In anticipation of April’s visit from Mystic Aquarium to talk about how Beluga Whales communicate, I thought a program where our scientists learned a little about “sound” was in order. And besides, what is more fun than creating a lot of really obnoxiously loud noises? 🙂

We started our program by talking about the nature of sound and how sounds are actually created.  When objects vibrate, the vibrations are projected into the air and create sound waves. Even though you cannot see sound waves with the naked eye, you can often feel sound vibrations. [If you’re looking to explore this further, how about testing out your very own “sound gun” at home? Trust me, it’s a blast!]

And most of the scientists successfully answered all of my tricky true and false questions. From the series of questions, we learned a lot of cool facts about sound:

• Outer space is the only truly silent place in our world…because there is no air to help distribute the sound waves.
• Sound vibrations can be carried through more than just air – they can also move through water, woods, metals, and plastics. As an example, Ludwig van Beethoven (the famous composer who was deaf) would often hold a long wooden stick in his teeth, resting the other end on a piano wire. When he played the piano, the vibrations from the piano wire would travel through the stick, through his teeth, through his skull bone, and then directly to his inner ear where he could make sense of the sounds.
• Snakes have no ears, but a bone inside a snake’s head picks up vibrations from the ground.
• Did you know that owls are a bit lopsided? They have one ear slightly lower than the other so that they always have one ear a little closer to sounds on the ground where they look for their food/prey.
• When you put a sea shell up to your ear, you are not actually hearing the ocean. The shell is picking up vibrations from all of the sounds occurring around you, and those sounds are making the air inside the shell vibrate and carry sound to your ear.
• If you ever hear someone’s stomach growling very loudly, you can say to them, “Your borborygmi is quite loud!” Borborygmi is the fancy scientific term used to describe the process that creates a growling stomach.

And I even found some cool examples of record-breaking sounds to share with our group:

• 

  Krakatoa

  The loudest natural sound in recorded history is still the volcanic eruption on the island of Krakatoa that occurred on August 27, 1883. The sound could be heard (and felt) 3,000 miles away!

• The pistol shrimp, only 2 inches long, can eject a powerful jet of water traveling at over 60 mph from it’s one over-sized claw. The snapping sound itself reaches 218 decibels (your eardrum ruptures at 150 decibels). And at the moment the jet of water explodes from the claw, portions of the stream can reach temperatures as hot as the sun!

• The loudest animal in the world, relative to size, is the water boatman.
• The loudest mammal is the blue whale; the loudest land mammal is the howler monkey; the loudest amphibian is the croqui frog; the loudest bird is the oilbird. [Source: National Geographic]
• Japan holds the world record for the most Theremin instruments playing in unison. What’s a Theremin? Check out the video below to find out…

But we never do just discussions in our Science Explorers Club…we’re scientists after all! So I had a full series of demonstrations and small experiments for us to do, to help us explore sound in a variety of ways.

Demonstration #1:  Star Wars Laser Sound Device

When George Lucas directed the earliest Star Wars movies (first released in 1977), money was tight. Nobody had ever made a science fiction feature film like this before. So when they needed to create the laser sounds made by the guns on the space ships, his effect team came up with an ingenious idea:  attach a funnel to a metal spring and just let the magic happen.

As a group, we were able to recreate something similar using just a classic metal slinky and a Styrofoam cup. My scientists all received a tiny slinky and a tube of Styrofoam created from a cup. The video below shows how you can create the sound effect using a standard-sized slinky and full-sized cup. This demonstration is always a favorite with my scientists!

Demonstration #2:  The Wave Machine

I have been itching to make this wave machine for YEARS, and I finally had time to do it for this program. There are a lot of how-to videos online from teachers and science enthusiasts. The video I was initially inspired by is at https://www.youtube.com/watch?v=VE520z_ugcU. The materials are very easy to come by.

Materials:

• Bamboo skewers (I found mine at my regular food store – I bought a pack of 100)
• Gummy bears (I picked up a few bags at the dollar store)
• The duct tape of your choice

The wave machine is very easy to create, but it does take some patience and some time. I used a ruler as a guide to make sure that my bamboo sticks were approximately the same distant apart. You do need to attach the two ends of your wave machine to something solid – I used to heavy tables. You will find that if you’re making a long wave machine like I did, the wave machine will start to tilt as you progress with the construction. You simply need to adjust the position of the gummy bears on various sticks to rebalance the full wave machine. The video below shows you my finished product. Our scientists had a great time testing out different wave speeds, etc. And best of all, you can simply detach the wave machine from each place you anchored it to, roll it up, and store it for use again in the future!

Experiment #1: Humming Hangers

This experiment never fails to impress! There are many sites that describe how to perform this experiment. It is a very simple experiment, but one with a very cool pay-off. You simply tie a piece of string or yarn (about 1-2 feet long) to each end of a metal clothes hanger.

• STEP ONE: Swing the hanger against a table or other solid object. What sound do you hear?
• STEP TWO: With the strings wrapped once around each of your index fingers, put your fingers in your ears and lean forward to swing the hanger against the solid object again. What sound do you hear now?

RESULT: The first sound should be a light dinging noise; the second sound should be almost like a loud gong. ANSWER: With the second attempt, you are giving sound a more direct, quicker path to your inner ear…for a much louder, and more accurate, representation of the sound created.

The Projects: Large and Small Sound Sandwiches

These noise makers are always a hit with my scientists. They are easy to make, and very easy to use.

Materials:

• Craft sticks, large and small (I used colorful ones just for some pizzazz, but note that the color from these sticks DOES leach out of the sticks so some kids may temporarily have red, blue, or green lips)
• Rubber bands of various sizes (you want to make sure that the rubber band will wrap flat around the sticks but will not completely cover the sticks…you should see a margin of the stick surrounding the rubber band on all sides)
• Drinking straws, cut up into 2″ pieces

You can click on the experiment title above to see pictures with a step-by-step explanation of exactly how to assemble the sound sandwiches. The videos below show you 1) the large soundmaker, and 2) the small soundmaker that we created as a group. They were fantastically fun! Our scientists noted that the larger sticks created a lower, deeper tone than the smaller sticks.

TAKING IT FURTHER:  Try creating a triple or quadruple stacked sound maker by adding another layer of sticks, straw pieces, etc….how does the quality of the sound change? Does the sound change at all, or does it stay the same?

Science Explorers will be back in May with the Science of Espionage! But until then, don’t forget about our visit from Mystic Aquarium on April 18th!