Colorful cauliflower

We had some extra cauliflower so we decided to do a capillary action experiment. We filled a small glass with water and food coloring and suspended some cauliflower over it with the stem in the water. We let it sit out overnight and in the morning Jr. scientist A came bounding over to me shouting "the experiment worked!" Clearly a winner.

Stalagmites and stalactites, take 3

Never willing to admit defeat, we've made another try at making stalagmites and stalactites. We noticed that the area around our crystal experiments was covered with crystals. It seems that the salt water evaporated in the hot sun, but was too heavy to stay in the air and condensed out. We decided to take advantage of this to try to grow stalactites. We put a mesh (a cut-out from a screen door) on top of the jar for our latest experiment, hoping it would catch the escaping evaporated salt water. We poured our crystal making materials into the jar while it was covered by the screen so some of the liquid would stay on the screen and start a layer of crystals for the rest to hang on to. We weren't able to grow stalactites with this technique, but we got an unexpected but happy result. The evaporated salt water seemed to get trapped inside the jar so we ended up with one big thick crystal that covered the bottom of the jar. Pretty cool. I want to try this in a disposable cup next time so we can easily get the crystal out to play with. It looks like we'll finally have crystals that aren't to delicate to handle.

Fizzy colors

Looking for a good experiment for Jr. scientist E, at my wife's suggestion I went back to an old fizzy standard - mixing baking soda and vinegar. To make it more interesting, I put down a drop of red food coloring and a drop of blue food coloring, with the baking soda and vinegar in the middle. As the fizzy mess spread, it took up the food coloring. Jr. scientist E just stared intently at the bubbly concoction (I think with interest!), getting transfixed each time I added more baking soda or vinegar to restart the fizzing.

Ice melting experiment

We had previously used salt to briefly drop the melting point of ice. This time we tried it on a larger scale. We made two ice cubes. The first one (red in the video) was made using water that had Epsom salt dissolved in it. The second one (green in the video) was made using plain water. This wasn't exactly the cleanest experiment - the plain water cube ended up noticeably bigger and was frozen for a shorter period since we already had salt ice cubes sitting around - part of a long-term experiment I'll write about when it's finished. But I expected the effect to be large enough that the general results would be unaffected. As shown in the video, the salt ice cube did melt much faster (about half an hour compared to 1.5 hours for the albeit larger plain water ice cube). You can see from the pool around the edge of the plate how much quicker the salt ice cube was melting. The two ice cubes also melted in very different ways. The plain water cube primarily just got smaller. It still had the typical smooth edges of an ice cube. The salt ice cube started looking very rough and "eaten away" even though it started out smooth. The one oddity was that the plain water ice cube started melting much quicker. We may need to do a more controlled experiment. Although Jr. scientist A enjoyed watching the ice cubes melt, I was surprised that he showed little interest in the sped up video, which I thought would be easier for him to grasp.

Making colored paper

We're trying to see how the sun affects different colored paper, so we decided to make our own colored paper with printer paper and food coloring. We cut strips of white paper and filled some shallow pans with water and food coloring. We let the strips soak in the pans overnight and moved them to wax paper the next morning to dry (flipping occasionally). Once they dried, we had pastel-colored paper!