Lifeboat Foundation

Nuclear physicists have found a new way to use the Relativistic Heavy Ion Collider (RHIC)—a particle collider at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory—to see the shape and details inside atomic nuclei. The method relies on particles of light that surround gold ions as they speed around the collider and a new type of quantum entanglement that’s never been seen before.

Through a series of quantum fluctuations, the particles of light (a.k.a. photons) interact with gluons—gluelike particles that hold quarks together within the protons and neutrons of nuclei. Those interactions produce an intermediate particle that quickly decays into two differently charged “pions” (π). By measuring the velocity and angles at which these π⁺ and π^- particles strike RHIC’s STAR detector, the scientists can backtrack to get crucial information about the photon—and use that to map out the arrangement of gluons within the nucleus with higher precision than ever before.

“This technique is similar to the way doctors use positron emission tomography (PET scans) to see what’s happening inside the brain and other body parts,” said former Brookhaven Lab physicist James Daniel Brandenburg, a member of the STAR collaboration who joined The Ohio State University as an assistant professor in January 2023. “But in this case, we’re talking about mapping out features on the scale of femtometers —quadrillionths of a meter—the size of an individual proton.”

2548–2530 BC. Egyptian Museum in Cairo, Egypt.

This Menkaure Triad is the most important piece of the entire set of statues found by George Reisner in the vicinity of the Giza temple. The sculpture stood out from the beginning for its realism, excellence, and austere beauty, qualities that have made it one of the most emblematic works of the Cairo Museum.

During excavations in Giza in 1908, the American Egyptologist George Reisner located diverse sculptural works of magnificent craftsmanship buried next to the temple of Menkaure.

What’s a message, really? Claude Shannon recognized that the elemental ingredient is surprise.

Using radar commonly deployed to track speeders and fastballs, researchers have developed an automated system that will allow cars to peer around corners and spot oncoming traffic and pedestrians.

The system, easily integrated into today’s vehicles, uses Doppler radar to bounce radio waves off surfaces such as buildings and parked automobiles. The radar signal hits the surface at an angle, so its reflection rebounds off like a cue ball hitting the wall of a pool table. The signal goes on to strike objects hidden around the corner. Some of the radar signal bounces back to detectors mounted on the car, allowing the system to see objects around the corner and tell whether they are moving or stationary.

“This will enable cars to see occluded objects that today’s lidar and camera sensors cannot record, for example, allowing a self-driving vehicle to see around a dangerous intersection” said Felix Heide, an assistant professor of computer science at Princeton University and one of researchers. “The radar sensors are also relatively low-cost, especially compared to lidar sensors, and scale to mass production.”

Amazon is laying off 18,000 employees, the tech giant said Wednesday, representing the single largest number of jobs cut at a technology company since the industry began aggressively downsizing last year.

In a blog post, Amazon CEO Andy Jassy wrote that the staff reductions were set off by the uncertain economy and the company’s rapid hiring over the last several years.

The cuts will primarily hit the company’s corporate workforce and will not affect hourly warehouse workers. In November, Amazon had reportedly been planning to lay off around 10,000 employees but on Wednesday, Jassy pegged the number of jobs to be shed by the company to be higher than that, as he put it, “just over 18,000.”

The so-called “Father of the Atomic Bomb” J. Robert Oppenheimer was once described as “a genius of the nuclear age and also the walking, talking conscience of science and civilization”. Born at the outset of the 20th century, his early interests in chemistry and physics would in the 1920s bring him to Göttingen University, where he worked alongside his doctoral supervisor Max Born (1882−1970), close lifelong friend Paul Dirac (1902−84) and eventual adversary Werner Heisenberg (1901−76). This despite the fact that even as early as in his youth, Oppenheimer was singled out as both gifted and odd, at times even unstable. As a child he collected rocks, wrote poetry and studied French literature. Never weighing more than 130 pounds, throughout his life he was a “tall and thin chainsmoker” who once stated that he “needed physics more than friends” who at Cambridge University was nearly charged with attempted murder after leaving a poisoned apple on the desk of one of his tutors. Notoriously abrupt and impatient, at Göttingen his classmates once gave their professor Born an ultimatum: “either the ‘child prodigy’ is reigned in, or his fellow students will boycott the class”. Following the successful defense of his doctoral dissertation, the professor administering the examination, Nobel Laureate James Franck (1882−1964) reportedly left the room stating.

“I’m glad that’s over. He was at the point of questioning me”

From his time as student at Harvard, to becoming a postgraduate researcher in Cambridge and Göttingen, a professor at UC Berkeley, the scientific head of the Manhattan project and after the war, the Director of the Institute for Advanced Study, wherever Oppenheimer went he could hold his own with the greatest minds of his age. Max Born, Paul Dirac, John von Neumann, Niels Bohr, Albert Einstein, Kurt Gödel, Richard Feynman, they all admired “Oppie”. When he died in 1967, his published articles in physics totaled 73, ranging from topics in quantum field theory, particle physics, the theory of cosmic radiations to nuclear physics and cosmology. His funeral was attended by over 600 people, and included numerous associates from academia and research as well as government officials, heads of military, even the director of the New York City Ballet.

Researchers from Carnegie Mellon University and the Chinese University of Hong Kong have developed a strategy for creating ultrahigh-resolution, complex 3D nanostructures out of various materials.

Carnegie Mellon University’s Yongxin (Leon) Zhao and the Chinese University of Hong Kong’s Shih-Chi Chen have a big idea for manufacturing nanodevices.

Continue reading “Shrinking hydrogels enlarge nanofabrication options” »

Many applications, from fiber-optic telecommunications to biomedical imaging processes require substances that emit light in the near-infrared range (NIR). A research team in Switzerland has now developed the first chromium complex that emits light in the coveted, longer wavelength NIR-II range. In the journal Angewandte Chemie, the team has introduced the underlying concept: a drastic change in the electronic structure of the chromium caused by the specially tailored ligands that envelop it.

Many materials that emit NIR light are based on expensive or rare metal complexes. Cheaper alternatives that emit in the NIR-I range between 700 and 950 nm have been developed but NIR-II-emitting complexes of non–precious metals remain extremely rare. Luminescence in the NIR-II range (1000 to 1,700 nm) is, for example, particularly advantageous for in vivo imaging because this light penetrates very far into tissues.

The luminescence of complexes is based on the excitement of electrons, through the absorption of light, for example. When the excited electron drops back down to its ground state, part of the energy is emitted as radiation. The wavelength of this radiation depends on the energetic differences between the electronic states. In complexes, these are significantly determined by the type and arrangement of the ligands bound to the metal.

Chemists from Rice University and the University of Texas at Austin discovered more isn’t always better when it comes to packing charge-acceptor molecules on the surface of semiconducting nanocrystals.

The combination of organic and inorganic components in hybrid nanomaterials can be tailored to capture, detect, convert or control light in unique ways. Interest in these materials is high, and the pace of scientific publication about them has grown more than tenfold over the past 20 years. For example, they could potentially improve the efficiency of solar power systems by harvesting energy from wavelengths of sunlight—like infrared—that are missed by traditional photovoltaic solar panels.

To create the materials, chemists marry nanocrystals of light-capturing semiconductors with “charge acceptor” molecules that act as ligands, attaching to the semiconductor’s surface and transporting electrons away from the nanocrystals.