We saw a lot of stuff at last night’s Science Slam at Keene Central School.

So much stuff I didn’t have time to see it all.

Here’s something I didn’t know.

An unopened 12oz can of CocaCola in a tank of water sinks. A can of Diet CocaCola in a tank of water floats.

The 4th grader who had this display had tested a few dozen items, and had a little display about density. She could explain density to me. “Density is how tightly packed together something is.” She could explain (sorta) why things float or sink. “Things that are more dense than water sink. Things that are less dense than water float.”

That was what I would have said in 4th grade. So I didn’t press the issue about how it’s actually displacement (specific gravity) that determines float-ness or sink-ness. She had a little ceramic boat floating in the tank, which kind of begged the question. How can something made of material that is more dense than water (ceramic – or a steel aircraft carrier) float? But I didn’t go there.

I did ask her if she’d tried other kinds of soda-pop besides Coke vs. Diet Coke. She hadn’t.

But I think maybe this summer, when I’m out on the deck with a variety of cans of fizzy drinks, I might do the experiment myself. I’d like to know if it’s really the difference in the kind of soda-pop, or if it’s a slight difference in the amount of air trapped in the can.

The grand finale, of course, was the edible car race. Silas’s car came in 3rd (if you don’t count that one other car’s wheel came off and rolled way far away).

Here’s the video: