It bugged me through the course of the show how they kept calling them "chain reaction machines" instead of the better known term of a "Rube Goldberg Machine."
I was wondering about that myself, so I did some Googling and found this:
Rube Goldberg is a registered trademark of Rube Goldberg Inc. who holds the Rube Goldberg copyrights and trademarks. While Rube Goldberg Inc. encourages educational, non-profit, and commercial reprint and use of Rube's work, permission to reproduce drawings and images or use our trademark (RUBE GOLDBERG) in any way or in any media (including presentations, training materials, etc. both in-house and to clients), must be secured prior to use and requested in writing.
So they can't call them "Rube Goldberg machines" by name because that's a trademarked term.