Simple harmonic motion.

To live is to learn. 

Welcome to our science lesson. Today we will study the pendulum.

These experiments require total concentration.

Uh-oh.

Sparky was struck by his Aunt Tamsin, who is far to big for that swing, and the outcome looked a little like this...

I didn't actually catch a picture of the swing-incident landing (being, at the time, engaged in the small chance of preventing the fall) but never fear. You get the general feel of the outcome given this picture, caught earlier in the day when he had a surprise plunge from a picnic table bench during lunch.

Fastest shutter in the west. 

I did get a hard time for taking a picture before rushing to help. 

I'm that mom.