# Dating the past

Tree rings, layers in ice and radiocarbon in old wood and bone give dates to things without calendars. Eclipses in old chronicles act as anchor points, because astronomers can compute exactly when each one happened.

Connects to:
- [Calendars](https://mapideas.org/i/ti_calendars)
- [Records of the sky](https://mapideas.org/i/hi_skyrecords)
- [Sources and voices](https://mapideas.org/i/hi_sources)
- [How do we know what happened?](https://mapideas.org/i/q_hist_know)
- [How long can a story stay true?](https://mapideas.org/i/q_hist_story)
- [How sure can a date be?](https://mapideas.org/i/q_hist_date)
- [The age of people](https://mapideas.org/i/ea_anthro)
- [Should this age be named?](https://mapideas.org/i/q_x_name_age)

Sources:
- [Wikipedia: Radiocarbon dating](https://en.wikipedia.org/wiki/Radiocarbon_dating)
- [Wikipedia: Dendrochronology](https://en.wikipedia.org/wiki/Dendrochronology)

Source: https://mapideas.org/i/hi_dating · open on the map: https://mapideas.org/#hi_dating