How did astronomers manage to probe the Universe with ever greater precision, to the point of building the largest telescopes in the world ? To answer this question, we must go back to the mid-19th century. At that time, a French physicist, Hippolyte Fizeau, laid the foundations for a technique that would revolutionise astronomical observation : interferometry. The principle consists of combining the light collected by several instruments in order to increase their resolving power, as if they formed a single, immense telescope. It was a bold idea for its time, requiring more than a century of theoretical and technological development to reach full maturity.
This scientific epic — in which the Paris Observatory played a major role — is made up of groundbreaking insights, technical innovations and international collaborations. From the first idea sketched on paper to modern instruments capable of revealing the most subtle details of stars and galaxies, Eitan Péchevis, an optical research engineer at LIRA, explains in a video how scientific perseverance transformed a visionary intuition into a major tool of contemporary astronomy.
