Jacob is a particle-based simulation tool developed by Vojko Valencic for constructing and conducting virtual experiments from the topics of electricity and magnetism. This tool, named Jacob ("Java constructive objects"), is designed for students and lecturers of electrical engineering. Constructive objects in Jacob are building blocks, e.g., charged particles, conductive elements, imaginary forces, gauges, etc., that assemble experimental scenes. The computational engine of Jacob then iteratively solves the scene by considering built-in natural principles of interaction between constructive objects. Each iteration step is visualized giving real-time look and feel of the simulated phenomenon.

Jacob is an open source program available under the terms of GNU (General Public License), allowing developers to fully modify it or extend it to suit their needs. Wolfgang Christian (Davidson College) and Robert Hanson (St. Olaf College) converted the Jacob program from Java to JavaScript and extended it to support asynchronous loading and saving of Jacob experiment files (*.jco). A selection of Jacob experiments can be run by clicking on the links in this page. To access additional Jacob experiments, download and unzip the Jacob experiment archive to your local computer and open them from within Jacob using the File | Load menu.

Note: The Javob window can be moved and resized by click-dragging the title and the lower right corner of the frame, respectively.