On this beautiful Labor Day, I woke up excited to get back to my science adventure! I apologize for not doing any experiments over the summer. You would probably think that I would get more done over the summer than over the school year but this was not the case. I am an intern at the Explora Science Museum and in summer we do camps all day, every week. I found myself working 40 hours a week, thus, I had no time to do my experiments. My summer there was wonderful having new experiences, learning, creating, and meeting marvelous people. I hope your summer was just as enjoyable! After the summer was over, I needed a couple of weeks to get into the swing of things for the school year. Now, here I am! Let’s get to the experiment.
This experiment can be thought of as a magic trick, yet not. It is SCIENCE!! I grabbed a simple jelly jar and took just the rim of the lid and twisted it on.
I filled the jar with water. I colored the water blue so that it would be easier for you guys to see.
Now we are set!
I could do this experiment over the sink but I am a scientist! I love to use test subjects. “Oh, brother?”. My little brother, Christopher, had graciously accepted to be my personal guinea pig like he has in the past! Holding the jar over his head I placed a index card on top of the jar.
I know what you are thinking, “Oh, this one! She’s done this already!!” I know I did, just bear with me and you will see the difference! With my hand holding the index card firmly, I flipped the whole thing over and, well, you know the rest!
As you can see, the index card stayed in place. But here is the part that is different than experiment number 24 from the last book. I grabbed the index card and I slowly pulled it away.
“GASP!!” is the word you are all saying. It looks good so far, but what about all the way?…. Christopher’s expression is one of fear.
TA-DA!!!
You may notice that on Christopher’s shoulder his shirt is wet. That is because when I pulled away the card, a little bit of water dripped on it. Then something unintentional happened, I accidentally tilted the jar.
It turns out that tilting the jar results in Niagara Falls.
Poor Chris….
Now some of you are still picking your jaws up off the floor but others are thinking, “There is something you are not telling us.” And you would be right. I haven’t been totally honest with you. Check out what I put in the lid.
Bingo! Plastic screen mesh.
Hey, if I told you first thing then it wouldn’t have been as shocking, right?
I wanted to try something that I had seen before but never did myself. I refilled the jar with water (this time it is not dyed blue) and took some toothpicks and tried to stick them through the holes of the mesh.
I did get a few in but I kept jiggling the jar and pushing on the mesh which resulted in, you guessed it, mini monsoon for Christopher.
With Christopher already pretty wet and he actually expressed the good feeling of the shower, I got rid of the rest of the water.
WAHAHAHAHA!!
Ok, with the fun on stand-by, let’s get to the science of the matter. So why did the index card stay in place before I removed it? The Atmospheric Pressure is greater on the outside of the jar than the pressure on the inside of the jar as we learned with experiment number 24. So the bigger question is, how did the water stay within the jar when the card was removed? As speculated, it’s surface tension. It’s that beautiful membrane that is on the surface of the water that is created by cohesion (the attraction of similar molecules toward each other). The water stays in the jar because the water molecules stay together (through cohesion) and forms a membrane between each tiny opening. The reason the water rushes out if you tip the jar is that air finds its way into the jar letting the water escape!! This is such cool and shocking science!
The WOW-rating for this experiment is a good 8.
I really enjoyed this one. Especially the part where I torture my poor brother. I know I am a horrible older sister!
I will be getting back to you all very soon! Have a great holiday!
