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Zenith Grant Awardee

John Barrow

University of Cambridge


Marianne Freiberger, University of Cambridge; Rachel Thomas, University of Cambridge

Project Title

Do Observers Matter? Exploring the physics of the observer

Project Summary

The classical view of physics is that observers have no impact on what they observe. Like birdwatchers in a perfect hide, they can stand back and watch events unfold, gathering unbiased information about how the world works. Careful and neutral observation has always been, and remains, a crucial component of science. Modern physics, however, tells a different story. Yet few people are aware of the many different, and often subtle, ways in which the observer enters the scientific picture. This lack of awareness of the important role observers play in physics denies many the knowledge and understanding necessary to judge the quality of scientific research they might read or hear about. Equally importantly, they miss out on the pleasure of seriously exploring concepts that appear to belong to science fiction, such as Boltzmann brains, alien observers, or the science of invisibility. Through accessible, engaging articles, interviews, podcasts, videos, and e-books, this substantial project will enable a diverse public audience, including high-school students and educators, to gain a better understanding of frontier research funded by FQXi.

Technical Abstract

In 1781, Kant introduced the potential importance of the mental categories that we impose on our reasoning about reality. It took another 100 years for scientists to recognize the role of the observer. Until the late-19th century observers were considered to have no impact on what was observed – like birdwatchers in a perfect hide. A significant change was introduced by Maxwell in 1872 with Maxwell\'s Demon. This thought-experiment seemingly allowed a molecular intelligence to violate the second law of thermodynamics. It led, over the next century, to profound understanding of the relations between information, computation and energy, together with the physical description of an \"observer\". Subsequent developments in quantum physics and cosmology introduced the \"observer\" in other ways that challenge us to understand their common factors and differences. Through accessible yet rigorous articles, interviews, ebooks, podcasts and videos, published on our award-winning Plus website, this project will provide an important link between researchers working on fundamental questions in physics and a significant international audience of the public, educators and young people. Building on our excellent track record in presenting complex mathematics and science to a general audience, this project aims to raise the public profile of the whole FQXi program.

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