3.114 - AMICOR (25)

3.114 AMICOR (25)

#Dra. Valderês Antonietta Robinson Achutti (*13/06/1931+15/06/2021)

 

Colhendo água, diretamente do Aquífero Guarani (Sítio Primavera, Viamão)

#Recomendado pela AMICOR Maria Inês Reinart Azambuja

#Biblioteca Pública Municipal: Os Caminhos de Proust

BIBLIOTECA PÚBLICA DO ESTADO DO RS - BPE

Vida e obra de Marcel Proust estão em exposição imperdível em Porto Alegre

#OUR WORLD IN DATA

We published a new topic page on Artificial Intelligence

#PhysicsWorld

Physicists measure the fine structure constant directly for the first time

09 Dec 2022

Angle of rotation: A light source (left) sends a beam of light through a topological insulator with an intrinsic magnetic field (centre), changing the direction of polarization by an angle that is given by the fine structure constant. (Courtesy: Tatiana Lysenko / TU Wien)

The value of the fine structure constant – perhaps the most important constant in nature as it dictates the strength of electromagnetism – has been measured directly by researchers in Austria and the US. The technique they used involves measuring how much the polarization of light rotates as it passes through a magnetic topological insulator, and while it is not as accurate as other methods, the researchers believe its directness could lead to cleaner tests of whether this supposed constant varies over time.

The fine structure constant, denoted α, is a dimensionless number with a physical interpretation that has evolved alongside physicists’ understanding of electromagnetism. When Arnold Sommerfeld introduced it in 1916, it was the velocity of an electron in the first circular orbit of the Bohr model of the atom, divided by the speed of light in vacuum. In quantum electrodynamics, it is the coupling constant that determines the strength of interactions between electrons and photons. What remains undisputed, however, is its centrality to physics, and the fact that it cannot be calculated theoretically – it is a free parameter that must be inserted into the Standard Model of particle physics. Its value is around 1/137, and if it were even slightly different – perhaps just 1/138 – it would rewrite the rules of chemistry and change stellar nuclear fusion so much that life could not exist./.../

#José Tadeu Arantes |Agência FAPESP – A interação forte é um ingrediente fundamental para a existência do Universo, tal como o conhecemos. É ela que aglutina os quarks para formar prótons e nêutrons. Estes, por sua vez, compõem os núcleos dos átomos. Recebe o nome de “forte” porque, na escala do núcleo, é de fato muito mais forte do que as outras três interações conhecidas: a gravitacional, a eletromagnética e a fraca. Por ser tão forte, é impossível encontrar quarks livres de forma estável na natureza.

O cálculo da força forte depende de um parâmetro que pode ser considerado uma das grandezas fundamentais da física: a constante de acoplamento forte, conhecida como “alpha_s”. Este é um número puro, adimensional, que vale, na média atual, 0,1179 ± 0,0009.

A edição de 2022 da Review of Particle Physics pode ser acessada em: https://pdg.lbl.gov/#gsc.tab=0.

  Este texto foi originalmente publicado por Agência FAPESP de acordo com a licença Creative Commons CC-BY-NC-ND. Leia o original aqui.

#News.ARTNET.com

Art History 5 Surprising Things We Learned About Leonardo da Vinci From Historian Martin Kemp’s New Online Masterclass

The online course offers an opportunity to get to know both the Renaissance master and the scholar who has devoted his career to studying the artist.

Menachem Wecker, November 25, 2022

A still from Martin Kemp's Da Vinci Masterclass. A 39-year-old producer and an octogenarian art historian have teamed up to create a digital masterclass about an artist who died more than 500 years ago.

#Leandro Mottin, lançamento
A avó dele, Da. Amália Leite Pereira, e outros membros da família, foram nossos clientes.

#TIME Health
Long COVID isn't the only post-viral illness

BY JAMIE DUCHARME

Health Correspondent

When talking about COVID-19, I often hear people say, “Wow, this virus can do anything!” From weird acute symptoms (remember COVID toes?) to devastating cases of Long COVID and serious organ damage, the effects of the SARS-CoV-2 virus are scarily diverse. But it’s a mistake to think that SARS-CoV-2 is unique in this respect. Lots of viruses—even common ones like influenza and Epstein-Barr (which triggers mono)—can cause serious, sometimes life-long complications, including chronic pain, crushing fatigue, and cognitive decline. And due to decades of neglect from the medical and scientific communities, we still don’t have a great understanding of why that is or what can be done to reverse these issues./.../ # NEUROSCIENCE | ALL TOPICS   What Causes Alzheimer’s? Scientists Are Rethinking... By YASEMIN SAPLAKOGLU After decades in the shadow of the reigning model for Alzheimer’s disease, alternative explanations are finally getting the attention they deserve. Read the article COSMOLOGY   Asymmetry Detected in the Distribution of Galaxies By KATIE McCORMICK New studies suggest that certain tetrahedral arrangements of galaxies outnumber their mirror images, potentially reflecting details of the universe’s birth.  Read the article Related:  Why This Universe? A New Calculation Suggests Our Cosmos Is Typical. By Charlie Wood COMBINATORICS   Infinite Patterns Appear in Numbers Described as Moving Systems By LEILA SLOMAN In two recent proofs, mathematicians have supercharged methods for determining the inevitability of infinite “sumsets” in large sets of integers. Read the article Related:  Landmark Math Proof Clears Hurdle in Top Erdős Conjecture By Erica Klarreich QUANTUM COMPUTING   One Quantum Advantage Survives a Classical Clobbering By ALLISON PARSHALL A quantum approach to data analysis that relies on the study of shapes will likely remain an example of a quantum advantage — albeit for increasingly unlikely scenarios. Read the blog QUANTA SCIENCE PODCAST   How the Physics of Nothing Underlies Everything Podcast hosted by SUSAN VALOT; Story by CHARLIE WOOD The key to understanding the origin and fate of the universe may be a more complete understanding of the vacuum. Listen to the podcast Read the article Around the Web How to Train Your Robot Scientists are teaching new robots old tricks by transforming their shape, reports Matthew Hutson for Scientific American. They train the robots by starting with an old one that has been trained to complete the task, then slowly morphing it to its new form. Robots often learn new tasks by manipulating their surroundings. AI researchers have found that this helps the machines learn about the real world. In June Allison Whitten reported for Quanta about the growing interest in “embodied AI.” eDNA Reveals Ancient Ecosystem With environmental DNA extracted from soil samples, scientists uncovered a two-million-year-old ecosystem in Greenland, reports Maddie Burakoff for The Associated Press. This is the oldest ecosystem revealed by DNA samples. Ancient DNA used to be precious. But now that scientists can sequence the abundant environmental DNA fragments preserved in soil or rock, millennia-old ecosystems are coming into focus. Monique Brouillette wrote about this for Quanta in 2019. #Quanta Mechanics Werner Heisenberg was only 31 when he was awarded the 1932 physics prize for the creation of quantum mechanics.  He is known for his uncertainty principle which says if you know the exact position of a particle you cannot know its exact momentum and vice versa. ALT 5 de dez de 2022