Science & Discovery in the 2nd century

24 sourced entries, 100 CE to 194 CE, oldest first. Also see Science & Discovery across every century or everything else in the 2nd century.

• 100In China, the wheelbarrow makes its first appearance.source
• 101Epictetus writes and publishes The Discourses of Epictetus (approximate date).source
• 104Nijmegen is renamed Ulpia Noviomagus Batavorum.source
• 106Aelianus Tacticus (or Aelian) writes his Taktike Theoria (approximate date).source
• 108Tacitus writes Histories, which covers the period from AD 69 to AD 96.source
• 110Suetonius, Roman historian, publishes Viris Illustribus ("On Famous Men" – in the field of literature).source
• 120A Kushan ambassadorial contingent visits with Hadrian.source
• 123Chinese scientist Zhang Heng adjusts the calendar to bring it into line with the four seasons.source
• 124Antinous becomes Hadrian's beloved companion on his journeys through the Roman Empire.source
• 130Claudius Ptolemaeus tabulates angles of refraction for several media.source
• 1416th recorded perihelion passage of Halley's Comet.source
• 142The Chinese Taoist alchemist Wei Boyang, author of the Kinship of the Three, is the first to describe an early form of gunpowder solution.source
• 150This is also the approximate date of completion of Ptolemy's monumental work Almagest. The geocentric cosmology contained in it holds sway for 1,400 years.source
• 150Antoninus Liberalis writes a work on mythology (Μεταμορφωσεων Συναγωγη) (approximate date).source
• 154Anicetus meets with Polycarp of Smyrna to discuss the Computus, the date of Easter in the Christian liturgical calendar.source
• 156The La Mojarra Stela 1 is produced in Mesoamerica.source
• 161Gaius' Institutiones are published.source
• 162Arrian, Greek historian and writer, publishes Indica, a work on India and its people.source
• 179Han dynasty China: The full title of the Nine Chapters on the Mathematical Art appears on two bronze standard measures dated to this year, yet there is speculation that the same book existed beforehand only under different titles. In the 3rd century, Liu Hui would provide commentary on this important early Chinese mathematical treatise.source
• 185A supernova now known as SN 185 is noted by Chinese astronomers in the Astrological Annals of the Houhanshu, making it the earliest recorded supernova.source
• 185Cleomedes discovers the refraction of light by the Earth's atmosphere.source
• 190Cleomedes teaches that the moon does not glow on its own, but rather reflects sunlight.source
• 191c. 191–192 – The sculpture of Commodus as Hercules, from Esquiline Hill, Rome, is made (it is now kept at Palazzo dei Conservatori, Rome).source
• 194Galen writes his manual on pathology, The Art of Curing (approximate date).source