Neutron stars are some of the densest objects in the universe. They are the core of a collapsed megastar that went supernova, have a typical radius of 10 km—just slightly more than the altitude of Mt. Everest—and their density can be several times that of atomic nuclei.
Physicists love extreme objects like this because they require them to stretch their theories into new realms and see if they are confirmed or if they break, requiring new thinking and new science.
For the first time, researchers have used lattice quantum chromodynamics to study the interior of neutron stars, obtaining a new maximum bound for the speed of sound inside the star and a better understanding of how pressure, temperature and other properties there relate to one another.
Dr. Rumi Chunara: “Our system learns to recognize more subtle patterns that distinguish trees from grass, even in challenging urban environments.”
How can artificial intelligence (AI) help improve city planning to account for more green spaces? This is what a recent study published in the ACM Journal on Computing and Sustainable Societies hopes to address as a team of researchers proposed a novel concept using AI with the goal of both monitoring and improving urban green spaces, which are natural public spaces like parks and gardens, and provide a myriad of benefits, including physical and mental health, combating climate change, wildlife habitats, and increased social interaction.
For the study, the researchers developed a method they refer to as “green augmentation”, which uses an AI algorithm to analyze Google Earth satellite images with the goal of improving current AI methods by more accurately identifying green vegetation like grass and trees under various weather and seasonal conditions. For example, current AI methods identify green vegetation with an accuracy and reliability of 63.3 percent and 64 percent, respectively. Using this new method, the researchers successfully identified green vegetation with an accuracy and reliability of 89.4 percent and 90.6 percent, respectively.
“Previous methods relied on simple light wavelength measurements,” said Dr. Rumi Chunara, who is an associate professor of biostatistics at New York University and a co-author on the study. “Our system learns to recognize more subtle patterns that distinguish trees from grass, even in challenging urban environments. This type of data is necessary for urban planners to identify neighborhoods that lack vegetation so they can develop new green spaces that will deliver the most benefits possible. Without accurate mapping, cities cannot address disparities effectively.”
A new algorithm, Evo 2, trained on roughly 128,000 genomes—9.3 trillion DNA letter pairs—spanning all of life’s domains, is now the largest generative AI model for biology to date. Built by scientists at the Arc Institute, Stanford University, and Nvidia, Evo 2 can write whole chromosomes and small genomes from scratch.
It also learned how DNA mutations affect proteins, RNA, and overall health, shining light on “non-coding” regions, in particular. These mysterious sections of DNA don’t make proteins but often control gene activity and are linked to diseases.
The team has released Evo 2’s software code and model parameters to the scientific community for further exploration. Researchers can also access the tool through a user-friendly web interface. With Evo 2 as a foundation, scientists may develop more specific AI models. These could predict how mutations affect a protein’s function, how genes operate differently across cell types, or even help researchers design new genomes for synthetic biology.
A new formula that connects a material’s magnetic permeability to spin dynamics has been derived and tested 84 years after the debut of its electric counterpart.
If antiferromagnets, altermagnets, and other emerging quantum materials are to be harnessed for spintronic devices, physicists will need to better understand the spin dynamics in these materials. One possible path forward is to exploit the duality between electric and magnetic dynamics expressed by Maxwell’s equations. From this duality, one could naively expect mirror-like similarities in the behavior of electric and magnetic dipoles. However, a profound difference between the quantized lattice electric excitations—such as phonons—and spin excitations—such as paramagnetic and antiferromagnetic spin resonances and magnons—has now been unveiled in terms of their corresponding contributions to the static electric susceptibility and magnetic permeability. Viktor Rindert of Lund University in Sweden and his collaborators have derived and verified a formula that relates a material’s magnetic permeability to the frequencies of magnetic spin resonances [1].
Join cognitive scientist and AI researcher Joscha Bach for an in-depth interview on the nature of consciousness, in which he argues that the brain is hardware, consciousness its software and that, in order to understand our reality, we must unlock the algorithms of consciousness.
So, to put it in a very straightforward way – the term “AI agents” refers to a specific application of agentic AI, and “agentic” refers to the AI models, algorithms and methods that make them work.
Why Is This Important?
AI agents and agentic AI are two closely related concepts that everyone needs to understand if they’re planning on using technology to make a difference in the coming years.
In the late 1960s, physicists like Charles Misner proposed that the regions surrounding singularities—points of infinite density at the centers of black holes—might exhibit chaotic behavior, with space and time undergoing erratic contractions and expansions. This concept, termed the “Mixmaster universe,” suggested that an astronaut venturing into such a black hole would experience a tumultuous mixing of their body parts, akin to the action of a kitchen mixer.
S general theory of relativity, which describes the gravitational dynamics of black holes, employs complex mathematical formulations that intertwine multiple equations. Historically, researchers like Misner introduced simplifying assumptions to make these equations more tractable. However, even with these assumptions, the computational tools of the time were insufficient to fully explore the chaotic nature of these regions, leading to a decline in related research. + Recently, advancements in mathematical techniques and computational power have reignited interest in studying the chaotic environments near singularities. Physicists aim to validate the earlier approximations made by Misner and others, ensuring they accurately reflect the predictions of Einsteinian gravity. Moreover, by delving deeper into the extreme conditions near singularities, researchers hope to bridge the gap between general relativity and quantum mechanics, potentially leading to a unified theory of quantum gravity.
Understanding the intricate and chaotic space-time near black hole singularities not only challenges our current physical theories but also promises to shed light on the fundamental nature of space and time themselves.
Physicists hope that understanding the churning region near singularities might help them reconcile gravity and quantum mechanics.
Have you ever questioned the deep nature of time? While some physicists argue that time is just an illusion, dismissing it outright contradicts our lived experience. In my latest work, Temporal Mechanics: D-Theory as a Critical Upgrade to Our Understanding of the Nature of Time (2025), I explore how time is deeply rooted in the computational nature of reality and information processing by conscious systems. This paper tackles why the “now” is all we have.
In the absence of observers, the cosmic arrow of time doesn’t exist. This statement is not merely philosophical; it is a profound implication of the problem of time in physics. In standard quantum mechanics, time is an external parameter, a backdrop against which events unfold. However, in quantum gravity and the Wheeler-DeWitt equation, the problem of time emerges because there is no preferred universal time variable—only a timeless wavefunction of the universe. The flow of time, as we experience it, arises not from any fundamental law but from the interaction between observers and the informational structure of reality.