The Tube

The way the ropes are set inside the tube will cause a seemingly complex and amazing movement pattern of the ropes. When the teacher pulls one end of the rope, another end will be pulled in with a seeming random pattern. The teacher can pull on rope ends clockwise at one time, then across the tube at another.

Materials: 1 tube (mailing tube or PVC pipe, approximately 30 cm), 1 plastic ring (optional, you can simply loop the lower rope over the upper rope), rubber stoppers or tape to seal the tube ends, 1 role of clothesline rope (for whole class), 1 toilet paper roll core (for each student group).

Procedure:

(1)Ask students to make OBSERVATIONS about what you’re doing with the tube.

(2)Pull the strings of the tube clockwise several times, and then across.

(3)Ask students to individually draw a tube and make a model of what they think is going on inside the tube. Have them share their models with a partner.

(4)Then, ask the students if they would like to direct you to make certain pulls so that they can better refine their models. Do this.

(5)Then, have students use the rope and toilet paper rolls (one per pair) and have them make actual models of the tube. At this point, you can let the students interact with the original tube or take requests from them about making particular pulls.

(6)At the end, have students share their models with each other.

(7)Explicit Reflection at end:

  1. How was the work we were doing here like that of scientists? (building models, making observations, changing our ideas, basing our models on evidence, etc.)
  2. How does this process show how scientific knowledge is TENTATIVE (ideas changed with additional information)
  3. What was the DATA you used in this process?
  4. What kinds of OBSERVATIONS did you make?
  5. What kinds of INFERENCES from those observations did you make?
  6. What could we do to be more sure about our explanations?
  7. We can’t open up our tube and see what’s inside. How is that like science?
  8. How is your model like or not like the original? How could this impact your findings?

From Lederman, N. & Abd-El-Khalick, F. (1998). Avoiding De-Natured Science: Activities that Promote Understandings of the Nature of Science. In McComas, ed. The Nature of Science in Science Education: Rationales and Strategies. Kluwer Academic Publishers: Dordrecht.