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Archive for the ‘cosmology’ category: Page 25

Oct 14, 2024

Study: Dark matter doesn’t exist, the universe is 27 billion years old

Posted by in category: cosmology

The universe has always held mysteries that spark our curiosity. As we currently understand it, the fabric of the universe comprises three primary components: ‘normal matter,’ ‘dark energy,’ and ‘dark matter.’ However, new research is turning this established model on its head.

Enter Rajendra Gupta, a seasoned physics professor who isn’t afraid to question the status quo. With years of research under his belt, Gupta is shaking up our understanding of the universe.

Gupta, based at the University of Ottawa, conducted a study that suggests we might not need dark matter or dark energy to explain the workings of the universe. This bold claim is turning heads in the scientific community.

Oct 14, 2024

An Extraordinary Cosmic Alignment

Posted by in category: cosmology

A rare configuration of seven galaxies aligned behind a galaxy cluster allows researchers to probe with high precision the dark matter distribution within the cluster.

Oct 14, 2024

Heavy Element Formation Limited in Failed Supernovae

Posted by in categories: cosmology, particle physics

Despite its intensity, the gravitational collapse of certain massive stars does not produce an abundance of heavy elements.

About half of the elements heavier than iron are made by the r, or rapid, process. A nucleus captures neutrons so quickly that radioactive decay is forestalled until the neutron-heavy nucleus finally emits electrons and neutrinos and settles at a new, higher atomic number. Besides normal supernovae and neutron-star mergers, the r process is also suspected to occur in so-called collapsars. These are rapidly rotating massive stars that collapse without producing a regular supernova once they exhaust their fuel. However, simulations by Coleman Dean and Rodrigo Fernández of the University of Alberta, Canada, have now undermined that r-process conjecture [1].

A collapsar’s progenitor is massive enough that it forms a black hole. To shed its prodigious angular momentum, it also forms a thick, unstable accretion disk. During the collapse, nuclei in the stellar envelope break apart, and their protons combine with electrons in the envelope to produce neutrons and neutrinos in large numbers. These neutrons could turn the disk into a favorable, if fleeting, site for the r process to forge and disperse heavy elements—provided that this neutron-rich matter can be ejected.

Oct 14, 2024

Webb Telescope Unveils an Early Universe Galaxy Growing From the Inside Out

Posted by in category: cosmology

Using the James Webb Space Telescope, astronomers have for the first time observed a galaxy in the early universe growing from the inside out, a mere 700 million years after the Big Bang.

This galaxy, significantly smaller yet more mature than expected, demonstrates unique growth patterns with its dense core and rapidly forming star outskirts.

Astronomers have employed the NASA /ESA James Webb Space Telescope (JWST) to observe the ‘inside-out’ growth of a galaxy in the early universe, a mere 700 million years after the Big Bang.

Oct 14, 2024

Objects previously regarded as black holes may actually be wormholes

Posted by in categories: cosmology, physics

Some scientists believe black holes might be wormholes, offering shortcuts through space and time

A team of physicists from Sofia University in Bulgaria has proposed a fascinating theory that wormholes, hypothetical tunnels linking different parts of the universe, could be hiding in plain sight. These wormholes may resemble black holes so closely that current technology cannot distinguish between the two, according to a new study reported by New Scientist.

Oct 13, 2024

Decoding algorithms for surface codes

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

Now in Quantum: by Antonio deMarti iOlius, Patricio Fuentes, Román Orús, Pedro M. Crespo, and Josu Etxezarreta Martinez https://doi.org/10.22331/q-2024-10-10-1498


Antonio deMarti iOlius1, Patricio Fuentes2, Román Orús3,4,5, Pedro M. Crespo1, and Josu Etxezarreta Martinez1

1Department of Basic Sciences, Tecnun — University of Navarra, 20,018 San Sebastian, Spain. 2 Photonic Inc., Vancouver, British Columbia, Canada. 3 Multiverse Computing, Pio Baroja 37, 20008 San Sebastián, Spain 4 Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain 5 IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain.

Continue reading “Decoding algorithms for surface codes” »

Oct 13, 2024

Gravity can exist without mass, dark matter could be myth: Study

Posted by in category: cosmology

A new study challenges the existence of dark matter, proposing that gravity can arise from ‘topological defects’ in spacetime.

Oct 12, 2024

Black holes might not be entirely black or even true holes

Posted by in categories: cosmology, singularity

Dark Stars Could Explain Dark Matter and Fast Radio Bursts, Challenging Our Understanding of Black Holes

A theory suggests that black holes, rather than being empty voids in space, might actually be “dark stars” filled with incredibly dense and exotic matter. This concept could provide new insights into two of the universe’s greatest mysteries: the nature of black holes and the elusive dark matter.

Black holes, as understood through Albert Einstein’s general theory of relativity, are regions in space where matter is so compact that it warps space-time, creating a gravitational pull so intense that even light cannot escape. The center of a black hole is believed to contain a singularity, an infinitely small and dense point where gravity becomes infinitely strong. This singularity is surrounded by an event horizon, a boundary beyond which light and matter cannot escape.

Oct 12, 2024

Why the black hole information paradox still hasn’t been solved

Posted by in categories: cosmology, quantum physics

But you might notice that something is missing: this radiation doesn’t seem to encode, in any way, knowledge of the information that went into the creation of the black hole in the first place. Somewhere along the way, information was destroyed. That’s the key puzzle behind the black hole information paradox. No one seriously disputes the initial setup of the puzzle: that information exists, and that the information (and entropy) does in fact go into the black hole both when it’s first created and also as it grows. What is up for debate, and what in fact is the big question behind the information paradox, is whether that information comes back out again or not.

The way we calculate what comes out of a black hole via Hawking radiation, despite the fact that Hawking radiation has been around for a full half century as of 2024, hasn’t changed all that much over the past 50 years. What we do is assume the curvature of space from general relativity: the fabric of space is curved by the presence of matter and energy, and general relativity tells us exactly by how much.

We then perform our quantum field theory calculations in that curved space, detailing the radiation that comes out as a result. That’s where we learn that the radiation has the temperature, spectrum, entropy, and other properties we know that it possesses, including the fact that it doesn’t appear to encode that initial information when the radiation comes out.

Oct 11, 2024

Transcendence: Enlightenment, Singularity & The Fermi Paradox

Posted by in categories: cosmology, existential risks, media & arts, singularity

Many seek a path to enlightenment through study and meditation, but what does science tell us about transcendence? And could entire civilizations seek to leave this reality behind?

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