Decomposing the dark matter of sparse autoencoders.
Joshua Engels, Logan Riggs, Max Tegmark MIT 2024 https://arxiv.org/abs/2410.
On mapping concepts in artificial neural networks with sparse autoencoders: we find that map errors exhibit…
Imposing time-dependent strain on a magnetic disk induces vortex dynamics and offers a path toward energy-efficient spintronic devices.
Nanoscopic magnetic vortices made from electron spins could be used in spintronic computers (see Research News: 3D Magnetism Maps Reveal Exotic Topologies). To this end, researchers need an energy-efficient way to excite these vortices into a so-called gyrotropic mode—an orbital motion of the vortex core around the central point. The direction of this orbital motion would determine which of two binary states the vortex represents. Vadym Iurchuk at the Helmholtz-Zentrum Dresden-Rossendorf, Germany, and his colleagues have now demonstrated such a method by imposing a time-varying strain on a magnetic material [1].
The excitation of gyration dynamics by an oscillating strain was suggested by a separate team in 2015 [2]. The idea involves depositing a magnetic film, in which magnetic vortices form spontaneously, on a piezoelectric substrate. Applying an alternating voltage to the substrate transfers a time-varying mechanical strain to the film, dynamically perturbing its magnetic texture. This perturbation displaces a vortex core from its equilibrium position, thereby exciting the gyrotropic mode.
The U.S. National Science Foundation (NSF) Daniel K. Inouye Solar Telescope, the world’s most powerful solar telescope, designed, built, and operated by the NSF National Solar Observatory (NSO), achieved a major breakthrough in solar physics by directly mapping the strength of the magnetic field in the solar corona, the outer part of the solar atmosphere that can be seen during a total eclipse. This breakthrough promises to enhance our understanding of space weather and its impact on Earth’s technology-dependent society.
The corona: the launch pad of space weather.
The Sun’s magnetic field generates regions in the Sun’s atmosphere, often rooted by sunspots, that store vast amounts of energy that fuel explosive solar storms and drive space weather. The corona, the Sun’s outer atmosphere, is a superheated realm where these magnetic mysteries unfold. Mapping coronal magnetic fields is essential to understanding and predicting space weather — and to protect our technology in Earth and space.
Observing anything and everything within the human brain, no matter how large or small, while it is fully intact has been an out-of-reach dream of neuroscience for decades.
Three new innovations from an MIT-based team enables high-resolution, high-throughput imaging of human brain tissue at a full range of scales, and mapping connectivity of neurons at single-cell resolution.
Recently Danielson, Satishchandran, and Wald (DSW) have shown that quantum superpositions held outside of Killing horizons will decohere at a steady rate. This occurs because of the inevitable radiation of soft photons (gravitons), which imprint a electromagnetic (gravitational) “which-path’’ memory onto the horizon. Rather than appealing to this global description, an experimenter ought to also have a local description for the cause of decoherence. One might intuitively guess that this is just the bombardment of Hawking/Unruh radiation on the system, however simple calculations challenge this idea—the same superposition held in a finite temperature inertial laboratory does not decohere at the DSW rate. In this work we provide a local description of the decoherence by mapping the DSW setup onto a worldline-localized model resembling an Unruh-DeWitt particle detector.
For the first time, scientists have taken near-daily measurements of the sun’s global coronal magnetic field, a region of the sun that has only been observed irregularly in the past. The resulting observations are providing valuable insights into the processes that drive the intense solar storms that impact fundamental technologies, and thus lives and livelihoods, here on Earth.
How do the characteristics of Neptune-like exoplanets, also known as exo-Neptunes, differ from each other? This is what a recent study published in Astronomy and Astrophysics hopes to address as an international team of researchers investigated a new classification known as the “Neptunian Ridge”. This complements previous classifications of “Neptunian Desert” and “Neptunian Savannah”, with the former identifying exo-Neptunes that are rare in number but orbit very close to their parent stars while the “Neptune Savannah” describes exo-Neptunes that orbit much farther out. This study holds the potential to help astronomers better understand the formation and evolution of exo-Neptunes throughout the cosmos.
For the study, the researchers used confirmed and candidate exoplanets that comprise the Kepler DR25 catalog to ascertain the characteristic variations in exo-Neptunes while providing additional insights into the formation and evolution of exo-Neptunes, as well. In the end, they determined that this “Neptunian Ridge” exists as a middle-ground between the “Neptunian Desert” and “Neptunian Savannah”, with the former hypothesized to have formed from moving inward in their system from high-eccentricity tidal migration and the latter forming from disk-driven migration, which occurs right after planetary formation.
“Our work to observe this new structure in space is highly significant in helping us map the exoplanet landscape,” said Dr. David Armstrong, who is an Associate Professor of Physics at the University of Warwick and a co-author on the study. “As scientists, we’re always striving to understand why planets are in the condition they are in, and how they ended up where they are. The discovery of the Neptunian ridge helps answer these questions, unveiling part of the geography of exoplanets out there, and is a hugely exciting discovery.”
Randal Koene discusses Whole Brain Emulation on the H+ Magazine podcast. He touches on the subjects of connectomics, neural mapping, optogenetics, and neural prosthesis.
The Allen Institute for Immunology has released its first Human Immune Health Atlas, a comprehensive single-cell reference dataset that offers unprecedented insight into the landscape of healthy human immune cells from childhood through adulthood.
Comprehensive dataset maps the landscape of healthy immune cells across the human lifespan.
Storytelling has evolved beyond mere narration—it’s now about immersion, interaction, and creating a deep emotional connection. Few organizations understand this better than National Geographic, a brand renowned for bringing the natural world to life through visually stunning, fact-driven content. With their latest digital experience, “Into the Amazon,” National Geographic has raised the bar even higher, blending cutting-edge technology with unparalleled storytelling to offer audiences a front-row seat to one of the planet’s most vital ecosystems: the Amazon rainforest.
At a time when the world’s environmental challenges are more pressing than ever, National Geographic’s “Into the Amazon” doesn’t just inform viewers; it transforms how we understand the Amazon’s role in the global ecosystem. This article explores how innovative technologies—such as interactive 3D mapping, augmented reality, and immersive media formats —are being harnessed to deliver a uniquely engaging experience. It also reflects on the broader implications for the future of digital storytelling, where technology and narrative merge to create impactful, lasting impressions.
As digital media continues to dominate, audience expectations have shifted. Passive consumption is no longer enough—today’s audiences crave interaction, engagement, and experiences that go beyond the screen. Immersive storytelling, particularly in the environmental and scientific fields, has emerged as a powerful tool to captivate and educate.
