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Quasicrystals Grow Smoothly Around Obstacles

Large-scale obstacles to crystal growth can throw the whole lattice off kilter, but quasicrystals can accommodate them without losing their atomic-scale order.

When a growing crystal encounters an obstacle, the orderly array of atoms may have to adjust in ways that create lattice defects or large-scale rearrangements. But a research team has found through experiments that peculiar materials called quasicrystals can take such disruptions in stride [1] The quasicrystalline lattice, which is orderly but not periodic, can accommodate obstacles without sacrificing its order, thanks to a type of rearrangement unique to quasicrystals. The work suggests the possibility of making quasicrystalline metal alloys that are more durable than conventional alloys.

Quasicrystals, discovered in 1984, are typically compounds composed of metals such as aluminum, nickel, and manganese. X-ray diffraction seems to show that their atomic lattices have symmetries that aren’t permitted in conventional crystals, such as pentagonal or decagonal symmetry. But these symmetries can exist in small regions because quasicrystals are not conventional crystals—you can’t shift the atomic lattice in space and then superimpose it exactly on the original lattice.

Shocking Discovery About Earth’s Magnetosphere Challenges Decades of Theory

The area of space influenced by Earth’s magnetic field is called the magnetosphere. Within this protective bubble, scientists have observed an electric force that moves from the morning side of the planet toward the evening side. This vast electric field plays a crucial role in generating disturbances in near-Earth space, including geomagnetic storms.

Because electric forces move from positive to negative charges, researchers once believed that the morning side of the magnetosphere carried a positive charge while the evening side was negative. However, new satellite data has revealed the reverse: the morning side is actually negatively charged, and the evening side is positively charged.

This unexpected finding led a research group from Kyoto University, Nagoya University, and Kyushu University to take a closer look at the mechanisms that shape the magnetosphere.

China Brought Something Unexpected Back From The Far Side of The Moon

Dust from the far side of the Moon has yielded an unexpected microscopic treasure we’ve never seen before.

A close examination of lunar material collected during the China National Space Administration’s Chang’e-6 mission revealed specks of dust from a kind of water-bearing meteorite so fragile it seldom survives the trip through Earth’s atmosphere.

It’s the first confirmed debris of a type of meteorite known as Ivuna-type carbonaceous chondrite – or CI chondrite – ever to be found on the Moon, demonstrating that fragile, water-bearing asteroids can leave microscopic traces embedded in the lunar regolith.

Chinese researchers use FAST to capture millisecond-scale radio bursts from starspot regions

A Chinese research team using the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), dubbed the “China Sky Eye,” has for the first time unambiguously detected millisecond-scale radio bursts from starspot regions. This creates a new way to directly probe small-scale stellar magnetic fields and shed light on the origins of stellar magnetic activity, according to the research team on Sunday.

The research team, led by Professor Tian Hui from the School of Earth and Space Sciences, Peking University recently published its findings in Science Advances.

This study has filled a long-standing gap in the understanding of small-scale magnetic fields on stars beyond the solar system and provides new insights into the mechanisms behind their coronal eruptions and space weather activity, the team said.

Time-delay snapshots enable scientists to identify dynamics in chaotic systems

Many of the world’s most important systems, such as the atmosphere, turbulent fluids, and even the motion of planets, behave unpredictably due to chaos and noise. Scientists often study these systems through their “invariant” measures, long-term statistical behaviors, rather than individual paths. While useful, these measures have a fundamental limitation: completely different systems can share the same statistics, making it impossible to identify the underlying dynamics.

Researchers led by mathematician Yunan Yang have introduced a new way forward, using time-delay snapshots. Their work, “Invariant Measures in Time-Delay Coordinates for Unique Dynamical System Identification,” was published in Physical Review Letters on Oct. 17.

An invariant measure is a way of assigning size or probability to parts of a system that remain unchanged when the system is transformed or evolves. Time-delay snapshots use invariant measures that are expressed in time-delay coordinates—linking present observations to their past values—and providing enough information to distinguish between systems.

AGI is still a decade away

Reinforcement learning is terrible — but everything else is worse.

Karpathy’s sharpest takes yet on AGI, RL, and the future of learning.

Andrej Karpathy’s vision of AGI isn’t a bang — it’s a gradient descent through human history.

Karpathy on AGI & Superintelligence.

* AGI won’t be a sudden singularity — it will blend into centuries of steady progress (~2% GDP growth).

* Superintelligence is uncertain and likely gradual, not an instant “explosion.”

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