Sam The Science Kid Experiment 4: Stalactite Interrupted

Well, 4 weeks in and we’ve got our first failed experiment. The idea was to make some homegrown stalactites and stalagmites, and here’s what was involved:

  • Two jars
  • Some yarn
  • Two binder clips
  • Baking soda
  • Warm water

Sam filled both jars with warm water, then spooned baking soda into each one. She kept trying to lick her finger, coat it in baking soda, then lick it off, which I found gross but ultimately harmless. This made her want to eat more of it.

I had her keep stirring until no more baking soda would dissolve in the water.

Sam asked the pretty astute question of where the baking soda was going when it seemed to disappear, to which I replied “Uhhhhh…” as I frantically cast my memory back to my 10th grade science class and tried to remember. I gave her some kind of half-assed explanation about the baking soda molecules sticking to the ends of the water molecules and sort of fitting “in between” the water molecules. It turns out that this explanation was indeed more right than wrong, but it was all over her head in any case. So I focused on teaching her the concepts of a “solution” and “saturation.”

Anyway, after we had our warm water saturated with baking soda, I cut a piece of string, weighted the ends down with binder clips, and dropped one end in each jar:

I told Sam that I hoped the baking soda would form gather on the yarn and drop down the center to form a stalactite just like water and minerals do in caves over years and years. I asked her for her prediction:

I predekt it will grow 2 inches in 7 days.

Unfortunately things didn’t work out. After about 7 days we got this:

Something about this reminds me of Tetsuo in that Akira movie.

That’s got a pretty good head going on it, but the progress pretty much stopped there. I don’t know why –maybe we didn’t get enough baking soda in there, maybe the yarn wasn’t supposed to hang down into the jars that far, who knows?

Alas, this was Sam’s entry after 8 days:

It grow 0 inches in 7 days. Crest is grow on the yorn. It was wite.

Maybe we’ll have better luck next week.

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