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Archive for the ‘cosmology’ category: Page 284

Dec 25, 2019

Astrophysicists Developed a New Theory to Explain ‘Dark Energy’

Posted by in categories: cosmology, physics

The fact that our Universe is expanding was discovered almost a hundred years ago, but how exactly this happens, scientists realized only in the 90s of the last century, when powerful telescopes (including orbital ones) appeared and the era of exact cosmo.

International Journal of Modern Physics has published an article by the IKBFU Physics and Mathematics Institute Artyom Astashenok and the Institute’s MA student Alexander Teplyakov. The article refers to the issue of the “Dark Enegry” and an assumption is made that the Universe has borders.

Artyom Astashenok told:

Dec 24, 2019

A New Test for the Leading Big Bang Theory

Posted by in category: cosmology

Cosmologists have predicted the existence of an oscillating signal that could distinguish between cosmic inflation and alternative theories of the universe’s birth.

Dec 23, 2019

Massive star Betelgeuse is dimming and could soon go supernova

Posted by in category: cosmology

Dozens of astronomers from around the world including experts from the USA and Australia have taken to Twitter to discuss the phenomenon and whether it means an explosion is imminent.

Dec 21, 2019

The universe’s rate of expansion is in dispute – and we may need new physics to solve it

Posted by in categories: computing, cosmology, physics

Next time you eat a blueberry (or chocolate chip) muffin consider what happened to the blueberries in the batter as it was baked. The blueberries started off all squished together, but as the muffin expanded they started to move away from each other. If you could sit on one blueberry you would see all the others moving away from you, but the same would be true for any blueberry you chose. In this sense galaxies are a lot like blueberries.

Since the Big Bang, the universe has been expanding. The strange fact is that there is no single place from which the universe is expanding, but rather all galaxies are (on average) moving away from all the others. From our perspective in the Milky Way galaxy, it seems as though most galaxies are moving away from us – as if we are the centre of our muffin-like universe. But it would look exactly the same from any other galaxy – everything is moving away from everything else.

To make matters even more confusing, new observations suggest that the rate of this expansion in the universe may be different depending on how far away you look back in time. This new data, published in the Astrophysical Journal, indicates that it may time to revise our understanding of the cosmos.

Dec 17, 2019

No Dark Energy? No Chance, Cosmologists Contend

Posted by in category: cosmology

A study challenged the evidence for the mysterious antigravitational force known as dark energy. Then cosmologists shot back.

Dec 16, 2019

Scientists Are Searching for a Mysterious Force to Explain the Universe’s Anomalies

Posted by in categories: cosmology, particle physics

Teams have looked for a “fifth force” in the universe within the Earth’s mantle, ultra-vacuum chambers, and in hypothetical particles such as “X17.” Finding it could help explain mysteries around dark matter and dark energy.

Dec 16, 2019

Physicist proposes a new approach in modeling the evolution of the universe

Posted by in categories: cosmology, evolution

A physicist from RUDN University has proposed a new theoretical model for the interaction of spinor and gravitational fields. He considered the evolution of the universe within one of the variants of the widespread Bianchi cosmological model. In this case, a change in the calculated field parameters led to changes in the evolution of the universe under consideration. Upon reaching certain values, it began to shrink down to the Big Bang. The article was published in the journal The European Physical Journal Plus.

The spinor field is characterized by its behavior in interaction with gravitational fields. Dr. Bijan Saha of RUDN University focused on the study of a nonlinear spinor field. With its help, he explained the accelerated expansion of the universe. The study of a spinor field with a non-minimal coupling made it possible to describe not only the expansion of the universe, but also its subsequent contraction and the resulting Big Bang within the framework of the standard Bianchi .

The basic calculations performed by Bijan Saha allow moving away from the isotropic of the Friedman-Robertson-Walker universe (FRW) that is most often used. According to this traditional model, the properties of the universe are independent of the direction in which they are considered. The physicist has put forward an alternative: an anisotropic model in which such dependence exists. On the one hand, the “classical” isotropic model describes the of the modern universe with great precision. On the other hand, there are theoretical arguments and that lead to the conclusion that an anisotropic phase existed in the distant past.

Dec 16, 2019

How the Many-Worlds theory of Hugh Everett split the Universe

Posted by in categories: cosmology, quantum physics

Sean Carroll is a theoretical physicist at the California Institute of Technology. He specialises in quantum mechanics, gravitation, cosmology, statistical mechanics and foundations of physics. His latest book is Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime (2019). He lives in Los Angeles.

2,600 words.

Dec 13, 2019

Black Hole Discovery Challenges the Laws of Physics

Posted by in categories: cosmology, physics

Astronomers discover a black hole that shouldn’t exist.

Dec 13, 2019

Paradox-Free Time Travel Possible With Many Parallel Universes

Posted by in categories: cosmology, physics, time travel

If you were to travel back in time to kill your grandparents — let’s ignore the ‘why’ here, for the sake of argument — you would never have been born. Which means there was nobody to kill your grandparents. Which means you were actually born after all, which… hold up, what’s going on here?!

These kinds of brain-breaking paradoxes have been puzzling us forever, inspiring stories ranging from “Back to the Future” to “Hot Tub Time Machine.”

Now, New Scientist reports that physicists Barak Shoshany and Jacob Hauser from the Perimeter Institute in Canada have come up with an apparent solution to these types of paradoxes that requires a very large — but not necessarily infinite — number of parallel universes.