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Category: Physics

The human brain’s complexity teeters at the edge of chaos, physicists say

The human brain’s complexity teeters at the edge of chaos, physicists say

Science Alert reports: The human brain is said to be the most complex object in the known Universe. Its 89 billion neurons each have around 7,000 connections on average, and the physical structure of all those entities may be balanced precariously on a knife’s edge, according to a new study. Two physicists at Northwestern University in the US – Helen Ansell and István Kovács – have now used statistical physics to explain the complexity seen in a highly detailed 3D…

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The new math of how large-scale order emerges

The new math of how large-scale order emerges

Philip Ball writes: A few centuries ago, the swirling polychromatic chaos of Jupiter’s atmosphere spawned the immense vortex that we call the Great Red Spot. From the frantic firing of billions of neurons in your brain comes your unique and coherent experience of reading these words. As pedestrians each try to weave their path on a crowded sidewalk, they begin to follow one another, forming streams that no one ordained or consciously chose. The world is full of such emergent…

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Earth’s upper atmosphere could hold a missing piece of the universe, new study hints

Earth’s upper atmosphere could hold a missing piece of the universe, new study hints

Paul Sutter writes: Earth may be swimming through an ocean of dark matter — and waves in that invisible ocean lapping against our planet’s upper atmosphere may generate detectable radio waves that allow us to finally find this elusive component of the universe, according to new theoretical research. A wealth of astrophysical and cosmological evidence points to the existence of dark matter, from the inexplicable rotation curves of certain galaxies to the growth of the largest structures in the universe….

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A wave of retractions is shaking physics

A wave of retractions is shaking physics

MIT Technology Review reports: Recent highly publicized scandals have gotten the physics community worried about its reputation—and its future. Over the last five years, several claims of major breakthroughs in quantum computing and superconducting research, published in prestigious journals, have disintegrated as other researchers found they could not reproduce the blockbuster results. Last week, around 50 physicists, scientific journal editors, and emissaries from the National Science Foundation gathered at the University of Pittsburgh to discuss the best way forward.“To be…

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Consciousness came before life

Consciousness came before life

Stuart Hameroff, Anirban Bandyopadhyay, and Dante Lauretta writes: Most scientists and philosophers believe that life came before consciousness. Life appeared on Earth about 3.8 billion years ago; consciousness and feelings, it’s said, evolved later due to complex biological information processing, perhaps only recently in brains with language and tool-making abilities. In fact, though, there’s good reason to think that consciousness preceded life, and was central to making life and evolution possible. What is life? It is often described as its…

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The universe as a network of rivers

The universe as a network of rivers

The universe as a network of rivers: This remarkable new map reveals how galaxies flow like water, following the pull of gravity across hundreds of millions of light years. https://t.co/krsqjnnoa3 pic.twitter.com/192Q28SrM9 — Corey S. Powell (@coreyspowell) April 26, 2024 Astrobites reports: Cosmography is the science of cartography, but applied to the Universe by mapping out the Large Scale Structures such as voids, filaments and superclusters. While galaxy surveys are able to create such maps from just looking at spatial information…

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The universe may be dominated by particles that break causality and move faster than light, new paper suggests

The universe may be dominated by particles that break causality and move faster than light, new paper suggests

Live Science reports: Could the cosmos be dominated by particles that move faster than the speed of light? This model of the universe agrees surprisingly well with observations, a pair of physicists has discovered. In a new paper that has yet to be peer-reviewed, the physicists propose that our universe is dominated by tachyons — a hypothetical kind of particle that always moves faster than light. Tachyons almost certainly don’t exist; going faster than light violates everything we know about…

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Mysterious ‘unparticles’ may be pushing the universe apart, new theoretical study suggests

Mysterious ‘unparticles’ may be pushing the universe apart, new theoretical study suggests

Live Science reports: The ever-accelerating expansion of the universe may be driven by a mysterious form of matter called “unparticles,” which do not obey the Standard Model of particle physics, a new theoretical paper suggests. Scientists widely acknowledge that the universe is expanding, though the cause of that expansion remains elusive. One of the most popular proposed explanations is a mysterious entity called dark energy in the form of a cosmological constant, which leads to expansion at a rate independent…

