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When heat flows backwards: A neat solution for hydrodynamic heat transport

When we think about heat traveling through a material, we typically picture diffusive transport, a process that transfers heat from high-temperature to low-temperature as particles and molecules bump into each other, losing kinetic energy in the process. But in some materials, heat can travel in a different way, flowing like water in a pipeline that—at least in principle—can be forced to move in a direction of choice. This second regime is called hydrodynamic heat transport.

Heat conduction is mediated by movement of phonons, which are collective excitations of atoms in solids, and when phonons spread in a material without losing their momentum in the process, you have phonon hydrodynamics.

The phenomenon has been studied theoretically and experimentally for decades, but is becoming more interesting than ever to experimentalists because it features prominently in materials like graphene, and could be exploited to guide heat flow in electronics and energy storage devices.

Five ways quantum technology could shape everyday life

The unveiling by IBM of two new quantum supercomputers and Denmark’s plans to develop “the world’s most powerful commercial quantum computer” mark just two of the latest developments in quantum technology’s increasingly rapid transition from experimental breakthroughs to practical applications.

There is growing promise of quantum technology’s ability to solve problems that today’s systems struggle to overcome, or cannot even begin to tackle, with implications for industry, national security and everyday life.

So, what exactly is quantum technology? At its core, it harnesses the counterintuitive laws of quantum mechanics, the branch of physics describing how matter and energy behave at the smallest scales. In this strange realm, particles can exist in several states simultaneously (superposition) and can remain connected across vast distances (entanglement).

Experiment relies on pulsars to probe dark matter waves

Dark matter is a type of matter that is predicted to make up most of the matter in the universe, yet it is very difficult to detect using conventional experimental techniques, as it does not emit, absorb, or reflect light. While some past studies gathered indirect hints of its existence, dark matter has never been directly observed; thus, its composition remains a mystery.

One hypothesis is that dark matter is made up of axionlike particles with an extremely low mass, broadly referred to as ultralight axionlike dark matter (ALDM). As these particles are exceedingly light, predictions suggest that they would behave more like waves than individual particles on a galactic scale.

The PPTA collaboration, a large team of researchers based at different institutes worldwide, applied a new approach to search for ALDM by cross-correlating polarization data of pulsars, neutron stars that spin rapidly and emit highly regular beams of radio waves. This approach, termed the “Pulsar Polarization Array (PPA),” entails measuring the polarization position angles of a series of pulsars and how they changed over time and with respect to pulsar spatial position.

Could electronic beams in the ionosphere remove space junk?

A possible alternative to active debris removal (ADR) by laser is ablative propulsion by a remotely transmitted electron beam (e-beam). The e-beam ablation has been widely used in industries, and it might provide higher overall energy efficiency of an ADR system and a higher momentum-coupling coefficient than laser ablation. However, transmitting an e-beam efficiently through the ionosphere plasma over a long distance (10 m–100 km) and focusing it to enhance its intensity above the ablation threshold of debris materials are new technical challenges that require novel methods of external actions to support the beam transmission.

Therefore, Osaka Metropolitan University researchers conducted a preliminary study of the relevant challenges, divergence, and instabilities of an e-beam in an ionospheric atmosphere, and identified them quantitatively through numerical simulations. Particle-in-cell simulations were performed systematically to clarify the divergence and the instability of an e-beam in an ionospheric plasma.

The major phenomena, divergence and instability, depended on the densities of the e-beam and the atmosphere. The e-beam density was set slightly different from the density of ionospheric plasma in the range from 1010 to 1012 m−3. The e-beam velocity was changed from 106 to 108 m/s, in a nonrelativistic range.

A smashing success: Relativistic Heavy Ion Collider wraps up final collisions

Just after 9 a.m. on Friday, Feb. 6, 2026, final beams of oxygen ions—oxygen atoms stripped of their electrons—circulated through the twin 2.4-mile-circumference rings of the Relativistic Heavy Ion Collider (RHIC) and crashed into one another at nearly the speed of light inside the collider’s two house-sized particle detectors, STAR and sPHENIX. RHIC, a nuclear physics research facility at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory has been smashing atoms since the summer of 2000. The final collisions cap a quarter century of remarkable experiments using 10 different atomic species colliding over a wide range of energies in different configurations.

The RHIC program has produced groundbreaking discoveries about the building blocks of matter and the nature of proton spin and technological advances in accelerators, detectors, and computing that have far surpassed scientists’ expectations when this discovery machine first turned on.

“RHIC has been one of the most successful user facilities operated by the DOE Office of Science, serving thousands of scientists from across the nation and around the globe,” said DOE Under Secretary for Science Darío Gil. “Supporting these one-of-a-kind research facilities pushes the limits of technology and expands our understanding of our world through transformational science—central pillars of DOE’s mission to ensure America’s security and prosperity.”

Big Bang Thought of the Day by Nobel Laureate Peter Higgs, “The Big Bang made the universe explode into existence. The Higgs boson made it stay.” How Peter Higgs’ “God Particle” settled decades of competing universe theories

Big Bang Thought of the Day by Nobel Laureate Peter Higgs, “The Big Bang made the universe explode into existence. The Higgs boson made it stay.” The universe formed 13.8 billion years ago. But matter could not exist without mass. In 1964, Peter Higgs proposed a solution. His Higgs boson explains why particles gained weight after the Big Bang. Confirmed in 2012 at CERN, it settled decades of cosmic theory conflicts. This discovery reshaped modern physics and cosmology forever.

Water molecules actively reshape chiral catalyst structure, research shows

Researchers have analyzed the stepwise hydration of prolinol, a molecule widely used as a catalyst and as a building block in chemical synthesis. The study shows that just a few water molecules can completely change the preferred structure of prolinol. The research is published in the Journal of the American Chemical Society.

Physical chemistry applies the principles and concepts of physics to understand the basics of chemistry and explain how and why transformations of matter take place on a molecular level. One of the branches of this field focuses on understanding how molecules change in the course of a chemical reaction or process.

Understanding the interactions of chiral molecules with water is crucial, given the central role that water plays in chemical and biological processes. Chiral molecules are those that, despite comprising the same atoms, cannot be superimposed on their mirror image in a way similar to what happens with right and left hands or a pair of shoes.

Physicists solve a quantum mystery that stumped scientists for decades

Physicists at Heidelberg University have developed a new theory that finally unites two long-standing and seemingly incompatible views of how exotic particles behave inside quantum matter. In some cases, an impurity moves through a sea of particles and forms a quasiparticle known as a Fermi polaron; in others, an extremely heavy impurity freezes in place and disrupts the entire system, destroying quasiparticles altogether. The new framework shows these are not opposing realities after all, revealing how even very heavy particles can make tiny movements that allow quasiparticles to emerge.

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