Symmetry: the dynamical way

This week we present an awesome multilanguage software, written in Flash for Windows, Mac and Linux platforms. It is a modern presentation of symmetry aimed to students of all levels, including children.


As I am sure by now all readers have figured out, I am lazy. I don’t feel like writing reviews, especially as they would be enthusiastically monotous: the material I’m posting about is, obviously, what I have enjoyed and what my children have enjoyed (everything we post about, has been used and studied by us: this blog, in contrast to other websites out there, does what it says and says what it does). I am posting for two reasons: one is to save others the waste of time in locating quality material among oceans of cheap junk (I hope you appreciate my altruistic spirit). The second one is very selfish: I wish to hear your thoughts, and especially, if you try out the material, to know how you’ve been using it. Of course feel free to ask me similar questions, if you’d like.



We start the software-of-the-week series with Jenn3D. I don’t know what Jenn stands for, but my children say it has to do with “genial”. It’s a free program for Win and Mac; sources are available and can be compiled for other platforms. Look it up at

The program presents a wide variety of regular and semiregular polytopes, that get to be embedded into the 3-sphere and stereographically projected on the affine 3-space. The resulting 3D object can be “ordinarily” manipulated inside the screen. To fully understand the program, it’s best to have an idea of conformal mapping in 2D and 3D, and an intuitive notion (if not a formal one) of projective plane and projective 3-space, but it’s really enjoyable by anybody, even supposed math-haters. Yes, it was tested by our team under the severest conditions.