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The total solar eclipse across North America sees citizens become scientists

As the total solar eclipse becomes visible when it streaks past North America, ‘citizen scientists’ are at work, beaming radio signals to support scientific experiments.

Karthik Vinod

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A total solar eclipse captured in 1994 from France. Credit: Wikimedia

Monday’s total solar eclipse lent unearthly vibes all round in North America. Across North America where the solar eclipse’s shadow streaked past for nearly two hours, all chatter subsided. Even radio signals would’ve gone awry in places, as people across the US, Canada and Mexico America peered at the sky as the color slowly drained from the sky when the moon eclipsed the sun. 

If it hadn’t been for the red tendril-like features extending out from the sun in several captures of the eclipse event, one would’ve thought that our sun collapsed into a black hole – in fact, reminiscent of Gargantua from Christopher Nolan’s Interstellar (2014)

Chatter soon broke out on the internet following the first sighting. Pictures of the solar eclipse was shared across social media platforms, taken from places and vantage points within and outside of the shadow’s trajectory across North America. 

The red-tendril-like features, or the solar prominence as it’s described by astronomers, is a plume of plasma that outlines the sun’s extensive but otherwise invisible magnetic field. The plasma trails the shape of the field lines there, giving it the appearance of that filament.  Moreover, the white hot corona in the image is remarkably over millions of degrees hotter than the sun’s outer layer. The invisible beauty of our sun now is unraveled as we see the naked truth, with the surrounding sky turning pitch black of empty space in the meantime. 

A solar prominence event where loops of hot plasma is wound in a loop by the sun’s magnetic field. Credit: NASA

Features like the prominence have long been known to astronomers for centuries. Solar eclipses are perhaps amongst the only times when day-light astronomy could be done.

History is replete with records of scientists making important discoveries during solar eclipses. For example, in 1868, the French astronomer Pierre Janssen detected a signature of a then unknown element inadvertently as he observed a solar eclipse from Madras State in colonial India. Further detections by the English astronomer Norman Lockyer later in the same year conclusively established the new element – named helium ( after the Greek ἥλιος or helios meaning the sun).

Not just that, the English astrophysicist Arthur Eddington carried out experiments involving sunlight amidst the solar eclipse in 1919, whose results had Albert Einstein’s theory of general relativity prevail over Isaac Newton’s gravitational theory. Eddington and other researchers had captured the precise deflection angle by which the sun’s gravitational field bent light from background stars.

Fast forward to today, Monday’s solar eclipse left an open window to do some important science. Not of the sun, but investigating the interactions between the sun and earth’s upper atmosphere – particularly the ionosphere, which lies above the stratosphere, at over 60 to 300 km. Everyday long distance radio communication is possible because the radio transmissions get deflected by this layer, which is ionized (presence of charged atoms and negatively charged electrons), in part due to solar radiation from the sun.

But during solar eclipses, the ionosphere is suddenly caught in disarray, even hampering radio communications. However, Monday’s solar eclipse found ways to turn even ordinary citizens into scientists, beaming radio signals at the ionosphere in an effort at scientific experimentation and establishing alternate forms of communication. 

The Ham Radio Science Citizen Investigation (HamSCI) is one effort in the US during Monday’s eclipse that linked up amateur radio ham operators across North America, for data gathering.

As much as there is genuine scientific curiosity motivating the experiments, there are clear societal reasons why these efforts are more important than ever. Understanding how reflective the ionosphere can be, should help better inform emergency response teams to use forms of radio signaling that may work effectively amidst hostile space weather – as it did during Hurricane Irma in 2017. 

A radio ham set. Credit: Wikimedia

With citizens as both participants and organizers, they can help scientific estimates of the electron density in the ionosphere and how much it attenuates there.

The more modern rendition of participatory science, or ‘citizen science’, makes its presence felt during these times, as they keep the culture and ancient tradition that is astronomy alive in new ways. And in doing so, their efforts stand testimony to how ordinary people can take up the lead in place of scientists, to act in service of both science and society. 

