A modern valve trumpet/French Horn/tuba uses multiple valves to "compute" the proper length to achieve a certain set of notes. Since the small lengths of tubing "add" to one another, I claim that these are "computers". At 07:32 AM 3/21/2017, James Propp wrote:

In conjunction with the Global Math Project, I'm putting together a list of videos showing interesting forms of binary calculation, using water in cups, trains on tracks, etc.:

http://mathenchant.org/binary.html

I'm aware that the categorization of the links is a bit inconsistent; I plan to fix that before I publicize the webpage broadly. For now I'm mostly looking for more interesting links, and I figure that some of you will know about things I'm unaware of.

I also am chasing the idea (mirage?) of a robust, cheap, easy-to-build binary calculator that could be taken on as an in-class project by students around the world. (Call it the mathematical equivalent of the penny-a-shot rotavirus vaccine.) I have no idea how to build such a thing, but maybe some really clever person has already figured it out.

Thanks,

Jim Propp