Variations of historical experiments
Elena Kyriaki is a high school Physics teacher from Belgium. In the article below she tells us about her experiences in a Comenius III project “Hands on Science”, where teachers reproduced historical experiments in the school laboratory.
In the Comenius III project “Hands on Science” some teachers decided to work with historical experiments. The idea was to try to reproduce these experiments in the school laboratory, while:
- it would be an opportunity for our students to realize the difficulties the pioneer experimentalists had to overcome,
- it would be didactic to study the solutions to the practical problems which brilliant scientists thought off, and
- it would be exciting to follow the process step by step until the breakthrough.
Soon we discovered that reproducing historical experiments worked fine with our students. It raised their interest for the old stories and the scientific process.
On the other hand, setting up an historical experiment is not an easy job. Sometimes a whole team of experts is needed. It is nice to watch an accurate reproduction on educational documentaries or the copies of original experimental devices exhibited in museums. We decided not to “compete” with them. Instead, we thought that it would be interesting to try to design some variations of the original experiments in our school laboratory.
The first question was: How would a researcher design his experiment today? What tools would e.g. Galileo use to perform the Free Fall experiments? Probably, he would use position sensors. Still, he had to use slopes to slow down the motion and take better measurements of the distance travelled and the speed.
|Picture1: The experimental device|
A good example of what came out from our part of the project is an experiment that my colleague, Lambrini Papatsimpa, a Physics teacher, designed. She used the idea of the slope from Galileo’s Free Fall experiment in implementing a variation of the Electromagnetic Induction experiment of Faraday.
A bar magnet moves down a slope and induces a Voltage to a solenoid at the bottom of the slope, or vice versa. With different sensors you can measure the Voltage, the Magnetic Field in the coils, the position and the speed of the magnet and display on computer screen the resulting graphs.
1. The induced Voltage (emf=Electromotive Force) in the solenoid occurs only during the movement of the magnet.
2. The polarity of the induced Voltage (emf) depends on the direction of the magnet's movement.
3. The induced Voltage (emf) depends on the rate of change of the magnetic field.
|Picture 2: The sensors’ graphs taken by students of the Experimental school of the University of Athens.|
I find the experiment quite simple to set up and didactic. The sensors’ graphs give the values of the different magnitudes to compare. It is a good example of working in a creative way, applying a new approach to historic experiments.