I love my Newton's cradle, and various versions have amused me for decades now. Harrod's popularized them as desktop toys way back when, but not because they're scientifical.
They're just plain fun.
They're also as obvious as the nose on a polar bear's face. Five balls banging against each other, in unexpected yet predictable and repeatable ways.
Just don't use the words inertia or force, or, Zeus forbid, Newton's Third Law.
Give a pair of children a Newton's cradle. Hold up a ball (or let one of them do it), and let it fall.
Hold up two, and do the same.
Have the children take turns predicting what will happen.
Then put the toys away for a few days.
No worksheets. No quizzes. No fancy words. Just a piece of the universe delivered unadulterated to the few minds left on Earth capable of seeing things for what they simply are.
4 years ago