If you recall, a few weeks ago, I was trying desperately to return home from Tampa, Florida. I had to be home by eight o'clock in the morning to get to the boys' school for the Science Olympiad. Becky and I had volunteered to spend the day teaching kids about electricity. Honestly, I was really looking forward to it, and it would have broken my heart to miss it.
That is why, when my plane bound for Dulles set down in Raleigh at 11pm due to storms, I had to rent a car and drive all night to get to Purcellville in time for the science fair. I pulled into the school in my rental car at exactly 7:45 am (after sleeping for three hours in South Hill, Virginia). I was exhausted, but I had made it! And the energy of the kids would keep me awake until evening.
Becky and I had chosen three experiments to show the kids various properties of electricity and radiation. The first experiment was to use six lemons and make a battery out of them by placing copper and zinc into them, connected with wires. The lemons should provide enough "juice" to power a small flashlight bulb.
Our second experiment was to place an iron nail and a bunch of pennies in a vinegar and salt solution. In this experiment, you basically galvanize the iron nail in copper, bringing shiny copper atoms off the pennies and onto the nail.
Finally, our piece de resistance was the cosmic ray detector. I was somewhat dubious about this one, but it was worth the try. Essentially, you get a bottle filled with alcohol vapor, and then you chill the bottom side of it in dry ice, and warm the top of it with your hand. The alcohol is supposed to set up a cloud-like vapor in which you can see tiny streaks like jet trails--those streaks are caused by cosmic rays, which cause the alcohol to condense. You can even deflect the rays with a strong magnet.
So, that was our line-up. We had four one-hour sessions, twelve kids each. Our intention was to have the kids participate in these experiments themselves with some real hands-on learning.
But things didn't go exactly to plan. Our lemons were... well, lemons. They didn't light the battery at all. So Becky did a little soft-shoe and said it was because they didn't have enough acid in them, and showed the kids how the light bulb lit up with a regular battery. Oooh. Ahhh. This must have been impressive, because several of the kids now remember it as the lemons lighting up the bulb.
The copper nail trick worked the first two sessions, but after that, it didn't seem to take anymore. I suppose it was because the bowl was dirty after a while, or something. But regardless, I used a little slight of hand with the older coppery nails from session one and two, and all the kids thought the experiment worked great.
The cosmic ray detector was an unmitigated failure the first three sessions, and it was only on the last session, after Becky ran home to get a heating pad and we added more alcohol, that we actually produced not a cloud of alcohol, but at least a fine alcoholic snow. So I quickly yelled, "There it is! Do you see that kids?!"
To which, several kids replied, "I see it! I see it!"
Good enough for me.
We had to improvise too, because as we got better at the experiments, we got quicker, consuming our experiments in only fifteen minutes of the allotted hour.
Having lots of time on our hands, and some duds for experiments, we decided to play with Eddie's electronics kit, and of course, the dry ice chips.
First of all, I would stick a big chunk of the dry ice in a cup of water, and it would bubble away madly, producing that wonderfully satisfying mad scientist smoke. The kids loved it.
Then, I would take a piece of dry ice and put it on a spoon. The warm spoon was enough to rupture the ice microscopically on its surface, causing it to vibrate and dance around on the spoon. Again, very satisfying.
Then, Becky showed the kids how if you took a penny and pressed it hard against the ice, it would scream at you. This was from all the microscopic escaping carbon dioxide under pressure. The kids were thrilled by this.
So, in the end, our electricity station was a dud, but the dry ice station was a big hit. I guess that shows you, sometimes in science, you have to be flexible with your methods.
The two teachers, Mr. Jenkins and Mr. Applin, sent us some nice thank you letters from the kids. They really drive home what the kids enjoyed about the day. Here are some of my favorite excerpts:
Thank you for your participation in this year's science Olympiad. Your expertise captivated our students' imagination and excitement.
Jim Jenkins, John Applin
Dear Mr. Scott Harris, Ms. Becky Harris...
Thank you so much for coming to my school and teaching us science and what you guys do. I had so much fun at every center but most of all I hope you had fun. Each center was like ten minutes because time flies by fast when you're having fun because we were at each center for fifty nifty minutes.
The next center I went [to was] electricity is radiating that was also fun. We put pennies on dry ice and it sounded like a scream and that is how it got its name the screaming penny. Also I learned dry ice doesn't melt it turns into gas that is what I was very interested in. Then we put the dry ice in a cup full of water and first it bubbled then it had smoke coming from the glass but it was gas but it looked like a mad scientist lab it was so much fun at that center.
Dear Mr. Harris
I loved how we did all of those cool experiments. My favorite one was when the dry ice made snow in that jar. When the dry ice sizzled when you put it on the spoon. All of that stuff was awsome. My friends said it was boring, but I think that was because the experiment with the snow didn't work.
I guess I didn't fool him after all. And this one:
Dear Mr. and Mrs. Harris,
Your station was awesome! I like the part about the screaming penny. Also the automatic night light was cool. The dry ice on the spoon was also really cool. Thanks for the stuff you did with us!
They really did like that ice. Good thing we had some. And more:
My favorite station was the electricity is radiating station. I loved this experiment because their were so many things at the one center. In the experiment our group made lemon batteries, turn iron nails into copper nails and made rain. Another reason why I enjoyed this center was because you could never expect what was going to happen.
I learned a lot of cool stuff at the science center. I was surprised to learn that citric acid could let electricity pass through. I learned this in the lemon battery experiment. But the experiment that really surprised me was the copper nail. We put 20 pennies in a glass bowl with an iron nail and the nail turned to copper.
My favorite experiment was the one with the dry ice. I have never seen dry ice up close before. Dry ice is so amazing and I found it really cool because of what it did. It made water boil and it gave off a white mist. Thank you for the great experience with science.
P.S. Electricity is Radical!
We really hit a chord with that kid! Isn't that cool?! Finally:
Thank you for letting us help with some of the experiments. My favorite experiment was when we put wires in a lemon and it lit up a light bulb.
Yes, that's how I choose to remember it too, Sean. Worked perfectly.