Chemistry Demonstrations and Fourth-graders: A Volatile Mixture?

Last week, I attended the regional meeting of the National Science Teachers Association held here in Minneapolis. I enjoyed seeing so many enthusiastic science teachers attending the sessions and wandering around the exhibit hall.

But when did schools start hiring such young teachers? Nearly all of them were quite a bit younger than me. And I’m not that old!   I’m only … well, let’s just say that I’m a seasoned professional.

Instead of feeling old when I left the meeting, however, I felt young and inspired. I particularly enjoyed watching some of the chemistry demonstrations that presenters were teaching to the teachers. As we participated in these hands-on activities, I could sense the energy and excitement rising in the room. It was the same feeling I get when I put on chemistry shows in my children’s classrooms.

I even started thinking back to the first chemistry show I ever witnessed, when I was a fourth-grader at Meeker Elementary School in Ames, Iowa.

Several years ago I wrote up my memories of that chemistry show, and here’s a copy of that brief essay:

The magic of chemistry first reveals itself to me in 1965, during Spring Break of my fourth-grade year, when my family goes on vacation to the big city of Chicago. The highlight of the trip is the visit to the Museum of Science and Industry. As we amble through the museum, we learn about coal mines and submarines. We see a plastic human heart pumping red and blue fluid throughout a life-size model of a human body. We find out about all kinds of machines, from levers and pulleys to the internal combustion engine. And at 2:00 pm, we gather on bleachers in an open area near the lobby to watch a demonstration of “The Wonderful World of Chemistry.”


I’m seated in the front row. Facing us, on a little stage, is a long table covered with glass bottles of various shapes, sizes, and colors. Placed at one end of the table are a banana, a wooden board, and a pink rubber ball. The ball is exactly the same kind as one I use to play “bounce and catch” at home on my front porch.


The noisy crowd of parents and children quiets down as a man in a white coat steps behind the table and faces us. A red rose is pinned to his lapel. A bright blue balloon rises above him, held in his right hand. He’s wearing glasses that have little plastic shields on the side. This man sure has my attention.


He starts the show by pouring two colorless liquids together, turning them first pink and then purple as he says some magic words. As he mixes other liquids and solids, he creates smoke and fog, makes a volcano overflow, and sets off a loud explosion.


Finally, he tells us that it’s time for the grand finale. He still hasn’t touched the banana or ball. I wonder what he’s going to do with them; maybe he’ll give them out as prizes to kids in the audience. I could always use another pink bouncy ball.


He reaches below the table and pulls out a big metal container with a lid on it. He puts on heavy white gloves and uses a long set of tongs to lift the lid off the container. Fog rises from it. Using a metal scoop shaped like the ladle my Mom uses to serve punch at Christmas time, he scoops up some liquid from the container. We can all see that it’s colorless and bubbling. Suddenly he bends over and pours it on the concrete floor right in front of the audience. I can hear it splatter on the floor. I pull back away from it, just like everyone around me. We don’t want to get splashed with this mysterious bubbling liquid. But as soon as it hits the floor, it disappears. It’s gone. None of us got wet, but I did feel a puff of cool air.


The man in the white coat tells us that this liquid is called “liquid nitrogen,” and it’s colder than the coldest Chicago winter. Grabbing the blue balloon, he holds it down on the table and pours a scoop of liquid nitrogen over it. The balloon shrivels up like a huge raisin, making a crinkly sound as it shrinks. The man lets go of it, and it just lies there. But then, right in front of our eyes, it starts to grow, take shape again, and rise into the air.


Next, the man takes the banana. Holding it with his tongs, he lowers it into the liquid nitrogen container for half a minute. When he takes it out of the liquid, he grips it in his gloved hand, and he picks up the board and a nail. Using the “Banana Hammer,” he pounds the nail right into the board. We ooh and ahh and applaud. I guess he won’t be giving out that banana as a prize.


Finally, he reaches for the bouncy ball and drops it in the liquid nitrogen container. After a minute or so, he fishes it out using the metal scooper. Picking it up, he turns around and throws it at the concrete wall behind him. I get ready to grab it when it bounces back toward the audience. But it doesn’t bounce. It shatters into many small pieces. I wonder if he’ll put the ball back together as the grand finale, but it doesn’t work that way, I soon find out.


Before he leaves, however, he has one final demonstration for us. He unpins the red rose from his lab coat lapel, dips it in the liquid nitrogen, and then bangs it on the table. Tiny red pieces of frozen rose petals fly across the table. I’m not sure if I’m supposed to clap or cry. As everyone around me begins to applaud, I hesitantly join in. Even if the rose incident doesn’t sit quite right with me, I decide that chemistry is indeed wonderful, and I’m going to learn more about it when I grow up.

Published in: on November 9, 2009 at 1:10 pm  Comments (2)  
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Making Room for Dad

There’s an interesting conversation going on over at the “Motherlode” Parenting blog at the New York Times website.  The opening salvo in the post, “Making Room for Dad,” reads:

Men should want to be more involved fathers, yes. But women have to let them.

A number of the people commenting on the blog refer to the phenomenon of Moms complaining about Dads not doing enough parenting, but then micro-managing them (and thereby discouraging them)  if they do get involved.  Others, however, seem to feel that men are simply incompetent.

What’s my perspective?  See comment #21.

 

Published in: on November 3, 2009 at 3:59 pm  Leave a Comment  
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A Nobel Lesson: Listening to Telomerase

Earlier this month, while pundits bickered non-stop about Obama’s Peace Prize, the Nobel Prize with a profound lesson for humanity slipped by with little hullabaloo. I’m referring, of course, to the Nobel Prize for Medicine, awarded “for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase.”

Nature has much to teach us, if we’re willing to learn. When William Blake wrote, “To see a world in a grain of sand, And a heaven in a wild flower,” he was offering solid advice.

So what can we learn from telomeres?

One of life’s basic challenges is to ensure that essential life lessons are passed effectively from generation to generation. Nature’s elegant solution, developed over several billion years, is telomeres. At the cellular level, “life lessons” are the genetic information contained in the chromosomes’ DNA. Cells that fail to pass along these lessons completely and accurately will not survive.

Telomeres are structures that protect the ends of chromosomes. During chromosomal replication, these structures safeguard the “lessons” from degradation. Cells even have a special enzyme—telomerase—that keeps the telomeres healthy and intact. Without telomeres, cells age rapidly and the organism dies.

And this is where the wisdom of the telomeres can help us. At the societal level, essential “life lessons” are passed down as values, laws and cultural wisdom. Communities, nations and civilizations that fail to pass along life lessons will not survive.

The moral of the story is that we must develop societal structures that protect the two ends of life—childhood and old age. If we fail to protect the lessons found in these two ends, we will see our society wither and die.

Although not a molecular biologist, Hubert Humphrey echoed the telomeres’ wisdom when he said, “The moral test of government is how it treats those who are in the dawn of life, the children; [and] those who are in the twilight of life, the aged…”

Many of today’s most pressing policy questions deal with the beginning of life (issues such as child poverty, health insurance and pre-school education) or the ending of life (issues such as how to provide cost-effective and humane health care at the end of life). If we want to survive as a society, we must do a better job of providing structures—social telomeres—to protect these two ends.

Published in: on November 1, 2009 at 8:13 am  Comments (1)  
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