The "waterfall" entry into the water exhibit. We had to go through this entry several times.
The lights exhibit. Adam tried explaining to Addie how you could block out one light and have just a single color shadow, or combine colors to make new colored shadows. However, she really was more interested in just seeing what her shadow looked like when she moved.
Overall, the Science Museum was a lot of fun. It is definitely geared for older kids, but we were able to find enough things that the girls could do to keep their interest.