Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog – Page 4

Get the latest international news and world events from around the world.

Log in for authorized contributors

NASA finds extreme star collision in unlikely spot

A fleet of NASA missions has likely uncovered a collision between two ultradense stars in a tiny galaxy buried in a huge stream of gas. Astronomers have never seen this type of explosive event in an environment like this before—and it may help solve two outstanding cosmic mysteries. A paper describing these results is forthcoming in The Astrophysical Journal Letters and currently available on the arXiv preprint server.

Neutron stars are the cores left behind after a star much heavier than the sun runs out of fuel, collapses on itself, and then explodes. They are small (only a dozen or so miles across) but slightly more massive than the sun, making them amazingly dense. Astronomers consider them to be some of the most extreme objects in the universe.

In recent years, astronomers have collected data on collisions, or mergers, of two neutron stars inside of moderately sized or large galaxies. This latest discovery, however, shows that a neutron star collision may take place inside a tiny galaxy.

Resolving Barrier Crossing in Protein Folding

High-temporal-resolution fluorescence measurements reveal how quickly proteins cross energy barriers separating unfolded and folded states.

Proteins are the active molecules of life. To carry out their functions, they adopt specific structures, or “folds.” Biophysicists have long been fascinated by the “protein-folding problem”: How does the sequence of amino-acid building blocks encode the protein’s ultimate fold, and how can folding occur so quickly and reliably? The folding process can be understood as a diffusive random walk through the large space of possible configurations, culminating in the crossing of an energy barrier to reach the folded state. The time spent exploring unfolded configurations can span many orders of magnitude and has been measured with various experimental techniques. By contrast, the comparatively short time to ultimately cross the energy barrier—known as the transition-path time—had never been measured in a naturally occurring protein under biologically relevant conditions.

Ultrafast computing: Light-driven logic tops 10 terahertz in WS₂

The future for our computers will literally be at the speed of light. Extremely short light pulses can perform ultrafast logical operations: these are the findings of a study recently published in the journal Nature Photonics. The study represents an important step toward developing a new generation of information processing technologies, potentially hundreds of times faster than what we have at present.

Today’s computers rely on the movement of electrical charges inside transistors; however, these can only achieve a maximum frequency whose physical limits are hard to overcome. Unlike traditional electronics, based on the movement of electric charges, this innovative approach manipulates the state of electrons in matter by the use of oscillating light.

As Giulio Cerullo of the Politecnico di Milano explained, “We have shown that light can be used not only to transmit information, but also to process it. With the use of ultra-short laser pulses, we can control the quantum states of matter on time scales of a few millionths of a billionth of a second, i.e. at the same frequencies as light oscillations, speeds previously unknown in electronics.” These operations are performed at rates above 10 terahertz, over a hundred times faster than the best modern electronic devices.

Hybrid synthetic strategy unlocks previously unattainable molecular architectures

The molecular-scale design of materials is one of the major frontiers in modern science. Flat, highly conjugated organic molecules are already used in advanced technologies such as chemical sensors, optoelectronic devices, and energy conversion systems. One of the most promising strategies to enhance their performance involves “linking” multiple units together, extending their electronic structure and thereby modifying their properties.

However, as these architectures grow in complexity, their synthesis becomes extremely challenging. In many cases, the molecules lose solubility and become nearly inaccessible through traditional solution-based methods. This limitation has hindered the construction of increasingly large and functional molecular structures for years.

Research led by Luis M. Mateo and Diego Peña at the Center for Research in Biological Chemistry and Molecular Materials (CiQUS) has overcome this barrier using a hybrid strategy. First, they synthesize carefully designed phthalocyanine units in solution. These units are then deposited onto a metal surface, where they react with each other to form a new extended structure composed of five cross-shaped, fused phthalocyanines. This approach combines the precision of classical solution chemistry with the possibilities offered by on-surface synthesis under controlled conditions.

Unexpected magnetic response in gold and silver atomic contacts contradicts previous theoretical predictions

Researchers from the Department of Physics and the University Institute of Materials at the University of Alicante (UA) and the Low Temperature and High Magnetic Field Laboratory at the Autonomous University of Madrid (UAM) have succeeded in measuring, for the first time, the electrical conductance of gold and silver atomic contacts subjected to extreme magnetic fields of up to 20 teslas, an intensity equivalent to 400,000 times Earth’s magnetic field.

