Quantum Systems Defy Freezing Logic

Researchers investigated the Mpemba effect in quantum systems, a phenomenon where hotter water can freeze faster than cooler water. This quantum Mpemba effect retains memory of its initial conditions, affecting its thermal relaxation later. The team used two systems with quantum dots and discovered the thermal quantum Mpemba effect across various conditions, suggesting possible broader applications beyond thermal analysis.



Hotter quantum systems can cool faster than initially colder equivalents.

Does hot water freeze faster than cold water? Aristotle may have been the first to tackle this question that later became known as the Mpemba effect.

This phenomenon originally referred to the non-monotonic initial temperature dependence of the freezing start time, but it has been observed in various systems — including colloids — and has also become known as a mysterious relaxation phenomenon that depends on initial conditions.

What Is the Mpemba Effect?
The Mpemba effect is a counterintuitive phenomenon where hot water can freeze faster than cold water under certain conditions. Named after Erasto Mpemba, a Tanzanian student who observed this effect in the 1960s and subsequently brought it to the attention of the scientific community, the phenomenon has been a topic of curiosity for centuries, with references dating back to the likes of Aristotle. The exact cause of the Mpemba effect is still a topic of debate among scientists.

Recent Findings
Now, a team of researchers from Kyoto University and the Tokyo University of Agriculture and Technology has shown that the temperature quantum Mpemba effect can be realized over a wide range of initial conditions.

“The quantum Mpemba effect bears the memory of initial conditions that result in anomalous thermal relaxation at later times,” explains project leader and co-author Hisao Hayakawa at KyotoU’s Yukawa Institute for Theoretical Physics.  READ MORE...

Fusion Power with Microwaves

Structure of Heliotron J device. Credit: KyotoU/Heliotron J group

Plasma physicists from Ukraine, Germany and Japan collaborate to spark fusion power.

Despite being forced to evacuate the Kharkiv Institute of Physics and Technology due to the Russia-Ukraine war, lead author Yurii Victorovich Kovtun has collaborated with Kyoto University to create stable plasmas using microwaves. Plasmas must be maintained at the correct density, temperature, and duration for nuclear fusion to occur. 

The research team, including the Max Planck Institute for Plasma Physics, has identified three critical steps in plasma production and utilized the Heliotron J device to study fusion plasma discharges. They discovered that blasting 2.45-GHz microwaves without alignment of the magnetic field produced a dense plasma, which could potentially simplify fusion research in the future.

Lead author Yurii Victorovich Kovtun, despite being forced to evacuate the Kharkiv Institute of Physics and Technology amid the current Russia-Ukraine war, has continued to work with Kyoto University to create stable plasmas using microwaves.

Getting plasma just right is one of the hurdles to harnessing the massive amounts of energy promised by nuclear fusion.

Plasmas — soups of ions and electrons — must be held at the right density, temperature, and duration for atomic nuclei to fuse together to achieve the desired release of energy.

One recipe involves the use of large, donut-shaped devices with powerful magnets that contain a plasma while carefully aligned microwave generators heat the atomic mixture.  READ MORE...

Greenwashing Scam

A Chevron drilling site near Midland, Texas. It’s unlikely PR firms will be able to serve the fossil-fuel industry as they have in the past. Photograph: Jessica Lutz/Reuters


This week a peer-reviewed study confirmed what many have suspected for years: major oil companies are not fully backing up their clean energy talk with action. Now the PR and advertising firms that have been creating the industry’s greenwashing strategies for decades face a reckoning over whether they will continue serving big oil.

The study compared the rhetoric and actions on climate and clean energy from 2009 to 2020 from the world’s four largest oil companies – ExxonMobil, Chevron, Shell, and BP. Writing in the journal Plos One, researchers from Tohoku University and Kyoto University in Japan conclude that the companies are not, in fact, transitioning their business models to clean energy.

“The magnitude of investments and actions does not match discourse,” they write. “Until actions and investment behavior are brought into alignment with discourse, accusations of greenwashing appear well-founded.”

Although this isn’t the first time that oil companies have been accused of overstating their climate bona fides, it has never been set out quite so comprehensively, according to environmental sociologist Dr Robert Brulle at Brown University. “This is the first robust, empirical, peer-reviewed analysis of the activities–of the speech, business plans, and the actual investment patterns of the major oil companies regarding their support or opposition to the transition to a sustainable society,” he says.

Brulle says PR firms and advertising agencies that have created campaigns around the oil firms’ net-zero claims are now on notice. “There’s no plausible deniability that they are unaware of the activities of these companies after this paper has been published,” he says. “This paper clearly shows that these companies aren’t walking the talk.”  READ MORE...