A colleague suggested that J try dropping objects on different surfaces (physics). I was going to wait a few days, but little man took it upon himself to continue the project.
He decided to take all of his BOOM! materials and throw them off the deck onto the concrete below (gravity):
Here are all the objects he gathered up and dropped:
He also learned that not all objects he found would fit in between the railings, which caused some frustration (spacial awareness/social-emotional):
That is, until he realized that now that his table is cleared off, it makes for great climbing (gross motor).