Eugen Merzbacher

The Early History of Quantum Tunneling

Molecular spectra, electron emission from metals, and alpha decay provided fertile ground in the 1920s for applying the new ideas of quantum mechanics.

An Evolving Physical System: The State of the American Physical Society

Among all the terms that we use casually in talking about physics, without feeling the need to define or explicate them, the winner of the Citation Derby is probably the word “system.” Explicitly or by implication, the “physical system” defines the context in every class we teach, every seminar we give, every paper we write. Talking about physics without specifying the system is a vacuous exercise, and we exhort our students from the first day to think clearly about the system under consideration—what it includes and what it does not include, its relevant characteristics, its observable aspects, its degrees of freedom and its response to external influences and perturbations.