Field record · Biological mechanism
Sea turtles
Placed beside migratory birds as two biological solutions to 'which way now?' Placed beside Hōkūleʻa only as an editorial parallel of ocean travel. No claim that voyagers learned from turtles, or turtles from voyagers.
This correspondence holds · Sources checked · Experimental work from the 1990s onward
Observed
- Loggerhead hatchlings can detect both the intensity and inclination of Earth's magnetic field.
- Kenneth and Catherine Lohmann's laboratory work showed that turtles can use magnetic values as map information, not only as a compass heading.
- Adults of several species return to natal regions to nest, a fact compatible with a learned or inherited magnetic map.
Connection
Placed beside migratory birds as two biological solutions to 'which way now?' Placed beside Hōkūleʻa only as an editorial parallel of ocean travel. No claim that voyagers learned from turtles, or turtles from voyagers.
- Biological mechanism
- Editorial parallel
Interpretation
A map can live in a body. That does not make every map the same kind. The turtle's field is physics sensed by flesh. The canoe's star compass is a taught practice. The Magi's star is a sign in a story.
Placed beside
Keep the difference visible
This record
Sea turtles
Biological mechanism
Beside
Migratory birds
Biological mechanism
Beside
Hōkūleʻa, Star of Gladness
Historical transmission
Beside
Kosmos, as order
Linguistic descent
Mechanism
Known biological. Geomagnetic orientation in sea turtles is experimentally supported. How the sense is transduced remains researched. Existence of the map-and-compass behavior is what this plate claims.
Open questions
What would a honest comparison between a magnetic map and a star compass actually measure?
Where does analogical wonder stop being information?
Sources
- Lohmann, Lohmann, and colleagues, geomagnetic map in sea turtles · Experimental literature from the 1990s onward showing intensity and inclination used as positional cues.
- NOAA Fisheries, sea turtle navigation overview · Public agency context for the animals. Not a substitute for the laboratory papers.
Related records
Canonical plate. · Sources checked.