Polar night

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

Field Hierarchy

Parent
Biology 36M papers	Physics 33M papers	Quantum mechanics 13.3M papers	Geography 13.2M papers
Geology 10.4M papers	Ecology 8.1M papers	Meteorology 2.8M papers	Astronomy 2.7M papers
Oceanography 2.6M papers		Climatology 706k papers
Current
Polar night 1,483 papers
Child

Trends

Notes

History