Advertisement

Lessons can come from the strangest situations

October 11, 2002|by LISA TEDRICK PREJEAN

Who was the first American in space?

A. John Glenn

B. Neil Armstrong

C. Alan Shepard

For the correct answer, check the end of this column.

Apparently, it's a tough question. When the top five contestants in the Miss America Pageant were asked, no one got it right.

A fairer question for someone who's 20 could have been based on the Challenger explosion. I remember that day in January 1986 like it was yesterday. I was in my college photography class .... oh, wait. Someone's who's 20 would have turned 4 that year.

Advertisement

Hmmm. Guess I'm older than I think. Maybe that's why I can remember these things.

Plus, I've had some incentive to brush up on my knowledge of the space program.

There's a 7-year-old boy in my house.

Recently he asked a question that made me wonder if he's really reading when he retreats to his room or if he's actually planning a top-secret mission.

"So, Mom, what's the sound barrier and how can we break through it?"

There was one word that stood out above all the rest.

We.

I wanted to tell him that I have no desire to break through anything, except maybe an egg shell or two when I make french toast.

But, like a good mom, I said, "Well, there's probably a good explanation on NASA's Web site. Let's go there and see."

I found a great article on sonic booms at www.nasaexplores.com. There's also two experiments that are fun and easy to set up. And, I referred to "The Handy Answer Book for Kids (and Parents)" by Judy Galens and Nancy Pear, a resource I've mentioned many times.

First off, I wanted a simple way to explain what the sound barrier is.

When planes fly at moderate speeds, air has time to move aside and let the plane through. Imagine a plane flying through the sky faster than the speed of sound, which is about 1,120 feet per second. (That's almost three times around a standard high school track - in one second.) The air molecules in front of the plane become crowded. They have no where to go, so when the plane flies through them, the impact creates a boom. This is breaking through the sound barrier.

Since I don't have the resources to illustrate that (thank goodness), I decided to try the NASA explores experiments with my son and a few of his friends.

We used balloons to show that sound is made when something shakes or vibrates.

Here's how it works: One child holds his blown-up balloon beside his ear while another child speaks against the balloon.

The kids had a ball with this, because not only does it sound funny when you hear someone talk against a balloon; it also feels funny when you're the one doing the talking. You can feel the vibrations on your lips. (Yes, I tried it. Someone had to demonstrate, you know.)




Here's the other experiment: To show what sound waves would look like if you could see them, place a few inches of water in a dishpan or other plastic container.

Ask your child to touch the surface of the water with a tongue depressor or pencil. The water should move away from the object, forming a set of circular waves.

Then, starting at one end of the container, ask your child to drag the wooden object slowly across the surface of the water in a straight line. Experiment with various speeds and watch the shapes of the waves change.

If we could see sound waves, that's what we'd see. And their inability to move out of the way when a plane travels faster than the speed of sound causes the noise called a sonic boom.

That's one trip I don't think I'll make with my son.




So who was the first American in space? If you picked Alan Shepard, you listened during history class.

If you picked Glenn or Armstrong, don't be too tough on yourself. You could be Miss America.

Lisa Tedrick Prejean writes a weekly column for The Herald-Mail's Family page. Send e-mail to her at lisap@herald-mail.com.

The Herald-Mail Articles
|
|
|