Zenith Grant Awardee
Lidia del Rio
University of Bristol
Co-Investigators
Renato Renner, ETH Zurich; ,
Project Title
Many worlds, many times: Emergent observers in non-probabilisitic theories
Project Summary
Do you remember the childhood books where you could choose how the story ended? The book asks you to make decisions or roll dice; based on the result you jump to a certain page, where the story takes a different turn. So works quantum theory: upon performing a measurement, several outcomes are possible, but we only experience one. According to many-worlds interpretations, all possibilities are real, in the same way that all stories are contained in the book. If you had to reconstruct the book from its loose pages, how would you distinguish past and future of a storyline from different alternatives? You could search the pages for traces of each other: the future may remember the past, but alternative stories do not refer to each other. We apply the same principle to time and observations within quantum theory. This allows us to find notions of local time, and ask questions such as \"when can two agents agree on a time?\" or \"why do we have memory of the past but not of alternatives?\"
Technical Abstract
Here we use a non-probabilistic framework to explore the concepts of time and many worlds within quantum theory. We bring together three building blocks: the Page-Wootters formalism of time as correlations, the notion of local knowledge via coarse-grainings of a global picture, and a mapping between wave functions and the sets of possible outcomes of measurements. Together, these building blocks put time on an equal footing with alternative \'worlds\' resulting from quantum measurements. In order to distinguish past and present from different alternatives, we search for compatibility conditions and causal relations between agents\' observations. In addition, we will relax the Page-Wootters formalism to explore minimal clocks and notions of common time between different agents. inally, we study how properties of physical systems affect the kind of knowledge they may hold – the agents they may represent.
QSpace Latest
PressRelease: Shining a light on the roots of plant “intelligence”
All living organisms emit a low level of light radiation, but the origin and function of these ‘biophotons’ are not yet fully understood. An international team of physicists, funded by the Foundational Questions Institute, FQxI, has proposed a new approach for investigating this phenomenon based on statistical analyses of this emission. Their aim is to test whether biophotons can play a role in the transport of information within and between living organisms, and whether monitoring biophotons could contribute to the development of medical techniques for the early diagnosis of various diseases. Their analyses of the measurements of the faint glow emitted by lentil seeds support models for the emergence of a kind of plant ‘intelligence,’ in which the biophotonic emission carries information and may thus be used by plants as a means to communicate. The team reported this and reviewed the history of biophotons in an article in the journal Applied Sciences in June 2024.