Laser light coherence offers a consistent approach

Researchers at the University of Basel have developed a new approach to applying thermodynamics to microscopic quantum systems.


In 1798, the officer and physicist Benjamin Thompson (a.k.a. Count Rumford) observed the drilling of cannon barrels in Munich and concluded that heat is not a substance but can be created in unlimited amounts by mechanical friction.


Rumford determined the amount of heat generated by immersing the cannon barrels in water and measuring how long it took the water to reach boiling. Based on such experiments, thermodynamics was developed in the 19th century. Initially, it was at the service of the Industrial Revolution and explained, physically, for instance, how heat can be efficiently converted into useful work in steam engines.

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How most of the universe's visible mass is generated

This illustration shows how the strong interaction evolves with distance, generating more than 98% of the ground and excited state of the nucleon masses. This evolution of strong-interaction dynamics is described within the CSM approach. At distances comparable to the size of a hadron, ~10–13 cm, its relevant constituents are no longer the bare quarks and gluons of QCD. Instead, dressed quarks and dressed gluons emerge when bare quarks and gluons are surrounded by clouds of strongly coupled quarks and gluons undergoing continual creation and annihilation. Credit: Jefferson Lab/Shannon West

Deep in the heart of the matter, some numbers don't add up. For example, while protons and neutrons are made of quarks, nature's fundamental building blocks bound together by gluons, their masses are much larger than the individual quarks from which they are formed.


This leads to a central puzzle … why? In the theory of the strong interaction, known as quantum chromodynamics or QCD, quarks acquire their bare mass through the Higgs mechanism. The long-hypothesized process was confirmed by experiments at the CERN Large Hadron Collider in Switzerland and led to the Nobel Prize for Peter Higgs in 2013.

Yet the inescapable issue remains that "this mechanism contributes to the measured proton and neutron masses at the level of less than 2%," said Victor Mokeev, a staff scientist and phenomenologist at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility.

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All roads in ancient Rome stretched far longer than previously known

This photo provided by Adam Pažout shows a fragment of a Roman milestone that was erected along the road Via 

Nova Traiana in Jordan. Credit: Adam Pažout/Itiner-e via AP

As the saying went, all roads once led to Rome—and those roads stretched 50% longer than previously known, according to a new digital atlas published Thursday.


The last major atlas of ancient Roman road networks was published 25 years ago. Since then, advances in technology and other newly accessible sources have greatly expanded researchers' ability to locate ancient roadways.

Over five years, a team of archaeologists combed through historical records, ancient journals, locations of milestones and other archival data. Scientists then looked for clues in satellite imagery and aerial photography, including recently digitized photos taken from planes during World War II.

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Tiny living robots made from lung cells could one day deliver medicine inside the body

A brand-new engineering approach to generate "designer" biological robots using human lung cells is underway in Carnegie Mellon University's Ren lab. 

Referred to as AggreBots, these microscale living robots may one day be able to traverse through the body's complex environments to deliver desired therapeutic or mechanical interventions, once greater control is achieved over their motility patterns. 

In new research published in Science Advances, the group provides a novel tissue engineering platform capable of achieving customizable motility in AggreBots by actively controlling their structural parameters.

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Physicists model vacuum tunneling in a 2D superfluid

In 1951, physicist Julian Schwinger theorized that by applying a uniform electrical field to a vacuum, electron-positron pairs would be spontaneously created out of nothing, through a phenomenon called quantum tunneling.

The problem with turning the matter-out-of-nowhere theory into Star Trek replicators or transporters? Enormously high electric fields would be required—far beyond the limits of any direct physical experiments.

As a result, the aptly-named Schwinger effect has never been seen.

Now theoretical physicists at the University of British Columbia (UBC) have described a parallel effect in a more manageable system. In their model, they substitute a thin film of superfluid helium for the vacuum, and the background flow of the superfluid for the massive electrical field.

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Forget materialism, a simple life is happier, research shows

In an age where billionaires and conspicuous consumption are increasingly on display, new Otago-led research shows a simple life really is a happier life.


The study led by the University of Otago—Ōtākou Whakaihu Waka Department of Marketing researchers has been published in the Journal of Macromarketing.


After setting out to understand the relationship between consumption and well-being, the researchers found people are happier and more satisfied when adopting sustainable lifestyles and resisting the temptations of consumerism.

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Theories on dark matter's origins point to 'mirror world' and universe's edge

Two recent studies by Professor Stefano Profumo at the University of California, Santa Cruz, propose theories that attempt to answer one of the most fundamental open questions in modern physics: What is the particle nature of dark matter?


Science has produced overwhelming evidence that the mysterious substance, which accounts for 80% of all matter in the universe, exists. Dark matter's presence explains what binds galaxies together and makes them rotate. 

