Were Miguel de Cervantes and Johannes Kepler alive at the same time?
Yes. Miguel de Cervantes and Johannes Kepler were alive at the same time for 44 years, from 1571 to 1616.
Johannes Kepler was 44 when Miguel de Cervantes died.
Johannes Kepler
German mathematician and astronomer
Born 27 December 1571 · died 15 November 1630, aged 58