phenomenologic exploration, analyzing how to build explanations on observed
phenomena and how to found interpretative aspects in a coherent and rigorous
way. Students have to reflect on their own knowledge in electromagnetism and to
put in the field the competence of using their electromagnetic knowledge in a new
context. They are stimulated in the production of interpretative models and in the
connections between science and in meaningful connections between classical and
quantum physics technology. They analyze the history of the superconductivity
discoveries and technological applications. They use kits for educational experiments and multimedia materials developed within the framework of European projects MOSEM 1–2 (Kedzierska et al. 2010; Greczylo et al. 2010; MOSEM2 Group
2011).
For the educational laboratory, we developed new systems for temperature
dependence of resistivity measurements in a wide range of resistivity values
(Gervasio and Michelini 2009), that we integrate in path proposal. Our educational
proposal for a phenomenological exploration of superconductivity in secondary
school is integrated in the electromagnetism curricula and for the feasibility study
we support a group of teachers for research-oriented school implementation
(Michelini and Viola 2011). From 2010 research experimentations were conducted
in 20 different classes of eight different Italian schools with 393 students. Results
documented the systematic interest of the students, which was not limited to the
simple observation of phenomena unusual and surprising, but mostly focused on the
exploration of interpretative hypotheses. Results of research-based school implementation showed that the personal involvement in the exploration of the collection
of the many problematic proposed situations activates the planning of further
explorations, aimed to test hypotheses able to explain the superconductor behavior.
Starting from the ordinary electrical and magnetic properties of matter, students
recognize the peculiar characteristics of the superconductivity behavior at liquid
nitrogen (LN) temperature, comparing it to those of an ideal conductors and of
diamagnetic materials (Stefanel et al. 2014).
The strategy adopted includes the following phases: presentation of a situationproblem, experimental exploration of it, student individual hypothesis for explanation and/or planning of a further exploration, discussion in little group to reach a
common decision, discussion in large group at the end of each problematic issue.
The following explorative steps are the core of the path proposal:
(S1) Interaction between a little strong magnet (M 1 ) and an YBCO disk at room
temperature (T room ) and at liquid nitrogen temperature (T NL ). An YBCO disk at
room temperature (T room ) does not present magnetic properties. When it reaches
the temperature of T NL , the levitation of the magnet occurs. This phenomenon
called Meissner effect is analyzed by students as well as the stability of the
levitation.
(S2) Comparison of the Meissner Levitation and the cases of magnetic suspensions.
Interaction between two free magnets shows the rotation of one of them to attract
the opposite pole of the other and suspension occurs only when we constrain
magnets to face the same pole for example putting them in a tube. Levitation
110
M. Michelini
phenomena and how to found interpretative aspects in a coherent and rigorous
way. Students have to reflect on their own knowledge in electromagnetism and to
put in the field the competence of using their electromagnetic knowledge in a new
context. They are stimulated in the production of interpretative models and in the
connections between science and in meaningful connections between classical and
quantum physics technology. They analyze the history of the superconductivity
discoveries and technological applications. They use kits for educational experiments and multimedia materials developed within the framework of European projects MOSEM 1–2 (Kedzierska et al. 2010; Greczylo et al. 2010; MOSEM2 Group
2011).
For the educational laboratory, we developed new systems for temperature
dependence of resistivity measurements in a wide range of resistivity values
(Gervasio and Michelini 2009), that we integrate in path proposal. Our educational
proposal for a phenomenological exploration of superconductivity in secondary
school is integrated in the electromagnetism curricula and for the feasibility study
we support a group of teachers for research-oriented school implementation
(Michelini and Viola 2011). From 2010 research experimentations were conducted
in 20 different classes of eight different Italian schools with 393 students. Results
documented the systematic interest of the students, which was not limited to the
simple observation of phenomena unusual and surprising, but mostly focused on the
exploration of interpretative hypotheses. Results of research-based school implementation showed that the personal involvement in the exploration of the collection
of the many problematic proposed situations activates the planning of further
explorations, aimed to test hypotheses able to explain the superconductor behavior.
Starting from the ordinary electrical and magnetic properties of matter, students
recognize the peculiar characteristics of the superconductivity behavior at liquid
nitrogen (LN) temperature, comparing it to those of an ideal conductors and of
diamagnetic materials (Stefanel et al. 2014).
The strategy adopted includes the following phases: presentation of a situationproblem, experimental exploration of it, student individual hypothesis for explanation and/or planning of a further exploration, discussion in little group to reach a
common decision, discussion in large group at the end of each problematic issue.
The following explorative steps are the core of the path proposal:
(S1) Interaction between a little strong magnet (M 1 ) and an YBCO disk at room
temperature (T room ) and at liquid nitrogen temperature (T NL ). An YBCO disk at
room temperature (T room ) does not present magnetic properties. When it reaches
the temperature of T NL , the levitation of the magnet occurs. This phenomenon
called Meissner effect is analyzed by students as well as the stability of the
levitation.
(S2) Comparison of the Meissner Levitation and the cases of magnetic suspensions.
Interaction between two free magnets shows the rotation of one of them to attract
the opposite pole of the other and suspension occurs only when we constrain
magnets to face the same pole for example putting them in a tube. Levitation
110
M. Michelini