A glimpse into Feynman{'}s contributions to the debate on the foundations of quantum mechanics

The broad debate on foundational issues in quantum mechanics, which took place at the famous 1957 Chapel Hill conference on The Role of Gravitation in Physics, is here critically analyzed with an emphasis on Richard Feynman’s contributions. One of the most debated questions at Chapel Hill was whether the gravitational field had to be quantized and its possible role in wave function collapse. Feynman’s arguments in favor of the quantization of the gravitational field, based essentially on a series of gedanken experiments, are here discussed. Then the related problem of the wave function collapse, for which Feynman hints to decoherence as a possible solution, is discussed. Finally, another topic is analyzed, concerning the role of the observer in a closed Universe. In this respect, Feynman’s many-worlds characterization of Everett’s approach at Chapel Hill is discussed, together with later contributions of his, including a kind of Schrödinger’s cat paradox, which are scattered throughout the 1962-63 Lectures on Gravitation. Philosophical implications of Feynman’s ideas in relation to foundational issues are also discussed.