Web page: many of Galileo's manuscripts are now on the Internet, including this one showing an experimental protocol for checking his theory of. projectile motion. Credit: BIBLIOTECA NAZIONALE CENTRALE, FLORENCE

Galileo Galilei's personal manuscripts, in which he wrote down the ideas, calculations and drawings that led to his theory of mechanics, can now be viewed on the Internet. It is believed to be the first historical scientific document of such significance to be made available in this way.

The 300-odd Internet folios are high-resolution photographs of Galileo's loose-leaf notes — in effect, his laboratory notebooks — from the late 1580s, when he was a young professor at the University of Pisa and still a follower of Aristotle, to 1638, when he published his Discorsi on mechanics. This publication marked a turning point in the development of scientific reasoning and opened the door to modern mechanics.

The Internet publication is a combined project by the Italian National Library of Florence, where most of Galileo's original texts are held, the Institute and Museum for the History of Science in Florence, and the Max Planck Institute for the History of Science in Berlin. All of the Latin and Italian text in the manuscripts has been transcribed and is provided in Italian and English.

The text of the Discorsi is also on the web site and there are hypertext links between the notes and relevant pages in the Discorsi. The website will be modified in response to input from Galileo scholars.

“The Internet is changing the relationship between scholars, libraries and publishers”, says Jürgen Renn, director of the Berlin Max Planck Institute. Web access means scholars no longer need to travel to the National Library in Florence to access Galileo's work. Renn says plans to include the collected works of Albert Einstein were abandoned because of copyright problems.

The texts are available on or