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The year 1723 in science and technology involved some significant events.
Geophysics
- George Graham discovers diurnal variation in Earth's magnetic field.
- Antoine de Jussieu publishes De l'Origine et des usages de la Pierre de Foudre on the origins of fossils, prehistoric stone tools and meteorites.
Optics
- Giacomo F. Maraldi makes the first observation of the Arago spot, unrecognized at this time.
Births
- January 5 – Nicole-Reine Lepaute, French astronomer (died 1788)
- January 31 – Petronella Johanna de Timmerman, Dutch scientist (died 1786)
- February 17 – Tobias Mayer, German cartographer, astronomer and physicist (died 1762)
- April 30 – Mathurin Jacques Brisson, French zoologist (died 1806)
- November 12 – Saverio Manetti, Italian natural historian (died 1785)
Deaths
- August 26 – Anton van Leeuwenhoek, Dutch pioneer of the microscope (born 1632)