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Swirling forces, crushing pressures measured in the proton

Swirling forces, crushing pressures measured in the proton

Charlie Wood writes: Physicists have begun to explore the proton as if it were a subatomic planet. Cutaway maps display newfound details of the particle’s interior. The proton’s core features pressures more intense than in any other known form of matter. Halfway to the surface, clashing vortices of force push against each other. And the “planet” as a whole is smaller than previous experiments had suggested. The experimental investigations mark the next stage in the quest to understand the particle…

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Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Davide Castelvecchi writes: In hindsight, it seems prophetic that the title of a Nature paper published on 1 March 1974 ended with a question mark: “Black hole explosions?” Stephen Hawking’s landmark idea about what is now known as Hawking radiation1 has just turned 50. The more physicists have tried to test his theory over the past half-century, the more questions have been raised — with profound consequences for how we view the workings of reality. In essence, what Hawking, who…

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We finally know what turned the lights on at the dawn of time

We finally know what turned the lights on at the dawn of time

Science Alert reports: We finally know what brought light to the dark and formless void of the early Universe. According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic dawn were small dwarf galaxies that flared to life, clearing the fog of murky hydrogen that filled intergalactic space. “This discovery unveils the crucial role played by ultra-faint galaxies in the early Universe’s evolution,” says astrophysicist Iryna Chemerynska of the…

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A quantum trick implied eternal stability. Now the idea may be falling apart

A quantum trick implied eternal stability. Now the idea may be falling apart

Charlie Wood writes: It is a truth of both physics and everyday experience that things fall apart. Ice melts. Buildings crumble. Any object, if you wait long enough, gets mixed up with itself and its surroundings beyond recognition. But beginning in 2005, a series of breakthroughs made this death march seem optional. In just the right quantum setting, any arrangement of electrons or atoms would stay put for all eternity — even uneven arrangements thrumming with activity. The finding flew…

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Synchronization is one of the fundamental phenomena of nature

Synchronization is one of the fundamental phenomena of nature

Any oscillator — a pendulum, a spring, a firefly, a human heart cell — wants to match up with its neighbors. Mathematicians recently showed that synchronization is inevitable in expander graphs, a type of network found in many areas of science. https://t.co/SM4cUWupJf pic.twitter.com/rINEz3lTuf — Quanta Magazine (@QuantaMagazine) February 3, 2024 Leila Sloman writes: Six years ago, Afonso Bandeira and Shuyang Ling were attempting to come up with a better way to discern clusters in enormous data sets when they stumbled…

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Time is not an illusion. It is an object with physical size

Time is not an illusion. It is an object with physical size

Sara Walker and Lee Cronin write: A timeless universe is hard to imagine, but not because time is a technically complex or philosophically elusive concept. There is a more structural reason: imagining timelessness requires time to pass. Even when you try to imagine its absence, you sense it moving as your thoughts shift, your heart pumps blood to your brain, and images, sounds and smells move around you. The thing that is time never seems to stop. You may even…

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Does quantum theory imply the entire Universe is preordained?

Does quantum theory imply the entire Universe is preordained?

Eddy Keming Chen writes: Was there ever any choice in the Universe being as it is? Albert Einstein could have been wondering about this when he remarked to mathematician Ernst Strauss: “What I’m really interested in is whether God could have made the world in a different way; that is, whether the necessity of logical simplicity leaves any freedom at all.” US physicist James Hartle, who died earlier this year aged 83, made seminal contributions to this continuing debate. Early…

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Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Live Science reports: The supermassive black hole at the heart of our galaxy isn’t just spinning — it’s doing so at almost maximum speed, dragging anything near it along for the ride. Physicists calculated the rotational speed of the Milky Way’s supermassive black hole, called Sagittarius A* (Sgr A*), by using NASA’s Chandra X-ray Observatory to view the X-rays and radio waves emanating from outflows of material. The spin speed of a black hole is defined as “a” and given…

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