Claude Debussy - "Rêverie" - Diapos - Musique

"Rêverie"

Live: Cosmic Rays from Minnesota - Astronomy picture of the day - 2018 August 6

Live: Cosmic Rays from Minnesota 
Image Credit: Fermilab, NuMI, NOvA Collaboration

Explanation: Cosmic rays from outer space go through your body every second. Typically, they do you no harm. The featured image shows some of these fast moving particles as streaks going through Fermilab's NOvA Far Detectorlocated in Ash River, Minnesota, USA. Although the image updates every 15 seconds, it only shows cosmic rays that occurred over a (changing) small fraction of that time, and mostly shows only one type of particle: muons. TheNOvA Far Detector's main purpose is not to detect cosmic rays, though, but rather neutrinos from the NuMI beam shot through the Earth from Fermilab near Chicago, Illinois, USA, 810 kilometers away. Only a few neutrino events are expected in NOvA per week, though. The NuMI / NOvA experiment is allowing humanity to better explore the nature of neutrinos, for example how frequently they change type during their trip. Cosmic rays themselves werediscovered only about 100 years ago and can not only alter computer memory, but may have helped to create DNA mutations that resulted in, eventually, humans.

Carro movido a água salgada fez 150 mil quilómetros sem poluição - Artigo

A ideia de usar água como combustível é antiga, mas não é fácil de transportar para a prática. Neste momento, apenas um construtor está a testar um carro do género, a nanoFlowcell, uma marca experimental que acabou de completar 150 mil quilómetros em testes de estrada com o seu modelo mais recente, o citadino Quantino.

O sistema da nanoFlowcell funciona como uma célula de combustível, mas usa água salgada ionizada em vez de hidrogénio. Neste caso, o líquido com iões positivos fica separado do líquido com iões negativos. Quando ambos passam por uma membrana, os iões interagem, gerando energia elétrica que é usada para mover o automóvel. O resultado final é água, tal como numa célula de combustível de hidrogénio, permitindo ao automóvel funcionar com emissões zero e reabastecimento rápido.

Desde 2014 que a empresa alemã tem vindo a desenvolver protótipos, como o desportivo e-Sportlimousine, o crossover Quant F e o compacto Quantino. Estes têm sido testados em estrada, com o Quantino a mostrar a validade do conceito. Depois de ter completado 100 mil quilómetros em agosto do ano passado, o carro alemão atingiu agora os 150 mil quilómetros em meio ao tráfego. Durante os testes, conseguiu percorrer 1000 quilómetros durante 8 horas e 21 minutos, sem necessitar de reabastecimento.

Tuga Press

Trapezium: At the Heart of Orion - Astronomy picture of the day - 2018 August 5

Trapezium: At the Heart of Orion 
Image Credit: Data: Hubble Legacy Archive, Processing: Robert Gendler

Explanation: Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta-1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a recent dynamical study indicates that runaway stellar collisions at an earlier age may have formed a black hole with more than 100 times the mass of the Sun. The presence of a black hole within the cluster could explain the observed high velocities of the Trapezium stars. The Orion Nebula's distance of some 1,500 light-years would make it the closest known black hole to planet Earth.

Central Cygnus Skyscape - Astronomy picture of the day - 2018 August 4

Central Cygnus Skyscape 
Image Credit & Copyright: Mauro Narduzzi (acquisition) / Roberto Colombari (processing)

Explanation: Supergiant star Gamma Cygni lies at the center of the Northern Cross, famous asterism in the constellation Cygnus the Swan. Known by its proper name, Sadr, the bright star also lies at the center of this gorgeous skyscape, featuring a complex of stars, dust clouds, and glowing nebulae along the plane of our Milky Way galaxy. The field of view spans almost 4 degrees (eight Full Moons) on the sky and includes emission nebula IC 1318 and open star cluster NGC 6910. Left of Gamma Cygni and shaped like two glowing cosmic wings divided by a long dark dust lane, IC 1318's popular name is understandably the Butterfly Nebula. Above and left of Gamma Cygni, are the young, still tightly grouped stars of NGC 6910. Some distance estimates for Gamma Cygni place it at around 1,800 light-years while estimates for IC 1318 and NGC 6910 range from 2,000 to 5,000 light-years.

