Early in 1919, two teams of British astronomers embarked on a journey to the far reaches of the planet to observe a solar eclipse. Nearly eight months later, on Nov. 6, 1919, the teams presented their findings before a packed audience of scientists in London. Their announcement changed forever how humans view the universe.

The teams’ report, coming less than a year after the end of World War I, was noteworthy for another reason: It may have helped heal the wounds of war. The British eclipse expedition was designed to test a new theory of gravity proposed by Albert Einstein, a German-born scientist who had published his work behind enemy lines. If the British proved him right, his theory would topple that of Isaac Newton, a founding father of modern scientific thought and a national hero in Britain.

Newton had viewed gravity as a force that acts across space, pulling massive bodies together. Einstein replaced that notion with the radical proposition that gravity is space. Rather than stiff and immutable as the floorboards of a stage, space and time, he said, jiggles like jelly. A massive body dents this jiggly space-time much the way a lead weight sags a sheet of rubber. Earth is attracted to the sun not because of a force but because the sun has dimpled the space-time through which our planet must travel.

As early as 1911, Einstein had suggested a way to verify his outlandish proposal, known as the general theory of relativity. If a body is massive enough — like the sun — scientists should be able to observe the curved or bent path of all objects traveling in its vicinity, even particles of starlight. Through a telescope, the bending of starlight would show up as a change in the apparent position of the star compared with its position when the sun was in another part of the sky.