Laurie Letertre investigates the fundamental indeterminacy of spacetime at the Chair of Philosophy of Science. The project is funded by the ERC under the HORIZON-MSCA-2021-PF-01 call with project number 101109486.
It has been a long-lasting major mystery in modern physics that our current best theories, namely general relativity for spacetime and quantum mechanics (QM) for matter, are incompatible with each other, revealing deep conceptual flaws in the way we understand the physical world. We currently lack a truly fundamental theory of nature that provides a quantum description of space and time (i.e. a theory of quantum gravity (QG)). Yet, an important obstacle currently stands in the way of the current development of QG. Indeed, influential research programmes attempting to find a theory of QG yield theories in which spacetime is emergent, rather than fundamental. Such approaches, called emergent spacetime theories (ESTs), raise critical philosophical challenges for the very possibility of considering these theories as describing the fundamental physical world, beyond their mere mathematical content. There exists a gap between the mathematical nature of the theories and their postulated meaning. Such a gap is highly detrimental to the development of fundamental physics. The project FIndS intends to fill that gap by providing a clear, intelligible interpretation of what it means for spacetime to be emergent in ESTs. The project’s outputs are expected to contribute to the following scientific impacts. First, the research will provide a unified solution to the current conceptual obstacles of ESTs. In the long term, this can foster new knowledge in philosophy (of spacetime, emergence and indeterminacy), and quantum physics, thereby contributing to the objectives of the European Quantum Flagship initiative. Second, the research will promote a specific realist interpretative recipe that can, during and shortly after the project, be used as a defence of scientific realism in the face of theory change and proliferation. The researcher has a background in physics and quantum metaphysics (esp. of spacetime). FIndS is the ideal project to complete her expertise in that field.