![François Levrier on Twitter: "Galileo Galilei was born #OTD in 1564. One of the founders of modern science, he used a refractive telescope to expand our view of the sky, observing the François Levrier on Twitter: "Galileo Galilei was born #OTD in 1564. One of the founders of modern science, he used a refractive telescope to expand our view of the sky, observing the](https://pbs.twimg.com/media/FLnYTwAXsAEDyO-.jpg:large)
François Levrier on Twitter: "Galileo Galilei was born #OTD in 1564. One of the founders of modern science, he used a refractive telescope to expand our view of the sky, observing the
![File:Galileo's geometrical and military compass in Putnam Gallery, 2009-11-24.jpg - Wikimedia Commons File:Galileo's geometrical and military compass in Putnam Gallery, 2009-11-24.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/4/48/Galileo%27s_geometrical_and_military_compass_in_Putnam_Gallery%2C_2009-11-24.jpg)
File:Galileo's geometrical and military compass in Putnam Gallery, 2009-11-24.jpg - Wikimedia Commons
![File:Galileo Galilei (1564-1642). Oil painting by an Italian pain Wellcome V0023487.jpg - Wikimedia Commons File:Galileo Galilei (1564-1642). Oil painting by an Italian pain Wellcome V0023487.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Galileo_Galilei_%281564-1642%29._Oil_painting_by_an_Italian_pain_Wellcome_V0023487.jpg/800px-Galileo_Galilei_%281564-1642%29._Oil_painting_by_an_Italian_pain_Wellcome_V0023487.jpg)