CHF Chemistry WebQuest #1 The Junkyard of Ideas Home | Teacher's Guide | Next >

Introduction Your Task The Process and Resources Evaluation Conclusion

Introduction

Copernicus on a Polish banknote.

Five hundred years ago a Polish priest and astronomer named Nicolaus Copernicus shocked a lot of people with his radical idea that the earth orbited the sun, and not the other way around. In many elementary schools, children are taught that the reason Copernicus was able to make a better model of the solar system is that he was really smart and everyone else was really dumb. Furthermore, the children learn, we of the twenty-first century are infinitely smarter than those medieval morons because we accept the sun as the center of the solar system while our ancestors, in their infinite stupidity, did not.

Talk about smug! What we didn't learn in the first grade is that the notion that the earth moved around the sun had been proposed more than a thousand years earlier by a Greco-Egyptian thinker named Aristarchus. His idea was rejected by almost everyone. But his peers weren't stupid; it's just that the sun really does seem to move around the earth. To really tell that the earth moves around the sun, you need data. You need really accurate measurements of the motions of the sun, moon, stars, and planets, and you need lots of them. Without precise measurements of the motions of the objects in the sky, the sun really does seem to move around the earth.

Aristarchus didn't have that kind of data, so he couldn't prove his idea. Copernicus didn't either, to tell the truth. After Copernicus died, other astronomers spent years taking lots of measurements. Finally, an astronomer named Johannes Kepler was able to settle the issue. But it is only because we have more evidence today that we can accept that the earth moves around the sun.

As time moves on, and scientists gather more and more evidence, many of our theories are shown to be wrong, and end up in the big junkyard of ideas. In investigating the ideas we once embraced, we can gain some understanding of how science works. We can see how an idea may be accepted until an unexpected piece of data overturns everything we thought we knew. In addition, studying the failures of old theories gives us insight into theories that replaced them and just why these theories have come to be accepted.

Your Task

Chemistry, like any other science, has a big junkyard where its debunked theories rust away. In this activity, your mission is to explore a debunked theory and in doing so gain an understanding of the evidence that debunked it, and theories that have replaced it.

The Process and Resources

In this WebQuest you will work in teams. Your teacher is going to assign your team one of the debunked theories listed below. You are going to use electronic and other resources to investigate the theory, and answer a few questions about it. To get you started we have provided some resources where you can begin your search. A list of resources is given below each theory in the list.

1. Phlogiston
   Phlogiston Theory—created by Jim Loy.

   Demise of Phlogiston—created by Dr. Edwin Hall at Florida Community College at Jacksonville.

2. The plum pudding model of the atom
   Rutherford's Experiment—from the ChemTeam and Diamond Bar High School.

   Atoms & Ions—includes a step-by-step breakdown of the hypothesizing, experimentation, and theorization used in bringing down the plum pudding theory, from General Chemistry Online!, created by Fred Senese at Frostburg State University.

3. Colloidal theory of polymeric materials
   The Story of Rubber—from the Polymer Science Learning Center and the Chemical Heritage Foundation. Read the pages under the heading "Understanding Rubber."

4. The vital force and organic compounds
   Structure and Nomenclature of Hydrocarbons—a basic lesson in organic chemistry from Purdue University.

5. Protein as the body's main source of fuel
   Sportscience History Makers: Justus von Liebig—covers Liebig's theories of metabolism, from Sportscience.

   Justus von Liebig and Friedrich Wöhler—biographical sketches, part of Chemical Achievers from the Chemical Heritage Foundation.

For your team's assigned theory, answer the following questions:

1. What phenomenon did the theory attempt to explain?

2. In your own words, explain theory.

3. Describe the experiments and/or observed phenomena that led to the theory's downfall.

4. Describe in your own words theories that are now used to explain the phenomenon that your disproven theory once explained.

5. What evidence supports the newer theories?

6. Did any famous scientists support your team's assigned theory? If so name at least one and discuss in a few sentences some of that person's more lasting contributions to science.

Evaluation

Once you have researched your discarded theory, you will prepare a report of what you have found. Your teacher may assign the report to be done as a paper, an oral presentation, or as a website that you will create. To make things fair, everyone's reports will be graded using a standard scorecard.

Conclusion

After you have prepared your final reports, this activity concludes with a class discussion on the issue of debunked theories.

This CHF Chemistry WebQuest was created by Mark Michalovic.