Lifeboat Foundation

A team of physicists from the University of Konstanz and Ludwig-Maximilians-Universität München in Germany have achieved attosecond time resolution in a transmission electron microscope by combining it with a continuous-wave laser—offering new insights into light-matter interactions.

Electron microscopes provide deep insight into the smallest details of matter and can reveal, for example, the atomic configuration of materials, the structure of proteins or the shape of virus particles. However, most materials in nature are not static and rather interact, move and reshape all the time. One of the most common phenomena is the interaction between light and matter, which is ubiquitous in plants as well as in optical components, solar cells, displays or lasers. These interactions—which are defined by electrons being moved around by the field cycles of a light wave—happen at ultrafast time scales of femtoseconds (10^-15 seconds) or even attoseconds (10^-18 seconds, a billionth of a billionth of a second). While ultrafast electron microscopy can provide some insight into femtosecond processes, it has not been possible, until now, to visualize the reaction dynamics of light and matter occurring at attosecond speeds.

Now, a team of physicists from the University of Konstanz and Ludwig-Maximilians-Universität München have succeeded in combining a transmission electron microscope with a continuous-wave laser to create a prototypical attosecond electron microscope (A-TEM). The results are reported in the latest issue of Science Advances.

Most materials used for optical lighting applications need to produce a uniform illumination and require high mechanical and hydrophobic properties. However, they are rarely eco-friendly. Herein, a bio-based, polymer matrix-free, luminescent, and hydrophobic film with excellent mechanical properties for optical lighting purposes is demonstrated. A template is prepared by turning a wood veneer into porous scaffold from which most of the lignin and half of the hemicelluloses are removed. The infiltration of quantum dots (CdSe/ZnS) into the porous template prior to densification resulted in almost uniform luminescence (isotropic light scattering) and could be extended to various quantum dot particles, generating different light colors. In a subsequent step, the luminescent wood film is coated with hexadecyltrimethoxysilane (HDTMS) via chemical vapor deposition. The presence of the quantum dots coupled with the HDTMS coating renders the film hydrophobic (water contact angle ≈ 140°). This top-down process strongly eliminates lumen cavities and preserves the orientation of the original cellulose fibrils to create luminescent and polymer matrix-free films with high modulus and strength in the direction of fibers. The proposed optical lighting material could be attractive for interior designs (e.g., lamps and laminated cover panels), photonics, and laser devices.

In a story of lost and stolen books and scrupulous detective work across continents, a Caltech historian and his former student have unearthed previously uncounted copies of Isaac Newton’s groundbreaking science book Philosophiae Naturalis Principia Mathematica, known more colloquially as the Principia. The new census more than doubles the number of known copies of the famous first edition, published in 1687. The last census of this kind, published in 1953, had identified 187 copies, while the new Caltech survey finds 386 copies. Up to 200 additional copies, according to the study authors, likely still exist undocumented in public and private collections.

“We felt like Sherlock Holmes,” says Mordechai (Moti) Feingold, the Kate Van Nuys Page Professor of the History of Science and the Humanities at Caltech, who explains that he and his former student, Andrej Svorenčík (MS ‘08) of the University of Mannheim in Germany, spent more than a decade tracing copies of the book around the world. Feingold and Svorenčík are co-authors of a paper about the survey published in the journal Annals of Science.

Moreover, by analyzing ownership marks and notes scribbled in the margins of some of the books, in addition to related letters and other documents, the researchers found evidence that the Principia, once thought to be reserved for only a select group of expert mathematicians, was more widely read and comprehended than previously thought.

His “Spacesuit Lunar Toilet” can fit snugly into a spacesuit and beat almost 900 other entries worldwide.

Zyson Kang, 9, beat some 900 other children with his ‘Spacesuit Lunar Toilet’ invention to win NASA’s Lunar Loo Challenge.

Earth’s earliest beginnings from magma oceans to continents with elephants and oceans with Orcas can arguably be traced to the rise of Oxygen. That’s the topic of this week’s episode. Please have a listen.

From Pachyderms to Cetaceans, the largest mammals on Earth would arguably never have evolved to their gargantuan sizes without the third most abundant element in the Cosmos — Oxygen. Of course, life, even photosynthesis is possible without Oxygen, but for the cosmos to evolve the big-headed space aliens of our sci-fi dreams will likely take Oxygen — the most efficient energy carrier in the periodic table. How Oxygen became dominant on our own planet is the focus of today’s episode with guest Timothy Lyons, a biogeochemist at the University of California, Riverside.

Continue reading “Episode 24 --- How Oxygen Transformed Our Planet Earth” »

An international team of scientists have unveiled the world’s first production of a purified beam of neutron-rich, radioactive tantalum ions. This development could now allow for lab-based experiments on exploding stars helping scientists to answer long-held questions such as “where does gold come from?”

