Definition:Time/Unit/Great Year of Plato/Historical Note
< Definition:Time | Unit | Great Year of Plato
Jump to navigation
Jump to search
Historical Note on Great Year of Plato
The great year of Plato was never actually mentioned by Plato himself.
The concept was raised in the context of the precession of the equinoxes, supposed to have been discovered by Hipparchus of Nicaea.
It was Claudius Ptolemy who (mistakenly or dishonestly) who determined that the time period was $12 \, 960 \, 000$ days of $360$ years.
The actual period is approximately $25 \, 800$ years, referred to as a Platonic year.
Sources
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $12,960,000$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $12,960,000$