The Fifth International Conference on the History of Quantum Physics , or HQ5, is taking place from August 11 to 14 in Salvador, Brazil, hosted by the Federal University of Bahia. As an “IYQ Global Event,” it is receiving financial support through the International Year of Quantum Science and Technology that the United Nations proclaimed for 2025.

HQ5 revives a series that originated at the Max Planck Institute for the History of Science in Berlin in 2007. Subsequent conferences were held in Utrecht in 2008, Berlin again in 2010, and in Donostia-San Sebastian, Spain, in 2015.

Since the 1960s, the history of quantum physics has been the subject of more-or-less constant study, and the subject has rewarded the new methodological approaches brought to it by succeeding generations of scholars. In the 21st century, the HQ series has been invaluable in ensuring this work remains vital as we pass the centenary of the original revolution in quantum mechanics and as a new revolution takes place with the development of technologies grounded in foundational quantum behaviors.

In addition to the Federal University of Bahia, HQ5’s other organizing institutions are AIP, the Niels Bohr Archive in Copenhagen, and the Inter-Union Commission for the History and Philosophy of Physics. The conference is receiving additional sponsorship from the Brazilian National Council for Scientific and Technological Development (CNPq) and the International Union of Pure and Applied Physics.

HQ5’s organizing committee is Climério Silva Neto, Alexander Blum, Carla Almeida, Daniela Monaldi, Indianara Silva, Jinyan Liu, Roberto Lalli, Thiago Hartz, and Will Thomas. The advisory scientific committee is Alexei Kojevnikov, Christian Joas, Christoph Lehner, Connemara Doran, Ivã Gurgel, Jaume Navarro, John Norton, Joseph Martin, and Olival Freire, Jr.

Keynote lectures

Margriet van der Heijden, Women in the history of quantum physics: Beyond Knabenphysik

Hanoch Gutfreund, Quantum physics and dialectical materialism: The legacy of David Bohm

Danian Hu, China’s quantum journey: Prominent Chinese physics developments in the quantum century

Elise Crull, Hertha Sponer, maven of quantum spectroscopy

Alexei Kojevnikov, Revolutionary science in revolutionary society: Quantum mechanics and Soviet physics

Roundtables

Two decades of scholarship on the history of quantum mechanics

Coordinator: Daniela Monaldi

Participants: Elise Crull, Thiago Hartz, Alexei Kojevnikov, Jean-Philippe Martinez

Visions for the scholarship on the history of quantum mechanics

Coordinator: Will Thomas

Participants: Margriet van der Heijden, Jinyan Liu, Flavio Del Santo, Bernadette Lessel

Talks

Gonzalo Gimeno and Mercedes Xipell, Blurred orbits and blurred particles: Heisenberg’s 1926 helium atom

Tilman Sauer and Kristin Sellmann, From orbits to orbitals: Early visualizations of hydrogenic electron wave functions

Johannes-Geert Hagmann, Have you ever seen one? Contributions of laser spectroscopy to the first image of a trapped ion, 1970–1980

Julien Berry Minerbo, When the image is secondary: The Bachelardian atom

Vitória Chirazava, The duality of matter: Thomson and Davisson’s paths to electron diffraction

Noemi Bolzonetti, Bohr and Heisenberg: Debate on the γ-ray microscope

Alessio Rocci, The Solvay Science Project and the milestones of the (first) quantum revolution

Elena Schaa, A stroke of genius? The cultural roots and legacy of Heisenberg’s experience on Helgoland

Marcia Tiemi Saito, Sending madness to Copenhagen: The reception of Bohr’s ideas among non-physicists

Anja Skaar Jacobsen, Niels Bohr’s psychological analogies and quantum measurement

Diana Taschetto, Niels Bohr: The deeper insight

Christoph Lehner, The tangled tale of entanglement: New discoveries from Schrödinger’s research notes

Michelle Frank, Chien-Shiung Wu and the early entanglement experiments

Donald Salisbury, An analysis of the role of local gauge symmetry in the historical development of quantum theory

Jean-Philippe Martinez, From Dirac matrices to Mathematica: Quantum physics and the rise of computer algebra systems

Rafael Velloso Luz and Antonio A. P. Videira, Hans Thirring on quantum theory: The interplay between natural philosophy and physical conceptual systems

Flavio Del Santo, Against the “nightmare of a mechanically determined universe": Why Bohm was never a Bohmian

Bernadette Lessel, On Louis de Broglie‘s use of unified field theory in his quest for realism in quantum physics

Viktor Dodonov, Evolution of concepts of “uncertainty” since 1927: Various forms of “uncertainty relations” in 2025

Kostas Gavroglu, The (in)explicable quantum world of the very cold: Some historiographical issues

Daniela Monaldi, From Bose-Einstein statistics to photon statistics: The statistical style of scientific reasoning in the genesis of quantum optics

Gautier Depambour, From the foundations of quantum mechanics to quantum optics: How John Clauser and Alain Aspect came to study the quantum properties of light

Luca Campagnoni, Cosmic-ray experimental physicists and quantum mechanical theorists in the 1930s: A new archival source about Bruno Rossi

Ivã Gurgel, Thiago Hartz, and Christian Joas, The CERN Theoretical Study Group in Copenhagen, 1952–1957: Scientific collaboration, the history of quantum theory, and postwar transformations in the practices of physicists

Roberto Lalli, Fusion energy research as a diplomatic tool in European integration: A network approach

Posters

Beñat Monfort Urkizu, A posteriori theory adjustments in early universe cosmology: Lessons from high energy physics

Charnell Long, Recovering Carolyn Parker’s contributions to physics, 1917–1966

Colleen Seidel, Just Marie Curie? Female nuclear physicists in (West) German physics textbooks, circa 1960– 2020

Francisco Calderón, Uses of value judgments in quantum field theories: Towards a feminist philosophy of physics?

Mar Rivera Colomer, Revisiting the history of quantum physics: Oral histories, representation, and the case of Ana María Cetto Kramis

Michiel Bron, How to deal with a nuclear petro-state? Geopolitical consequences of an intertwined history of nuclear and oil

Mylena Amoedo, The Franco-Brazilian contribution to the study of decoherence: The academic trajectory of Luiz Davidovich until his collaboration with Serge Haroche’s experimental group at the ENS

S. Prashant Kumar, The symmetry eaters: Group theory and intellectual property claims in Indian relativistic quantum mechanics

Silvia Castillo Vergara, An information-based approach to quantum mechanics: Distinguishability, Turing machines, and quantum coding at the Center for Theoretical Physics, UT Austin, 1976–1987

Siyuan Zhang, The evolution and dynamics of high-resolution-power spectroscopes in studying the fine structure of the hydrogen spectrum, 1920s–1930s

Sofia Guilhem Basilio, Erwin Schrödinger’s philosophy of science and his embrace of the Bohr-Kramers-Slater (BKS) theory

William Thomas
American Institute of Physics
wthomas@aip.org

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