“OK, Chocolate Man, let’s see what you’ve got,” says physics teacher Andrew Fiala.
High school students in Fiala’s class eagerly crowd around Jonathan Wisner’s machine. They can see it has enough chocolate for everyone in the class.
Wisner starts the chocolate distribution machine by dropping a weight attached to a string that twirls a peg attached to a bar.
At the end of the bar, an extra-large nut bangs into the piece of chocolate, knocking it down a chute and into the waiting hand of a classmate.
Cheers erupt and hands reach out to get their piece of chocolate.
“Good job!” says Fiala, “Generally, we think of a fulcrum moving side to side, but this acts as a wheel. You have five machines present and five energy transfers. Cool. You got extra credit.”
The students in Fiala’s class have an advantage over most students: they can turn concepts they learn into physical form. On this day, sprawled out over table tops and covering the floor of the classroom, lay various platforms with pulleys, sticks, poles, strings, knobs, planes, nuts and bolts attached.
Matchbox cars, dominos, Legos, Dove chocolate candies and dog kibble sit amongst the cobbled-together machines.
Fiala has asked his students to create Rube Goldberg gadgets to demonstrate the physics concept of energy transfer.
Fiala’s instruction sheet explained, “Rube Goldberg was an award-winning cartoonist, who drew machines and contraptions of marvelous complexity and ingenuity to perform such basic tasks as scratching your back or killing a mosquito.”
Each project a student created had to include five simple machines of at least three different types.
The devices had to transfer energy from one object to another, such as when a marble hits a domino. Using the same objects, such as a domino hitting another domino, would not count as an energy transfer.
Fiala’s instructions make it clear that using two objects at once would not count as two energy transfers. For example, a car hitting a book, which traveled along with the car to hit another object, would not count as an energy transfer.
Demonstrating how their machines worked allowed students to see this lesson.
“Students have to fulfill tasks to prove they know that level of knowledge,” said Fiala.
Therein lies the challenge of his physics course: students must demonstrate they understand a concept — not just find the right answer.
“I’ve had students drop this course because they say, ‘Every time I ask Mr. Fiala a question, he answers with another question,’” he said.
However, the essence of science is to answer a question — not find the right answer, he said.
Often in the effort to prove a theory, scientists find more questions than answers.
For Fiala, creating tests or worksheets that give the right answer won’t determine if students understand a concept, but projects and tests based on Bloom’s Taxonomy can. Written in 1956 to aid the creation of curriculum, Bloom’s Taxonomy helps teachers determine whether students truly comprehend, have knowledge of, can apply and analyze, relay information to others and evaluate what their teacher taught them.
Fiala uses Bloom’s Taxonomy to ask questions that make the students prove they have absorbed his lessons.
• Describe what happened when the energy transferred from the release mechanism (the object that started the energy transfer) to the end.
• Can you provide a definition of energy transfer?
• Do you know another instance of energy transfer in nature?
And just because Fiala makes his students work, does not mean they do not have fun.
Wisner said he had fun building his chocolate machine.
“It seemed simple to feed people chocolate,” he said, “It’s fun to understand how it works.”
Noel Struening built a machine to raise a flag made of red, yellow and black Legos up a miniature flagpole.
“A marble will hit the domino and go off the table pulling the flag up the pole,” said Struening.
To demonstrate, he dropped the marble, it rolled down a ramp, hit the dominos, they fell off the side of the table and the flag ran up the pole.
“Nice,” said Fiala as the rest of the students clapped in appreciation.