Por que sonhamos? - Artigo

Sonhar é uma das coisas mais estranhas que acontece com os seres humanos. 

Pesquisas recentes conseguiram evidênciar sobre o que é sonhar.

A hipótese de que o sonho está ligado à vida em vigília foi sugerida por Sigmund Freud no início do século 20.

Deve-se ter em mente que sonhos são de dificil interpretação, uma vez que acontecem inteiramente na cabeça de uma pessoa e no momento em que ela não consegue comunicar com outros.

Para estudar o assunto, uma equipa de pesquisadores do Laboratório do Sono da Universidade de Swansea, no Reino Unido, recrutou 20 estudantes voluntários que passaram  muitas noites no Laboratório do Sono, onde permaneceram monitorados por métodos de eletroencefalogramas não invasivos.

Desta forma, os cientistas foram capazes de observar e registar a atividade das ondas cerebrais associadas ao sono, concluindo que sonhos com maior impacto emocional eram mais prováveis de serem incorporados ao sono do que sonhos tediosos e inebriantes.

Jornal Ciência

Central Lunar Eclipse - Astronomy picture of the day - 2018 August 3

Central Lunar Eclipse 
Image Credit & Copyright: Anthony Ayiomamitis (TWAN)

Explanation: Reddened by scattered sunlight, the Moon in the center is passing through the center of Earth's dark umbral shadow in this July 27 lunar eclipse sequence. Left to right the three images are from the start, maximum, and end to 103 minutes of totality from the longest lunar eclipse of the 21st century. The longest path the Moon can follow through Earth's shadow does cross the shadow's center, that's what makes such central lunar eclipses long ones. But July 27 was also the date of lunar apogee, and at the most distant part of its elliptical orbit the Moon moves slowest. For the previous lunar eclipse, last January 31, the Moon was near its orbital perigee. Passing just south of the Earth shadow central axis, totality lasted only 76 minutes. Coming up on January 21, 2019, a third consecutive total lunar eclipse will also be off center and find the Moon near perigee. Then totality will be a mere 62 minutes long.

Eclipse over the Gulf of Poets - Astronomy picture of the day - 2018 August 2

Eclipse over the Gulf of Poets 
Image Credit & Copyright: Paolo Lazzarotti

Explanation: The total phase of the July 27 lunar eclipse lasted for an impressive 103 minutes. That makes it the longest total lunar eclipse of the 21st century. The Moon passed through the center of Earth's shadow while the Moon was near apogee, the most distant point in its elliptical orbit. From start to finish, the entire duration of totality is covered in this composite view. A dreamlike scene, it includes a sequence of digital camera exposures made every three minutes. The exposures track the totally eclipsed lunar disk, accompanied on that night by bright planet Mars, as it climbs above the seaside village of Tellaro, Italy. In the foreground lies the calm mediteranean Gulf of La Spezia, known to some as the Gulf of Poets. In the 3rd century BCE, heliocentric astronomer Aristarchus also tracked the duration of lunar eclipses, though without the benefit of digital clocks and cameras. Using geometry he devised a way to calculate the Moon's distance from the eclipse duration, in terms of the radius of planet Earth.

Astronomy picture of the day - 2018 August 1 - The Iris Nebula in a Field of Dust

The Iris Nebula in a Field of Dust 
Image Credit & Copyright: Franco Sgueglia & Francesco Sferlazza

Explanation: What blue flower grows in this field of dark interstellar dust? The Iris Nebula. The striking blue color of the Iris Nebula is created by light from the bright star SAO 19158 reflecting off of a dense patch of normally dark dust. Not only is the star itself mostly blue, but blue light from the star is preferentially reflected by the dust -- the same affect that makes Earth's sky blue. The brown tint of the pervasive dust comes partly from photoluminescence -- dust converting ultraviolet radiation to red light. Cataloged as NGC 7023, the Iris Nebula is studied frequently because of the unusual prevalence there of Polycyclic Aromatic Hydrocarbons (PAHs), complex molecules that are also released on Earth during the incomplete combustion of wood fires. The bright blue portion of the Iris Nebula spans about six light years. The Iris Nebula, pictured here, lies about 1300 light years distant and can be found with a small telescope toward the constellation of Cepheus.

Evard Grieg - "Morning mood" - Video - Music

"Morning mood"