1 The Tausk Controversy in the Foundations of Quantum Mechanics: Politics, Mentorship and a Dissenters Disappearance Abbreviated title: Tausk Controversy in the Foundations of Quantum Mechanics Osvaldo Pessoa Jr. Depto. de Filosofia, FFLCH Universidade de Sªo Paulo Av. Prof. Luciano Gualberto, 315 05508-900, Sªo Paulo, SP, Brazil Tel./Fax: +55-11-3091-3761 e-mail: opessoa@usp.br Olival Freire Jr. Programa em Ensino, Histria e Filosofia das CiŒncias (UFBa-UEFS) Inst. de Fsica, Universidade Federal da Bahia 40210-340, Salvador, BA, Brazil e-mail: freirejr@ufba.br Alexis De Greiff A. Departamento de Sociologa/Centro de Estudios Sociales Universidad Nacional de Colombia BogotÆ, Colombia e-mail: ahdegreiffa@unal.edu.co Abstract: In 1966, the Brazilian physicist Klaus Tausk circulated a preprint from the International Centre for Theoretical Physics, in Trieste, criticizing the theory put forward by Daneri, Loinger & Prosperi on the measurement problem in quantum mechanics. This led to a heated controversy, which reflected two opposing camps within the orthodox interpretation of quantum theory, represented by LØon Rosenfeld and Eugene Wigner. But the controversy also went beyond the strictly scientific issues, involving the political context of the Cold War, the relations between developed and Third world countries, the use of social skills, and personal idiosyncrasies. Key words: foundations of quantum mechanics; measurement problem; scientific controversy; International Centre for Theoretical Physics; Third World science; Klaus S. Tausk Biographical notes: Osvaldo Pessoa Jr. is professor of philosophy of science at the Universidade de Sªo Paulo, and has worked on the measurement problem in quantum mechanics. Olival Freire Jr. teaches history of physics at the Universidade Federal da Bahia. He has worked on the history of the foundations of quantum mechanics. Alexis De Greiff has published on discourses and practices of South-North scientific exchange in the 20th century, and teaches at the Universidad Nacional de Colombia.