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Category: cosmology

Wormholes may not exist—we’ve found they reveal something deeper about time and the universe

Wormholes are often imagined as tunnels through space or time—shortcuts across the universe. But this image rests on a misunderstanding of work by physicists Albert Einstein and Nathan Rosen.

In 1935, while studying the behavior of particles in regions of extreme gravity, Einstein and Rosen introduced what they called a “bridge”: a mathematical link between two perfectly symmetrical copies of spacetime. It was not intended as a passage for travel, but as a way to maintain consistency between gravity and quantum physics. Only later did Einstein–Rosen bridges become associated with wormholes, despite having little to do with the original idea.

But in new research published in Classical and Quantum Gravity, my colleagues and I show that the original Einstein–Rosen bridge points to something far stranger—and more fundamental—than a wormhole.

Ancient Type II supernova discovered from universe’s first billion years

Using the James Webb Space Telescope (JWST), an international team of astronomers has discovered a new Type II supernova. The newly detected supernova, named SN Eos, exploded when the universe was only 1 billion years old. The finding was reported January 7 on the arXiv pre-print server.

Supernovae (SNe) are powerful and luminous stellar explosions. They are important for the scientific community as they offer essential clues into the evolution of stars and galaxies. In general, SNe are divided into two groups based on their atomic spectra: Type I (no hydrogen in their spectra) and Type II (showcasing hydrogen spectral lines).

Type II SNe are the result of rapid collapse and violent explosion of massive stars (with masses above 8.0 solar masses). Type II core-collapse supernovae (CC SNe), which can be brighter than the total emission of their host galaxies, allow astronomers to probe the final stages of stellar evolution, and studies of early-universe Type II CC SNe could be crucial to constrain early stellar evolution models.

NASA’s Hubble Examines Cloud-9, First of New Type of Object

A team using NASA’s Hubble Space Telescope has uncovered a new type of astronomical object — a starless, gas-rich, dark-matter cloud considered a “relic” or remnant of early galaxy formation. Nicknamed “Cloud-9,” this is the first confirmed detection of such an object in the universe — a finding that furthers the understanding of galaxy formation, the early universe, and the nature of dark matter itself.

“This is a tale of a failed galaxy,” said the program’s principal investigator, Alejandro Benitez-Llambay of the Milano-Bicocca University in Milan, Italy. “In science, we usually learn more from the failures than from the successes. In this case, seeing no stars is what proves the theory right. It tells us that we have found in the local universe a primordial building block of a galaxy that hasn’t formed.”

The results, published in The Astrophysical Journal Letters, were presented at a press conference Monday at the 247th meeting of the American Astronomical Society in Phoenix.

Dark Stars May Solve Three of JWST’s Biggest Cosmic Mysteries

New observations from the James Webb Space Telescope have revealed unexpected features in the early universe, including unusually bright galaxies, rapidly forming black holes, and compact objects that defy conventional explanations. A new study led by Colgate Assistant Professor of Physics and As

Is There A Simple Solution To The Fermi Paradox?

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Around 2 billion years ago, life had plateaued in complexity, ruined the atmosphere, and was on the verge of self-annihilation. But then something strange and potentially extremely lucky happened that enabled endless new evolutionary paths. The first eukaryote cell was born. This may also explain why there are no aliens.

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Cool world episode: • the odds of life — THIS CHANGED MY MIND

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Ghost Particles Interacting With Dark Matter Could Solve a Huge Cosmic Mystery

A new investigation of the early Universe led by Poland’s National Centre for Nuclear Research has just found that there may be an interaction between two of the most elusive components of the cosmos.

By combining different kinds of observations, cosmologists have shown that what we see is more easily explained if neutrinos, aka ‘ghost particles’, weakly interact with dark matter.

With a vexing certainty of three sigma, the signal isn’t strong enough to be definitive, but is also too strong to be a mere hint or noise in the data.

The Dark Halo That Never Lit Up

Galaxies announce themselves through the light of billions of stars, all embedded in vast clumps, or “halos,” of dark matter. But researchers may have spotted, for the first time, a starless halo of dark matter—containing only a gas cloud. The result was announced by Rachael Beaton of the Space Telescope Science Institute in Maryland at the meeting of the American Astronomical Society in Phoenix, Arizona. Using observations from the Hubble Space Telescope, Beaton and her collaborators showed that the object, known as Cloud-9, contains a negligible amount of stars [1]. “There is nothing like this that we have found so far in the Universe,” Beaton said in a press conference last week.

Cloud-9’s makeup—as inferred from radio and optical observations—would qualify it as the first example of a REionization-Limited H I Cloud (RELHIC), a starless dark matter halo filled with neutral hydrogen gas (H I). RELHICs are thought to be leftovers of dark matter clumps that couldn’t accrue a sufficient amount of gas to form stars, says the project’s principal investigator Alejandro Benítez-Llambay of the University of Milano-Bicocca in Italy. A RELHIC is “a tale of a failed galaxy,” he says.

Starless halos arise naturally within the standard paradigm of cosmology: the lambda cold dark matter (ΛCDM) model, where Λ refers to a “cosmological constant” that describes dark energy. According to ΛCDM, dark matter can cluster into halos that provide the gravitational backbone for galaxy formation. The model also predicts that there is a critical mass below which halos would be too small to ever form stars. Spotting unlit halos might sound hopeless, but simulations by Benítez-Llambay and collaborators in 2017 suggested that halos within a narrow mass range may exist as RELHICs (a term they coined) [2]. According to their calculations, RELHICs would have masses close to the critical value for galaxy formation. Crucially, the compact, hydrogen-filled cores of these objects provide a potential observational window, since hydrogen clouds have a characteristic radio emission.

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