The great American solar eclipse from the 20th Century to today

A photo of a young Albert Einstein taken sometime between 1921 and 1923, six years earlier, Einstein published his Theory of General Relativity. Photo Credit: Library of Congress

WASHINGTON (Sinclair Broadcast Group) - At the turn of the 20th century, scientists were making significant advancements in eclipse study.


Albert Einstein published his Theory of General Relativity in 1915. He proposed “that gravity is not an actual force, but is instead a geometric distortion of space-time not predicted by ordinary Newtonian physics,” according to NASA. The greater the mass and gravitational pull, the greater distortion. This would apply to all objects moving through space in a vacuum, including rays of light.

To understand if this distortion occurs during an eclipse, measurements are needed of the star placements around the sun before, during and after the eclipse takes place. Because the sky does not always completely darken, this made Einstein theory difficult to test during solar eclipses more than a century ago. On June 8, 1918, a total solar eclipse stretched across the country from Washington to Flordia.

But it was the following year in 1919, Sir Arthur Eddington, a British physicist, attempted to test Einstein’s theory by measuring the placement of stars by taking photographs during a solar eclipse.


“The curvature of such threads is being carefully studied with the view of learning more about the magnetism of the sun,” one report wrote in the Washington Evening Star newspaper.

After the Sept. 10, 1923, solar eclipse, Manger White of the San Diego Sun, won the 1924 Pulitzer Prize for vividly reporting on the celestial event. The Washington Evening Star newspaper, which ended circulation in 1981, wrote about the questions scientists still had regarding the study of eclipses.

“The sun rotates in about twenty-five days. Does the Corona rotate with it? We are trying to find out. The corona contains a substance or substances unknown on the earth,” the newspaper wrote.

We now know that sun rotates on its axis “in about 27 days,” according to NASA. The solar rotation itself varies by latitude; meaning the corona won’t change much when we observe the eclipse Aug. 21. We also know that the sun is mostly made up of Hydrogen gas in the form of plasma.

Ivona Cetinic, NASA scientist with the Universities Space Research Association, said that by studying the sun we gain a greater understanding of life on earth.

“It starts off with this little plant like organisms that use solar energy to convert inorganic lifeless carbon into life form and also produce oxygen that we breathe. So, it is really crucial for us to understand the impact of sun on our climate but also life on earth,” Cetinic said.

She added that the discoveries and advancements made in the study of the sun and eclipses within the last hundred years have grown from the discoveries that proceeded them in a synergistic relationship.

“Each of these advances steps on top of each other and opens up a new way and a new door and brings a new dimension to our knowledge,” Cetinic said.


The last contiguous solar eclipse, meaning the eclipse crossed over states that bordered each other, was Feb. 26, 1979. The line of totality entered the United States between Washington and Oregon then traveled up into Canada. ABC News issued a special live report of the event on television.

As the eclipse neared the point of full totality over Oregon, the anchor described the scene as “midnight in Portland.”

As the eclipse reached totality, crowds off camera could be heard cheering.

When the event reached its conclusion, anchor Frank Reynolds signed off saying “not until Aug. 21, 2017, will another eclipse be visible from North America, that’s 38 years from now. May the shadow of the moon fall on a world at peace.”

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