Considering  the content of particle of a short introductory course in particle physics for high school students

 

A group of about 15 teachers from HST2002 met to discuss what they viewed as appropriate content for a section of a physics course in which the subject of particle physics was given no more than 6 hours time.

 

The discussion was not meant to be an in-depth analysis: its purpose was to get a feeling of whether there was a consensus of opinion or whether views were polarized. The discussion, itself, was kept to no more than one hour.

 

 

The outcomes

 

  1. It was recognized that the constraint of 6 hours teaching time meant that the content depended heavily upon whether the material came at the beginning of the students’ physics course or whether it came at the end. If it came at the end then it would be expected that the students would have built up a framework of supporting concepts like pictures of the atom, the nucleus, radioactivity etc. They would have been introduced, at some point, to differences between the classical world and the quantum world. If it came at the end of the course then the 6 hours could be spent considering some aspect of particle physics in a little depth. If it came at the beginning then the treatment might be limited.

 

  1. The first suggestions to emerge were that the students might be introduced to the subject from a historical perspective. A brief history of the subject might be given with students looking at the progression from atomic physics to nuclear and then particle physics in the 20th century. It was pointed out that the study of radioactivity might be an appropriate ‘doorway’ into the subject. This would involve considering the constituents of the nucleus together with a recognition that whilst electrons emerge in beta decay, they could not exist in the nucleus or in the nucleons prior to the decay. This would lead to a consideration of the creation of particles etc. It was recognized that even though the treatment might have a historical perspective, the students should end up knowing about quarks, leptons and interactions.

 

  1. It was then suggested that it might be better to avoid the need to trace a historical development and start directly with the current view of the composition of matter in terms of quarks, leptons and interactions. Students could be shown how the range of detected particles could all be built up from the small families of quarks and antiquarks. Detector images could be used to bring out the reality of the particles. It was agreed that, with this approach, it would be appropriate to introduce concepts like E=mc2, particle creation and annihilation and antimatter.

There was a suggestion that in a short treatment lasting only 6 hours, the students might be limited to considering particles that could be built from up and down quarks together with their antiparticles, or that the treatment might stretch to include the strange quark so that the students would be able to understand the composition of the kaons and get a view of the interpretation of the ‘zoo’ of particles in terms of a few building blocks.

 

There was some discussion about whether to include the idea of using Feynman vertices to illustrate the interactions and decays but there was some feeling that this kind of treatment might belong to a longer course rather than the 6 hour fleeting visit to the subject. Whatever the content, it was felt that there was a need to make students aware of the fact that nature can be described in terms of four fundamental interactions and that they should have an awareness of conservation laws.

 

  1. Another perspective to emerge was that the 6 hour treatment might do more than simply consider the details of particle construction and interactions. It might be designed to bring out the links between cosmology and particle physics, the connections between the submicroscopic world, the structure and evolution of the universe. It might also show how the quest to understand composition of matter, through academic laboratory institutions like CERN leads to revolutionary technical spin off with powerful applications in medicine, industry and commerce; it enriches and drives our culture.

 

If this were to be the perspective of the 6 hour treatment then it was pointed out that much particle physics could be introduced in other areas of a traditional physics course. For example, the students’ consideration of the motion of charged particles in electric and magnetic fields could be linked to the design of accelerators and detectors etc.

 

 

Conclusion

 

            Some of the participants were a little surprised at the eventual direction of the discussion. At the beginning of the discussion, some felt that the specification of content would be easy and that the physics itself would determine a natural sequence of concepts and topics. But the constraint of 6 hours teaching time seemed to suggest that any formal treatment and development of the subject might be difficult and that overviews and general considerations of the impact of the study of particle physics on culture and society might be the basis of the content.

 

At the end of the discussion, it was recognised that with that group of participants, at that time, there was no real clear consensus on the content of a 6 hour limited treatment of particle physics within a high school physics programme. This outcome is understandable in the context of the wide range of cultures and approaches from which the participants were drawn.

 

 

Peter Dunne