Has the Earth’s Rotation Changed?
Kant asks whether the length of the day can vary across Earth’s history. He seeks physical causes capable of gradually altering rotation, particularly interactions associated with tides.
Understanding the text
The essay answers a question proposed by the Berlin Academy. Apparent celestial stability becomes something to explain rather than a guarantee of immutability.
Key points
- 01
Measurable history
Daily regularity can conceal changes too slow for ordinary observation to detect.
- 02
Tides and resistance
Water movement offers a possible mechanism linking terrestrial rotation with gravitational interaction.
- 03
Hypothesis and evidence
A plausible cause does not replace observations needed to establish the actual magnitude of its effect.
How to read it
Distinguish the proposed mechanism, eighteenth-century evidence, and contemporary astronomical measurements.
Editions & sources
Summaries and key points are original editorial interpretations. They accompany reading the work and do not replace an edition of the text. Editorial method ↗