Gotthilf Heinrich Ludwig HagenGotthilf Heinrich Ludwig Hagen
- February 3
) was a German physicist
and hydraulic engineer
Hagen was born in Königsberg, Brandenburg-Prussia (today Kaliningrad, Russia).
Independentlly of Jean Louis Marie Poiseuille (1797-1869) Hagen in 1839 carried out the first carefully documented friction experiments in low-speed tube laminar flow, from which the Hagen-Poiseuille law has arised.