Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: energy – Page 2

A quantum heat engine that simultaneously provides work and refrigeration

The laws of thermodynamics state that heat naturally flows from hotter systems or regions to colder systems or regions until a state of thermal equilibrium is reached. This simple principle underpins the operation of numerous technologies, ranging from refrigerators to power plants.

Yet quantum systems, which are governed by quantum mechanics, can exhibit unusual behaviors that cannot be explained by classical physics. These behaviors could be used to create innovative thermal devices.

Researchers at Qufu Normal University, the University of Hong Kong and the University of Palermo recently observed an anomalous thermal effect that allows a quantum system to absorb heat from colder thermal reservoirs. This unusual effect, outlined in a paper in Physical Review Letters, was leveraged to develop a new quantum heat engine that simultaneously produces work (i.e., mechanical energy created by converting heat into motion or power) and refrigeration.

Risks of solar storms may be underestimated, warn researchers

The effects of extreme space weather may be larger than previously thought, research in the journal Nature reveals. The paper, titled “Regression to the mean can explain saturation of geomagnetic storms,” is led by Dr. Nithin Sivadas of NASA’s Goddard Space Flight Center and co-authored by Dr. Maria Walach from Lancaster University.

Space weather—caused by fluctuating electric fields in Earth’s magnetic field and upper atmosphere—can affect technologies on and around Earth in several ways. Extreme geomagnetic storms are among the less frequent but more severe forms of space weather.

Extreme geomagnetic storms are temporary disturbances in the plasma and magnetic field around Earth that can disrupt global satellite communications, cause extensive power outages and affect how much radiation astronauts and pilots are exposed to.

Extragalactic positron-annihilation hotspots might mean Milky Way produces far more positrons than thought

Positrons—the antimatter counterpart of electrons—are created in high-energy cosmic processes. When normal matter meets its antimatter counterpart, they annihilate, or vanish, and produce a distinctive 511 keV gamma-ray signal. Scientists use this signal to detect where these annihilations occur.

Now, 20 years’ worth of this kind of data has revealed that positron annihilations might be happening in unexpected places and at far greater rates than previously thought. The new study, published in Astronomy & Astrophysics, describes how astronomers are interpreting a new positron annihilation map and whether the results represent true annihilations or just imaging artifacts.

Quantum Zeno effect could freeze computations as qubit systems scale up

The promise of quantum computing is to solve complex problems faster and more energy-efficiently than today’s supercomputers—from optimizing logistics to simulating molecules. This goal is coming within reach as the number of qubits—the computational units of quantum computing—increases.

But in addition to the technological challenges of scaling, there is another, less-considered issue: In the New Journal of Physics, researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) demonstrate that, in extreme cases, the so-called quantum Zeno effect can nearly halt computational processes as the number of qubits increases—a dreaded phenomenon comparable to a traditional computer “freezing.”

“The quantum Zeno effect is a previously overlooked obstacle to a certain class of quantum computers,” says Dr. Gernot Schaller, head of Quantum Technologies at HZDR’s Institute of Theoretical Physics. These so-called adiabatic quantum computers operate according to a special principle: Their qubits are always in their ground state, the lowest energy state. To solve a computational problem, the qubits’ energy landscape is gradually altered—slowly enough for them to adapt continuously and follow the changing ground state. Once the transformation is complete, the ground state immediately encodes the solution to the problem.

Magnetic clues inside atomic nuclei help explain how elements form in stars

A scientific team led by Facility for Rare Isotope Beams, or FRIB, has identified the origin of a mysterious excess of low-energy gamma rays emitted by the nucleus zinc-70. They found that the excess is caused by magnetic transitions within the nucleus. The study, “Magnetic Character of the Low-Energy Enhancement in 70 Zn,” published in Nature, sheds light on a long-standing puzzle in nuclear physics and has far-reaching implications for astrophysics.

The collaboration included scientists from 25 institutions in the United States, Canada, Italy, Germany, Norway and South Korea.

Microscale roughness breakthrough defies 80 years of fluid dynamics

Logically, you would think a sleek surface has optimal aerodynamics—but recent research at Tohoku University turns this fundamental principle on its head. Applying an irregular microscale surface texture reduced the aerodynamic drag of a test model. The innovation has potential applications in the design of fuel-efficient vehicles. The study is published in the Journal of Fluid Mechanics.

For more than 80 years, a fundamental principle of fluid dynamics has held that smoother surfaces produce less aerodynamic drag. However, a research group led by associate professor Aiko Yakeno at the Institute of Fluid Science, Tohoku University, has overturned this long-standing assumption. By applying Distributed Micro-Roughness (DMR)—irregular microscale surface textures—to a test model, the team achieved the world’s first experimental demonstration of up to 43.6% aerodynamic drag reduction.

By reducing drag in this innovative way, researchers may be able to reduce fuel consumption and CO₂ emissions across aviation, automotive, marine and rail transportation in the future.

Two-color lasers aim electron currents through semiconductor with no electric field

Researchers at the University of Michigan have created a device that enables them to control the flow of electrons through a semiconductor using only laser light—no electrical power source required. The device was built to explore fundamental physics and realize a previously unobserved behavior, but it could also open doors for new applications in areas that bridge optics and electronics, including sensing, imaging and telecommunications.

The paper is published in the journal Physical Review Letters.

The phenomenon could help improve how signals are sent through and between devices, as well as create new opportunities to store more information in those signals.

/* */