Tuesday, January 04, 2011

Let It Ride: Four Accidental Experiments

I was eager to get back to school after our two week break to see the kids, of course, but I was equally curious about the status of a few inadvertent experiments we'd left behind when we'd locked the doors for 2010.

As you'll recall if you've been reading here, we (I) made the mistake of leaving uncovered an aquarium in which we'd been nursing along various types of sprouts when the pineapple express came through, dumping 4-5 inches of rain and flooding our little world, causing the death of at least one worm, the carcass of which we could see pressed up against the glass. (I've not included the grisly photo in this post. If you must see it, click here.)

The damage done, we decided to "let it ride" for awhile and observe what happened.

Well, one thing that happened was that Seattle has been experiencing one of its rare winter freezes and I arrived at school to find lots of cool frozen things for the kids to play with.

But the coolest thing of all was the 2-inch thick sheet of ice on the top of the aquarium.

It was a particular reward for the kids who could pull themselves away from the ice smashing fest taking place on the other side of the outdoor classroom, the glass sides giving a perfect opportunity to view just how ice forms on the surface of water. Only a few of the kids took the opportunity to explore it, discovering that the ice was actually floating on the water, while also noting that the worm carcass was by now nearly completely decomposed, leaving only a whisp of its former plumpness.

And speaking of worms, the freeze had me concerned about the live ones in our worm bin. This is our first winter tending worms and it's been quite cold for several days. With our worm bin being raised off the ground in a converted sensory table, I was more than a little worried that the bed had frozen solid. When Charlie L.'s mom Shelly arrived on the scene to work the garden station, I told her that one of the "activities" was to help the kids discover whether or not the worms had survived. I'd provided a bucket of warm water to help with the task of thawing the soil enough to dig.

Within minutes, however, Dennis had discovered that the freeze was only a few inches deep. His idea, one we adopted, was to just remove the frozen dirt into our "rotting bed"

We were then able to dig around, discovering to our delight that there were still live worms in there. We stopped counting at 10 living and 0 dead.

The freeze also had me curious about another of our garden experiments. Jody's mom Jennifer had worked with the kids to get some broccoli and spinach starts going indoors, with the idea of transplanting them in the garden as early as possible. They'd been sitting in our window sill, thriving away, but with the prospect in front of us of them going without water for two weeks, we decided their best chance of survival would be in the garden, even if we'd neglected the hardening off process. A handful of kids chopped the pea vines into the soil, augmenting it with a few handfuls from the worm bin, then got the fledgling plants in the ground just before leaving for the holidays. 

Fortunately, we'd also had the brilliant idea of giving each of our transplants (along with our onions and garlic) their own mini-greenhouses made from 2-liter soda bottles. Would that be enough to protect them from the freeze?

I'm no expert, but the leaves were all still green yesterday, giving me hope.

The final experiment on my mind was one we'd started indoors several weeks ago. The Pre-K class had performed the experiment of adding vinegar and baking soda to a jar of water and popcorn kernels.

It's a fairly standard preschool science exploration. The idea is that carbon dioxide bubbles attach themselves to the kernels and when enough of them are attached, they carry the individual kernels to the surface, where the bubbles pop, letting the kernel again drop to the bottom to collect more bubbles. It's often referred to as something like the "dancing popcorn experiment."

In our case, our popcorn kernels were already mixed up with some dry kidney beans and sunflower seeds and I was too lazy to separate them so we just threw a handful including all three seeds into the jar.  Originally, the bubbles had done their regular thing with the popcorn, the beans had sunk to the bottom, and the sunflower seeds had floated on top. Fortunately, we'd let this one ride as well, leaving the jar on a counter top over the course of several weeks for observations.

Within a few days, we noticed that the few remaining bubbles were now able to lift the beans, leading us to speculate that having spent time in the water had made the beans less dense. The sunflower seeds were still floating on the surface, which meant they were still less dense than the water. This new revelation in hand, I would have tossed the whole thing, but several of the kids wanted to see what would happen if we left it awhile longer. My private prediction was that the beans in water would eventually lead to a mushy, smelly mess, which is why I'd entered the classroom yesterday morning, after over a month of soaking, anticipating a nose full. Nothing. This told me that the lid has a pretty tight seal. But our eyes told us that something unanticipated had happened.

With no more carbon dioxide bubbles to lift them, the popcorn kernels and beans remained on the bottom of the jar, but look at the sunflower seeds. There they are, suspended like magic in the middle of the water. Now that's a pretty cool result. We're speculating that the seeds have now absorbed enough water that they are more or less the same density as the water.

We decided to "let it ride" awhile longer.

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Scott said...

Science is so fun...even if it is accidental.

miss merril said...

I think this post should be next to the dictionary definition of "emergent curriculum" - wonderful!

Ms. Erin's HeartRoom said...

I didn't know about the popcorn kernels! We will have to try this! Hmm...now to find the perfect observation tank. Thanks Teacher Tom!

Sherry and Donna said...

Oh boy! And I get excited when we get a thin slither of ice on a puddle in our winters! I really do need to spend a winter in the northern hemisphere I think!

Donna :) :)

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