Wallal means "sweet water", a source of fresh water. It is located next to Eighty Mile Beach on the lands of the Nyangumarta people of Western Australia's Kimberley region — looking out to the Indian Ocean and upwards to the starry skies of the southern hemisphere.
At the beginning of the 20th century, it had a telegraph station and a Nyangumarta population of about 100 people.
In 1922, explorers arrived whose principal interest was in starry skies and a new idea about space and time. We know that idea as Albert Einstein's Theory of General Relativity and it was an extraordinary, all-encompassing vision.
Einstein suggested that gravitational objects experiencing gravitational attraction towards each other, warped space-time around them – curving as it did so. Light from a distant star would bend as it entered our Sun's gravitational field.
This idea could be tested by capturing light beams on photographs, provided they were not blotted out by the overwhelming light of the Sun. People had the cameras, they just needed a total solar eclipse to test the theory.
An eclipse was due on September 21, 1922 that would begin in Somalia, then pass through Christmas Island and many different locations on the Australian mainland — the first of those locations was Wallal.
The University of Western Australia had an enterprising foundation Professor of Mathematics and Physics who was determined that Wallal would play a role. Professor Alexander Ross formed a collaboration with astronomers from the University of California's Lick Observatory, rebuking the British astronomers who chose to concentrate their efforts on Christmas Island.
The Lick Observatory team was headed by William Wallace Campbell, who had already tried to test Einstein's theory by photographing solar eclipses but none of the images had provided conclusive proof that Einstein was correct.
Campbell sailed from San Francisco to Australia, and after long rail journeys arrived in Perth along with a team from Canada. On August 20, the expedition sailed for Broome with Ross and a team from the Perth Observatory. There they met a husband-and-wife team from India, before heading to Wallal, where the Nyangumarta helped unload more than 35 tonnes of equipment.
A darkroom was created by pitching a tent between trees but it proved too dusty. In the end, the photographs that would change the world of science were developed in what are now the ladies' toilets of the Broome Bowling Club – in those days, the Broome Coastal Radio Station.
A host of instruments measured temperature, air pressure, humidity and the wind. Accurate time measurements came by the "wireless" from the Perth and Adelaide observatories, as well as observatories at Annapolis in the United States and Bordeaux in France.
The immense effort proved worthwhile; of all the photographs of the 1922 Solar Eclipse, those taken at Wallal were the best and most useful. Human effort and determination were aided by clear skies and ideal weather for the task.
Einstein could take a bow. The observations, Campbell reported, agreed "exactly with Einstein's prediction".
To learn more about UWA's celebration of the Wallal Expedition Centenary, click here.
