Thermoremanent magnetisation (south-pointing fish)
Imantación por termorremanencia (pez que señala el sur)
- Date
- 1044 · confidence high
- Place
- Kaifeng, Henan, China
- Credited to
- Zeng Gongliang (Wujing zongyao)
- People
- 👤 Zeng Gongliang998–1078
- Field
- Cosmos & Earth
What was discovered
An iron sheet shaped like a fish was heated red-hot and cooled while oriented north-south, becoming magnetised; floating on water, it pointed south. It is the first description of thermoremanent magnetisation.
The phenomenon was not studied scientifically in Europe until Gilbert (1600).
What it led to
- magnetic needles without the need for magnetite
- water compass for orientation
Built on
- Lodestone spoon compass (Si Nan)