceed the internal gravity that binds the star together. In other words, the difference in the black hole's gravitational pull on the near and far sides of the star, along with the inertial pull as the star swings around the black hole, stretches the star out into a stream. "Basically it spaghettifies," >> James Guillochon
Joshua Sokol. Star-Swallowing Black Holes Reveal Secrets in Exotic Light Shows. August 8, 2018.
giovedì 22 settembre 2022
# life: apropos of quasi-stochastic (bizarre) landscapes in high-dimension, a case of double RAG-time inside a black hole with vortices
mercoledì 11 ottobre 2023
# phys: a quantum gravity hypothesis on infalling matter (hunting for extreme Kerr black holes)
giovedì 7 marzo 2019
# gst astro: approaches to hack a black hole (to distinguish scrambled information from noise)
paper.1
Adam Mann. Physicists May Have Found a Way to 'Untangle' Information Trapped in a Black Hole. Mar 6, 2019
https://www.livescience.com/64935-black-hole-information-paradox.html
K. A. Landsman, C. Figgatt, et al. Verified quantum information scrambling. Nature. volume 567, pages 61–65 (2019) Mar 6, 2019.
https://www.nature.com/articles/s41586-019-0952-6
paper.2
Mike McRae. Physicists Want to Use Quantum Particles to Find Out What Happens Inside a Black Hole. Mar 6, 2019.
Beni Yoshida, Norman Y. Yao. Disentangling Scrambling and Decoherence via Quantum Teleportation. Phys. Rev. X 9, 011006. Jan 9, 2019
https://journals.aps.org/prx/abstract/10.1103/PhysRevX.9.011006