My son has always experimented with stuff. I think he got that part from me. During the school holidays, we are always trying new stuff. We experiment with food recipes, always trying out new destinations, always trying to make things from everyday found-in-the-home materials.
Whenever he'd ask me a question on how something works, I'd show him. If I did not know, we'd find out together. Once he had an idea of how to figure his way around, I'd let him figure out his experiment himself.