Click to download and possibly see the movie [Cliquez pour télécharger et voir éventuellement le film]

The numerical irreversibility of the bidimensional billiard [L'irréversibilité numérique du billard bidimensionnel].




This simulation has a duration of 512 time steps. At t=0 just one particle starts moving (at the center). Between t=255 and t=256, all velocities are reversed. Unfortunately, the system state at time t=512 is very different from the initial state (at time t=1). In actuality, this system is very sensitive to initial conditions and therefore, it is sensitive to rounding-off errors; this phenomenon can be seen on this picture The same bidimensional rectangular billiard with 41x56 random particles studied on two different computers -the Green one and the Red one- where the same computation is done on two different computers: the Green one (a PC under Linux) and the Red one (a SGI O200 under IRIX 6.5).


See a related picture:

The numerical irreversibility of the bidimensional billiard -1376 particles-


(CMAP28 WWW site: this page was created on 02/25/2000 and last updated on 12/23/2024 08:44:57 -CET-)



[See all related pictures (including this one) [Voir toutes les images associées (incluant celle-ci)]]

[Please visit the related ImagesDidactiques picture gallery [Visitez la galerie d'images ImagesDidactiques associée]]
[Please visit the related ParticleSystems picture gallery [Visitez la galerie d'images ParticleSystems associée]]
[Please visit the related SensitivityToRoundingOffErrors picture gallery [Visitez la galerie d'images SensitivityToRoundingOffErrors associée]]

[Go back to AVirtualMachineForExploringSpaceTimeAndBeyond [Retour à AVirtualMachineForExploringSpaceTimeAndBeyond]]

[The Y2K Bug [Le bug de l'an 2000]]

[Site Map, Help and Search [Plan du Site, Aide et Recherche]]
[Mail [Courrier]]
[About Pictures and Animations [A Propos des Images et des Animations]]


Copyright © Jean-François COLONNA, 2000-2024.
Copyright © France Telecom R&D and CMAP (Centre de Mathématiques APpliquées) UMR CNRS 7641 / École polytechnique, Institut Polytechnique de Paris, 2000-2024.