Karthik is a science writer, and co-founder of Ed Publica. He writes and edits the science page. He's also a freelance journalist, with words in The Hindu, a prominent national newspaper in India.

Space & Physics

The Story of the World’s Most Underrated Quantum Maestro

As the world celebrates the 131st birth anniversary of S.N. Bose, EdPublica explores the theoretical physicist’s unparalleled contributions to the field of quantum mechanics

Karthik Vinod

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It’s 1924, and Satyendra Nath Bose, going by S.N. Bose was a young physicist teaching in Dhaka, then British India. Grappled by an epiphany, he was desperate to have his solution, fixing a logical inconsistency in Planck’s radiation law, get published. He had his eyes on the British Philosophical Magazine, since word could spread to the leading physicists of the time, most if not all in Europe. But the paper was rejected without any explanations offered. 

But he wasn’t going to give up just yet. Unrelenting, he sent another sealed envelope with his draft and this time a cover letter again, to Europe. One can imagine months later, Bose breathing out a sigh of relief when he finally got a positive response – from none other than the great man of physics himself – Albert Einstein. 

In some ways, Bose and Einstein were similar. Both had no PhDs when they wrote their treatises that brought them into limelight. And Einstein introduced E=mc2 derived from special relativity with little fanfare, so did Bose who didn’t secure a publisher with his groundbreaking work that invented quantum statistics. He produced a novel derivation of the Planck radiation law, from the first principles of quantum theory. 

Satyendra Nath Bose at Kolkata in 1915. Credit: Wikimedia Commons

This was a well-known problem that had plagued physicists since Max Planck, the father of quantum physics himself. Einstein himself had struggled time and again, to only have never resolved the problem. But Bose did, and too nonchalantly with a simple derivation from first principles grounded in quantum theory. For those who know some quantum theory, I’m referring to Bose’s profound recognition that the Maxwell-Boltzmann distribution that holds true for ideal gasses, fails for quantum particles. A technical treatment of the problem would reveal that photons, that are particles of light with the same energy and polarization, are indistinguishable from each other, as a result of the Pauli exclusion principle and Heisenberg’s uncertainty principle. 

Fascinatingly, last July marked the 100 years since Einstein submitted Bose’s paper, “Planck’s law and the quantum hypothesis” on his behalf to Zeitschrift fur Physik.

Fascinated and moved by what he read, Einstein was magnanimous enough to have Bose’s paper translated in German and published in the journal, Zeitschrift für Physik in Germany the same year. It would be the beginning of a brief, but productive professional collaboration between the two theoretical physicists, that would just open the doors to the quantum world much wider. Fascinatingly, last July marked the 100 years since Einstein submitted Bose’s paper, “Planck’s law and the quantum hypothesis” on his behalf to Zeitschrift fur Physik. 

With the benefit of hindsight, Bose’s work was really nothing short of revolutionary for its time. However, a Nobel Committee member, the Swedish Oskar Klein – and theoretical physicist of repute – deemed it a mere advance in applied sciences, rather than a major conceptual advance. With hindsight again, it’s a known fact that Nobel Prizes are handed in for quantum jumps in technical advancements more than ever before. In fact, the 2001 Nobel Prize in Physics went to Carl Wieman, Eric Allin Cornell, and Wolfgang Ketterle for synthesizing the Bose-Einstein condensate, a prediction made actually by Einstein based on Bose’s new statistics. These condensates are created when atoms are cooled to near absolute zero temperature, thus attaining the quantum ground state. Atoms at this state possess some residual energy, or zero-point energy, marking a macroscopic phase transition much like a fourth state of matter in its own right. 

Such were the changing times that Bose’s work received much attention gradually. To Bose himself, he was fine without a Nobel, saying, “I have got all the recognition I deserve”. A modest character and gentleman, he resonates a lot with the mental image of a scientist who’s a servant to the scientific discipline itself.

He was awarded the Padma Vibhushan, the highest civilian award by the Government of India in 1954. Institutes have been named in his honour, but despite this, his reputation has little if no mention at all in public discourse. 

