Invisible paintings

We made some invisible paintings, dipping paintbrushes into lemon juice. We tried to get them to appear by heating them in the sun, but that wasn't warm enough. Instead, we found out that putting them in the oven at 350 degrees for about 5 minutes made them show up quite well. Jr. scientist A was quite proud of his now-visible paintings and decided to put them up on the fridge (o.k., the picture above was mine, which Jr. scientist A didn't deem good enough to put on the fridge!).

Unconventional bubble maker

Once again we used pressure created by warming air. We took a frozen empty bottle (my new motto is always keep an empty bottle in the freezer) and dipped the opening in bubble mix to form a soapy film over the opening. We put the bottle down and slowly a bubble started growing out of bottle. Squeezing the bottle, we could make the bubble grow quicker - o.k., it's just from the warmth from my hands, but it looks like I'm squeezing the bubble out of the bottle. Jr. scientist A had great fun popping each bubble as it formed.

Dancing pill bottle

Following up on our rubber band-powered boat, we made a dancing pill bottle. We drilled a hole in the top of a pill bottle. Then we put a rubber band around a popsicle stick and stuck the rest of the rubber band through the hole in the cap. We wrapped the other end of the rubber band around the bottom of the bottle and put the cap on the bottle. Finally, we spun the popsicle stick around to wind up the rubber band. I was hoping we might get a little helicopter-like lift out of it, but instead, it made the bottle dance around - still pretty neat.