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Confirming Einstein

September 21, 2022

For William Campbell and his team from Lick Observatory, it had been a long journey. It took months to sail from California to Australia, travel the full width of the country, then sail to a remote beach on the western coast. It took weeks more for the team of 30 men and five women to set up its equipment. And all of that to see five minutes of darkness — a total solar eclipse — 100 years ago today.

Campbell and his team were trying to confirm observations made during an eclipse in 1919. If they were successful, they’d provide key proof of Albert Einstein’s theory of gravity.

Einstein published his theory in 1915. Among other things, it predicted that stars and other massive objects would “warp” the space around them. The effect could be seen during a total eclipse. Astronomers would measure the positions of stars that appeared near the Sun. If Einstein was right, there’d be a tiny shift compared to the usual positions of the stars.

Observations in 1919 confirmed Einstein’s theory. But there were questions about the results. So astronomers tried again in 1922.

Campbell’s team was one of several to make the attempt. And it was the most successful by far. Its pictures showed more than a hundred stars around the Sun. Painstaking analysis confirmed that the light of the stars closest to the Sun had been deflected by the Sun’s gravity — once again proving Einstein right.

Script by Damond Benningfield

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