After learning about the lever, wheel and axle, pulley, inclined plane, wedge and screw, the students designed a future Hilltop playground, one that included examples of each simple machine studied.

Wheels are the archetype of a primitive, caveman-level technology. But in fact, they're so ingenious that it wasn't until 3500 B.C. that someone invented them. By that time — it was the Bronze Age — ...

The tricky thing about the wheel is not conceiving of a cylinder rolling on its edge. It's figuring out how to connect a stable, stationary platform to that cylinder Wheels are the archetype of a ...