Ana María Cetto Kramis (born 1946) studied physics at Universidad Nacional Autónoma de México and biophysics at Harvard University. As a faculty member back in Mexico, she spent over half a century delving into the fundamentals of quantum physics, with a singular focus on its stochastic interpretation. In addition to her theoretical work, she founded Latindex and has become a key figure in the open access movement. She has also had a long and influential contribution to international scientific cooperation. Her professional and personal journeys culminate with the dynamization of the International Year of Quantum Science and Technologies 2025, aiming to shed light on her understanding of quantum science and of science as a whole. This chapter is mostly based on an oral history, which is here also revisited as a historiographical methodology from its early use at the origins of the history of quantum physics.
A covariant generalization of a non-relativistic stochastic quantum mechanics introduced by de la Peña and Cetto is formulated. The analysis is done in space-time and avoids the use of a non-covariant time evolution parameter in order to search for Lorentz invariance. The covariant form of the set of iterative equations for the joint coordinate and momentum distribution function
Q(x,p) is derived and expanded in power series of the charge of the particle. Then, solutions of the zeroth order in the charge of the iterative equations for
Q(x,p) are considered. For them, it follows that the space-time probability density
ρ(x) and the function
S(x) which gradient defines the mean value of the momentum at the space time point
x, define a complex function
ψ(x) which exactly satisfies the Klein-Gordon (KG) equation. It is argued that when the KG solution is either of positive or negative energy, the total number of particles conserves in the random motion. It follows that the total number of particles conserves when
ψ(x) composed alternatively of pure positive or negative energy modes. In addition, solutions for the joint distribution function in lowest order, satisfying the positive condition are also found. They suggests a possible link with the Couder's experiments on droplet movements over oscillating liquid surfaces.