Earth and Environment

Physicists typically have two frameworks for considering mechanics – a classical picture, looking at larger-scale objects, or a quantum picture, considering things on a subatomic scale. Where the boundary between these two pictures lies is an open question. Dr Khaled Mnaymeh from National Research Council Canada and Carleton University argues that this boundary does not exist. Through his analysis of Bell’s inequality, configuration space, and counterfactual definiteness, his work highlights the importance of considering these foundational principles in our study of the world around us.

A significant debate continues between scholars in the astronomical community regarding the early history of our solar system. It’s been hypothesised that the solar system experienced a dramatic cataclysm a short while —in cosmological terms— after the Earth and Moon solidified. Dubbed the Late Heavy Bombardment theory, disturbances in gas giant orbits may have caused a sudden hailstorm of comets and asteroids to be hurled towards the inner planets. Lunar rock samples collected from craters during Apollo missions seemed to support the idea, but new evidence is demanding a rethink.

Professor Yi-Gang Xu and his team examined samples recovered from the Chang’e-6 mission in 2024, and they suggest a more gradual change in the frequency of asteroid impacts, rather than a sudden, violent cataclysm.

Nothing can ever be perfectly still, no matter how cold you make it. Take solid nitrogen, for example, which freezes at a bone-chilling -210 °C. You might expect its molecules to be frozen rigidly in place but, even at such extreme temperatures, they have a life of their own. At the microscopic level, quantum effects become important and random fluctuations ensure that molecules of solid nitrogen will jitter unceasingly. In the limit of absolute zero temperature, these tiny movements can have a considerable influence on the properties and behaviour of whole materials. New work published by a collaboration of scientists from Slovenia and the UK has sought to develop a better understanding of the effects of this quantum motion.

Studying the behaviour of plasma – a state of matter beyond the familiar three: solid, liquid, and gas – is crucial for our understanding of planets, stars, and the possibility of generating unlimited energy on Earth through the process of nuclear fusion. Specialist equipment is needed to produce extreme kinds of plasma in the laboratory but, once created, they last for less than a billionth of a second. How do you study something so fleeting? To address this problem, a team of researchers from Spain have proposed a design for a simple new device so that proton beams may be used to study faster and faster processes.

Both Raman fibre lasers (lasers based on stimulating molecules to emit photons at a given frequency shift from the pump laser) and Rare Earth fibre lasers (which use rare earth elements to emit light) work as fibre-based laser sources. Scientists have become interested in Raman fibre lasers because Rare Earth lasers have power limitations, due to the excess heat generated by the lasing process. Dr Yaakov Glick and his colleagues in the Applied Physics Division, at Soreq Nuclear Research Centre in Yavne, Israel, collaborating internationally with other groups, have worked to increase the power of Raman fibre lasers, while simultaneously enhancing their brightness.

The magnetic field around our planet, along with unique radioactive decay processes, can cause the generation of Alfvén waves. Dr Gerald Smith of Positronics Research LLC has been researching how we can observe these waves and the unique atoms formed in these processes. By looking at data locally and how these particle events are represented at telescopes and monitoring systems around the globe, Dr Smith observes their impacts and points to their potential in future interplanetary exploration.

Dr Niloofar Vardian at the SISSA school has advanced our understanding of black hole interiors through precise mathematical modelling. Her recent publication sheds light on previously inaccessible aspects of black hole dynamics, deepening our knowledge of these mysterious and difficult-to-study phenomena.

Space weather events can have dramatic effects on Earth’s magnetic field, potentially disrupting everything from power grids to GPS systems. Dr Ying Zou and her colleagues Dr Jesper Gjerloev and Shin Ohtani from Johns Hopkins University Applied Physics Laboratory led a groundbreaking investigation into an extraordinary disturbance in Earth’s magnetic field that occurred in April 2023. This unprecedented event is reshaping our understanding of how solar activity can trigger extreme space weather that impacts our technological systems.

Deok-Young Lee from the Korea Advanced Institute of Science and Technology and collaborator Dr Sin Hyuk Yim, affiliated with South Korea’s Agency for Defense Development work together to lead the advancement of quantum sensing technology. Their innovative research in developing rubidium-xenon gas cells has improved the precision and efficiency of atom spin gyroscopes, significantly driving forward the field of quantum measurement.

