If you’ve ever read a science fiction story, you know the dangers of time travel. Someone returns to the past and alters something that completely remakes the present and the future, usually with disastrous effect. So it went last month with Los Angeles Unified School District Superintendent Alberto Carvalho. Carvalho was forced to shutter schools...

Imagine a classroom of curious elementary students grasping clipboards, eager to conduct an experiment to see if the small car they built can protect their egg “passenger” in a head-on collision. It’s a lesson that not only reinforces their understanding of engineering design, but also offers practical examples of physics in action. And it’s fun....