Grinding clarity: The discovery of the telescope

Refractor Cincinnati observatory (© Smith’s Illustrated Astronomy)

One thousand years ago, an Arab scientist described the amazing magnifying properties of a glass lens. It took another three hundred years before an accurate lens was made, and another three hundred before it was discovered that lenses could be combined to make optical instruments. That launched one of the most extraordinary and important scientific discoveries ever. 

As Francis Rolt discovers, the magnifying lens made possible the development of the telescope, first recorded in 1608 when Hans Lipperhey petitioned the States General of the Netherlands for a patent, as did Antonie van Leeuwenhoek of Delft around the same time. How did this discovery come about? How have scientists used and developed lenses over time?

Francis looks at the way the glass lens was developed by Dutch lens grinders, how it has altered history and our understanding of the universe. 

Producer: Francis Rolt

Broadcast: April 2, 1999