Deep Time · Side by side

Two chapters, the same questions asked of both

Put two Deep Time chapters next to each other — their evidence base, the dating methods behind them, the live debates, and the questions still open.

Documented476 – 1500 CE

Middle Ages

What survived antiquity, what was copied, and what was lost in transmission.

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Documented1438 – 1533 CE

Inca

Road systems, khipu record-keeping, and stonework still being reverse-engineered.

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The evidence base

Charters, chronicles, manuscript libraries, standing buildings, archaeology of towns and farms, and increasingly dendrochronology and ancient DNA.

Monumental stone architecture, the road network, khipu cord records, Spanish administrative inspections, and Andean archaeology across a vast altitudinal range.

How we know
MethodWhat it constrains
DendrochronologyTimber in standing buildings and waterlogged depositsCan date felling to a year, which anchors both buildings and climate records.
Ancient pathogen genomicsDental pulp from plague-period burialsIdentifies the pathogen and its lineage. Mortality rates still come from documentary estimates.
Charter and archival analysisLand grants, court rolls and account booksProvides granular economic and legal data, skewed toward institutions that kept archives.
MethodWhat it constrains
Architectural and quarry analysisTool marks, unfinished blocks and abandoned quarry stonesDocuments shaping and transport methods. Exact logistics of the largest blocks are still modelled.
Khipu structural studyCord, knot type, ply direction and colour in surviving khipuNumerical content is readable. Whether narrative content is encoded remains open.
Colonial administrative recordsInspections and tribute assessmentsPreserves detail about the Inca system through a Spanish administrative lens.
Where specialists disagree
  • How severe was post-Roman economic contraction in the west?

    Pottery distribution and settlement data show sharp regional variation.

  • What ended the medieval period?

    The boundary is a historiographic convenience, drawn differently by region and discipline.

  • Do khipu encode language as well as numbers?

    Some khipu resist purely numerical interpretation; no reading has been independently reproduced.

  • What was Machu Picchu for?

    Royal estate is the leading reading, based on a colonial land document and site layout.

Still open
  • How did climate shifts interact with famine and plague?
  • How much rural life is recoverable outside manorial records?
  • How much manuscript material still sits uncatalogued in European libraries?
  • Can khipu be read beyond accounting?
  • How were labour obligations organised across the whole empire?
  • How much high-altitude archaeology remains unsurveyed?