# phys: stable vortex loops intersected by point singularities (in magnets)

<< Vortex rings are remarkably stable structures that occur in a large variety of systems (..) Although vortex rings have also been predicted to exist in ferromagnets, they have not yet been observed. >>

AA << imaged three-dimensional structures forming closed vortex loops in a bulk micromagnet. The cross-section of these loops consists of a vortex–antivortex pair and, on the basis of magnetic vorticity (they) identify these configurations as magnetic vortex rings. >>

<< In addition, (they) observe stable vortex loops intersected by point singularities at which the magnetization within the vortex and antivortex cores reverses. >>

Claire Donnelly, Konstantin L. Metlov, et al. Experimental observation of vortex rings in a bulk magnet. Nature Physics. doi: 10.1038/ s41567-020-01057-3. Nov 30,  2020.

https://www.nature.com/articles/s41567-020-01057-3

Magnetic vortices come full circle. 

Paul Scherrer Institute. Nov 30, 2020.

https://phys.org/news/2020-11-magnetic-vortices-full-circle.html

# life: apropos of ghosts, a bizarre answer to my previous post, the 'cosmic ghost' ...

<<  They were on a mission to count sheep when they found something they had not counted on. >>

Peter Szekely. Reuters: Space oddity? Monolith in Utah desert mystifies helicopter crew. Nov 25, 2020.

https://www.reuters.com/article/us-usa-monolith/space-oddity-monolith-in-utah-desert-mystifies-helicopter-crew-idUSKBN28501O

Also

apropos of unsubstantiated belief (e.g. paranormal belief, anomalistic psychology, ...) why so many people believe in 'ghosts'. FonT.  19 Nov 19, 2020.

https://flashontrack.blogspot.com/2020/11/life-apropos-of-unsubstantiated-belief.html

# life: apropos of unsubstantiated belief (e.g. paranormal belief, anomalistic psychology, ...) why so many people believe in 'ghosts'.

<< Unlikely as it might seem in the cold light of day, ghosts and hauntings are a mainstream area of belief. Recent studies by YouGov in the UK and the USA show that between 30% and 50% of the population says they believe in ghosts. Belief in ghosts also appears to be global, with most (if not all) cultures around the world having some widely accepted kind of ghosts. >> 

<< The existence of a ghost as an incorporeal (bodyless) soul or spirit of a dead person or animal is contrary to the laws of nature as we understand them, so it seems there is something here that calls for explanation. We can look at the worlds of literature, philosophy and anthropology for some of the reasons why people are so keen to believe. >> 

<< Looking at how the brain works, the experience of hallucinations is a lot more common than many people realise. The SPR (Society for Psychical Research), founded in 1882, collected thousands of verified first-hand reports of visual or auditory hallucinations (..)   https://psi-encyclopedia.spr.ac.uk/articles/ghosts-and-apparitions-psi-research-overview#footnote52_nux8rmw   (..) Another source of hallucinations is the phenomenon of sleep paralysis, (..) >> 

<< According to the Dutch philosopher Baruch Spinoza, belief comes quickly and naturally, whereas scepticism is slow and unnatural. In a study of neural activity, Harris and colleagues discovered that believing a statement requires less effort than disbelieving it. >>

<<  Given these multiple reasons for us to believe in ghosts, it seems that the belief is likely to be with us for many years to come. >> 

Anna Stone. ‘I see dead people’: why so many of us believe in ghosts. 

Oct 30, 2020. 

https://theconversation.com/i-see-dead-people-why-so-many-of-us-believe-in-ghosts-148886

Also

keyword 'paranormal belief' in PubMed

https://pubmed.ncbi.nlm.nih.gov/?term=paranormal+belief

keyword 'fantasmi' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=fantasmi

# chem: photocatalytic hydrogen production activity by single-atom alloy (SAA) cocatalyst

<< Photocatalysis, converting solar energy into chemical energy, has been recognized to be a very promising solution to current energy and environmental issues. >>

<< In contrast to the existing reports centered on co-catalysts, such as the development of non-noble metals, particle size and distribution control, exposed crystal facets and their interface contact with photosensitizers, the regulation on the surface charge state of co-catalysts by changing their microstructures provides vast opportunities for boosting photocatalysis, yet remains extremely rare. >> 

<< In this work, Dr. Jiang's research group (..) has achieved the goal of optimizing Pt surface charge states via the control of bimetallic Pd@Pt (Palladium@Platinum) microstructure and Pt coordination environment. >> 

<< As a result, all Pd@Pt/MOF (/Metal-Organic Framework) present excellent photocatalytic hydrogen production activity due to the electron-rich Pt sites benefited from charge redistribution effect. Moreover, the optimized Pd10@Pt1/MOF composite with SAA (Single-Atom Alloy) co-catalyst, which features the most electron-rich Pt, exhibits an exceptionally high photocatalytic hydrogen production activity, far surpassing its corresponding counterparts  >> 

