Ron Folman - Experiments at the interface of general relativity...(September 5, 2025)

Experiments at the interface of general relativity and quantum mechanics The two pillars of modern physics are the theories of general relativity and quantum mechanics. After decades of theoretical attempts to unify these two pillars under one theoretical framework (often referred to as quantum-gravity), these pillars remain independent. To some, this situation is so unnatural that they claim it actually hints that at least one of the theories is wrong in some fundamental way. As technology in quantum-optics labs improves, new experiments — working at the interface of these two theories — can be realized. Such experiments will hopefully provide new insights that will eventually allow for the sought-after unification to be finally achieved. Uploaded 22-09-25 In this talk, I will present three experiments conducted at this interface, two already realized and one planned. The first involves clock interferometry, in which a single clock in a spatial superposition experiences two different proper times due to gravitationally induced red shift. The second involves the observation of the Einsteinian equivalence principle, measured in the quantum domain. While the first two were realized with atoms, the third involves massive objects, specifically, nano-diamonds. Leaping by ten orders of magnitude in mass relative to the atomic experiments, the third experiment makes use of so-called active mass, where not only, but also, the gravitational field of earth needs to be taken into account. ~ This program supports high-risk and potentially high-return small-scale experimental projects aimed at new, ambitious discoveries beyond the current frontier of fundamental physics. “Small-scale” refers to table-top-size experiments or to ones that could fit in a typical university physics research lab. The meeting is intended to advance the supported science by stimulating discussions and the exchange of ideas, while also helping to build a sense of community amongst program grantees. For more information go here: https://www.simonsfoundation.org/event/table-top-experiments-pi-meeting/