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Archive for the ‘cosmology’ category: Page 364

Sep 17, 2018

Where Are We in Space? Astronomers Update Their Celestial Frame of Reference

Posted by in category: cosmology

How do you know where anything is in space? Sure, you can say, “Oh, that star, it’s the one in the middle of the Big Dipper,” but that’s not very useful in an era of incredible telescopes peeping at galaxies billions of light-years away. On January 1, 2019, scientists will adopt the newest, internationally standardized frame of reference to help locate things in space.

The third edition of the International Celestial Reference Frame, or ICRF-3, is the most up-to-date version of the International Astronomy Union’s standardized reference frame. Imagine the universe as a graph from geometry—scientists need a place to put the origin and axes.

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Sep 17, 2018

AI helps unlock ‘dark matter’ of bizarre superconductors

Posted by in categories: cosmology, robotics/AI

Machine learning supports 20-year-old theory of bizarre electron behaviour in high-temperature superconductor.

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Sep 17, 2018

Stephen Hawking’s ‘ghosts’ may have been found

Posted by in category: cosmology

All the evidence shows our universe emerged from a single event: an eruption commonly known as the Big Bang.

What preceded that point is a mystery.

But it has significant implications.

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Sep 16, 2018

Why Is M-Theory the Leading Candidate for Theory of Everything?

Posted by in categories: cosmology, particle physics, quantum physics

It’s not easy being a “theory of everything.” A TOE has the very tough job of fitting gravity into the quantum laws of nature in such a way that, on large scales, gravity looks like curves in the fabric of space-time, as Albert Einstein described in his general theory of relativity. Somehow, space-time curvature emerges as the collective effect of quantized units of gravitational energy — particles known as gravitons. But naive attempts to calculate how gravitons interact result in nonsensical infinities, indicating the need for a deeper understanding of gravity.

String theory (or, more technically, M-theory) is often described as the leading candidate for the theory of everything in our universe. But there’s no empirical evidence for it, or for any alternative ideas about how gravity might unify with the rest of the fundamental forces. Why, then, is string/M-theory given the edge over the others?

The theory famously posits that gravitons, as well as electrons, photons and everything else, are not point-particles but rather imperceptibly tiny ribbons of energy, or “strings,” that vibrate in different ways. Interest in string theory soared in the mid-1980s, when physicists realized that it gave mathematically consistent descriptions of quantized gravity. But the five known versions of string theory were all “perturbative,” meaning they broke down in some regimes. Theorists could calculate what happens when two graviton strings collide at high energies, but not when there’s a confluence of gravitons extreme enough to form a black hole.

Continue reading “Why Is M-Theory the Leading Candidate for Theory of Everything?” »

Sep 16, 2018

The “Dark Matter” of Bizarre Superconductors

Posted by in categories: cosmology, information science, quantum physics, robotics/AI

Machine-learning algorithms are helping to unravel the quantum behaviour of a type of superconductor that has baffled physicists for decades.

Researchers used artificial intelligence to spot hidden order in images of a bizarre state in high-temperature superconductors.

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Sep 16, 2018

The New Hunt for Dark Matter

Posted by in category: cosmology

In the over two-decades-long search for dark matter, scientists so far have come up short. In recent years though, construction of new experiments and upgrades to already existing detectors are giving new hope that we’re closer than ever to understanding dark matter.

One of those new efforts is SABRE, an international collaboration that will house multiple detectors working in tandem in the southern and northern hemispheres: two at Italy’s Gran Sasso National Laboratory, and another at an underground lab in an Australian gold mine.

Continue reading “The New Hunt for Dark Matter” »

Sep 13, 2018

Opportunity, Phone Home!

Posted by in categories: cosmology, space travel

The dust is settling on the Red Planet. Is the remaining Mars Exploration Rover about to rise and shine after three months of slumber? MER Project Manager John Callas returns with a realistic yet hopeful assessment. He also tells us what Opportunity will be asked to do after we hear from her. Planetary Society Senior Editor Emily Lakdawalla returns with a preview of China’s next two missions to the Moon, one of which will make the first-ever farside landing. How close is the nearest black hole? We’ll get the answer as Bruce and Mat explore the night sky in this week’s What’s Up.

Wake up Opportunity!

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Sep 11, 2018

This Is Why Dark Energy Must Exist, Despite Recent Reports To The Contrary

Posted by in category: cosmology

An Oxford physicist tries to cast doubt on dark energy, but the data says otherwise.

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Sep 10, 2018

Galaxy Punches Through Neighbor to Spawn Giant Ring of Black Holes

Posted by in category: cosmology

New observations from NASA’s Chandra X-ray Observatory reveal a very bright source of X-rays that is likely powered by either a ring of stellar-mass black holes or neutron stars located 300 million light-years from Earth.

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Sep 9, 2018

Taking the First Picture of a Black Hole

Posted by in category: cosmology

ESO, european organisation for astronomical research in the southern hemisphere.

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