The team observed that, when applying these fields, the conductance of the gold contacts decreases by around 15%, an unexpected result in noble metals such as gold (Au) and silver (Ag). Furthermore, they detected modifications in the formation process of the atomic contact itself, which were particularly marked in silver. These findings contradict previous theoretical predictions, which anticipated a practically non-existent magnetic dependence in pure Au and Ag.

The discovery, published in Physical Review Research, adds a new piece to the knowledge of electronic transport physics at the atomic scale. Achieving a noticeable response to a magnetic field from a conductor consisting of a single atomic channel, as occurs in these metals, is extremely difficult. The results suggest that functional materials can be designed by combining noble metals with magnetically active systems.

Chemical shifts help track molecules breaking apart in real time

When molecules fall apart, their electric charge doesn’t stay put—it rearranges as bonds stretch and break. An international team of scientists has now tracked these ultrafast changes in the small molecule fluoromethane (CH₃F). It was the first time that the Small Quantum Systems (SQS) instrument at European XFEL could deliver detailed insights into transient states during chemical reactions. The research is published in the journal Physical Review X.

These intermediate states, that only exist temporarily while the reaction is ongoing, are often the key drivers of chemistry and therefore crucial to understand. Over the long term, that kind of insight can support progress in areas such as atmospheric science (where sunlight-driven reactions and fragmentation pathways shape air chemistry), as well as the study of complex molecular systems including biomolecules and proteins, where local excitation and charge transfer can trigger structural change.

In the experiment, the researchers first triggered the reaction with an optical laser pulse. Next, they used the X-ray laser pulses that the European XFEL produces, to eject an electron from the core of either the fluorine or the carbon atom in the molecule. They measured the electron’s kinetic energy, which reveals how strongly it was bound inside the atom. That binding energy is extremely sensitive to the local electrical environment, producing so-called “chemical shifts” that act like a fingerprint of the charge distribution surrounding the atom from which the electron has been ejected.

Mining the dark transcriptome: Synthesizing the first potential drug molecules from long noncoding RNA

A team from University of Toronto Engineering is the first to synthesize long noncoding RNA (lncRNA) outside the cell—a new approach to drug discovery that has already yielded some promising anti-inflammatory molecules. The team was inspired by advances in the field of messenger RNA (mRNA) and protein replacement therapies. They realized that a similar approach could be used to deliver lncRNA to the body, unlocking a potential new source of drugs.

“Only about 25% of our DNA encodes for proteins, including everything from insulin for regulating blood sugar to antibodies for immune defense,” says Professor Omar F. Khan, senior author on a paper published in Science Signaling that describes the new discovery.

“Proteins are made via messenger RNA, or mRNA, which conveys the instructions for how to build proteins from our genes to our ribosomes, the part of our cells where proteins are assembled.”

Why anger feels close to fear: Brain charts emotion in a map-like way

It is well established in psychology that humans conceptualize emotions by features known as valence (the degree of pleasantness or unpleasantness) and arousal (the intensity of bodily reactions, such as rapid breathing or a racing heart).

If you think of “pleasantness” as longitude and “bodily reaction” as latitude, you can imagine a “mental map,” with nodes that “chart” knowledge of emotion.

The neural mechanisms giving rise to this configuration, however, have remained unclear.

Precisely measuring quantum signals in large spin ensembles

Quantum mechanical effects are known to be easily disrupted by disturbances from the surrounding environment, commonly referred to as noise. To minimize these disturbances, physicists often study these effects in small and carefully controlled systems, in which environmental noise can be minimized.

Researchers at Johns Hopkins University set out to study quantum effects in macroscopic spin ensembles, systems comprised of large numbers of spins (spins is the intrinsic angular momentum of elementary particles). Their paper, published in Nature Physics, introduces a new approach to directly observe quantum spin fluctuations in macroscopic spin ensembles, precisely monitoring their evolution over time.

“Quantum effects are typically observed and exploited in microscopic systems, where individual qubits can be precisely controlled and measured,” Alexander O. Sushkov, senior author of the paper, told Phys.org.

/* */