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Archive for the ‘cosmology’ category: Page 381

Oct 23, 2016

Physicist says our Universe could have spawned from a black hole

Posted by in categories: cosmology, mathematics, physics, singularity

According to our best understanding of the Universe, if you travel back in time as far as you can, around 13.8 billion years or so, you’ll eventually reach a singularity — a super-dense, hot, and energetic point, where the laws that govern space-time breakdown.

Despite our best attempts, we can’t peer past that singularity to see what triggered the birth of our Universe — but we do know of only one other instance in the history of our Universe where a singularity exists, and that’s inside a black hole. And the two events might have more in common than you’ve ever considered, as physicist Ethan Siegel explains over at Forbes.

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Oct 23, 2016

Our Dark-Energy-Dominated Accelerating Universe –“Flimsier Than Previously Thought”

Posted by in categories: cosmology, physics

Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace. Their conclusions were based on analysis of Type Ia supernovae — the spectacular thermonuclear explosion of dying stars — picked up by the Hubble space telescope and large ground-based telescopes. It led to the widespread acceptance of the idea that the universe is dominated by a mysterious substance named ‘dark energy’ that drives this accelerating expansion.

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Oct 22, 2016

So little we are…

Posted by in category: cosmology

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Oct 20, 2016

“Dark-Energy Star” or “Black Hole” –Scientists Question Source of LIGO Detection of Gravitational Waves

Posted by in categories: cosmology, physics

How, then, could we tell a gravastar from a black hole? It would be almost impossible to “see” a gravastar, because of the same effect that makes a black hole “black”: any light would be so deflected by the gravitational field that it would never reach us. However, where photons would fail, gravitational waves can succeed! It has long since been known that when black holes are perturbed, they “vibrate” emitting gravitational waves. Indeed, they behave as “bells”, that is with a signal that progressively fades away, or “ringsdown”. The tone and fading of these waves depends on the only two properties of the black hole: its mass and spin. Gravastars also emit gravitational waves when they are perturbed, but, interestingly, the tones and fading of these waves are different from those of black holes. This is a fact that was alreadyknown soon after gravastars were proposed.

After the first direct detection of gravitational waves that was announced last February by the LIGO Scientific Collaboration and made news all over the world, Luciano Rezzolla (Goethe University Frankfurt, Germany) and Cecilia Chirenti (Federal University of ABC in Santo André, Brazil) set out to test whether the observed signal could have been a gravastar or not.

When considering the strongest of the signals detected so far, i.e. GW150914, the LIGO team has shown convincingly that the signal was consistent with the a collision of two black holes that formed a bigger black hole. The last part of the signal, which is indeed the ringdown, is the fingerprint that could identify the result of the collision. “The frequencies in the ringdown are the signature of the source of gravitational waves, like different bells ring with different sound”, explains Professor Chirenti.

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Oct 18, 2016

Entangled Wormholes Could Pave the Way for Quantum Gravity

Posted by in categories: cosmology, quantum physics

The weird quantum phenomenon of entanglement could produce shortcuts between distant black holes.

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Oct 15, 2016

Scientists claim to have discover what existed BEFORE the beginning of the universe

Posted by in categories: cosmology, information science, mathematics, quantum physics

Nice.


There are many scientific and non-scientific varieties of the answer about what came before Big Bang. Some say there was literally nothing and some say a black hole or a multiverse. But now a group of mathematicians from Canada and Egypt have analyzed some cutting edge scientific theory and a complex set of equations to find what preceded the universe in which we live. Their research paper has been published in Nature.

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Oct 14, 2016

Before the Big Bang there was another universe and a new one will emerge after ours collapses

Posted by in categories: cosmology, physics

In their study, published on the pre-print server arxiv.org, Maha Salah, Fayçal Hammad, Mir Faizal and Ahmed Farag Ali have been able to look at the state of the universe before its beginning, creating a model of pre-Big Bang cosmology.

The cosmology of the universe can be modelled using the Einstein’s general theory of relativity. It predicts that the universe is expanding and the galaxies are all moving away from us. Also the further a galaxy is away, the faster it is moving away from us. This is used to predict the universe started with a Big Bang – if you reverse this expansion to go back in time, eventually we come to the point where the universe began.

At the point of Big Bang the laws of Einstein’s general theory of relativity seem to break down and it is not possible to use them to understand how the Big Bang occurred. So, how did the Big Bang happen and can we describe physics before the Big Bang? Can we describe physics before the creation of the universe? According to the team’s model, yes, we can.

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Oct 13, 2016

Hubble: Observable universe holds ten times more galaxies than previously thought

Posted by in category: cosmology

Not 100 billion galaxies but one trillion. Is this the missing mass then? No more “dark matter”?


The latest finding with the Hubble space telescope:

Observable Universe contains ten times more galaxies than previously thought

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Oct 11, 2016

Quantum Information Processing Near Spinning Black Holes

Posted by in categories: cosmology, quantum physics

Spinning black holes are capable of complex quantum information processes encoded in the X-ray photons.

The black holes sparked the public imagination for almost 100 years. Their presence in the universe has been long debated; however, the detection of X-ray radiation coming from the center of the galaxies, a feature of black holes, has put an end to the discussion and undoubtedly proven their existence.

The vast majority, if not all, of the known black holes were unveiled by detecting the X-ray radiation emitted by the stellar material accreting around them. Accretion disks emit X-ray radiation, light with high energy, due to the extreme gravity in the vicinity of black holes. X-ray photons emitted near rotating black holes not only exposed the existence of these phantom-like astrophysical bodies, but also seem to carry hidden quantum messages.

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Oct 2, 2016

Dark energy: Staring into darkness : Nature : Nature Research

Posted by in category: cosmology

The path to understanding dark energy begins with a single question: has it always been the same throughout the history of the Universe?

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