The following article expands on highlights and insights from one of our Expert Series events, which are exclusive for Young Scholars and their parents.
Authored by: John Steele
Introduction
Solar eclipses are perhaps the most spectacular astronomical events it is possible to see. They are caused by the moon passing in between the Earth and the sun and casting its shadow on part of the Earth’s surface, and those within the path located within the umbral shadow (known as the “path of totality”) will see the sun’s disc vanish, leaving what looks like a ring of fire around a black disc. The sky will become dark, the air cools, and stars become visible. And then after only a few minutes the sun will reappear, the stars vanish, and the sky turn bright again.
The spectacular nature of solar eclipses means that people – both astronomers and everyday people – throughout history have seen them. They were often interpreted as signs of coming evil and feared by those that saw them. But they were also carefully observed by astronomers who figured out what caused them and developed methods to predict the eclipse in advance. The earliest methods for predicting eclipses were developed by the ancient Babylonians in what is now Iraq more than 2,500 years ago.
Eclipses are still important in science today. It was through an observation of the bending of starlight as it passed close to the sun seem during a total solar eclipse in 1919 that Albert Einstein’s theory of relativity – probably the most well-known and important theory in physics developed in modern times – was first proven. Observations of the corona of the sun made during total eclipses are used by astronomers to study how solar storms impact us on earth. But it is not just modern observations that are used by scientists. Reports of eclipses observed by ancient astronomers from China, Babylon, Greece, and the Arab world are used to study the long-term changes in the Earth’s rotation.
Highlights
The first attempts to scientifically predict eclipses were made more than 2,500 years ago in ancient Babylonia. These predictions were quite successful and the so-called Saros cycle of 223 synodic months identified by the Babylonians is still used today to catalogue eclipses.
Seeing a total solar eclipse often inspired both feelings of fear and excitement among ancient people. Eclipses were thought to foretell something bad like a famine or a war, but they were also seen as spectacular visual events in the sky.
Using observations of ancient eclipses, scientists have been able to show that the Earth’s rotation is gradually slowing down.
Things students can do to explore this topic further
Many local astronomical societies, universities, libraries, and schools are arranging events to safely watch the total solar eclipse that will take place on April 8th. In general, local astronomy societies are a great resource to connect to, not just for eclipses but for all aspects of astronomy.
Make sure you use proper eye protection when looking at the sun during the eclipse. You could also try viewing it in different ways, such as using a pinhole camera. For example, simply punch a tiny hole in a piece of card and hold it a short distance away from flat surface such as a wall or another piece of card. Move the card with the pinhole around until you can see a projection of the sun. (Do not look through the pinhole at the sun without proper eye protection!). For instructions on how to set up a pinhole viewer, have a look at https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/safety/ which also has other suggestions for viewing the eclipse.
If you are using a pinhole camera, try to see if you can estimate the magnitude of the eclipse (percentage of the sun that is covered)
Resources
Lots of information about the 2024 eclipse, about how to safely observe it, and about eclipses in general can be found on the NASA website: https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/
The recent book Eclipse and Revelation: Total Solar Eclipses in Science, History, Literature, and the Arts, edited by Henrike C. Lange and Tom McLeish, contains chapters which look at eclipses from all sorts of perspectives: the modern science of eclipses, the history of eclipse observation and prediction, the way eclipses have inspired art, literature and music, the effect of eclipses on the weather, and the way that animals react to eclipses. Unfortunately, the book is not available in an open-access form, but it can probably be found in many libraries.
Speaker Bio:
John Steele is Professor of the History of the Exact Sciences in Antiquity at Brown University where he teaches and researches the history of ancient astronomy. He is the author of several books and many articles on the topic and has appeared in television documentaries and on podcasts talking about Babylonian and Greek astronomy.
Permission Statement
This article is provided as a service of the Davidson Institute for Talent Development, a 501(c)3 nonprofit dedicated to supporting profoundly gifted young people 18 and under. To learn more about the Davidson Institute’s programs, please visit www.DavidsonGifted.org.
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