Scientists have long studied the work of Subrahmanyan Chandrasekhar, the Indian-born American astrophysicist who won the 1983 Nobel Prize, but few know that his research on star and planet dynamics owes a deep gratitude to a near-forgotten woman: Donna Detty Elbert.
From 1948 to 1979, Elbert worked as a “computer” at Chandrasekhar, tirelessly creating and solving mathematical equations by hand. Although she co-authored with the Nobel laureate on 18 papers and Chandrasekhar enthusiastically acknowledged her fundamental contributions, her greatest achievement was not recognized until a UCLA postdoctoral researcher tied the threads in Chandrasekhar’s work that all led to Elbert.
Albert’s achievement? Scientist Susan Horn, who spent half a decade building on Elbert’s work, said, before anyone else, that conditions are ideal for a planet or star to generate its own magnetic field.
Now Horn and Professor of Earth, Planetary and Space Sciences at the University of California, Jonathan Orno, has published research into Proceedings of the Royal Society A In it they presented the newly named “Elbert Scale”, which details their predictions about the range of combinations that rotation, convection, and magnetism might posit to generate the best planet-wide magnetic field.
The authors say this work will help researchers in a variety of disciplines better understand conditions inside Earth and other planets and identify planets outside our solar system with potential to host life.
said Horn, who is now an associate professor at the Center for Research on Fluids and Complex Systems at Coventry University in the UK. “Chandrasekhar says in the footnotes that subtle and elegant ways of solving certain problems were actually put forward by Albert. His thesis on geophysical fluid dynamics and astrophysics was taken up, but not authored. Today, she would be considered a mathematician on her own right, but in the 1950s and 1960s, it was difficult for me to Women get more credit than entourage.”
Because Elbert’s discovery regarding the generation of planetary magnetic fields remained an integral part of her employer’s work, the discovery was generally attributed to Chandrasekhar, who shared the Nobel Prize in Physics for discoveries relating to stellar evolution And huge stars.
Horn said she hopes the work she and Orno have done to refine and expand Elbert’s original expectations will be a fitting – if belated – tribute to Albert, who died in 2019 at the age of 90.
Elbert Range: How planets and stars create magnetic fields
Planets generate their magnetic fields through the internal rotation of hot, electrically conductive fluids such as liquid metals or highly salty oceans. As the planet rotates on its axis, the motion of these fluids becomes orderly, generating planetary magnetic fields along the way. Scientists think so planets With magnetic fields it is more likely to sustain life because the magnetic field acts as a kind of cocoon that protects the planet from the surrounding space environment, which is often unfriendly, Orno said.
“The key is that you have all these fluid motions. Earth’s core is primarily made of liquid iron. As the planet slowly cools into space, the cooler upper portion of the liquid core sinks, and the hotter iron rises at the depth,” he explained.
The motion caused by this sinking and rising is known as convection. Thermal motions in electrically conductive materials, such as liquid iron in Earth’s core, can create electric currents that can then generate the planet’s global magnetic field.
Orno noted, “It is not clear whether thermal perturbation alone will generate a magnetic field on a planetary scale, but we do know that planetary rotation regulates perturbation into motion patterns that can.” In other words, he said, rotational forces called Coriolis forces move fluids in predictable ways as the planet rotates. “Elbert was the first to point out that when these rotational forces are comparable in strength to magnetic forces, convection will begin to regulate on the scale of the planet itself. It is a simple and plausible system.”
Elbert discovered this principle on her own while Chandrasekhar was on a summer lecture tour and presented it to him upon his return. He incorporated Elbert’s discovery into his own work and credited it in a footnote without going further into its significance.
But Horne jumped at Elbert’s work.
“What we did was look at how convection patterns in liquid metals differ and evolve when they are subject to both spin and magnetic fields,” Horne said. “We’ve found that there are different systems of thermal behavior, and we’ve located where these exact systems are. This work provides a whole host of new predictions that we will use to build future lab and digital models of planets and stars. magnetic field generation.”
The open-access paper, “Elbert’s Range of Magnetic Convection. I. Linear Theory,” is the first in a series of three papers that Horn and Orno plan to publish based on Elbert’s work.
Susan Horn et al., The Elbert Magnetic Convection Range. 1. Linear theory, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2022). DOI: 10.1098 / rspa.2022.0313
University of California, Los Angeles
the quote: Her work helped her boss win the Nobel Prize. Now Spotlight (2022, September 15) Retrieved September 16, 2022 from https://phys.org/news/2022-09-boss-nobel-prize-spotlight.html
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