Archive for the ‘cosmology’ category: Page 2

May 15, 2024

Dark matter: our new experiment aims to turn the ghostly substance into actual light

Posted by in category: cosmology

Andrea Gallo Rosso, Stockholm University A ghost is haunting our universe. This has been known in astronomy and cosmology for decades. Observations suggest that about 85% of all the matter in the universe is mysterious and invisible. These two qualities are reflected in its name: dark matter. Several experiments have aimed to unveil what it’s made of, but despite decades of searching, scientists have come up short. Now our new experiment, under construction at Yale University in the US, is offering a new tactic.

May 15, 2024

How Does Multiverse Theory Relate to Time Travel?

Posted by in categories: cosmology, physics, time travel

The theoretical physics and paradoxes of time travel often brush up against multiverse theory and the idea of alternate universes.

May 15, 2024

Neutron-rich nuclei reveal how heavy elements form

Posted by in categories: cosmology, nuclear energy, physics

Models for how heavy elements are produced within stars have become more accurate thanks to measurements by RIKEN nuclear physicists of the probabilities that 20 neutron-rich nuclei will shed neutrons.

Stars generate energy by fusing the of light elements—first hydrogen nuclei and then progressively heavier nuclei, as the hydrogen and other lighter elements are sequentially consumed. But this process can only produce the first 26 elements up to iron.

Another process, known as rapid neutron capture, is thought to produce nuclei that are heavier than iron. As its name suggests, this process involves nuclei becoming larger by rapidly snatching up stray neutrons. It requires extremely high densities of neutrons and is thus thought to occur mainly during events such as mergers of neutron and supernova explosions.

May 15, 2024

Ancient stars could make elements with atomic masses greater than 260

Posted by in categories: cosmology, particle physics

The first stars of the universe were monstrous beasts. Comprised only of hydrogen and helium, they could be 300 times more massive than the sun. Within them, the first of the heavier elements were formed, then cast off into the cosmos at the end of their short lives. They were the seeds of all the stars and planets we see today. A new study published in Science suggests these ancient progenitors created more than just the natural elements.

Except for , , and a few traces of other light elements, all of the atoms we see around us were created through astrophysical processes, such as supernovae, collisions of neutron , and high-energy particle collisions. Together they created heavier elements up to Uranium-238, which is the heaviest naturally occurring element. Uranium is formed in supernova and neutron star collisions through what is known as the r-process, where neutrons are rapidly captured by atomic nuclei to become a heavier element. The r-process is complex, and there is still much we don’t understand about just how it occurs, or what its upper mass-limit might be. This new study, however, suggests that the r-process in the very first stars could have produced much heavier elements with atomic masses greater than 260.

The team looked at 42 stars in the Milky Way for which the elemental composition is well understood. Rather than simply looking for the presence of heavier elements, they looked at the relative abundances of elements across all the stars. They found that the abundance of some elements such as silver and rhodium doesn’t agree with the predicted abundance from known r-process nucleosynthesis. The data suggests that these elements are the decay remnants from much heavier nuclei of more than 260 atomic mass units.

May 15, 2024

Tomato Genetics: A Unexpected Journey Into a “Parallel Universe”

Posted by in categories: cosmology, genetics

In a new study recently published by Science Advances, Michigan State University researchers reveal an unexpected genetic revelation about the sugars found in “tomato tar,” shedding light on plant defense mechanisms and their potential applications in pest control.

Tomato tar, a familiar nuisance of avid gardeners, is the sticky, gold-black substance that clings to hands after touching the plant. It turns out that the characteristic stickiness of the substance serves an important purpose. It’s made of a type of sugar called acylsugar that acts as a natural flypaper for would-be pests. “Plants have evolved to make so many amazing poisons and other biologically active compounds,” said Michigan State researcher Robert Last, leader of the study. The Last lab specializes in acylsugars and the tiny, hair-like structures where they’re produced and stored, known as trichomes.

