In May 1919, astronomer Arthur Eddington traveled to the island of Principe and the Brazilian city of Sobral to document a total solar eclipse. His objective was clear. He wanted to verify Albert Einstein’s general theory of relativity, which suggested that gravity acts as a warping of spacetime rather than a simple pulling force. Einstein predicted that the sun should bend the light of distant stars, a phenomenon impossible to observe during normal daylight due to solar glare.
The eclipse provided the necessary darkness to test this theory. Eddington set up telescopes at both sites and compared his photographs to established star maps. The data confirmed that stars appeared exactly where Einstein’s calculations predicted they would be. This experiment became one of the defining moments of 20th-century physics, proving that light waves are deviated by the gravity of large bodies.
Now, 107 years after that historic observation, the scientific community revisits this landmark event. Matthias Harksen, a doctoral student at the University of Iceland, intends to replicate the experiment during the current total solar eclipse. While the technology has moved forward since 1919, the core methodology remains accessible to anyone with a telescope and proper solar filtration equipment.
Harksen aims to demonstrate the continued relevance of Einstein’s work by encouraging others to participate in the observation. The history of this experiment serves as a reminder of how observation and rigorous testing define our understanding of the universe. For those interested in replicating this or observing the eclipse, the use of proper solar filters is a requirement for safety to avoid permanent eye damage.