Theories of Everything with Curt Jaimungal Aephraim Steinberg: The Physicist Who Measured Negative Time
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Apr 13, 2026 Aephraim Steinberg, experimental physicist probing quantum foundations and optics, known for novel tunneling and weak-measurement experiments. He describes measuring 'negative time' in atomic and photon experiments. Short, punchy conversations cover quantum trajectories, multiple light velocities and causality, weak measurements and post-selection, and how surprising timings keep showing up across different setups.
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Many Distinct Velocities And Causality Limits
- Multiple velocities matter: phase, group, information/front, and energy velocities can differ and sometimes exceed c in formulas, but information/front velocity bounds causality.
- Definitions of energy/information velocities depend on measurement choices and stored energy in media.
Quantum Times Split From Classical Equivalence
- Different quantum times (dwell, delay, arrival) that coincide classically can diverge quantum mechanically.
- Steinberg's experiments showed dwell (excitation) time equals arrival-time delay mathematically, even when negative.
Heisenberg Disturbance Bound Can Be Violated
- Heisenberg's uncertainty as disturbance (Heisenberg microscope) is a useful picture but not a universal bound on measurement disturbance.
- Masanao Ozawa's refined bound can be experimentally violated relative to Heisenberg's original disturbance formulation.
