I'm jealous of your setup. I've seen your photo a few times now and always wish I had the space (and not so lazy) to do the same.
Not at all. I started doing kitchen experiments with my daughter when she was 3. Once she gets how one conducts and the other doesn't, she'll be able to try different combinations and see how the current moves, degrades, etc. She may not learn the technology, but a four year old's ability to learn through experience is incredible. Don't forget, she learned English in less than two years using observation alone.
oops... I meant to say, she may not learn the terminology
I tell them to turn to the study of mathematics, for it is only there that they might escape the lusts of the flesh. -- Thomas Mann, "The Magic Mountain"