By Science Mom
My five-year old son, Alexander, loves science. So each week, the two of us have pledged to do a science experiment. There are not too many rules – only that the experiment can be easily done in the kitchen of our apartment, and not leave too much of a mess. Last week, Alex tried to make rice bounce by putting it in a glass of carbonated liquid. It took us a few tries to get the experiment right, but eventually it worked.
This week, we had been thinking about doing an experiment to determine why it is sometimes hard to open a freezer door after it has just been closed. But then the folks at Talking Science gave Alex and me a wonderful kids science product to play with. It’s called Pop Bottle Science: 79 Amazing Experiments & Science Projects by Lynn Brunelle.
The Pop Bottle Science book comes in a large plastic bottle, which can be pulled apart to make a funnel or a bucket, depending on your scientific needs. The kit also contains a blue measuring cup, a set of yellow measuring spoons, some balloons and a cork.
So, Alex and I went looking through the book for an experiment to perform. We quickly found one that asked the question, “Can you make a bottle burp?” Alex – as a five-year-old boy who thinks anything to do with bodily functions is hysterical – started howling with laughter. “Burp!” he chortled. “The bottle is going to BURP!” Then he looked at me and hollered, “Do you think the bottle will say EXCUSE ME?” before doubling over with laughter.
The experiment seemed quite simple. Put a plastic bottle without a lid in the freezer for an hour. Take it out, and place a quarter that you have just rinsed in water where the bottle’s lid ought to be. Then, as the cool air molecules inside the bottle warm up to room temperature, the bottle should burp, slightly dislodging the quarter as it does so.
So we waited for the bottle to freeze, wet the quarter, put it on the bottle, and waited. Nothing. We are not quite sure what we did wrong. Perhaps our freezer was not cold enough. Or maybe we just had a very polite bottle. But the molecules did not gather enough momentum, the quarter did not move, and the bottle did not burp.
Since we had not had instant success with the experiment we did the previous week trying to get rice to bounce, Alex, despite being deprived of a scientific burp, was philosophical. We decided to move onto another experiment in the book that asked “Can you get pepper to run away from your finger?”
Again, it’s a very simple procedure. Fill a small vessel with water, sprinkle some pepper on the surface, and then dip your finger in. The pepper will do nothing. But then rub your finger on some soap, and put it back in the vessel. The pepper should go shooting away from your finger to the sides of the vessel.
And that’s exactly what happened. When Alex put a clean fingertip in the peppery water, nothing happened. But when he put a soapy fingertip in, the pepper charged away like it was possessed.
I’m learning just as much as Alex from these experiments. In particular, I’m learning that when it comes to scientific experiments for kids, if something doesn’t happen in the first thirty seconds, it’s probably not going to happen at all, and you should either try the experiment again later or move on and do another one.
We’ll see if next week’s experiment bears this theory out.
Editor's Note: This is a re-post from mid-March, 2009. The original seems to have disappeared.