Findings such as the large-scale structure of the universe and measurements of the cosmic microwave background also prove that something as-yet undetermined permeates all that darkness.

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Gravity and quantum ripples may explain cosmic origins

A team of scientists led by expert Raúl Jiménez, ICREA researcher at the University of Barcelona's Institute of Cosmos Sciences (ICCUB), in collaboration with the University of Padua (Italy), has presented a revolutionary theory about the origins of the universe. 

The study, published in the journal Physical Review Research, introduces a radical change in the understanding of the first moments after the Big Bang, without relying on the speculative assumptions that physicists have traditionally assumed.

For decades, cosmologists have worked under the inflationary paradigm, a model that suggests that the universe expanded extremely rapidly, in a fraction of a second, thus paving the way for everything we observe today. 

But this model includes too many adjustable parameters—the free parameters—which can be modified. Scientifically, this poses a problem, as it makes it difficult to know whether a model is truly predicting or simply adapting to the data.

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Narcissism and other dark personality traits linked to AI cheating in art universities

Credit: Unsplash/CC0 Public Domain

In many countries, there is an academic cheating crisis with students misusing artificial intelligence tools like ChatGPT to write essays, dissertations and other assignments. According to new research, certain personality traits make some students more likely to pass off AI-generated work as their own.


In a study published in BMC Psychology, Jinyi Song of South Korea's Chodang University and Shuyan Liu of Baekseok University surveyed 504 Chinese art students. They found that students who scored highly for dark personality traits like narcissism, machiavellianism and psychopathy (collectively known as "the Dark Triad") were more likely to rely on AI tools like ChatGPT and Midjourney to do their work.


Although previous studies have revealed a link between dark personality traits and academic dishonesty, most research has focused on general student populations, not on specific groups such as art students.

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Discovery in quantum materials could make electronics 1,000 times faster

Researchers at Northeastern University have discovered how to change the electronic state of matter on demand, a breakthrough that could make electronics 1,000 times faster and more efficient.

By switching from insulating to conducting and vice versa, the discovery creates the potential to replace silicon components in electronics with exponentially smaller and faster quantum materials.

"Processors work in gigahertz right now," said Alberto de la Torre, assistant professor of physics and lead author of the research. "The speed of change that this would enable would allow you to go to terahertz."

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New theory proposes time has three dimensions, with space as a secondary effect

Time, not space plus time, might be the single fundamental property in which all physical phenomena occur, according to a new theory by a University of Alaska Fairbanks scientist.

The theory also argues that time comes in three dimensions rather than just the single one we experience as continual forward progression. Space emerges as a secondary manifestation.

"These three time dimensions are the primary fabric of everything, like the canvas of a painting," said associate research professor Gunther Kletetschka at the UAF Geophysical Institute. "Space still exists with its three dimensions, but it's more like the paint on the canvas rather than the canvas itself."

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Researcher proposes first-time model that replaces dark energy and dark matter in explaining nature of the universe

Dr. Richard Lieu, a physics professor at The University of Alabama in Huntsville (UAH), a part of The University of Alabama System, has published a paper in the journal Classical and Quantum Gravity that proposes a universe built on steps of multiple singularities rather than the Big Bang alone to account for the expansion of the cosmos.

The new model forgoes the need for either dark matter or dark energy as explanations for the universe's acceleration and how structures like galaxies are generated.

The researcher's work builds on an earlier model hypothesizing that gravity can exist without mass.

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A new dissipation-based method to probe quantum correlations

Quantum systems are known to be prone to dissipation, a process that entails the irreversible loss of energy and that is typically linked to decoherence. Decoherence, or the loss of coherence, occurs when interactions between a quantum system and its environment cause a loss of coherence, which is ultimately what allows quantum systems to exist in a, Super superposition of states.


While dissipation is generally viewed as a source of decoherence in quantum systems, researchers at Tsinghua University recently showed that it could also be leveraged to study strongly correlated quantum matter.

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Theoretical physicists completely determine the statistics of quantum entanglement

For the first time, theoretical physicists from the Institute of Theoretical Physics (IPhT) in Paris-Saclay have completely determined the statistics that can be generated by a system using quantum entanglement. This achievement paves the way for exhaustive test procedures for quantum devices.


The study is published in the journal Nature Physics.

After the advent of transistors, lasers and atomic clocks, the entanglement of quantum objects—as varied as photons, electrons and superconducting circuits—is at the heart of a second quantum revolution, with quantum communication and quantum computing in sight.

What's involved? Two objects prepared together in a quantum state—two horizontally or vertically polarized photons, for example—retain the memory of their common origin, even if they are moved far apart from each other. When the quantum state of the two entangled objects is measured—their polarization, in the proposed example—a distinct correlation is observed between the measurement results.

