Einstein Lectures Dahlem

Schrödinger’s cat is never dead and alive

24. Einstein Lecture with Prof. Dr. Dr. h.c. mult. Anton Zeilinger

The lecture will be held in German and will not be translated.

Anton Zeilinger is Professor Emeritus at the University of Vienna and Senior Scientist at the Institute for Quantum Optics and Quantum Information (IQOQI) Vienna of the Austrian Academy of Sciences (ÖAW).

After studying physics at the University of Vienna and obtaining his doctorate in 1971, Zeilinger was a research assistant at the Vienna Institute of Atomic Physics. In 1977, he moved to the Massachusetts Institute of Technology (MIT), where he worked with Clifford G. Shull, who later won the Nobel Prize in Physics. In 1979, Zeilinger assumed a professorship at the Vienna University of Technology, and in 1990 he was appointed to the University of Innsbruck. From 1999 to 2013, Zeilinger was Professor of Experimental Physics at the University of Vienna. From 2001 to 2004, Zeilinger was a Senior Humboldt Foundation Fellow at Humboldt University in Berlin. In 2004, he co-initiated the founding of the IQOQI of the Austrian Academy of Sciences (ÖAW) and remained director of the Vienna site until 2013. From 2013 to 2022, he was president of the ÖAW.

From the outset, Zeilinger has addressed the fundamental questions of quantum physics. After initially focusing on neutron interferometry, he later turned his attention to interferometry with atoms and molecules. He was ultimately awarded the Nobel Prize in 2022 for his work on quantum entanglement.

Date: Tuesday, November 25, 2025
Time: 6:00 p.m. s.t.
Location: Henry Ford Building, Freie Universität Berlin (Garystr. 35, 14195 Berlin). Prior registration is required.

Schrödinger's thought experiment, which he himself described as “bizarre,” entered popular science and pop culture some time ago and has been cited many times over the years. However, the general assumption that two quantum states can exist simultaneously, namely that the cat exists in a superposition of dead and alive, stems from a misunderstanding of the nature of quantum states.

The quantum state represents the observer's knowledge.

Based on this fact, Anton Zeilinger discusses fundamental thought experiments and real experiments in quantum physics. A bridge is built here between the early days of quantum mechanics and modern experiments, highlighting the central role of information in the interpretation of quantum physical states.