Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog – Page 3

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

Log in for authorized contributors

Waiting in line: Why six feet of social distancing may not be enough to stop airborne virus spread

We all remember the advice frequently repeated during the COVID pandemic: maintain six feet of distance from every other human when waiting in a line to avoid transmitting the virus. While reasonable, the advice did not take into account the complicated fluid dynamics governing how the airborne particles actually travel through the air if people are also walking and stopping. Now, a team of researchers led by two undergraduate physics majors at the University of Massachusetts Amherst has modeled how aerosol plumes spread when people are waiting and walking in a line.

The results, published recently in Science Advances, grew out of a question that many of us may have asked ourselves when standing in marked locations six-feet apart while waiting for a vaccine, to pay for groceries or to get a cup of coffee: what’s the science behind six-feet of separation? If you are a physicist, you might even have asked yourself, “What is happening physically to the aerosol plumes we’re all breathing out while waiting in a line, and is the six-foot guideline the best way to design a queue?”

To find answers to these questions, two UMass Amherst undergrads, Ruixi Lou and Milo Van Mooy, took the lead.

Some young suns align with their planet-forming disks, others are born tilted

Researchers at UC Santa Barbara, The University of Texas at Austin, Yale University and National Taiwan Normal University have found that a fair number of sun-like stars emerge with their rotational axis tilted with respect to their protoplanetary disks, the clouds of gas and dust from which solar systems are born.

“All have these disks, but we’ve known little about their orientations with respect to the spin axis of the host stars,” said UCSB associate physics professor Brendan Bowler, who studies how planets form and evolve through their orbits and atmospheres, and is senior author of a study in the journal Nature. Based on the general alignment of our own sun’s with those of the planets in our solar system, the assumption was that stars and their planet-forming disks emerge and rotate in or very close to alignment, he explained.

“This work challenges these centuries-old assumptions,” Bowler said.

Low-oxygen air slows Parkinson’s progression and restores movement in mice

Researchers from the Broad Institute and Mass General Brigham have shown that a low-oxygen environment—similar to the thin air found at Mount Everest base camp—can protect the brain and restore movement in mice with Parkinson’s-like disease.

The new research, in Nature Neuroscience, suggests that cellular dysfunction in Parkinson’s leads to the accumulation of excess oxygen molecules in the brain, which then fuel neurodegeneration—and that reducing could help prevent or even reverse Parkinson’s symptoms.

“The fact that we actually saw some reversal of neurological damage is really exciting,” said co-senior author Vamsi Mootha, an institute member at the Broad, professor of systems biology and medicine at Harvard Medical School, and a Howard Hughes Medical Institute investigator in the Department of Molecular Biology at Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham healthcare system.

Beyond words: Study maps the cognitive force of metaphor

Metaphors are a fundamental aspect of human language and cognition, allowing us to understand complex concepts and relationships by mapping them onto more familiar and concrete domains. However, the nature of metaphors and how they work is still not well understood.

In a new paper published in PLOS Complex Systems, Max-Planck-Institute for Mathematics in the Sciences researchers Marie Teich and Wilmer Leal together with director Jürgen Jost have developed a formal framework and large-scale empirical methodology to analyze metaphors and their role in conceptual theory.

The study confirms the fundamental assumption in conceptual metaphor theory that metaphors are enduring linguistic and cognitive structures, not merely rhetorical figures. Using complex systems tools, the researchers identified a metaphor network with distinctions between abstract and concrete categories, and two significant metaphorical processes: mappings from concrete to abstract topics and the emergence of new mappings between concrete domains.

Ultra-short RNA insertions offer scalable, cost-effective gene silencing for agriculture

A team of researchers from the Spanish National Research Council has made a significant advance in plant biotechnology by developing a new method for silencing genes. The novel technique uses ultra-short ribonucleic acid (RNA) sequences carried by genetically modified viruses to achieve genetic silencing, allowing the customization of plant traits. The work, published in the Plant Biotechnology Journal, opens up new avenues for crop improvement, functional genomics, and sustainable agriculture.

Viral vector technology involves modifying viruses, removing the genetic material that causes disease, to turn them into vehicles that carry the RNA sequence to be introduced into an organism. This technique, when applied to plants, has already proven effective under experimental conditions in inducing flowering and accelerating the development of improved crop varieties, modifying plant architecture to facilitate adaptation to mechanization, improving drought tolerance, and producing metabolites beneficial to human health, among other applications.

