Menu

Blog

Page 6821

Nov 7, 2020

Astrophysicists Solve Mystery of How Dark Matter Is Distributed in Galaxies

Posted by in categories: cosmology, physics

The gravitational force in the Universe under which it has evolved from a state almost uniform at the Big Bang until now, when matter is concentrated in galaxies, stars and planets, is provided by what is termed ‘dark matter.’ But in spite of the essential role that this extra material plays, we know almost nothing about its nature, behavior and composition, which is one of the basic problems of modern physics. In a recent article in Astronomy & Astrophysics Letters, scientists at the Instituto de Astrofísica de Canarias (IAC)/University of La Laguna (ULL) and of the National University of the North-West of the Province of Buenos Aires (Junín, Argentina) have shown that the dark matter in galaxies follows a ‘maximum entropy’ distribution, which sheds light on its nature.

Dark matter makes up 85% of the matter of the Universe, but its existence shows up only on astronomical scales. That is to say, due to its weak interaction, the net effect can only be noticed when it is present in huge quantities. As it cools down only with difficulty, the structures it forms are generally much bigger than planets and stars. As the presence of dark matter shows up only on large scales the discovery of its nature probably has to be made by astrophysical studies.

Nov 7, 2020

Earth Grows Fine Gemstones in Minutes – Crystals Could Grow Up to 3 Feet per Day in Some Cooling Magmas

Posted by in categories: sustainability, transportation

Rome wasn’t built in a day, but some of Earth’s finest gemstones were, according to new research from Rice University.

Aquamarine, emerald, garnet, zircon and topaz are but a few of the crystalline minerals found mostly in pegmatites, veinlike formations that commonly contain both large crystals and hard-to-find elements like tantalum and niobium. Another common find is lithium, a vital component of electric car batteries.

“This is one step towards understanding how Earth concentrates lithium in certain places and minerals,” said Rice graduate student Patrick Phelps, co-author of a study published online in Nature Communications. “If we can understand the basics of pegmatite growth rates, it’s one step in the direction of understanding the whole picture of how and where they form.”

Nov 7, 2020

Astronomers Discover Activity on Distant Centaur Planetary Object

Posted by in categories: particle physics, space

Centaurs are minor planets believed to have originated in the Kuiper Belt in the outer solar system. They sometimes have comet-like features such as tails and comae—clouds of dust particles and gas—even though they orbit in a region between Jupiter and Neptune where it is too cold for water to readily sublimate, or transition, directly from a solid to a gas.

Only 18 active Centaurs have been discovered since 1927, and much about them is still poorly understood. Discovering activity on Centaurs is also observationally challenging because they are faint, telescope time-intensive and because they are rare.

A team of astronomers, led by doctoral student and Presidential Fellow Colin Chandler in Northern Arizona University’s Astronomy and Planetary Science PhD program, earlier this year announced their discovery of activity emanating from Centaur 2014 OG392, a planetary object first found in 2014. They published their findings in a paper in The Astrophysical Journal Letters, “Cometary Activity Discovered on a Distant Centaur: A Nonaqueous Sublimation Mechanism.” Chandler is the lead author, working with four NAU co-authors: graduate student Jay Kueny, associate professor Chad Trujillo, professor David Trilling and Ph.D. student William Oldroyd.

Nov 7, 2020

Raspberry Pi 400 is out: $70 for a complete PC with a faster Pi 4 in a keyboard

Posted by in category: computing

The Raspberry Pi 400 comes with 4GB RAM, a faster Raspberry Pi 4 and a built-in heatsink to keep it cool.

Nov 7, 2020

Z boson

Posted by in category: particle physics

The Z boson is a neutral particle that mediates the weak force.

Nov 7, 2020

Scientists observe Z-boson production with two associated photons

Posted by in category: particle physics

Circa 2016 o,.o.


An international group of physicists has observed Z-boson production with two associated photons with later Z decay to electrons, muons or neutrinos at the ATLAS experiment at the Large Hadron Collider (LHC) in CERN.

Observation of this extremely rare physics process, predicted theoretically in 1960s, further validates the Standard Model ℠, according to ATLAS experiment contributor Dimitrii Krasnopevtsev.

Continue reading “Scientists observe Z-boson production with two associated photons” »

Nov 7, 2020

Analysis of a Martian meteorite reveals evidence of water 4.4 billion years ago

Posted by in category: space

A meteorite that originated on Mars billions of years ago reveals details of ancient impact events on the red planet. Certain minerals from the Martian crust in the meteorite are oxidized, suggesting the presence of water during the impact that created the meteorite. The finding helps to fill some gaps in knowledge about the role of water in planet formation.

There’s a longstanding question in about the origin of on Earth, Mars and other large bodies such as the moon. One hypothesis says that it came from asteroids and comets post-formation. But some think that water might just be one of many substances that occur naturally during the formation of planets. A new analysis of an ancient Martian adds support for this second hypothesis.

Several years ago, a pair of dark meteorites were discovered in the Sahara Desert. They were dubbed NWA 7034 and NWA 7533, where NWA stands for North West Africa and the number is the order in which meteorites are officially approved by the Meteoritical Society, an international planetary science organization. Analysis showed these meteorites are new types of Martian meteorites and are mixtures of different rock fragments.

Nov 7, 2020

World’s longest laser — 270 km long — created

Posted by in categories: engineering, internet

Circa 2009.


A 270-kilometre optical fiber has been transformed into the world’s longest laser, a feat its inventors believe will lead to a radical new outlook on information transmission and secure communications.

Engineering academics at Aston University, UK, are leading research into ultralong fiber lasers, to create a platform capable of delivering ‘next generation’ information transmission, including telecommunications and broadband.

Continue reading “World’s longest laser -- 270 km long -- created” »

Nov 7, 2020

Longest laser ranging experiment

Posted by in category: space

The McDonald Laser Ranging Station, near Fort Davis, Texas, USA, uses a laser to measure the distance between the Earth and the Moon to an accuracy of 1 cm (0.39 inches). It bounces a laser off reflective targets left on the lunar surface by three US Apollo missions and two Soviet Lunokhod missions. The distance between the centres of the Earth and the Moon is 385,000 km (239,000 miles), and the laser ranging has shown that the Moon is receding from the Earth at a rate of 3.8 cm (1.5 inches) per year. This is one of the most accurate distance measurements ever made.

Nov 7, 2020

Under Attack From Iran, Indian Rafale Jets Prefer Mid-Air Refueling Over Stop Over At Al Dhafra Airbase In The UAE

Posted by in categories: government, military

India has decided to fly the three Rafale fighter jets from France directly to India, which are scheduled to arrive on November 4, according to Indian government sources. The Indian Air Force will now have eight of the 36 Rafale jets in operation.