Science Club is a half-hour-long program that is held at the Harker Heights Public Library every Wednesday afternoon, expertly led by children’s librarian Amanda Hairston. Previous area touched on have been anatomy and the skeletal system, and even circuitry. Wednesday afternoon, however, saw Hairston tackling an even meatier subject with her young charges—physics.
“We like to do different disciplines within science, and this (today’s lesson) is almost like a magic trick for them to do, so they can have fun and even try at home,” said Hairston.
Though Science Club has a recommended age of 6 to 12, the assembled boys and girls on Wednesday ranged in age from 4 to 13, all of whom were joined by parents and guardians also interested in the day’s lesson.
Hairston began with an introduction to the afternoon’s topic, surface tension. “Surface tension is a force present within the surface layer of a liquid that causes the layers to behave like an elastic sheet. It is caused by the attraction between the molecules of the liquid.” She went on to say that, “Cohesion is a force that holds the molecules together in a solid or liquid.”
Knowing all of this would need further explanation, Hairston chose to show the children how surface tension works. She took an open bottle of water and, with nothing more than an index card to cover the opening, turned in straight upside-down, slowly removing the card, with no water coming out of the opening. No water came pouring out, amazing the kids, and demonstrating surface tension.
Hairston explained that tipping the bottle would break the surface tension, and would make the water come out, all the while inserting toothpicks into the opening of the still-upside-down bottle, further amazing everyone present as they watched the toothpicks float upward, then seeing the surface tension reform as if nothing had broken the opening. Removing the toothpicks, she then invited the children to try their hands at the experiment.
First up was 4-year-old Patrick Tamby, whose mother had brought him all the way from Copperas Cove to attend Science Club for the afternoon. His was the first hand in the air, and he made his way eagerly to the front of the table, got to see first-hand how the water wasn’t displaced as he moved the index card slowly away from the opening of the bottle, and even got to put a toothpick into the bottle.
Five-year-old Melanie Tjaden of Killeen was also one of the first to have her hand in the air. “I’m not usually shy,” she said, as she, too, took part in the fun.
One by one, everyone got a chance to see for themselves how surface tension worked. Then Hairston let them in on a little secret: there was a special cap that reduced the opening of the bottle, and let them all try the same experiment without the fitting. The results were a lot of fun, if a bit messy.
“Practice makes perfect,” Melanie said.
Children also got to experiment with putting different objects into the opening of the bottle to see if they would float as the toothpicks did, without much success, and which Hairston turned into a lesson on density.
Hairston said there would be longer variation of the lesson on Thursday night’s Family Night, also a Science Night. She also said there will be a special Science Club on Wednesday, Mar. 13, at 2 p.m. during Spring Break.