“Teaching means creating situations where structure can be discovered.” –Jean Piaget

Many science teachers struggle with the idea of free exploration. Free exploration takes advantage of the natural tendency for children to just mess around with materials, without following any rigid procedures. If you have ever watched a child playing in sand, you have seen free exploration.

I have observed some preservice teachers struggle with a hands-on science lesson because they pass out the materials to the children and then they try to explain what they should do with them. More experienced teachers know that once children start to interact with the materials, they begin to tune the teacher out. A better strategy, therefore, is to explain to the children all that they need to know before passing out the materials.

Free exploration purposely allows students to mess around with the materials. It is a shame that for so many teachers, science experiences are always canned (first do this, and then do this). I have no objections to well articulated experiences that lead to discovery, but students also need opportunities to mess about. Each time they change something and see the result, they are developing ideas and approaches that will deepen their abilities to design and understand experiments.

The virtual world can be a great place to mess around without causing a great mess! The activity object, “Space Objects Interaction Explorer,” presents a great canvas to mess around with. Students are presented with two celestial objects, larger than the other. By changing the size and direction of the arrow, they control their initial velocities. Then they hit the play button and the objects move according to their initial velocities, and their motion is immediately influenced by gravity. Lines are drawn as the planets move so the orbital paths are evident.

Experienced teachers also are aware that challenges can really keep students engaged, such as with GEM’s Bubble-ology, where the teacher walks around and says, “Okay, let’s see who can produce the largest bubble!” or “Wow, great! Now, can you blow a bubble within a bubble?”

In “Space Objects Interaction Explorer,” the first challenge is easy. Make the objects collide. A fiery explosion rewards success, but there is no big bang—of course, contrary to Hollywood misconceptions, sound does not travel in the vacuum of outer space.

The second challenge is to make the smaller object orbit the bigger one. Most children can’t do this at first, but neither can most adults. It is interesting that most adults know what an orbit is, but they can’t at first produce one. It is very different being able to define the term orbit versus being able to explain why an object orbits another. Through trial-and-error learning, both children and adults can get one object to orbit the other—and develop intuitive ideas about orbits.

Inevitably, the first orbit produced by the learner is not a circle but an elliptical orbit. The third challenge is to achieve a circular orbit. When this task is completed it helps students really understand that orbits are an interplay between velocity (moving tangentially to the orbit) and gravitational interaction. Then, when orbits are explained, students have the experiences to understand why they occur.

 The fourth challenge involves three objects and asks that two of the objects orbit the largest one, which I will call the star. In putting this together, students (and adults) usually place one object closer and one farther from the star. And they initially make the farthest one have the bigger initial velocity. When they hit play, the nearest object crashes into the star and the larger object shoots out of the star system. Through trial-and-error learning, students will get it right, and later when they learn that Mercury is the fastest moving planet, it isn’t just an isolated fact to be memorized, but becomes an example of a concept they already know.

The last challenge is, appropriately enough, the most difficult to achieve. Appropriate because the really smart kids that solved the other challenges with great speed are fully engaged as everyone else catches up. The challenge is to make the small object orbit the medium object as the medium object orbits the largest object, or in other words, they are challenged to create a moon that orbits a planet, while the planet orbits the star. Students can, of course, adjust the position and velocity of the objects, as well as their masses. Success with this challenge isn’t easy and it takes a lot of messing about, but it is fun to see the interactions and patterns drawn of the paths followed. And when success arrives, it feels sweet!

References:

Adaptive Curriculum. (accessed August 7, 2008). Space Objects Interaction Explorer. https://www.adaptivecurriculum.com/us/details/USSSM150202

Barber, J. (1987) Bubble-ology (Great Explorations in Math and Science). Berkeley: Lawrence Hall of Science, University of California. http://www.lawrencehallofscience.org/gems/

Hawkins, D. (1965). Messing about in science. Science and Children, 2(5), 5-9.

Piaget, J., & Inhelder, B. (1967). The Child’s Conception of Space. New York: W. W. Norton.