Today the results of the 1919 eclipse have been announced in the history of astronomy, supporting Albert Einstein’s theory of general relativity.
The Sun’s mass bends the path of light from the background star. In 1919, astronomers measured this deflection in the first test of Albert Einstein’s general theory of relativity. Astronomy: Roan Kelly
- The total solar eclipse of 1919 provided the first empirical test of Albert Einstein’s general theory of relativity, specifically measuring how the Sun distorts light from background stars.
- General relativity holds that any object with mass distorts space-time, causing all passing bodies, including light photons, to follow curved trajectories.
- Researchers on expeditions to northern Brazil and a western African island compared pre-eclipse stellar conditions to those observed during totality, with the goal of detecting an estimated shift of 1.75 arcseconds.
- Shifts of approximately 1.98 and 1.61 arcseconds were observed, consistent with the theory’s prediction, leading to the public announcement of the results on November 6, 1919, and increased Einstein’s recognition.
The first test of Albert Einstein’s general theory of relativity occurred just four years after it was published. During the total solar eclipse of May 29, 1919, British astronomer Sir Arthur Eddington and his colleagues studied the theory of how the Sun distorts light from background stars.
According to general relativity, any object with mass rotates in space-time. (The usual analogy is that it is similar to a bowling ball on a trampoline.) Therefore, any passing body will follow a curved trajectory; This is true whether the passing object is an orbiting satellite or light photons from a background object.
Researchers associated with the 1919 eclipse expedition traveled to two locations to observe totality: northern Brazil and a western island in Africa. According to general relativity, the apparent position of stars near the Sun will appear to vary by as much as 1.75 arcseconds. Scientists first measured the positions of stars in the Hydra star cluster as early as 1919. Eddington and his colleagues then recorded the locations of the stars during totality, and compared them to previous values. They found that, in fact, the background stars appeared to change by approximately the same amount that general relativity had predicted. (They measured 1.98 arcseconds and 1.61 arcseconds.) The researchers announced their data on November 6, 1919, and Einstein quickly became a household name.
