Lifeboat Foundation

The first dark comet—a celestial object that looks like an asteroid but moves through space like a comet—was reported less than two years ago. Soon after, another six were found. In a new paper, researchers announce the discovery of seven more, doubling the number of known dark comets, and find that they fall into two distinct populations: larger ones that reside in the outer solar system and smaller ones in the inner solar system, with various other traits that set them apart.

The findings were published on Monday, Dec. 9, in the Proceedings of the National Academy of Sciences.

Scientists got their first inkling that dark comets exist when they noted in a March 2016 study that the trajectory of “asteroid” 2003 RM had moved ever so slightly from its expected orbit. That deviation couldn’t be explained by the typical accelerations of asteroids, like the small acceleration known as the Yarkovsky effect.

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NASA has been monitoring an anomaly in Earth’s magnetic field, growing 40,000 miles above the planet’s surface between South America and southwest Africa.

This behavior highlights a critical issue: even systems designed for seemingly harmless tasks can produce unforeseen outcomes when granted enough autonomy.

The challenges posed by AI today are reminiscent of automated trading systems in financial markets. Algorithms designed to optimize trades have triggered flash crashes —sudden, extreme market volatility occurring within seconds, too fast for human intervention to correct.

Similarly, modern AI systems are built to optimize tasks at extraordinary speeds. Without robust controls, their growing complexity and autonomy could unleash consequences no one anticipated—just as automated trading once disrupted financial markets.

Using the X-shooter instrument at ESO’s Very Large Telescope (VLT), German astronomers have detected three new pre-white dwarfs, which turned out to be strongly hydrogen-deficient. The finding was reported in a research paper published December 20 on the pre-print server arXiv.

White dwarfs (WDs) are stellar cores left behind after a star has exhausted its nuclear fuel. Due to their high gravity, they are known to have atmospheres of either pure hydrogen or pure helium. However, a small fraction of WDs shows traces of heavier elements.

Although WDs have a relatively small size, comparable to that of the Earth, they are a few million times more massive than our planet. Pre-white dwarfs (PWDs) are a few times larger and slated to shrink in size, eventually becoming WDs within about a few thousand years.

Rous sarcoma virus, a pioneering discovery in cancer research, sheds light on how certain viruses can trigger uncontrolled cell growth, a hallmark of cancer.

Virtually all of Puerto Rico woke up on New Year’s Eve to find there was no electricity, as a power outage hit the U.S. territory.

Plus: Bytedance’s $7 billion loophole, AI-enabled robo-surgeons, the U.S. Treasury hack, and an IBM antitrust probe—in the latest edition of Fortune’s flagship tech newsletter.

When quantum electrodynamics, the quantum field theory of electrons and photons, was being developed after World War II, one of the major challenges for theorists was calculating a value for the Lamb shift, the energy of a photon resulting from an electron transitioning from one hydrogen hyperfine energy level to another.

The effect was first detected by Willis Lamb and Robert Retherford in 1947, with the emitted photon having a frequency of 1,000 megahertz, corresponding to a photon wavelength of 30 cm and an energy of 4 millionths of an electronvolt—right on the lower edge of the microwave spectrum. It came when the one electron of the hydrogen atom transitioned from the 2P_1/2 energy level to the 2S_1/2 level. (The leftmost number is the principal quantum number, much like the discrete but increasing circular orbits of the Bohr atom.)

Conventional quantum mechanics didn’t have such transitions, and Dirac’s relativistic Schrödinger equation (naturally called the Dirac equation) did not have such a hyperfine transition either, because the shift is a consequence of interactions with the vacuum, and Dirac’s vacuum was a “sea” that did not interact with real particles.

A new study shows that intelligence is best predicted by global brain connectivity, not just specific regions, indicating a more holistic neural basis for cognition. They examined fluid, crystallized, and general intelligence using fMRI data, finding that general intelligence had the strongest predictive power.

The human brain is the central organ that controls our body. It processes sensory information and enables us to think, make decisions, and store knowledge. Despite its remarkable capabilities, it is paradoxical how much remains unknown about this intricate organ.

Jonas Thiele and Dr. Kirsten Hilger, who leads the “Networks of Behavior and Cognition” research group at the Department of Psychology I at Julius-Maximilians-Universität Würzburg (JMU), are dedicated to unraveling the mysteries of the brain. Their latest research has been published in the scientific journal PNAS Nexus.