In a paper published in Physical Review Letters, the University of Surrey together with its partners detail how they used a new isotope-separation facility, called KISS, which is developed and operated by the Wako Nuclear Science Centre (WNSC) in the High Energy Accelerator Research Organization (KEK), Japan, to make beams of heavy tantalum isotopes.

The chemical element of tantalum is extremely difficult to vaporize, so the team had to capture radioactive tantalum atoms in high-pressure argon gas, ionizing the atoms with precisely tuned lasers. A single isotope of radioactive tantalum could then be selected for detailed investigation.

Scientists have long sought a system for predicting the properties of materials based on their chemical composition. In particular, they set sights on the concept of a chemical space that places materials in a reference frame such that neighboring chemical elements and compounds plotted along its axes have similar properties. This idea was first proposed in 1984 by the British physicist, David G. Pettifor, who assigned a Mendeleev number (MN) to each element. Yet the meaning and origin of MNs were unclear. Scientists from the Skolkovo Institute of Science and Technology (Skoltech) puzzled out the physical meaning of the mysterious MNs and suggested calculating them based on the fundamental properties of atoms. They showed that both MNs and the chemical space built around them were more effective than empirical solutions proposed until then. Their research supported by a grant from the Russian Science Foundation’s (RSF) World-class Lab Research Presidential Program was presented in The Journal of Physical Chemistry C.

Systematizing the enormous variety of chemical compounds, both known and hypothetical, and pinpointing those with a particularly interesting property is a tall order. Measuring the properties of all imaginable compounds in experiments or calculating them theoretically is downright impossible, which suggests that the search should be narrowed down to a smaller space.

David G. Pettifor put forward the idea of chemical space in the attempt to somehow organize the knowledge about material properties. The chemical space is basically a reference frame where elements are plotted along the axes in a certain sequence such that the neighboring elements, for instance, Na and K, have similar properties. The points within the space represent compounds, so that the neighbors, for example, NaCl and KCl, have similar properties, too. In this setting, one area is occupied by superhard materials and another by ultrasoft ones. Having the chemical space at hand, one could create an algorithm for finding the best material among all possible compounds of all elements. To build their “smart” map, Skoltech scientists, Artem R. Oganov and Zahed Allahyari, came up with their own universal approach that boasts the highest predictive power as compared to the best-known methods.

ReVector researchers have expertise in synthetic biology, human microbiome, and mosquito studies.

The American Society for Microbiology estimates that there are trillions of microbes living in or on the human body that constitute the human microbiome¹. The human skin microbiome (HSM) acts as a barrier between humans and our external environment, protecting us from infection, but also potentially producing molecules that attract mosquitos. Mosquitos are of particular concern to the Department of Defense, as they transmit pathogens that cause diseases such as chikungunya, Zika, dengue, West Nile virus, yellow fever, and malaria. The ReVector program aims to maintain the health of military personnel operating in disease-endemic regions by reducing attraction and feeding by mosquitos, and limiting exposure to mosquito-transmitted diseases.

Genome engineering has progressed to the point where editing the HSM to remove the molecules that attract mosquitos or add genes that produce mild mosquito repellants are now possible. While the skin microbiome has naturally evolved to modulate our interactions with the environment and organisms that surround us, exerting precise control over our microbiomes is an exciting new way to provide protection from mosquito-borne diseases.

Continue reading “DARPA Selects Teams to Modify Skin Microbiome for Disease Prevention” »

DARPA recently awarded contracts to five companies to develop algorithms enabling mixed teams of manned and unmanned combat aircraft to conduct aerial dogfighting autonomously.

Boeing, EpiSci, Georgia Tech Research Institute, Heron Systems, and physicsAI were chosen to develop air combat maneuvering algorithms for individual and team tactical behaviors under Technical Area (TA) 1 of DARPA’s Air Combat Evolution (ACE) program. Each team is tasked with developing artificial intelligence agents that expand one-on-one engagements to two-on-one and two-on-two within-visual-range aerial battles. The companies’ algorithms will be tested in each of three program phases: modeling and simulation, sub-scale unmanned aircraft, and full-scale combat representative aircraft scheduled in 2023.

“The TA1 performers include a large defense contractor, a university research institute, and boutique AI firms, who will build upon the first-gen autonomous dogfighting algorithms demonstrated in the AlphaDogfight Trials this past August,” said Air Force Col. Dan “Animal” Javorsek, program manager in DARPA’s Strategic Technology Office. “We will be evaluating how well each performer is able to advance their algorithms to handle individual and team tactical aircraft behaviors, in addition to how well they are able to scale the capability from a local within-visual-range environment to the broader, more complex battlespace.”