The program ThreeBody illustrates some solutions of the 3 bodies problem in celestial mechanic.

     ThreeBody is an application working in Version 1.02 under Mac OS® 7.6-9.2 or Mac OS X in Classic mode. In Version 2.00, it's working under Mac OS X Tiger and Leopard, as well as under Windows 98/XP/Vista. It's a scientific program for a general public: it's aim is to remain us a fundamental idea,i.e. that even in the case of a perfectly deterministic problem like the law of gravitation (le law in 1/r^2 from Isaac Newton), as soon as we have more than two bodies (planets), one cannot predict the asymtotic behavior (in the long range) of the system. So one may say that even in the case of a simple deterministic situation, the liberty is still alive.

    ThreeBody illustrate 3 cases in the situation where the 3 planets have the same mass. The two first cases are "classical" ones and very special in the sense that the trajectories are close and "stable":

1. Case of Lagrange (18the century).
2. Case of A. Chenciner & R. Montgomery.(1999) A remarkable periodic solution of the three body problem in the case of equal masses
3. Arbitray case.

    In the last case you may choose your initial contitions and discover the infinite variety of the possible trajectories.

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Download

Si vous désirez la version française, clicquez ici

     You can download ThreeBody version 1.0.2 in english by clicking on the link below (0.51 Mo):

Click here to download ThreeBody
ThreeBody can run on a 68k or PowerPC under Mac OS 7.6 to 9.2 or Mac OS X in Classic mode.
The program is distributed as a stuffed directory ThreeBody.US f.sit that you can unstuff with Stuffit Expander.

     You can download ThreeBody version 2.0.1 in english or french by clicking on the link below (6.28 Mo):

Click here to download ThreeBody for Mac
ThreeBody can run on a PowerPC/Intel under Mac OS X Tiger or Leopard.
The program is distributed as zip file. After expansion you get a disk image ThreeBody201.dmg that you can easely install in your Applications folder.



     You can download ThreeBody version 2.0.1 in english or french by clicking on the link below (3.07 Mo):

Click here to download ThreeBody for Windows
ThreeBody can run underWindows/98/XP/Vista.
The program is distributed as zip file SetUpThreeBody.zip that you can easely install after expansion by making a double click on this installer.

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