Sound science

MARQUETTE — Tuning forks and thunder machines can interest even very young kids, and that interest was on display Wednesday during the Peter White Public Library-sponsored event, “Sounds All Around.”

The Michigan Science Center, located in Detroit, put on the program at the Westwood Mall, the site of the library’s temporary children’s branch until renovations are completed.

Charles Gibson, director of innovation and outreach with the Michigan Science Center, gave demonstrations on sounds and led the youngsters in noise-related activities geared for students in grades one through six.

“This year, the theme for libraries is ‘Libraries Rock,’ so we’re taking sort of a spin on that, saying ‘Science Rocks,'” Gibson said.

Breaking down sound into elements was a goal of Wednesday’s workshop.

That meant talking about frequency, pitch, waves, Hertzes, amplitude and the like.

And fancy equipment wasn’t necessary to teach kids about sounds.

“We’ll use some really common and sort of household materials to be able to experiment with some of those things,” Gibson said. “We want, really, to make the science accessible to everybody. So, we don’t have a whole lot of stuff that you can’t see anywhere else.”

There was a reason things like a giant Slinky-type toy and Oobleck — the combination of corn starch and syrup — were used Wednesday.

“The idea is that we can inspire some kids to go home and try some of these things themselves and do some more activities at home,” Gibson said.

Some of the “Sounds All Around” activities didn’t even require just simple equipment.

Gibson moved across the room, asking the youngsters to first rub their hands together, then snap their fingers and, lastly, slap their hands on their thighs.

The procedure then was reversed.

The result was a realistic sound of a rainstorm starting, building to a crescendo and then waning.

“Just by using our bodies, we were able to kind of transform this room, and I bet you, if you close your eyes the whole time you did that, it’d almost just sound like a real rainstorm,” Gibson said.

That sort of activity was cerebral in nature.

“The thing that’s actually helping us understand what those sounds are is ultimately our brains,” Gibson said.

However, at its most basic element, sound is composed of vibrations, he said.

“If you knock on that table, that table starts to vibrate,” Gibson said.

He had more interesting visual aids to demonstrate sound, such as a “thunder machine” that made noise when a string was pulled. The string’s vibrations hit the drum, and the inside sounds started to bounce around, increasing in volume.

Another activity involved a tuning fork and ping pong ball. One young workshop participant hit the fork on the end of her shoe, and then moved it closer to the ping pong ball. The vibrations from the tuning fork transferred to the ball, causing it to move back and forth.

The youngsters then struck their tuning forks, after which they dunked them in a cup of water. The resulting vibrations made the water splash.

Another experiment involved a machine that made a connected plate, with sand on it, vibrate.

“Those waves that are traveling and vibrating through this entire plate, they’re bouncing around,” Gibson said. “They’re bouncing around on the side of the plate and they’re moving back and forth, and what happens is sometimes those waves bounce into each other, and when they bounce into each other, guess what happens? They stop.”

Where were the waves stopping? Right where the sand was collecting.

“So from the area where’s there’s sand, there’s no vibrations,” Gibson said.

When higher-pitched sounds were played, a different sand pattern took shape.

Keep in mind that the frequency of a sound determines its pitch. The higher the frequency, the higher the pitch.

“The length of those waves, as they vibrate through the plate, will change and will bounce around, and they’ll bump into each other in different places, which means that the sand will bump into each other in different places,” Gibson said.

Straw trumpets also were used to demonstrate sounds. Gibson blew through a straw, eliciting different sounds — and different laughs from the kids — by using straws of varying lengths.

“You can change the frequency of our straw by changing the length of our straw,” Gibson said.

The youngsters also made their own paper sandwiches, which were de facto harmonicas. These musical instruments were created using paper, Popsicle sticks, toothpicks and rubber bands.

Different pitches could be made by pinching the sides, for instance.

It took a little doing for some kids, but one parent made such a harmonica fairly quickly.

“Dad figured it out,” said Sarah Rehborg, PWPL Youth Services librarian.

Maddox Siefert, 9, of Negaunee, thought the activity was fun.

“I got it to make noise,” Maddox said.

The grand finale of the program, if you want to call it that, was Gibson making Oobleck, which was put on a device that created sound waves, causing it to turn solid.

“It looks like it has legs,” Gibson said.

The youngsters, though, wanted something more spectacular.

“Make it explode!” they yelled.

Gibson, though, tempered the experiment by just adjusting the waves.

However, he was asked what Oobleck tastes like.

“I don’t know,” Gibson said. “I wouldn’t want to try it.”

Christie Bleck can be reached at 906-228-2500, ext. 250. Her email address is cbleck@miningjournal.net.

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