Measurement obeying quantum statistics
What does this correlation depend on? First, the degree of entanglement between the two objects may vary, depending on the nature of the source of the entangled quantum objects—in the example, horizontally polarized photons may be produced more frequently than vertically polarized ones. Then, a choice of measurement must be made—such as selecting a direction in which to measure the polarization—which may impact its result.

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Gravity may arise from quantumness of space

Gravity is part of our everyday life. Still, the gravitational force remains mysterious: to this day we do not understand whether its ultimate nature is geometrical, as Einstein envisaged, or governed by the laws of quantum mechanics.

Until now, all experimental proposals to answer this question have relied on creating the quantum phenomenon of entanglement between heavy, macroscopic masses. But the heavier an object is, the more it tends to shed its quantum features and become "classical," making it incredibly challenging to make a heavy mass behave as a quantum particle.

In a study published in Physical Review X this week, researchers from Amsterdam and Ulm propose an experiment that circumvents these issues.

Classical or quantum?
Successfully combining quantum mechanics and gravitational physics is one of the main challenges of modern science. Generally speaking, progress in this area is hindered by the fact that we cannot yet perform experiments in regimes where both quantum and gravitational effects are relevant.

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The universe doesn't care about your precious standard model

This week, ALMA researchers reported the discovery of oxygen in the most distant known galaxy. Geologists believe unusual structures in rock in the desert regions of Namibia, Oman and Saudia Arabia may be evidence of an unknown microorganism. And a group of physicists may have generated a tiny charge of electricity using the Earth's rotational energy. But the biggest story by far is the second release of data from the DESI survey of the universe, which could upend the standard model:

DESI is coming for the standard model
An emerging generation of cosmological surveys launched this week with the second release of data from the Dark Energy Spectroscopic Instrument at Kitt Peak National Observatory in Arizona, which is mapping an unprecedentedly huge number of galaxies spanning 11 billion years of cosmic history in order to better understand dark energy.

Astronomers have known for many decades that the universe is expanding; in the 1990s, the first image of the cosmic microwave background—the echo of the big bang—revealed that this expansion is accelerating for unknown reasons. Astronomers call this expansion "dark energy," which translates to "we don't understand what this energy is."

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W boson measurement conundrum

One of the tiniest building blocks of the universe has a weigh-in problem, and Ashutosh Kotwal is determined to get to the bottom of it.


For nearly 30 years, the Duke physicist has led a worldwide effort to home in on the mass of a fundamental particle called the W boson.

It's the force-carrying particle that allows the sun to burn and new elements to form, so it's pretty important. Without it, the entire universe would be in the dark.

But in recent years the W boson has been the source of a rift in the physics world. That's because the two most precise measurements to date of its mass—essentially how much matter, or "stuff" the particle contains—don't line up.     READ MORE...

Quantum Machine Simulaton

Physicists have performed a simulation they say sheds new light on an elusive phenomenon that could determine the ultimate fate of the universe.

Pioneering research in quantum field theory around 50 years ago proposed that the universe may be trapped in a false vacuum—meaning it appears stable but in fact could be on the verge of transitioning to an even more stable, true vacuum state.

While this process could trigger a catastrophic change in the universe's structure, experts agree that predicting the timeline is challenging, but it is likely to occur over an astronomically long period, potentially spanning millions of years.

In an international collaboration between three research institutions, the team reports gaining valuable insights into false vacuum decay—a process linked to the origins of the cosmos and the behavior of particles at the smallest scales. The collaboration was led by Professor Zlatko Papic, from the University of Leeds, and Dr. Jaka Vodeb, from Forschungszentrum Jülich, Germany.  READ MORE...

Ancient Genomes

An international team of geneticists, led by those from Trinity College Dublin, has joined forces with archaeologists from Bournemouth University to decipher the structure of British Iron Age society, finding evidence of female political and social empowerment.

The researchers seized upon a rare opportunity to sequence DNA from many members of a single community. They retrieved over 50 ancient genomes from a set of burial grounds in Dorset, southern England, in use before and after the Roman Conquest of AD 43. The results revealed that this community was centered around bonds of female-line descent.

Dr. Lara Cassidy, Assistant Professor in Trinity's Department of Genetics, led the study that has been published in Nature.     READ MORE...

Dark Energy Does Not Exist NOW

One of the biggest mysteries in science—dark energy—doesn't actually exist, according to researchers looking to solve the riddle of how the universe is expanding.


Their analysis has been published in the journal Monthly Notices of the Royal Astronomical Society Letters.


For the past 100 years, physicists have generally assumed that the cosmos is growing equally in all directions. They employed the concept of dark energy as a placeholder to explain unknown physics they couldn't understand, but the contentious theory has always had its problems.


Now a team of physicists and astronomers at the university of Canterbury in Christchurch, New Zealand are challenging the status quo, using improved analysis of supernovae light curves to show that the universe is expanding in a more varied, "lumpier" way.     READ MORE...