Lev Vaidman (born 1955)
Russian-Israeli physicist and professor at Tel Aviv University, noted for theoretical work in the fundamentals of quantum mechanics: quantum teleportation, the Elitzur–Vaidman bomb tester (interaction-free measurement), and weak values.
Key Contributions
- Quantum teleportation — foundational theoretical work on transferring quantum states between locations.
- Elitzur–Vaidman bomb tester — an interaction-free measurement (IFM) scheme detecting an object’s presence without any physical interaction. Chosen as one of the “Seven Wonders of the Quantum World” by New Scientist (2010).
- Weak values — a formalism for describing quantum systems between measurements.
- Author/editor of the Stanford Encyclopedia of Philosophy entry on the many-worlds interpretation (many-worlds-interpretation, 2002–2026).
Contributions to the Many-Worlds Interpretation
Vaidman has been one of the most influential contemporary MWI theorists:
- Formalized the measure of existence of a world (μᵢ = |αᵢ|²), which parallels the probability measure in Everett (1957).
- Introduced self-location ignorance probability (post-measurement uncertainty; the “sleeping pill” argument) to explain the illusion of probability in the MWI.
- Proposed the Probability Postulate (Born–Vaidman rule): an observer’s subjective probability should be proportional to the total measure of existence of all worlds with that outcome.
- Proposed the Behavior Principle: we care about all our successive worlds in proportion to their measures of existence — which makes MWI believers behave conventionally (e.g., not playing quantum Russian roulette).
- Argues the MWI avoids action at a distance; the nonlocal correlations of Bell-type experiments are explained by the nonlocality (nonseparability) of worlds.
Career
Born 4 September 1955. Attended the 45th Physics-Mathematics School in Saint Petersburg; twice an All-Soviet Physics Olympiad winner (1st place 1971, 2nd 1972); 26th in the International Physics Olympiad (Bucharest, 1972). Emigrated to Israel at age 18.
References
- Wikipedia (2026). Lev Vaidman. 1