Photodetectors, or sensors which detect light and send information about the light via an electronic signal, are an essential piece of technology in modern optical science. Dr Stefan Koepfli from the Institute of Electromagnetic Fields, ETH Zurich in Switzerland, works with colleagues on the development and creation of these detectors. They look at how materials such as graphene can be used in these devices to improve the range of wavelengths that they can detect and also the speed at which they can transfer information.

Understanding how the building blocks of the world around us – such as protons and neutrons – can interact and synthesise various products can help us approach challenges such as clean energy. Sir Professor Ruggero Maria Santilli from The Institute for Basic Research considers how theories of quantum mechanics can be developed through his work on hadronic mechanics. By representing protons and neutrons as extended, Sir Santilli suggests how this could better account for processes in nuclear physics and a new outlook on clean nuclear energy via fusion.

Professor Andrei Khrennikov (Linnaeus University – Sweden) and Professor Emmanuel Haven (Memorial University of Newfoundland – Canada) utilise the mathematical framework of quantum theory to offer novel insights into the complexities of biological systems, cognition, decision-making, and other areas of social science, such as economics and finance. Their work showcases the potential of quantum-like models to decode the intricacies of non-physical systems, paving the way for innovative approaches to understanding the dynamics of life and thought, social processes and financial markets.

A novel method for producing singlet oxygen via stimulated Raman scattering (SRS) offers an innovative alternative to traditional photosensitizer-based techniques, promising safer and more efficient applications in disinfection, cancer treatment, and beyond. Professor Aristides Marcano Olaizola at Delaware State University is driving innovation in this critical field.

Professor Darin Acosta’s research at the CMS experiment utilises advanced muon detection, sophisticated trigger systems, and machine learning to deepen our understanding of the Higgs boson and explore the potential existence of dark matter. Based at Rice University in the USA, Professor Acosta’s work has long-reaching implications that are fundamental to our understanding of the universe.

Quantum mechanics relies on probabilities and uncertainties – for example, we cannot work out the outcome of a quantum system, but instead, we can suggest probabilities of certain outcomes. This has been troublesome for determinists, who instead believe that all outcomes are governed by a set of laws. Sir Professor Ruggero Maria Santilli from The Institute of Basic Research argues that if we extend our picture of quantum mechanics to his idea of hadronic mechanics, we can recover hidden variables and progressively recover determinism.

Controlling partial differential equations (PDEs) with parametric uncertainties is vital for system stability in science and engineering. Professor Francisco Jurado from Tecnológico Nacional de México (TecNM)/La Laguna addresses this challenging problem with a novel approach using adaptive backstepping boundary control for a one-dimensional modified Burgers’ equation. His innovative work tackles uncertainties in reactive and viscosity terms and considers Robin and Neumann boundary conditions, offering valuable insights into nonlinear PDE control.

Dr Christopher Singh at the Los Alamos National Laboratory in the USA conducts groundbreaking research into photonic devices. We find out here about the potential impacts of his work exploring quantum physics in radiation-heavy environments. His work informs progress across excitingly diverse sectors, including space exploration, nuclear energy, and healthcare.

Through a detailed analysis of mathematical frameworks, Professor Jean-François Pommaret challenges the established scientific consensus on gravitational waves, proposing that certain mathematical interpretations could question their existence. This article delves into the professor’s examination of the founding principles of general relativity, offering an insightful, alternative perspective on the ongoing dialogue between mathematics and physics.

Dr Michael Parker (Lexden Technologies) and Dr Christopher Jeynes (independent scholar) apply basic principles of thermodynamics to the topical issue of beta-decay bringing us an entirely new understanding of Time and Reality.

Dr Barry Ganapol from the University of Arizona and Dr Ó López Pouso from the University of Santiago de Compostela are working to address the fundamental challenge of solving the Fokker-Planck Equation as applied to radiation transport theory. They introduce a novel application of the Response Matrix/Discrete Ordinates method, achieving six-figure precision in modelling how radiation (specifically electrons and photons) scatters through small angles. This breakthrough could have significant implications for fields ranging from medical imaging to environmental science, enhancing our ability to predict and control radiation’s interaction with matter.

