Polar night

https://www.wikidata.org/wiki/Q190991

Field Hierarchy

Parent
Biology 34.8M papers	Physics 31.7M papers	Quantum mechanics 13.1M papers	Geography 11.1M papers
Geology 9.1M papers	Ecology 7.8M papers	Meteorology 2.6M papers	Astronomy 2.5M papers
Oceanography 2.4M papers		Climatology 637k papers
Current
Polar night 1,407 papers
Child

Trends

Notes

History