Last week I wrote about the Eyeballing game, an applet that tests your visual accuracy. It was created by a woodworker.

Well, as I was perusing his website I found another neat mathematical creation. He made a binary marble adding machine. He created this video showing it in action.

I encourage you to visit his website. He has built many other intricate wooden machines, such as a combination lock, tank treads, tripods, an apple grinder, a pipe organ and other marble machines.

It is easy to find solulutions to a^3+b^3=c^4 (70,105,35), (273,364,91), (266,665,133), etc. bit.ly/1FHrlwW3 days ago

Q from student:Who first stated Euler's identity, e^(iπ)=-1? It follows from Euler's formula e^(ix)=cosx+isinx, but Euler didn't plug in x=π 5 days ago