Einstein Lectures Dahlem

Schrödinger’s Cat Is Never Dead and Alive

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

The lecture will be held in German. No translation or interpretation will be provided.

Anton Zeilinger is professor emeritus at the University of Vienna and senior scientist at the Institute for Quantum Optics and Quantum Information - Vienna (IQOQI-Vienna) of the Austrian Academy of Sciences.

After studying physics at the University of Vienna and earning his doctorate in 1971, Anton Zeilinger worked as a research assistant at the Vienna Institute of Atomic Physics. In 1977, he joined the Massachusetts Institute of Technology (MIT), where he collaborated with Clifford G. Shull, who later received the Nobel Prize in Physics. He qualified as a university lecturer (Habilitation) at the Vienna University of Technology in 1979 and was appointed professor at the University of Innsbruck in 1990. Zeilinger’s distinguished career has included a professorship in experimental physics at the University of Vienna, several years as a Senior Humboldt Fellow at Humboldt-Universität zu Berlin, and the co-founding of the IQOQI in 2004, where he served as director until 2013. He was president of the Austrian Academy of Sciences from 2013 to 2022.

Since the beginning of his career, Zeilinger has explored the fundamental questions of quantum physics. His early research focused on neutron interferometry - a central principle of quantum mechanics describing the wave-like properties of neutrons. Later, he turned his attention to interferometry with atoms and molecules. Zeilinger was awarded the Nobel Prize in Physics in 2022 for his groundbreaking experiments using entangled quantum states.

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 – described by the quantum physicist himself as “bizarre” – entered popular science and pop culture some time ago and has been referenced countless times over the years. However, the widespread assumption that two quantum states can exist simultaneously – that Schrödinger’s cat in a closed box exists in a superposition of states (both dead and alive) – arises from a misunderstanding of the nature of quantum states.

The real issue lies in the relationship between the quantum state and the observer’s knowledge.

With this in mind, Anton Zeilinger will discuss how fundamental thought experiments relate to real-world experiments in quantum physics. His lecture bridges the early days of quantum mechanics with contemporary research, highlighting the central role of information in interpreting quantum physical states.