But what’s more upsetting is that, Bose is still a bit of a stranger in India, where he was born and lived. He studied physics at the Presidency College, Calcutta under the tutelage that saw other great Indian physicists, including Jagdish Chandra Bose and Meghnad Saha. He was awarded the Padma Vibhushan, the highest civilian award by the Government of India in 1954. Institutes have been named in his honour, but despite this, his reputation has little if no mention at all in public discourse. 

To his physicists’ peers in his generation and beyond, he was recognized in scientific lexicology. Paul Dirac, the British physicist coined the name ‘bosons’ in Bose’s honor (‘bose-on’). These refer to quantum particles including photons and others with integer quantum spins, a formulation that arose only because of Bose’s invention of quantum statistics. In fact, the media popular, ‘god particle’, the Higgs boson, carries a bit of Bose as much as it does of Peter Higgs who shared the 2013 Nobel Prize in Physics with Francois Euglert for producing the hypothesis. 

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New Dust Models Shed Light on the End Stages of Sun-like Stars

New Insights into Hydrogen-Deficient Stars: Study of Planetary Nebula IC 2003 Reveals Key Evolutionary Clues

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Credit: Wikiimages

Careful modelling of the thermal and ionization structure of planetary nebulae, based on observations from the Vainu Bappu Telescope in Kavalur, Tamil Nadu, India, has enabled astronomers to deepen their understanding of the formation and evolution of these unusual hydrogen-deficient stars.

Planetary nebulae are shells of gas and dust ejected by stars like our Sun after they exhaust the hydrogen and helium fuel in their cores—a fate our Sun is expected to face in approximately 5 billion years. As the star’s core contracts due to the lack of nuclear fusion, it heats up and emits intense far-ultraviolet radiation. In the past, these stars appeared planet-like when viewed through small telescopes, a resemblance that led to their name.

While most stars in this late phase of their lives produce core remnants surrounded by tiny residual hydrogen envelopes, about 25% of them exhibit a deficiency of hydrogen and are instead rich in helium on their surfaces. Some of these stars also display strong mass loss and emission lines of ionized helium, carbon, and oxygen, characteristics identified as Wolf-Rayet (WR) features.

IC 2003, a rare planetary nebula, features a hydrogen-deficient central remnant star with WR characteristics.

Image credit: PIB

Although the evolutionary status of typical central stars of planetary nebulae is well-understood, the mechanisms behind the formation of hydrogen-poor stars remain largely unclear. The physical and chemical structures of the nebulae surrounding these stars provide valuable clues about their origin and evolution, making it essential to study their gas and dust in detail.

To investigate this further, astronomers from the Indian Institute of Astrophysics (IIA), an autonomous institute under the Department of Science and Technology, observed IC 2003 using the optical medium-resolution spectrograph (OMR) attached to the 2.3-meter Vainu Bappu Telescope at the Vainu Bappu Observatory in Kavalur, Tamil Nadu. “We also used ultraviolet spectra from the IUE satellite and broadband infrared fluxes from the IRAS satellite archives for this study,” said K. Khushbu, the lead author and Ph.D. student. These combined observations provided critical insights into the role of gas and dust in shaping the thermal structure of the nebula, ultimately enabling the team to derive precise parameters for the central star.

The models they used revealed that the nebula’s parameters, including the ionizing source’s mass and temperature, were significantly different from those predicted by dust-free models. “This study highlights the importance of dust grains in the thermal balance of ionized gas and helps explain the large temperature variations seen in nebulae, which are often key to resolving abundance discrepancies in astrophysical nebulae,” explained Prof. C. Muthumariappan, the supervisor and co-author of the study. “We used a one-dimensional dusty photo-ionization code, CLOUDY17.3, to simulate data from ultraviolet, optical, and infrared observations,” he added.

