Today the Oberstufe had the good fortune of welcoming accomplished engineer and physicist extraordinaire Stefan Novotny to our Thursday program. This marks the start of a bi-monthly series where we will be engaged on all topics “energy”.

Yesterday we heard that our homework for today would be to bring something along that we understand as a source of energy, literally the first thing that came to our mind. There were many batteries, a few flashlights and Jonas brought along a water wheel. Of course my own object was a tin of coffee. Stefan himself brought a bicycle wheel that converts potential energy (a suspended weight) into kinetic energy (the turning wheel) and thereafter into electrical energy and finally into light energy (a lamp). Through these examples, and many diagrams we came to understand the many different forms that energy can take and can be transformed into. For instance, it was fascinating to learn how electrons are transferred between certain substances during friction (a plastic sleeve rubbed against Hans’s head) and also the chemical reaction that takes place during combustion (C and O bonding to become CO2) when a match is lit.

Stefan also came prepared with a slideshow which gave us a glimpse into how energy has been understood since Aristotle, through Newton, Galileo and Einstein. We learned how physicists approach their work by observing the rules of nature and transferring them into a model. Perhaps most crucially we learned about the units of measurement that allow us to work more easily with models and calculations. Here the distinction between Si basic units (e.g. l, h, t) and more concrete units of measurement (e.g. m, s, kg) was important.

We also learnt the important distinction between Work, Energy and Performance. Work, being the mechanical work that is exercised on a body by a power, energy being the source of power needed for work (that can also be stored), and performance being the amount of work that can be done in a certain amount of time. It is easy to see why these concepts can be confused but I thought it was fascinating how each can be applied to any of our examples.