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Category: Physics

Quantum physicists discover ‘negative time’ in strange experiment

Quantum physicists discover ‘negative time’ in strange experiment

Live Science reports: Quantum physicists are familiar with wonky, seemingly nonsensical phenomena: atoms and molecules sometimes act as particles, sometimes as waves; particles can be connected to one another by a “spooky action at a distance,” even over great distances; and quantum objects can detach themselves from their properties like the Cheshire Cat from Alice’s Adventures in Wonderland detaches itself from its grin. Now researchers led by Daniela Angulo of the University of Toronto have revealed another oddball quantum outcome:…

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John Wheeler saw the tear in reality

John Wheeler saw the tear in reality

Amanda Gefter writes: When Johnny Wheeler was 4 years old, splashing in the bathtub in Youngstown, Ohio, he looked up at his mother and asked, “What happens when you get to the end of things?” The question would haunt him for the rest of his life. What happens when you get to the bottom of space? What happens when you get to the edge of time? It would lead him to suggest that space-time can’t be the true fabric of…

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In an epic cosmology clash, rival scientists begin to find common ground

In an epic cosmology clash, rival scientists begin to find common ground

Science News reports: The biggest clash in cosmology might be inching closer to resolution, thanks to the James Webb Space Telescope. Scientists disagree over the universe’s expansion rate, known as the Hubble constant. There are two main methods for measuring it — one based on exploding stars called supernovas and the other on the universe’s oldest light, the cosmic microwave background. The two techniques have been in conflict for a decade, in what’s known as the “Hubble tension.” If this…

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Does chaos theory square classical physics with human agency?

Does chaos theory square classical physics with human agency?

Erik Van Aken writes: A slight shift in Cleopatra’s beauty, and the Roman Empire unravels. You miss your train, and an unexpected encounter changes the course of your life. A butterfly alights from a tree in Michoacán, triggering a hurricane halfway across the globe. These scenarios exemplify the essence of ‘chaos’, a term scientists coined during the middle of the 20th century, to describe how small events in complex systems can have vast, unpredictable consequences. Beyond these anecdotes, I want…

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Physicists pinpoint the quantum origin of the greenhouse effect

Physicists pinpoint the quantum origin of the greenhouse effect

Joseph Howlett writes: In 1896, the Swedish physicist Svante Arrhenius realized that carbon dioxide (CO2) traps heat in Earth’s atmosphere — the phenomenon now called the greenhouse effect. Since then, increasingly sophisticated modern climate models have verified Arrhenius’ central conclusion: that every time the CO2 concentration in the atmosphere doubles, Earth’s temperature will rise between 2 and 5 degrees Celsius. Still, the physical reason why CO2 behaves this way has remained a mystery, until recently. First, in 2022, physicists settled…

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‘Metaphysical experiments’ probe our hidden assumptions about reality

‘Metaphysical experiments’ probe our hidden assumptions about reality

Amanda Gefter writes: Metaphysics is the branch of philosophy that deals in the deep scaffolding of the world: the nature of space, time, causation and existence, the foundations of reality itself. It’s generally considered untestable, since metaphysical assumptions underlie all our efforts to conduct tests and interpret results. Those assumptions usually go unspoken. Most of the time, that’s fine. Intuitions we have about the way the world works rarely conflict with our everyday experience. At speeds far slower than the…

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The physics of cold water may have jump-started complex life

The physics of cold water may have jump-started complex life

Veronique Greenwood writes: Once upon a time, long ago, the world was encased in ice. That’s the tale told by sedimentary rock in the tropics, many geologists believe. Hundreds of millions of years ago, glaciers and sea ice covered the globe. The most extreme scenarios suggest a layer of ice several meters thick even at the equator. This event has been called “Snowball Earth,” and you’d think it would be a terrible time to be alive — and maybe, for…

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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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