Dr Olalla Castro-Alvaredo of the City University of London (UK) and her collaborators are advancing our understanding of an important phenomenon of quantum mechanical systems known as entanglement and, especially, its mathematical measures. Symmetry-resolved entanglement entropy is one such measure. Their study focuses on special quantum states which are excited with respect to a ground state. The research shows how the entanglement amongst quantum particles can be measured and assesses the contribution to the entanglement of quasiparticle excitations, particularly in the presence of additional symmetries.

Understanding the electronic behaviour of fuel cell catalysts can be difficult using standard experimental techniques, although this knowledge is critical to their fine-tuning and optimisation. Dr Jiatang Chen at the University of Western Ontario works with colleagues to use the cutting-edge valence-to-core X-ray emission spectroscopy method to determine the precise electronic effects of altering the amounts of platinum and nickel in platinum-nickel catalysts used in fuel cells. Their research demonstrates the potential application of this technique to analysing battery materials, catalysts, and even cancer drug molecules.

Dr Marcus Noack and Dr Mark Risser, researchers at Lawrence Berkeley National Laboratory, have recently proposed a significant advancement in the area of machine learning and data science that promises significant computational improvements: the enhancement of exact Gaussian Processes for large datasets, significantly improving data analysis capabilities for samples even beyond 5 million data points.

The Principle of Least Action is a well-known tool for mathematicians and theoretical physicists. Simply put, the Principle of Least action states that, for a system to progress from one state to another, the variation in the average kinetic energy of the system minus the average potential energy of the system will be as little as possible. Dr Ivan Kennedy from the University of Sydney has found that the application of this important theorem, combined with the idea of a pervasive quantum field, to processes such as chemical reactions, atmospheric phenomena, and stellar structure, yields some unexpected but exciting results.

One of the most fundamental chemical phenomena in existence is that of the carbon-carbon bond. It gives carbon atoms the ability to form the backbone of all organic chemistries; without it, life itself could not exist. Therefore, understanding how to make, break and manipulate this crucial bond is the secret to unlocking endless potential options for chemical synthesis. Professor Jeremy May and his team at the University of Houston, USA, have been developing methods to control the formation of these bonds, significantly furthering the field of organic synthesis.

Superconducting quantum computers offer exciting potential for the future but are currently limited by their low operating temperature. Professor John Miller and his team at the University of Houston have been working on these problems, looking at how we can operate superconducting quantum systems at higher temperatures and considering the properties of charge density wave materials. He also highlights the applications of this work in quantum information processing.

Our understanding of physics changed dramatically in the 20th century, with the advent of the Standard Model of Particle Physics, which builds on quantum mechanics and Einstein’s theory of relativity – two of the most successful theories in the history of science. However, we know that our theories are incomplete, but finding out what’s beyond the Standard Model is difficult because it’s such a successful theory. Professor Alison Lister and her colleagues at the University of British Columbia and around the world are poking holes in the Standard Model, towards finding a new theory that gives a more complete description of the universe.

Metallic glasses are extraordinary materials that can be formed by rapidly cooling certain mixtures of molten metals. Their unique properties make them extremely desirable for various technological applications. However, scientists do not fully understand the processes that drive the formation of metallic glasses, and as such, they remain difficult to design and optimise for specific purposes. Dr Nicholas Mauro and his team at St. Norbert College in Wisconsin have been researching metallic glasses to understand exactly how these materials form from various molten alloys. By understanding the mechanisms that lead to the formation of metallic glasses, the team’s work aids in the design of new metallic glasses and enables their optimisation for specific technological applications.

The ability to generate stable and reproducible plasma is central to many aspects of research and technology. Through his research, Professor Michel Moisan and his team at Université de Montréal (UdeM) explored the capabilities of various devices they patented that produce plasma columns simply and efficiently, using radiofrequency or microwaves. Applications of these devices range from the sterilisation of medical equipment, to purifying noble gases such as xenon for ion-thrusters that ensure the repositioning of communication satellites.

A combination of dwindling oil reserves and increasing pollution means that the plastic industry must be urgently transformed before it’s too late. The efforts of researchers, including Dr Jinwen Zhang and his colleagues at Washington State University, mean that solutions are becoming increasingly available. Through the development of malleable and self-healable plastics, created from both existing petrochemical and renewable chemical feedstocks, Dr Zhang’s team is creating stronger, more resilient plastics that can be easily recycled.