1820s in science

thumb|upright=0.89|right|This earliest known surviving heliographic engraving, printed from a metal plate made in 1825 by Joseph Nicéphore Niépce using his "heliographic process". The plate was exposed under an ordinary engraving. Heliography was also used to capture View from the Window at Le Gras|a scene directly from nature with a camera.

overview of natural science-related events during the year of 1820

overview of natural science-related events during the year of 1823

overview of natural science-related events during the year of 1826

overview of natural science-related events during the year of 1824

overview of natural science-related events during the year of 1821

overview of natural science-related events during the year of 1829

overview of natural science-related events during the year of 1822

overview of natural science-related events during the year of 1825

overview of natural science-related events during the year of 1827

overview of natural science-related events during the year of 1828