Single-atom alloy: Superb cocatalyst for photocatalysis. Science China Press. Oct 28, 2020. 

https://phys.org/news/2020-10-single-atom-alloy-superb-cocatalyst-photocatalysis.html  

Yating Pan, Yunyang Qian, et al. Precise fabrication of single-atom alloy co-catalyst with optimal charge state for enhanced photocatalysis. National Science Review, nwaa224. doi: 10.1093/ nsr/nwaa224. Sep 3, 2020. 

https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaa224/5900997

# brain: the hypothesis that a brain organoid (a lab-grown brain) can reach consciousness.

<< In Alysson Muotri’s laboratory, hundreds of miniature human brains, the size of sesame seeds, float in Petri dishes, sparking with electrical activity. 

These tiny structures, known as brain organoids, are grown from human stem cells and have become a familiar fixture in many labs that study the properties of the brain. Muotri, a neuroscientist at the University of California, San Diego (UCSD), has found some unusual ways to deploy his. He has connected organoids to walking robots, modified their genomes with Neanderthal genes, launched them into orbit aboard the International Space Station, and used them as models to develop more human-like artificial-intelligence (AI) systems. (..) But one experiment has drawn more scrutiny than the others. In August 2019, Muotri’s group published a paper in Cell Stem Cell (*) reporting the creation of human brain organoids that produced coordinated waves of activity, resembling those seen in premature babies. The waves continued for months before the team shut the experiment down. This type of brain-wide, coordinated electrical activity is one of the properties of a conscious brain. >> 

Sara Reardon. Can lab-grown brains become conscious? Nature 586, 658-661. doi: 10.1038/ d41586-020-02986-y. Oct 27, 2020. Correction Nov 4, 2020.

https://www.nature.com/articles/d41586-020-02986-y     

(*)  Trujillo CA, Gao R, et al. Complex Oscillatory Waves Emerging from Cortical Organoids Model Early Human Brain Network Development. Cell Stem Cell. 2019 Oct 3;25(4):558-569.e7. doi: 10.1016/ j.stem.2019.08.002. Aug 29, 2019. 

https://pubmed.ncbi.nlm.nih.gov/31474560/

https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(19)30337-6

# gst: apropos of nano vortices: the stabilization of skyrmions by weak higher-order exchange interactions

<< Tiny magnetic whirls that can occur in materials—so-called skyrmions— hold high promises for novel electronic devices or magnetic memory in which they are used as bits to store information. A fundamental prerequisite for any application is the stability of these magnetic whirls. >>

<< Previously, a standard model of the relevant magnetic interactions contributing to the (energy) barrier has been established. >>

<< one type of magnetic interactions has so far been overlooked. In the 1920s Werner Heisenberg could explain the occurrence of ferromagnetism by the quantum mechanical exchange interaction which results from the spin dependent "hopping" of electrons between two atoms. "If one considers the electron hopping between more atoms, higher-order exchange interactions occur," says Dr. Souvik Paul, (..). However, these interactions are much weaker than the pair-wise exchange proposed by Heisenberg and were thus neglected in the research on skyrmions. >>

<< Based on atomistic simulations and quantum mechanical calculations (..)  (AA) have now explained that these weak interactions (at a higher temperature than room temperature) can still provide a surprisingly large contribution to skyrmion stability. Especially the cyclic hopping over four atomic sites (..) influences the energy of the transition state extraordinarily strongly (..), where only a few atomic bar magnets are tilted against each other. Even stable antiskyrmions were found in the simulations which are advantageous for some future data storage concepts but typically decay too fast. >>

Julia Siek­mann. Scientists find a new mechanism for the stabilization of skyrmions. Kiel University. Sep 21, 2020.

https://phys.org/news/2020-09-scientists-mechanism-stabilization-skyrmions.html

Paul, S., Haldar, S., von Malottki, S. et al. Role of higher- order exchange interactions for skyrmion stability. Nat Commun 11, 4756. doi: 10.1038/ s41467-020-18473-x. Sep 21, 2020.

https://www.nature.com/articles/s41467-020-18473-x   

# life: the 'built-in float' of an ancient marine predator

<< About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. >>

<< Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we've identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey, >> Qing-Hua Shang.

<< Perhaps this small, slow-swimming marine reptile had to be vigilante for large predators as it floated in the shallows, as well as being a predator itself, >> Xiao-Chun Wu.

Taylor & Francis. Ancient marine predator had a built-in float. Oct 28, 2020. 

https://phys.org/news/2020-10-ancient-marine-predator-built-in.html

Qing-Hua Shang, Xiao-Chun Wu, Chun Li. A New Ladinian Nothosauroid (Sauropterygia) from Fuyuan, Yunnan Province, China. Journal of Vertebrate Paleontology. doi: 10.1080/ 02724634.2020.1789651. Oct 29, 2020.

https://www.tandfonline.com/doi/10.1080/02724634.2020.1789651