How a total eclipse broke gravity wide open and proved Einstein right

Solar eclipses are an amazing sight that had inspired some amazing science. The upcoming April 8 eclipse will provide numerous opportunities for professional and amateur scientists, but those experiments will likely not measure up to one of the most important ones of the modern era.

(KXAN) -- Solar eclipses are an amazing sight that has inspired some amazing science. The upcoming April 8 eclipse will provide numerous opportunities for professional and amateur scientists, but those experiments will likely not measure up to one of the most important ones of the modern era.

On May 29, 1919, a total solar eclipse passed over the Earth and in the process proved Albert Einstein's theory of relativity.

According to Eclipse1919.org, the eclipse was observed by scientists Sir Arthur Eddington on the island of Principe, just off the coast of Africa, and a team consisting of Andrew Claude de le Cherois Crommelin and Charles Davidson in Sobral, Brazil. The teams were dispatched by astronomer Frank Watson Dyson to capture images of the sun during the eclipse in hopes of testing Einstein's theory.

Einstein's theory of relativity was published by the former patent clerk in 1915. It essentially boils down to massive objects in space, like a star, are capable of warping space and time due to their immense gravity. This warping includes things passing near that mass, like light.

For instance, a star that would normally be behind the sun would appear visible from Earth. This is because the sun's gravity would warp the light around it.

But how do you see a star in the middle of the day?

Proving relativity with an eclipse

Using an eclipse, scientists hoped to take photographs of the night sky that would become visible during totality. In the process, they hoped to photograph stars warped by the sun's gravity.

Einstein at this point wasn't famous or even known outside of scientific circles. His initial research, published in 1911, led to several expeditions to test the theory. All of those expeditions failed, which turned out to be lucky for Einstein. His initial calculations on how much the sun's gravity would warp light were actually off.

Eddington read about Einstein's theory in 1916 during World War I. A Quaker and conscientious objector, Eddington avoided being drafted after Dyson agreed to sponsor his trip to test Einstein's theory.

The two expeditions set off. Using photographic plates made of glass, they were able to capture the images of the night sky during totality, when the sun is completely blocked by the moon.

The photographs showed what Einstein predicted. Stars that were behind the sun were actually visible, their light warped by the sun's gravity.

The results of the expedition were announced in September 1919. Published around the world, they elevated Einstein to fame. In 1921, he was brought to England where he presented his theory of relativity to a crowd of around 1,000 people at the University of Manchester. He was then awarded an honorary degree of Doctor of Science.

The experiment was repeated multiple times in the years since. During the eclipse in 1922, scientists replicated the project in Australia. This experiment was used to confirm the results.

Other science with an eclipse

While the Eddington Experiment is the most famous bit of eclipse science, it isn't the only experiment. During the 2024 eclipse, NASA is planning to conduct several projects to study the corona of the sun and its inner atmosphere.

Observing animals is also the focus of the 2024 eclipse. The Solar Eclipse Safari project is a citizen science project asking people to document animal behavior during the eclipse. The group is looking to collect data on not just animals in the path of totality, but also those living outside it.

While NASA wants people to gather sounds from nature. The Eclipse Soundscapes Project is a citizen science project funded by NASA Science Activation. They're asking people to record the sounds of nature during the eclipse to help us understand the impacts the event will have on our ecosystem.