Fourmilab Foucault Pendulum is a realistic model of a Foucault pendulum for the Second Life virtual world.
In February, 1851 Léon Foucault invited people to the Paris Observatory "to observe the rotation of the Earth", then, a few weeks later, installed a much larger apparatus in Paris's Panthéon. The apparatus Foucault invented to directly show the Earth's rotation, now called a Foucault pendulum, took advantage of a unique property of a swinging pendulum: the plane in which the pendulum bob swings (unless perturbed by outside forces such as wind or friction) remains fixed with respect to the distant stars. As the Earth rotates, the plane in which the pendulum swings will appear to rotate, or precess, through time. The rate of precession depends upon the latitude at which the pendulum is installed: at the north or south pole, it would make one revolution per sidereal day (the time it takes the distant stars to return to the same position in the sky as the day before). At the latitude of Paris, Foucault's pendulum precessed around 11.3° per hour. (The precession rate goes as the sine of the latitude.)
Fourmilab's Foucault Pendulum brings this demonstration into Second Life. You can install the pendulum wherever you wish to lend a bit of the nineteenth century discovery of science to your decor. The pendulum is highly configurable, and can be customised to your preferences via chat commands. In addition, the model, script, and all associated materials are delivered with full permissions so you can modify them as you like or use them as the foundation for your own projects.
This repository contains all of the software and resources, including programs in Linden Scripting Language, notecards, and development documentation. The actual model is built within Second Life and these components are installed within it. (The model is very simple: just eight "prims" linked together into one object.)
The complete model is available for free in the Second Life Marketplace. This repository contains everything in the model (except the prims, which are objects built within Second Life), plus additional resources for developers who may wish to extend or adapt the model as they wish. The model is delivered with "full permissions": those who obtain it are free to copy, modify, and transfer it to other users within Second Life.
All of this software is licensed under the Creative Commons Attribution-ShareAlike license. Please see LICENSE.md in this repository for details.