Calculus is the temporal branch of mathematics. It studies how properties and functions change over time and it has applications in every analytical discipline. In Actionscript it crops up in all the tweening functions and all the 3D engines, where matrix calculus is used to perform transforms in 3D space.
Until recently the credit for the invention of Calculus was a hotly debated subject for mathematical historians. Both Isaac Newton and Gottfried Leibniz developed similar theories around the late 17th century and there is much debate over who got there first. According to recent research however they could have been beaten to the principles by around 2000 years.
In the digital age it is hard to imagine taking an old book, scraping off all it's text, then writing over it again - but that is what a palimpsest is. In the 13th century a monk, needing parchment for a new prayer book, set about reworking an old book for the purpose. The book he reworked contained copies of works by the 3rd century BC engineer and mathematician, Archimedes of Syracuse.
The contents of one of the works, entitled 'The Method', was unknown to scholars until recent multi-spectral analysis revealed it's contents. Images from the palimpsest and more about the project can be found at http://www.archimedespalimpsest.org/
via Long Now