Red beams and dots of light hover in the physics lecture hall

«Atoms should be seen not so much as the smallest particles that make up matter, but rather as signposts on a map that guide us through the world of physical and chemical phenomena,» say the two professors Dr. Wilfried Sommer and Dr. Dirk Rohde. Both are passionately committed to teacher training at the Kassel Teacher Training College and the University of Marburg. Their joint project strengthens students in scientific discussions and raises their awareness of natural phenomena.

Scientists have been trying to grasp matter as a concept since ancient times. From the atomists Leucippus and Democritus in the fifth century BC to modern scientists such as Bohr, Schrödinger and Heisenberg – they all had different ideas. These range from indivisible spheres to quantum mechanical wave functions including the associated probability distributions.

Sommer and Rohde use modern technology to create interactive learning environments. They use video technology in their twice-weekly lessons to give students a deeper understanding of complex physical and chemical concepts. In a pilot project, they test what hybrid forms of teaching and learning can look like in an upper school online campus. The framework is an eleventh grade elective class.

The physicist Niels Bohr once said: «There is no quantum world. There is only an abstract quantum description. It is wrong to think that it is the task of physics to describe nature as it is. Physics is only concerned with what we can say about nature.» Similar to maps that symbolically represent the real world, atoms also serve to bring together specific aspects of matter in an abstract way: for example, energy, mass and charge. Accordingly, the title of Sommer and Rohde's compulsory elective lesson is «Atoms – interrelationships between matter and form».

Sommer tests this approach in the first part of the project in the physics lecture hall of the Kassel Teachers' Seminar. He invites the eleventh grade students to participate. Students from the Marburg school and project partner Rohde as a chemistry teacher are also involved. In the second part of the project, they reverse the roles: Rohde will teach his students in the chemistry laboratory at the Marburg Waldorf School and Sommer will follow the chemistry part with his students from Kassel. «We've been familiar with video technology since coronavirus,» says Sommer. «The technology is very inexpensive, around 2,000 euros for a good camera, a very good microphone and a suitable monitor for each location. This allows us to teach students at several locations at the same time and train their teachers.» This teaching approach can be extended to a number of schools and also to different subjects.

After a welcome, Sommer begins each lesson with a technical vocabulary exercise that builds on the previous lessons. He uses circuits and diagrams to practise with the students how concrete electrical systems are converted into abstract models. Today he draws a circuit on the board: a cathode and an anode, both made of metal, in an almost empty space, almost a vacuum. If the cathode is heated, an electrical zone forms above it. This changes when voltage is applied between the cathode and anode. This phenomenon becomes visible when the diluted residual gas is made to glow electrically. The terms are in the room. The students know what they need to focus on in the following experiment.

«No phenomenon is a phenomenon unless it is an observable phenomenon.» With these words, Niels Bohr emphasized the importance of observation in science. He shaped our current view of atomic physics and quantum phenomena. Bohr emphasized that direct observations help us to understand scientific concepts. According to Sommer and Rohde, our observations already contain many of the symbolic forms that we later abstract into scientific concepts.

Sommer now fetches a table with an experimental setup from the preparation room. A glass tube stands on a pump. «You have to put on the protective masks. The pump is about to create a vacuum in the glass tube.» Sommer points to the two metal rings on the left and right side of the glass tube. Both electrodes are connected to a high-voltage power supply. Sommer switches the device on and applies an impressive 5,000 volts. Nothing can be seen in the tube yet. The pump slowly sucks the air out of the glass tube, whereupon a red beam lights up between the cathode and anode. The air pressure is further reduced. Finally, glowing dots appear to the right and left of the metal rings at the ends of the glass tube. Sommer explains that these are caused by a coating on the glass tube, which is electrically stimulated to glow. He hands a student a magnet. She moves it along the tube, whereupon one of the rays is deflected. Sommer adds that there is always the same ratio of charge and mass, which the students can immediately relate to their previous knowledge. The term electron beam makes sense to them.

«Does a television tube work like this?» asks Yara. She should try to deflect the beam beyond the cathode. «That's extremely difficult.
Why?» Sommer wants to talk to the students about ions in the next lesson. David asks: «What's that flying in the tube?» «The glass tube is a small particle accelerator,» says Yara.

This teaching approach shows students that scientific concepts are linked to decisions to pursue certain aspects of a field of phenomena and to grasp them abstractly. In this sense, they are tools to formally describe, perhaps even explain, the world. They are not direct representations of reality. By observing phenomena themselves and discussing the choices made on the way to abstraction, students learn both to distinguish between subjective experience and abstract concept and to see connections. Sommer has written a whole series of books containing teaching examples similar to those described. These can be a resource for teachers who want to enrich their methodology and get students excited about science in innovative ways. Schools interested in deepening their science curriculum are encouraged to contact the two experts Sommer and Rohde (wilfried.sommer@alanus.edu). Participation in one of the next atom projects offers not only students but also teachers the opportunity to benefit from this new phenomenological approach and to expand their knowledge of physical and chemical terminology.