The universe in a grain of sand

          @misc{ scivideos_PIRSA:11020105,
            doi = {10.48660/11020105},
            url = {https://pirsa.org/11020105},
            author = {Weinstein, Steve},
            keywords = {Quantum Foundations},
            language = {en},
            title = {The universe in a grain of sand},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2011},
            month = {feb},
            note = {PIRSA:11020105 see, \url{https://scivideos.org/index.php/pirsa/11020105}}
          }
          

Abstract

Recently rediscovered results in the theory of partial differential equations show that for free fields, the properties of the field in an arbitrarily small volume of space, traced through eternity, determine completely the field everywhere at all times. Over finite times, the field is determined in the entire region spanned by the intersection of the future null cone of the earliest event and the past null cone of the latest event. Thus this paradigm of classical field theory exhibits a fascinating form of nonlocality. I'll discuss this result and what it tells us about the possibility of constructing a classical, nonlocal theory which accommodates all the phenomena we observe.