Portrait of Galileo with two of his telescopes, 1610
© Science Museum / Science & Society Picture Library
This is a replica of the earliest refracting telescopes made by Galileo Galilei (1564-1642). They consist of a convex objective lens and a smaller concave eyepiece lens. The former, gathers light from a distant object and forms them into an upside-down image. In turn, the eyepiece lens clarifies the image by bending the light into parallel lines. Galileo used this telescope to see the moon, the milky way and four of Jupiter's planets. Galileo was an Italian astronomer and physicist and an outstanding representative of the movement which transformed medieval natural philosphy into modern science.