stonehenge and similar to give solstice information and the solar year
lunisolar calendars - attempts to match lunar cycles into the solar year
sun dials to give time of day
Babylonians:
sidereal month - time it takes the Moon to pass twice a “fixed” star
synodic month - time interval between two consecutive occurrences of a particular phase
anomalistic month - average time the Moon takes to go from perigee to perigee—the point in the Moon's orbit when it is closest to Earth
draconic month - the period in which the Moon returns to the same node of its orbit;
Saros cycle of eclipses - 223 synodic (lunar) months or approx. approximately 6585.3211 days (18 years and 10-12 days depending on leap years)
Three periodicities related to lunar orbit, the synodic month, the draconic month, and the anomalistic month coincide almost perfectly each saros cycle.
6-7thC BC: Roman calendar which had intercalarus years with a short Feb of 23-4 days (28 days in common years which were 355 days) and an extra intercalarus month of 27-28 days in intercalarus years (377-378 days)
6thC BC: incorrect geocentric model of the universe proposed by Anaximander and main concept of everything rotating around earth was perpetuated, and standardised by Claudius Ptolemaeus in 2ndC AD as the Ptolemaic model until Copernican revolution changed the concept to a heliocentric model
5thC BC: Metonic cycle of the moon phases of approx. 19 years (6940 days) by which time the moon phases occur at same time of year named after Meton of Athens
5thC BC: ancient Greek philosopher Parmenides
devised a
mathematical model of how the moon and planets moved and this model was presumably used to create what appears to be the
first mechanical computer - the intricate geared Antikythera Mechanism found on a Roman ship
2)
3rdC BC: heliocentric concept proposed by Aristarchus of Samos but seemingly lost and not accepted again until 16-17thC AD
45BC: Julian calendar introduced as a reform of the Roman calendar
a 3 normal years of 365 days and then one leap year of 366 days
removed the extra intercalarus month
Jan, Aug and Dec 31 days not 29, Feb 28 and 29 in leap year, Apr, Jun, Sep, Nov 30 days not 29 days
still used in parts of the Eastern Orthodox Church and in parts of Oriental Orthodoxy as well as by the Berbers
2ndC AD: Claudius Ptolemaeus standardised the geocentric model which became the Ptolemaic model
5thC AD: Indian mathematician Aryabhata, correctly insisted that the earth rotates about its axis daily, and that the apparent movement of the stars is a relative motion caused by the rotation of the earth, contrary to the then-prevailing view, that the sky rotated. This was not accepted by Western world until 16thC with Copernicus
1252: Alfonsine tables of ephemerides - new Spanish tables based on earlier astronomical works and observations by Islamic astronomers and contemporary Spanish and Jewish astronomers
1543: Nicolaus Copernicus published De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) triggered the Copernican Revolution of the heliocentric concept of the solar system
1551:Erasmus Reinhold published his Prutenic Tables astronomical ephemeris
1601: Johannes Kepler - suggested elliptical orbits and gravitation model of orbits and lunar link with tides which had been noted by sailors; inverse-square law governing the intensity of light;
1627: Johannes Kepler publishes his Rudolphine Tables of ephemirides
1582: Gregorian calendar introduced by Pope Gregory XIII to replace the Julian calendar to reduce the average length of the year from 365.25 days to 365.2425 days and thus corrected the Julian calendar's drift against the solar year which meant that the Julian calendar gained a day every 128 years.
18-19thc AD: realisation that the sun is not the centre of the universe