Lifeboat Foundation

Researchers report a new, highly unusual, structured-light family of 3D topological solitons, the photonic hopfions, where the topological textures and topological numbers can be freely and independently tuned.

We can frequently find in our daily lives a localized wave structure that maintains its shape upon propagation—picture a smoke ring flying in the air. Similar stable structures have been studied in various research fields and can be found in magnets, nuclear systems, and particle physics. In contrast to a ring of smoke, they can be made resilient to perturbations. This is known in mathematics and physics as topological protection.

A typical example is the nanoscale hurricane-like texture of a magnetic field in magnetic thin films, behaving as particles—that is, not changing their shape—called skyrmions. Similar doughnut-shaped (or toroidal) patterns in 3D space, visualizing complex spatial distributions of various properties of a wave, are called hopfions. Achieving such structures with light waves is very elusive.

We can frequently find in our daily lives a localized wave structure that maintains its shape upon propagation—picture a smoke ring flying in the air. Similar stable structures have been studied in various research fields and can be found in magnets, nuclear systems, and particle physics. In contrast to a ring of smoke, they can be made resilient to perturbations. This is known in mathematics and physics as topological protection.

A typical example is the nanoscale hurricane-like texture of a magnetic field in magnetic thin films, behaving as particles—that is, not changing their shape—called skyrmions. Similar doughnut-shaped (or toroidal) patterns in 3D space, visualizing complex spatial distributions of various properties of a wave, are called hopfions. Achieving such structures with light waves is very elusive.

Recent studies of structured light revealed strong spatial variations of polarization, phase, and amplitude, which enable the understanding of—and open up opportunities for designing—topologically stable optical structures behaving like particles. Such quasiparticles of light with control of diversified topological properties may have great potential, for example as next-generation information carriers for ultra-large-capacity optical information transfer, as well as in quantum technologies.

“Although this research field has been very active for more than 20 years, this is the first field-result that experimentally demonstrates lightning guided by lasers,” the researchers wrote in the study. “This work paves the way for new atmospheric applications of ultrashort lasers and represents an important step forward in the development of a laser based lightning protection for airports, launchpads or large infrastructures.”

Lightning emerges when atmospheric static electricity, generated by the friction of ice clumps and rain in stormclouds, separates electrons from atoms. The negatively charged electrons then pool at the stormcloud’s base and attract positive charges from the ground. As electrons steadily accumulate, they begin to overcome the resistance of the air to their flow, ionizing the atmosphere below them as they approach the ground in multiple forking (and invisible) “leader” paths. When the first leader path makes contact with the ground, electrons hop to the earth from the point of contact, discharging from the bottom up in a flash of lightning (called the return stroke) that travels to the top of the cloud.

The study has shown that the use of intense lasers can be used to divert lightning, much like conventional “Franklin rods.”

According to a report published in Nature Photonics.

Continue reading “Lasers as lightning rods just became a reality thanks to a new study” »

An experimental campaign was conducted on the Säntis mountain in north-eastern Switzerland during the summer of 2021 with a high-repetition-rate terawatt laser. The guiding of an upward negative lightning leader over a distance of 50 m was recorded by two separate high-speed cameras.

A terawatt laser filament is shown to be able to guide lightning over a distance of 50 m in field trials on the Säntis mountain in the Swiss Alps.

This weekend, Mayor of Paris Anne Hidalgo told Le Parisien that Parisians will get to vote whether they want to ban free-floating electric scooters or not. As I explained last week, Dott, Lime and Tier, the three scooter companies currently operating in the city, have operating licenses that are set to expire on March 23rd, 2023. And the fate of those services could have wide implications across the micromobility sector.

“If Parisians want to own their own scooter, there’s no issue. But we have a real issue with free-floating scooters. It’s not climate-friendly. Employees working for these companies are not properly treated,” Mayor of Paris told Le Parisien.

“That’s why I’m going to ask a question to Parisians in a vote that is going to take place on Sunday, April 2nd so that I can understand what they want,” she added.

Climate change is the biggest challenge of our time. To slow down global warming, we need to rethink how we generate and consume energy. Facing significant structural changes in supply and demand, we are in the middle of an energy transition with a strong need for action.

To reach a net zero economy by 2050 we have to swiftly replace fossil fuels in power generation with renewable, clean and secure sources. At the same time technologies powered by fossil-fuels must be replaced by electrified applications such as those seen in electric vehicles or heat pumps. Microelectronics plays a decisive role in respective applications.

Infineon’s semiconductor solutions enable the provision of green energy as well as the electrification of applications in the industrial, mobility and consumer sectors. Our semiconductor solutions are vital to decarbonization, they are key elements in creating a better future.

The meteorite and explosion-site quasicrystals were both uncovered by a team that includes Luca Bindi of the University of Florence, Italy, and Paul Steinhardt of Princeton University. In those previous cases, the materials were subjected to extremely high-pressure, high-temperature shock events—analysis of the meteorite sample revealed the temperature reached at least 1,200 °C and the pressure 5 GPa, while the New Mexico sample reached 1,500 °C and closer to 8 GPa. These transient, intense conditions contorted the materials’ atoms, forcing them to arrange into patterns unseen for usual laboratory conditions.

The explosion-site sample was found in a rock-like substance made of sand that had been fused together with copper wires from a measurement device that had been set up to monitor the atom-bomb test. As a trained geologist, Bindi was aware that similar substances—so-called fulgurites—are created when lightning strikes a beach or a sand dune. He wondered if lightning-fused samples might also contain quasicrystals, so he and the team set about collecting and analyzing the structures of as many fulgurites as they could lay their hands on.

Luck was on their side. In a fragment of a storm-created fulgurite from the Nebraskan Sand Hills—grass-stabilized sand dunes in northern Nebraska—the team found a micron-sized fragment of a quasicrystal with a previously unseen composition and pattern. Specifically, the newly discovered quasicrystal has a dodecagonal—12-fold symmetric—atomic structure. Such ordering is impossible in ordinary crystals, Bindi says, and is unusual even for quasicrystals (both the meteorite and explosion-site quasicrystals, as well as most lab-made ones, have fivefold symmetric patterns). “This was all more than [we] could have hoped for in such a long-shot search,” Steinhardt says.

Multiple agencies concurred this week that 2022 was among the hottest years on record—a continuation of a dangerous trend that experts say underscores the need to move rapidly away from fossil fuels, the primary source of planet-heating pollution.

The World Meteorological Organization confirmed Thursday that last year was one of the hottest since record-keeping began. Citing its analysis of six international datasets, the WMO said that the average global temperature in 2022 was roughly 1.15°C above preindustrial (1850−1900) levels.

“The persistence of a cooling La Niña event” prevented 2022 from being even hotter, but “this cooling impact will be short-lived and will not reverse the long-term warming trend caused by record levels of heat-trapping greenhouse gases in our atmosphere,” said the United Nations weather agency.