Toggle light / dark theme

Hungry, Hungry White Dwarfs: Solving the Puzzle of Stellar Metal Pollution

Dead stars known as white dwarfs, have a mass like the sun while being similar in size to Earth. They are common in our galaxy, as 97% of stars are white dwarfs. As stars reach the end of their lives, their cores collapse into the dense ball of a white dwarf, making our galaxy seem like an ethereal graveyard.

Despite their prevalence, the chemical makeup of these stellar remnants has been a conundrum for astronomers for years. The presence of heavy metal elements—like silicon, magnesium, and calcium—on the surface of many of these compact objects is a perplexing discovery that defies our expectations of stellar behavior.

“We know that if these heavy metals are present on the surface of the white dwarf, the white dwarf is dense enough that these heavy metals should very quickly sink toward the core,” explains JILA graduate student Tatsuya Akiba. “So, you shouldn’t see any metals on the surface of a white dwarf unless the white dwarf is actively eating something.”

Science Experiments That Will Change The World — Rupert Sheldrake, PhD

I love the first line.


In this video I spoke with Rupert Sheldrake about the science experiments that will change the world, taking us from morphic resonance, telepathy to aging research.

Find out about Rupert here:
www.sheldrake.org.
/ rupertsheldrakephd.
Proc Royal Soc B aging paper discussed: https://www.sheldrake.org/files/pdfs/.

Find me on Twitter — / eleanorsheekey.

Support the channel.

Solar Composition Altered by Plasma Waves

New solar observations indicate that plasma waves are responsible for the Sun’s outer atmosphere having different abundances of chemical elements than the Sun’s other layers.

The solar corona is a halo of hot, tenuous plasma that surrounds the Sun out to large distances. It is visible during solar eclipses (Fig. 1) but is usually outshone by the glare of the Sun’s surface, or photosphere. The corona has different abundances of chemical elements than the rest of the Sun, and a longstanding question has been why this disparity exists. New solar measurements by Mariarita Murabito at the Italian National Institute of Astrophysics (INAF) and colleagues suggest that the difference is caused by plasma waves dragging easily ionized elements from the Sun’s lower atmosphere into the corona [1]. This finding could lead to a better understanding of the structure of stars.

The corona is of great interest to solar physicists, partly because it produces the solar wind—an outflow of hot gas from the Sun. The solar wind is most evident to us on Earth when its particles become trapped in Earth’s magnetic field and collide with our atmosphere, causing an aurora. An important problem in solar physics is to determine which coronal structures generate the solar wind and how solar conditions affect the outflow’s properties. The elemental composition of the solar wind sheds light on its origins, as this composition does not change once the gas leaves the Sun. The solar wind can be directly sampled by spacecraft in situ, and its elemental abundances can be compared to coronal abundances inferred from spectroscopy.

Researchers develop organic photoredox catalysts with enhanced stability and recyclability

In recent years, global environmental concerns have prompted a shift toward eco-friendly manufacturing in the field of organic synthetic chemistry. In this regard, research into photoredox catalytic reactions, which use light to initiate redox or reduction-oxidation reactions via a photoredox catalyst, has gained significant attention. This approach reduces the reliance on harsh and toxic reagents and uses visible light, a clean energy source.

Promethium Discovery Set to Rewrite Chemistry Textbooks

Scientists have made a significant breakthrough in understanding the properties of promethium, a rare earth element with elusive characteristics despite its use in modern technology.

Researchers have uncovered the properties of a rare earth element that was first discovered 80 years ago at the very same laboratory. Their discoveries open a new pathway for the exploration of elements critical in modern technology, from medicine to space travel.

Promethium was discovered in 1945 at Clinton Laboratories, now the Department of Energy’s Oak Ridge National Laboratory, and continues to be produced at ORNL in minute quantities. Some of its properties have remained elusive despite the rare earth element’s use in medical studies and long-lived nuclear batteries. It is named after the mythological Titan who delivered fire to humans and whose name symbolizes human striving.

Functionalization of Polymer Networks for Diverse Applications

While silicon has been the go-to material for sensor applications, could polymer be used as a suitable substitute since silicon has always lacked flexibility to be used in specific applications? This is what a recent grant from the National Science Foundation hopes to address, as Dr. Elsa Reichmanis of Lehigh University was recently awarded $550,000 to investigate how polymers could potentially be used as semiconductors for sensor applications, including Internet of Things, healthcare, and environmental applications.

Illustration of an organic electrochemical transistor that could be developed as a result of this research. (Credit: Illustration by by Ella Marushchenko; Courtesy of Reichmanis Research Group)

“We’ll be creating the polymers that could be the building blocks of future sensors,” said Dr. Reichmanis, who is an Anderson Chair in Chemical Engineering in the Department of Chemical and Biomolecular Engineering at Lehigh University. “The systems we’re looking at have the ability to interact with ions and transport ionic charges, and in the right environment, conduct electronic charges.”

Quantum Coherence: Harvard Scientists Uncover Hidden Order in Chemical Chaos

If you zoom in on a chemical reaction to the quantum level, you’ll notice that particles behave like waves that can ripple and collide. Scientists have long sought to understand quantum coherence, the ability of particles to maintain phase relationships and exist in multiple states simultaneously; this is akin to all parts of a wave being synchronized. It has been an open question whether quantum coherence can persist through a chemical reaction where bonds dynamically break and form.

Now, for the first time, a team of Harvard scientists has demonstrated the survival of quantum coherence in a chemical reaction involving ultracold molecules. These findings highlight the potential of harnessing chemical reactions for future applications in quantum information science.

“I am extremely proud of our work investigating a very fundamental property of a chemical reaction where we really didn’t know what the result would be,” said senior co-author Kang-Kuen Ni, Theodore William Richards Professor of Chemistry and Professor of Physics. “It was really gratifying to do an experiment to find out what Mother Nature tells us.”

/* */