Lifeboat Foundation

Hubble Finds That Betelgeuse’s Mysterious Dimming Is Due to a Traumatic Outburst

Observations by NASA ’s Hubble Space Telescope are showing that the unexpected dimming of the supergiant star Betelgeuse was most likely caused by an immense amount of hot material ejected into space, forming a dust cloud that blocked starlight coming from Betelgeuse’s surface.

Hubble researchers suggest that the dust cloud formed when superhot plasma unleashed from an upwelling of a large convection cell on the star’s surface passed through the hot atmosphere to the colder outer layers, where it cooled and formed dust grains. The resulting dust cloud blocked light from about a quarter of the star’s surface, beginning in late 2019. By April 2020, the star returned to normal brightness.

Novel two-dimensional materials are currently a hot research topic around the world. Of special interest are van der Waals heterostructures, which are made up of individual layers of different materials held together by van der Waals forces. The interactions between the different layers can give the resulting material entirely new properties.

Double layer unlocks crucial properties

There are already van der Waals heterostructures that absorb up to 100 percent of light. Single-layers of molybdenum disulfide offer absorption capacities in this range. When light is absorbed, an electron vacates its original position in the valence band, leaving behind a positively charged hole. The electron moves to a higher energy level, known as the conduction band, where it can move freely.

MEDAN, Indonesia — Indonesia’s rumbling Mount Sinabung erupted Monday, sending a column of volcanic materials as high as 16,400 feet into the sky and depositing ash on villages.

It is the second eruption since Saturday after the volcano sat dormant for more than a year.

Falling grit and ash accumulated up to 2 inches in already abandoned villages on the volcano’s slopes, said Armen Putra, an official at the Sinabung monitoring post on Sumatra Island.

Imagine plugging in to your brick house.

Red bricks—some of the world’s cheapest and most familiar building materials—can be converted into energy storage units that can be charged to hold electricity, like a battery, according to new research from Washington University in St. Louis.

Continue reading “Storing energy in red bricks” »

Scientists at the University of Bath have taken an important step towards understanding the interaction between layers of atomically thin materials arranged in stacks. They hope their research will speed up the discovery of new, artificial materials, leading to the design of electronic components that are far tinier and more efficient than anything known today.

Smaller is always better in the world of electronic circuitry, but there’s a limit to how far you can shrink a silicon component without it overheating and falling apart, and we’re close to reaching it. The researchers are investigating a group of atomically thin materials that can be assembled into stacks. The properties of any final material depend both on the choice of raw materials and on the angle at which one layer is arranged on top of another.

Dr. Marcin Mucha-Kruczynski who led the research from the Department of Physics, said: “We’ve found a way to determine how strongly atoms in different layers of a stack are coupled to each other, and we’ve demonstrated the application of our idea to a structure made of graphene layers.”

Researchers have found electrons that behave as if they have no mass, called Dirac electrons, in a compound used in rewritable discs, such as CDs and DVDs. The discovery of ‘massless’ electrons in this phase-change material could lead to faster electronic devices.

The international team published their results on July 6 in ACS Nano, a journal of the American Chemical Society.

The compound, GeSb₂Te₄, is a phase-change material, meaning its atomic structure shifts from amorphous to crystalline under heat. Each structure has individual properties and is reversible, making the compound an ideal material to use in electronic devices where information can be written and rewritten several times.

Ultrashort laser pulses induce unusual sound waves via a structural instability in a material.

RIKEN physicists have initiated unusual sound waves in a flake using ultrashort pulses of laser light and then created videos of their movement using electron microscopy. This advance should help engineers to achieve higher precision control of heat flow and sound in nanodevices using light.

Certain materials contain both electric dipoles and magnetic moments. An experiment demonstrates that these properties can be coupled in previously unrecognized ways, leading to advanced functionality. Domain patterns inverted by a uniform magnetic field.

Scientists have developed a new prediction of the shape of the bubble surrounding our solar system using a model developed with data from NASA missions.

All the planets of our solar system are encased in a magnetic bubble, carved out in space by the Sun’s constantly outflowing material, the solar wind. Outside this bubble is the interstellar medium—the ionized gas and magnetic field that fills the space between stellar systems in our galaxy. One question scientists have tried to answer for years is on the shape of this bubble, which travels through space as our Sun orbits the center of our galaxy. Traditionally, scientists have thought of the heliosphere as a comet shape, with a rounded leading edge, called the nose, and a long tail trailing behind.

Research published in Nature Astronomy in March and featured on the journal’s cover for July provides an alternative shape that lacks this long tail: the deflated croissant.