Galileo could not have built the world’s first astronomical telescope without a revolutionary new theory of optics that he must have kept secret, argue historians of science.
The Renaissance physicist, mathematician, philosopher and astronomer Galileo Galilei is perhaps best known for his work on gravity, relative motion and the discovery of numerous astronomical objects such as Jupiter’s four largest moons, the phases of Venus and so on.
But just as remarkable is Galileo’s work as an optical engineer on the design of the telescope. Galileo didn’t invent the telescope but he did adapt the design of the spyglass for astronomical purposes.
In fact, Galileo’s improvements were extraordinary. Between the summer 1609 and the beginning of January 1610, Galileo increased the magnification of his telescope by a factor of 21. He also introduced a number of modifications, such as the ability to control its aperture, that helped to reduce optical aberrations.
It was these changes that turned an ordinary spyglass into a revolutionary astronomical instrument.
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