De niece: I've seen a scientist!
De uncle: Where was this?
De niece: We saw a scientist at preschool.
De uncle: Oh... what did he look like?
De niece: Not "he". "She".
The visit evidently had a big impact. I gather that the scientist came to visit preschool, and showed everyone how to do some experiments. De niece was able to tell me how the various experiments worked, and we were able to reproduce them at home.
The first involved sticking a pin into a balloon without letting it burst. The trick is to find the dark spot on the balloon surface, where there is less tension and the pin can go in without a catastrophic rip of the skin. She was able to get the pin in, and then we went even further with a metal skewer. The end result was a neat little hole, that could be stopped with the finger, and which otherwise gently deflated the balloon.
We also tried a control. Here's a shot of the two of us discussing the end result of a balloon where the pin was inserted into the stretched out parts of the balloon.
De other niece also joined in. De scientist niece had two more experiments for us all to try. One involved sultanas in carbonated water. You should try this too. Drop a few sultanas into a glass of carbonated water or lemonade, and explain why they do what they do.
And here is de other niece with vinegar and bicarb of soda. The glass had about three centimeters of vinegar to start with.