By modeling the photoelectric heating of the nebula caused by the dust grains, the researchers were able to replicate the thermal structure observed in the planetary nebula. “We even reproduced the large temperature gradient typically seen in nebulae with WR stars. Our determination of element abundances, such as helium, nitrogen, and oxygen, differs significantly from the values obtained empirically,” Khushbu noted.

The study also provided accurate grain size distributions within the nebula and highlighted the crucial role of photoelectric heating in explaining temperature variations. From their models, the researchers derived accurate values for the luminosity, temperature, and mass of the central star. They concluded that the star’s initial mass was 3.26 times that of the Sun, indicating it was a more massive star.

This research advances our understanding of the complex processes at work in the evolution of hydrogen-deficient stars and offers valuable insights into the origins of the unique features observed in planetary nebulae.

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MIT team finds the smallest asteroids ever detected in the main belt

This marks the first time such small asteroids in the asteroid belt have been spotted, potentially leading to better tracking of near-Earth objects that could pose a threat

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Credits: Image: Ella Maru and Julien de Wit

Asteroids that could potentially impact Earth vary greatly in size, from the catastrophic 10-kilometer-wide asteroid that caused the extinction of the dinosaurs to much smaller ones that strike far more frequently. Now, an international team of researchers, led by physicists at MIT, has discovered a new way to spot the smallest asteroids in our solar system’s main asteroid belt, which could provide critical insights into the origins of meteorites and planetary defense.

The team’s breakthrough approach allows astronomers to detect decameter asteroids—those just 10 meters across—much smaller than those previously detectable, which were about one kilometer in diameter. This marks the first time such small asteroids in the asteroid belt have been spotted, potentially leading to better tracking of near-Earth objects that could pose a threat.

“We have been able to detect near-Earth objects down to 10 meters in size when they are really close to Earth,” said lead author Artem Burdanov, a research scientist at MIT’s Department of Earth, Atmospheric and Planetary Sciences. “We now have a way of spotting these small asteroids when they are much farther away, so we can do more precise orbital tracking, which is key for planetary defense.”

The team used their innovative method to detect over 100 new decameter asteroids, ranging from the size of a bus to several stadiums wide. These are the smallest asteroids ever found in the main asteroid belt, located between Mars and Jupiter, where millions of asteroids orbit.

The findings, published today in Nature, have the potential to improve asteroid tracking efforts, which are critical for understanding the risk of future impacts. Scientists hope that the method could be applied to identify asteroids that may one day approach Earth.

The research team, which includes MIT planetary science professors Julien de Wit and Richard Binzel, as well as collaborators from the University of Liege, Charles University, and the European Space Agency, among others, utilized the James Webb Space Telescope (JWST) for their discovery. JWST’s sensitivity to infrared light made it an ideal tool for detecting the faint infrared emissions of asteroids, which are far brighter at these wavelengths than in visible light.

The team’s approach also relied on an imaging technique called “shift and stack,” which involves aligning multiple images of the same field of view to highlight faint objects like asteroids. This technique was originally developed for exoplanet research but was adapted for asteroid detection.

The researchers believe that these new findings will help improve our understanding of asteroid population

By processing over 10,000 images of the TRAPPIST-1 system—collected to study the planets in that distant star system—the researchers identified eight known asteroids and an additional 138 new ones. These newly discovered asteroids are the smallest main belt asteroids ever detected, with diameters as small as 10 meters.

“This is a totally new, unexplored space we are entering, thanks to modern technologies,” Burdanov said. “It’s a good example of what we can do as a field when we look at the data differently. Sometimes there’s a big payoff, and this is one of them.”

The researchers believe that these new findings will help improve our understanding of asteroid populations, including the many small objects that result from collisions among larger asteroids. Miroslav Broz, a co-author from Charles University in Prague, emphasized the importance of studying these decameter asteroids to model the creation of asteroid families formed from larger, kilometer-sized collisions.

De Wit, a co-author, highlighted the significance of the discovery: “We thought we would just detect a few new objects, but we detected so many more than expected, especially small ones. It is a sign that we are probing a new population regime, where many more small objects are formed through cascades of collisions.”

(With inputs from MIT)

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