I had a blast with this meeting! It was one of those nights where the kids were (relatively) well behaved, I had more parent volunteers than I hoped for AND all the experiments worked! Plus, they're super easy.
We had 4 stations: Taste, Heart, Eyes and Reflex (aka Nerves and Muscles). With groups of about 5 kids, we were able to rotate stations every 7 or so minutes, with Heart taking the longest. We did finish early (only took about 45 minutes total), but honestly, I think I needed a short meeting anyway.
In Taste, we tried to find our taste threshold for sugar. I debated also doing salt and vinegar as well, but I wasn't sure how long it would take and didn't want to deal with the boys' reaction to the vinegar! I based it off of this article from Scientific American. We had four sugar solutions: 10%, 1%, 0.1% and 0.01%, all by weight. I may have been picked on for my precision, but I only weighed it in ounces, not grams, so the instrumentation tolerance is off a bit! :) I was able to taste the 10% (cloyingly sweet) and the 1% (slightly sweet). Next time, I want to try 1% sugar with different concentrations of salt and see where it goes from tasting sweet to tasting salty (yeah, that's the food scientist in me!). Some of the kids mentioned they tasted the cotton swab more than the the sugar, but that's probably because I told them to suck on the swab instead of painting the solution on their tongue. I thought it would just be easier without all the tongues sticking out!
Heart was probably my favorite, because I was a little worried it wasn't going to work and it was totally successful! I wanted the kids to see how activity would impact their pulse, but measuring a pulse can be challenging for an adult. Then I found these directions! I was a bit skeptical that a lump of clay and a straw would work, but it sounded good in theory. I grabbed the pile of valentine-gift-sized containers of play-doh from the arts and crafts drawer and a bunch of coffee stirrers and it worked really well! It works better when the play-doh is more of a ball than flattened, but you can watch the stirrer flick in time with the pulse. I think every kid was able to see an increase after running around for one minute.
For Reflex, we did the old "drop the yard stick" experiment. I found a great conversion chart for distance to time (and of course I can't find the link again, will update when I do). Best part of this one: I had a faster reaction time than at least one of my boys :) Next time, I'll have them try it with their dominant and non-dominant hand and see if there's a difference.
Finally, we tested our peripheral vision for Vision. I knew this one wasn't going to give us great results, because how many 9 year olds do you know that won't try to look where they're not supposed to look! I based the experiment on this one from Science Buddies, but changed the design of the visor. I took a paper plate and cut it in half, then made a notch for a nose to fit in the middle. I then poked a hole directly across from the nose notch and slide a red plastic coffee stirrer through the hole and taped it in place. I then printed off rectangles in red, blue and green, and folded them in half and taped them to coffee stirrers (yep, I have a seemingly unlimited supply!) to make little 2" square colored flags. The kids partnered up, with one holding the visor to his face and the other sliding the flag in from the edge or out from the center. I was impressed that the green flags looked gray to me before I could see the color. Of course, almost every kid saw the color right at the edge. Hmm...
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