[2] Alt was born in 1950 in Wolfersweiler, a town in Saarland that later became incorporated into Nohfelden.
[1] He became a student of Kurt Mehlhorn at Saarland University, where he completed his Ph.D. in 1976 on algorithms for parsing context-free languages.
[3] At the Free University of Berlin, he became the doctoral advisor of many successful students,[1] including Otfried Cheong (1992), Johannes Blömer (1993), Christian Knauer (2002), Carola Wenk (2002), and Maike Buchin (2007).
[3] The Free University of Berlin held a symposium on 2015 in honor of Alt's 65th birthday.
[1] At the same International Symposium on Computational Geometry, Alt's work with Michael Godau on using Fréchet distance to measure the similarity of shapes (announced at the 1992 symposium and published in a 1995 journal paper) was given the SoCG Test of Time Award.