Fantastic Contraption
One of the folks at the Tcl Conference mentioned a website called Fantastic Contraption, at which you build odd little machines intended to convey a package from here to there. It’s a physics game, and geometry, weight, and traction are all very important. After it was mentioned, it was not an uncommon sight to see attendees playing it on their laptops while the sessions were on-going.
My younger son, the 9-year-old engineer, has been rapt for the last hour.