Towards a fluid computer

In 1991, Moore (Nonlinearity 4:199–230, 1991) raised a question about whether hydrodynamics is capable of performing computations. Similarly, in 2016, Tao (J Am Math Soc 29(3):601–674, 2016) asked whether a mechanical system, including a fluid flow, can simulate a universal Turing machine. In this e...

ver descrição completa

Detalhes bibliográficos
Autores: Cardona, Robert, Miranda Galcerán, Eva|||0000-0001-9518-5279, Peralta-Salas, Daniel
Tipo de documento: artigo
Data de publicação:2025
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/427302
Acesso em linha:https://hdl.handle.net/2117/427302
https://dx.doi.org/10.1007/s10208-025-09699-6
Access Level:Acceso aberto
Palavra-chave:Euler equations
Beltrami fields
Turing machines
Computational complexity
Turing completeness
Universality
Àrees temàtiques de la UPC::Matemàtiques i estadística::Equacions diferencials i integrals
Descrição
Resumo:In 1991, Moore (Nonlinearity 4:199–230, 1991) raised a question about whether hydrodynamics is capable of performing computations. Similarly, in 2016, Tao (J Am Math Soc 29(3):601–674, 2016) asked whether a mechanical system, including a fluid flow, can simulate a universal Turing machine. In this expository article, we review the construction in Cardona et al. (Proc Natl Acad Sci 118(19):e2026818118, 2021) of a “Fluid computer” in dimension 3 that combines techniques in symbolic dynamics with the connection between steady Euler flows and contact geometry unveiled by Etnyre and Ghrist. In addition, we argue that the metric that renders the vector field Beltrami cannot be critical in the Chern-Hamilton sense (Chern and Hamilton in On Riemannian metrics adapted to three-dimensional contact manifolds, Springer, Berlin, 1985). We also sketch the completely different construction for the Euclidean metric in R^3 as given in Cardona et al. (J Math Pures Appl 169:50–81, 2023). These results reveal the existence of undecidable fluid particle paths. We conclude the article with a list of open problems.