Sunday, March 08, 2026

Scientists unveil universal aging mechanism in glassy materials

Chinese Academy of Sciences Headquarters

"Glass" has a unique and distinct meaning in physics—one that refers not just to the transparent material we associate with window glass. Instead, it refers to any system that looks solid but is not in true equilibrium and continues to change extremely slowly over time. Examples include window glass, plastics, metallic glasses, spin glasses (i.e., magnetic systems), and even some biological and computational systems.

When a liquid is cooled very quickly—a process called quenching—it doesn't have time to organize into a crystal but becomes stuck in a disordered state far from equilibrium. Its properties—like stiffness and structure—slowly evolve through a process called "aging."

Now, a research team from the Institute of Theoretical Physics of the Chinese Academy of Sciences has proposed a new theoretical framework for understanding the universal aging behavior of glassy materials.

The study reveals a fundamental mechanism that governs how glasses—from simple spin systems to complex network glasses such as amorphous silica—slowly evolve over time.

To understand the aging process, the researchers developed a generalized trap model (GTM) grounded in the material's energy landscape: a multidimensional map of all possible configurations and the energy barriers that separate them. According to the GTM, aging is driven by activated hopping across these energy barriers. A universal distribution of barrier heights, incorporating crucial finite-size corrections, governs the system's slow, nonequilibrium dynamics.

The theory predicts that during nonequilibrium aging, the system undergoes "weak ergodicity breaking" at a temperature higher than the conventional glass transition temperature. In statistical physics, "ergodic" refers to a system that explores all possible configurations consistent with its energy. In contrast, the term "ergodicity breaking" refers to an equilibrium system becoming trapped in a subset of possible states, unable to explore all configurations. Weak ergodicity breaking occurs in nonequilibrium systems and describes a system that continues to evolve but remains correlated with its initial configuration even after prolonged aging.

By applying the GTM to four distinct models, including the random energy model (a spin glass), the Weeks-Chandler-Andersen model (a simple atomic glass), and amorphous silica (a network glass), the researchers demonstrated that glass aging behavior follows universal mathematical laws. A key finding is that the logarithmic decay of the two-time correlation function, a hallmark of aging, is directly linked to the finite size of "activation clusters," or groups of particles that rearrange together during the aging process.

In the Weeks-Chandler-Andersen model, this insight allowed the researchers to extract a static length scale from the nonequilibrium dynamics, extending its observable growth range from a mere factor of two to three to a full order of magnitude. This provides strong supporting evidence for the random first-order transition (RFOT) theory, a leading theory of the glass transition.

This work provides a unified phase diagram that describes both ergodic and weakly non-ergodic phases in spin and structural glasses, offering a powerful tool for understanding these ubiquitous yet complex materials. These findings have implications not only for materials science but also for other complex systems, such as protein dynamics and even the training of deep learning algorithms, where similar slow relaxation processes are observed.

Journal

Science Advances

DOI

10.1126/sciadv.aec4416

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Universal activated aging and weak ergodicity breaking in spin and structural glasses

Forest Damage In Europe To Rise By Around 20% By 2100 Even If Warming Is Limited To 2°C

March 8, 2026

By Eurasia Review

Forest damage in Europe caused by wildfires, storms and bark beetle outbreaks is projected to increase compared to recent decades under all analysed climate scenarios, according to a new international study, published in the scientific journal Science, with contributions from the Potsdam Institute for Climate Impact Research (PIK).

Even in a scenario with warming limited to roughly 2°C, annually disturbed forest area could rise from about 180,000 to roughly 216,000 hectares per year by the end of the century, compared to the already unprecedented levels of disturbances from 1986 to 2020. In a scenario in which fossil fuel use continues to increase, annually disturbed forest area could double, reaching nearly 370,000 hectares per year by the end of the century.

“In the future, Europe’s forests are likely to absorb less carbon,” says Christopher Reyer, scientist at PIK and co-author of the study. “If forests take up less carbon, or potentially even release more than they absorb, this increases pressure on other sectors such as transport and agriculture to reduce their emissions more rapidly. At the same time, forest management needs to focus more strongly on building resilient forests.”

According to the study, forests in Southern and Western Europe will be particularly affected and will undergo the strongest changes in forest disturbance. Northern Europe is expected to be less severely impacted overall, though hotspots of future forest damage are also likely to emerge there. The study was led by researchers at the Technical University of Munich (TUM).

Canadian drinking water at risk long after wildfires, UBC study warns

University of British Columbia

Canada’s drinking water can remain at risk long after wildfires burn out, according to a UBC-led global review that found water-quality impacts often emerge months or years later—not just immediately after a fire.

Researchers analyzed 23 studies across 28 watersheds worldwide, comparing pre- and post-fire levels of sediment, nutrients, metals, organic carbon, ions and wildfire-fighting chemicals. Across climates, contamination often intensified over time, particularly when storms or snowmelt washed stored ash and debris into rivers.

The findings carry particular weight for Canada, where wildfire activity has intensified. In 2023, over 15 million hectares burned, more than twice the previous national record.

Alberta studies show long-lasting impacts

The review focused on studies tracking water quality for at least six months to determine whether impacts fade or grow.

“The same delayed contamination pattern kept appearing,” said Raúl de León Rábago, study author and master’s student in civil engineering.

After the 2016 Fort McMurray wildfire, rivers showed elevated sediment, nitrogen, phosphorus and lead even where less than one-quarter of the watershed had burned. The Regional Municipality of Wood Buffalo increased annual treatment chemical spending by roughly $500,000 to manage wildfire-related changes in raw water.

In Alberta’s southern Rockies following the 2003 Lost Creek wildfire, phosphorus and nitrogen remained high for years. Floods in 2013 washed stored ash and soil back into rivers, causing phosphorus levels to jump to seven to nine times higher, with some increases persisting more than 14 years downstream. Similar long-term effects have been documented internationally.

“Imagine emptying a bucket of ash into a bathtub,” said Dr. Qingshi Tu, assistant professor in the faculty of forestry and environmental stewardship. “When the water is stirred, the ash resurfaces. That’s what can happen in watersheds after large fires.”

Smoke and firefighting chemicals add to risk

Across the reviewed studies, wildfire activity increased sediment, nutrients, heavy metals and polycyclic aromatic hydrocarbons—chemicals formed when vegetation and other materials burn. Smoke can also carry contaminants into unburned watersheds.

Canada relies heavily on long-term fire retardants such as Phos-Chek in B.C. and Alberta. These products contain nutrients and trace metals that can fuel algal blooms and raise treatment costs. After the Fort McMurray wildfire, higher chemical dosing was required to treat wildfire-affected water.

Protecting communities through long-term monitoring

Researchers note that water utilities’ ability to respond depends on fire intensity, duration, size, what burned, weather conditions and treatment system design. Not all systems have equal capacity to adapt, and smaller communities with limited budgets face greater risk from prolonged post-fire impacts.

The team is developing a model linking wildfire behaviour, smoke and river systems to help Canadian utilities anticipate multiyear risks. They say fire-prone provinces such as B.C. and Alberta need coordinated long-term water monitoring and preparedness planning, especially when fires burn near drinking water sources.

“Canada is entering a new era of wildfire risk,” said Dr. Loretta Li, senior author and UBC civil engineering professor. “If we want to protect drinking water, we have to treat wildfire impacts as long-term, not short-term.”