Erich Rudolf Alexander Regener (12 November 1881 – 27 February 1955) was a German physicist known primarily for the design and construction of instruments to measure cosmic ray intensity at various altitudes.Regener was born in Schleusenau (Wilczak) near Bromberg (Bydgoszcz), West Prussia. He studied physics from 1900 to 1905 at the University of Berlin under Emil Warburg and from 1909 worked with Heinrich Rubens.