Arago (1810): the first experimental result against the ether
Aristotle: The first encyclopedist
Around Kepler's "Dream"
Associated Sturm-Liouville systems
Astronomical Symbolism in Australian Aboriginal Rock Art
Astronomy and astronomers in Jules Verne's novels
Astronomy and the Fall of Babylon
Astrophysical Paradoxes, long version
Asymptotic freedom: history and interpretation
At the other end of the sun's path. A new interpretation of Machu Picchu
Atomic Modeling in the Early 20th Century: 1904 - 1913
Australian Aboriginal Geomythology: Eyewitness Accounts of Cosmic Impacts?