Now, the method developed by the CSIC, together with the Valencian University Institute for Research on the Conservation and Improvement of Agrodiversity (COMAV) and the Italian Department of Applications and Innovation in Supercomputing (Cineca), represents an optimization of technological platforms to accelerate the development and validation of agricultural applications based on viral vectors.

Friction that cools: Threshold effects enable self-stopping robot swarms

How can a horde of active robots be automatically brought to a standstill? By arresting their dynamics in a self-sustained way. This phenomenon was discovered by physicists at Heinrich Heine University Dusseldorf (HHU) and La Sapienza University in Rome. The threshold principle of static friction with the ground plays a decisive role here: it removes the kinetic energy of two robots after a mutual collision so efficiently that they can no longer set themselves in motion.

The researchers describe in the journal Nature Communications that this fundamental effect can also be used to construct controllable moving systems.

Friction creates heat, as anyone knows who has rubbed their hands together in winter weather. And costs energy. Road friction on vehicle tires, for example, will cause a moving car to steadily slow down unless the accelerator is used.

Scientists achieve direct measurement of quantum metric tensor in black phosphorus

Quantum distance refers to a measure of quantum mechanical similarity between two quantum states. A quantum distance of one means that the two quantum states are the same, whereas a quantum distance of zero implies that they are exactly the opposite. Physicists introduced this concept in the realm of theoretical science a long time ago, but its importance has been increasingly recognized in the field of physics only in recent times.

In the last few years, many have tried to measure the quantum distance of electrons in real , but a direct measurement of the quantum distance and thus quantum metric tensor—a key geometric quantity in modern physics defined in terms of the distance between nearby quantum states—has remained elusive so far.

Since the quantum metric tensor is highly relevant in explaining and understanding fundamental physical phenomena in solids, it is, therefore, crucial to come up with an effective methodology for its direct measurement in solid-state systems.

Ultrafast light switch achieved with asymmetric silicon metasurfaces in nanophotonics

In nanophotonics, tiny structures are used to control light at the nanoscale and render it useful for technological applications. A key element here is optical resonators, which trap and amplify light of a certain color (wavelength).

Previous methods of controlling these resonances were more like a dimmer switch: You could weaken the resonance or slightly shift its color. However, genuine on-and-off switching was not possible, as the resonators always remain fundamentally coupled with the light.

A team led by Andreas Tittl, Professor of Experimental Physics at LMU, has now precisely achieved this breakthrough, together with partners from Monash University in Australia. As the researchers report in the journal Nature, they have developed a new method for controlling the coupling between nanoresonators and light in a targeted manner on ultrafast timescales. In this way, a resonance can be created from nothing within a few picoseconds or made to vanish completely again.

Newly derived optical formula shines a light on organic crystal altermagnet candidate

Researchers have uncovered the magnetic properties and underlying mechanisms of a novel magnet using advanced optical techniques. Their study focused on an organic crystal believed to be a promising candidate for an “altermagnet”—a recently proposed third class of magnetic materials. Unlike conventional ferromagnets and antiferromagnets, altermagnets exhibit unique magnetic behavior.

“Unlike typical magnets that attract each other, altermagnets do not exhibit net magnetization, yet they can still influence the polarization of reflected light,” points out Satoshi Iguchi, associate professor at Tohoku University’s Institute for Materials Research. “This makes them difficult to study using conventional optical techniques.”

To overcome this, Iguchi and his colleagues applied a newly derived general formula for light reflection to the organic crystal, successfully clarifying its and origin. The work is published in the journal Physical Review Research.

A dual ion beam tests new steel under fusion energy-producing conditions

A new class of advanced steels needs more fine-tuning before use in system components for fusion energy—a more sustainable alternative to fission that combines two light atoms rather than splitting one heavy atom. The alloy, a type of reduced activation ferritic/martensitic or RAFM steel, contains billions of nanoscale particles of titanium carbide meant to absorb radiation and trap helium produced by fusion within a single component.

When subjected to and concentrations representative of fusion, the titanium-carbide precipitates initially helped trap helium but later dissolved under high damage levels. After dissolving, the alloy swelled as it was no longer able to disperse and trap helium, which could compromise system components.

The first-of-its-kind systematic investigation led by University of Michigan engineers was published in Acta Materialia and the Journal of Nuclear Materials in a series of three papers.

/* */