Try one, Try two, Try Green, Try Blue

The world’s greatest inventions were not made overnight.  Cars, planes and even the telephone took inventors a lot of time to create.  I learned this during my many failed attempts to create a “dinosaur” footprint and a sand artwork for the kids’ section of the Zoological Society of Milwaukee’s Alive magazine.

It all started with a brainstorming session. The goal was to come up with dinosaur activities that teach kids about paleontology. The original idea was to have kids and parents make a cast of a dinosaur footprint in a sandbox. Then they would make plaster out of some household items and let the sun bake the plaster in the sand. It sounded so easy.


This large footprint was an early version. I pressed it into 50 pounds of sand prior to the first failed plaster mixture.

This is how many inventors come up with ideas. They begin with a brainstorming session to think of something that will fill a need or improve upon another object. Once the inventor has an inclination, he or she attempts to construct it. As inventors build, they tinker with the object in a series of trials and errors. This allows them to see what worked and what didn’t. To get to the finished product, inventors continue the trials until there are no errors.

One inventor who became very familiar with the concept of trial and error was Thomas Edison. He tested his light bulb and electric circuit many times and failed. The way Edison looked at it was: “I have not failed. I have just found 10,000 ways that won’t work.”  It took Edison 1 ½ years to create and test the parts of his electrical circuit. He tweaked his design and made changes, testing it again and again for errors. In the end, he created the first working light bulb, which stayed lit for about 13 1/2 hours (today’s light bulbs can last 1,000 to 2,500 hours).

Although I didn’t spend 1 ½ years testing our kids activities, they went through many scrupulous stages of trial and error. For instance, I found “a lot of ways that don’t work” with the dinosaur footprint cast that can be seen in the April 2010 Alive magazine. As you read below, you will see how our project changed again and again and why my roommates still laugh at me today.   

The first trial:


The First Error:  The mixture of glue, water and green food coloring was slowly absorbed by the sand. So I ended up with no cast of a footprint.

I began the project in the snowy Midwestern winter. So I wasn’t going to be digging in any sand boxes.  Instead, I purchased a large plastic storage container and filled it with 50 pounds of sand. I proceeded by drawing a footprint design about the size of an 8 1/2-by-11-inch sheet of paper. I glued the sheet to cardboard, cut it out and then made my footprint mold. Knowing that I wasn’t going to have the sun be bright enough to warm the project through my window, I clipped a bending reading lamp to the container and aimed it at the sand.

The first error: 

The problem was in the plaster formula I found online. It was made of glue, water and green food coloring (this was to make the footprint more colorful). The result: The sand absorbed the fluid and then became hard, moldy-green-colored sand.

The second trial:

 I took the hard sand out of the box and proceeded to make a new mold.  I tried a new plaster mixture of water, glue, green food coloring and flour.  My thought was that if I added flour to the mixture, the sand couldn’t possibly absorb it because it would be too thick.  My thought process was correct…. 

The second error: 


The Second Error: This was supposed to be a footprint cast. Instead, it became a blob-- of flour, glue, water and green food coloring. It never hardened, even after baking it under a reading lamp.

In fact, the mixture was so thick that the reading lamp couldn’t become warm enough to dry it at all.  The result was the creation of a green blob in my footprint mold.

The third trial:

At this point I had established the two ends of the spectrum.  Water and glue made a plaster that was too easily absorbed by sand.  On the other hand, water, glue and flour created a thick blob that was impervious to heat lamps.  Using the process of elimination, I made a revolutionary breakthrough.  A mixture of flour and water and blue food coloring (I ran out of green) should be what Goldilocks would have wanted: not too watery and not too gooey. 

The third error: 

After 10 hours of waiting, I lifted the reading lamp to reveal the dry top of a footprint.  With a rush of excitement, I grabbed around the outsides of the footprint and flipped it over.  Only to find that the reading lamp couldn’t heat up the bottom of the footprint enough to dry. So with the twist of the wrist, I found that the moist top began to flop everywhere.

The fourth trial: 

Now that I knew the new mixture would dry, I tried to make a smaller footprint. I figured that the reading lamp could heat a footprint about half the size. Ten hours later, I unveiled the first footprint that held its shape even though it was still soft. When I came into the Zoological Society office, I showed my boss what I had created.  She asked if I had baked it. With a confused look on my face, I said, “No, I’ve been using a reading lamp to cook it in the sand.” She told me if I made my sand mold and plaster footprint in a pan and then put it in the oven, it would become hard. I went home rather confused that night. I knew my way around a kitchen, and prior to that I’ve never come across a recipe that said “add 8 cups of sand and bake for 40 minutes.”

As a last try, I filled a baking pan with sand, pressed my footprint into it and filled it with white plaster.  With my roommates puzzling over why I was making a sand cake, I sat for 40 minutes hoping that my footprint wouldn’t burn in the 350-degree oven.  When I began to smell the warm musty smell of cooked sand, I pulled my pan out to find a dinosaur cast.  No sooner did the sand cool down, did I flip my footprint to find that it was as hard as a rock.

Once the project was completed, it was almost comical to see how it changed through the process of trial and error.  In the beginning, it was an outside sandbox excavation and it ended up being an inside-your-oven culinary art.  The comedy and errors didn’t end there.  When I returned to this project two weeks later, I found that my footprint had begun to crack and turn green with mold.  I realized that after all that work my project still could use another round of trials.  

By Benjamin Wright