In a surprising discovery, researchers have found acylsugars, once thought to be found exclusively in trichomes, in tomato roots as well. This finding is a genetic enigma that raises as many questions as it does insights.

May 14, 2024

XMM-Newton’s Stunning X-Ray Vision Unmasks Mysterious Cosmic Structure

Posted by in category: cosmology

New observations reveal that X-ray emissions from the Cloverleaf odd radio circle are linked to merging galaxy groups, offering new insights into these mysterious cosmic structures.

Astronomers have discovered enormous circular radio features of unknown origin around some galaxies. Now, new observations of one dubbed the Cloverleaf suggest it was created by clashing groups of galaxies.

Studying these structures, collectively called ORCs (odd radio circles), in a different kind of light offered scientists a chance to probe everything from supersonic shock waves to black hole behavior.

May 12, 2024

AI and Physics Combine to Reveal the 3D Structure of a Flare Erupting around a Black Hole

Posted by in categories: cosmology, physics, robotics/AI

Scientists believe the environment immediately surrounding a black hole is tumultuous, featuring hot magnetized gas that spirals in a disk at tremendous speeds and temperatures. Astronomical observations show that within such a disk, mysterious flares occur up to several times a day, temporarily brightening and then fading away.

Now a team led by Caltech scientists has used telescope data and an artificial intelligence (AI) computer-vision technique to recover the first three-dimensional video showing what such flares could look like around SagittariusA* (Sgr A the supermassive black hole at the heart of our own Milky Way galaxy.

The 3D flare structure features two bright, compact features located about 75 million kilometers (or half the distance between Earth and the sun) from the center of the black hole. It is based on data collected by the Atacama Large Millimeter Array (ALMA) in Chile over a period of 100 minutes directly after an eruption seen in Xray data on April 11, 2017.

May 12, 2024

Giant Structure Lurking in Deep Space Challenges Our Understanding of The Universe

Posted by in categories: cosmology, space travel

A colossal structure in the distant Universe is defying our understanding of how the Universe evolved.

In light that has traveled for 6.9 billion years to reach us, astronomers have found a giant, almost perfect ring of galaxies, some 1.3 billion light-years in diameter. It doesn’t match any known structure or formation mechanism.

Continue reading “Giant Structure Lurking in Deep Space Challenges Our Understanding of The Universe” »

May 11, 2024

Nick Bostrom’s ‘Deep Utopia’ On Our AI Future: Can We Have Meaning And Fun?

Posted by in categories: cosmology, robotics/AI

A new book by Nick Bostrom is a major publishing and cultural event. His 2014 book, Superintelligence, helped to wake the world up to the impact of the first Big Bang in AI, the arrival of deep learning. Since then we have had a second Big Bang in AI, with the introduction of transformer systems like GPT-4. Bostrom’s previous book focused on the downside potential of advanced AI. His new one explores the upside.

Deep Utopia is an easier read than its predecessor, although its author cannot resist using some of the phraseology of professional philosophers, so readers may have to look up words like “modulo” and “simpliciter.” Despite its density and its sometimes grim conclusions, Superintelligence had a sprinkling of playful self-ridicule and snark. There is much more of this in the current offering.

The structure of Deep Utopia is deeply odd. The book’s core is a series of lectures by an older version of the author, which are interrupted a couple of times by conflicting bookings of the auditorium, and once by a fire alarm. The lectures are attended and commented on by three students, Kelvin, Tessius and Firafax. At one point they break the theatrical fourth wall by discussing whether they are fictional characters in a book, a device reminiscent of the 1991 novel Sophie’s World.

May 11, 2024

All Human Existence May Have Begun in a Black Hole, Some Scientists Believe

Posted by in categories: cosmology, evolution

There’s an intriguing possibility that the emergence of conscious life is not just a coincidence, but an inevitable outcome of cosmic evolution.

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