Abstract:

Many teachers and university students had no systematic course in physics, astronomy cosmology, or the foundations of science in their curriculum. Their conception of how science works, their perception of scientific laws, space, time and knowledge of the universe was formed from movies or from limited experience from their own reading. We have been providing a general course at the university for several years, in which we try to introduce the great progress in scientific knowledge as well as sophisticated research methods to the participants. We guide students from familiar terms to new concepts, showing the historical process of theory maturation and the ongoing validation of concepts by ingeniously designed and sophisticated constructed experiments.

We want to expose students to the situations that thinkers have dealt with, even though they have not yet had the opportunity for a rigorous experiment at the time. Exploratory experiments are difficult to implement in the course, so we have prepared several thought experiments for students. Thought experiments use only the human imagination. They are most often given in the form of a "story" of some sort, which is considered on the basis of clear assumptions and reasoning; the story asks what if...

A thought experiment represents a theoretical intermediate step in situations where the physical realization of the experiment is impossible or would not yield convincing results at a given level of knowledge and technology. Our students first become familiar with a specific historical thought experiment, looking to see what assumptions were made and what supporting arguments were advanced to support the author's conception. The analysis, moreover, helps students understand that sometimes, until science obtains empirical data that decide in favor of one concept or another, different explanations can persist side by side in parallel.

In this paper, we will present and discuss 3 assignments compiled from historical sources.
1. Aristotelian thought experiment to show the earth could not move. Aristotle puts the stationary Earth at the centre; that the Earth does not move is evidenced by the fact that a stone thrown vertically upwards returns along the same trajectory to the same place from which it was thrown.
2. Galileo's thought experiment "On Falling Bodies" as an argument against Aristotle's conception where bodies fall at different speeds
3. In Dialogue on the Two Chief World Systems, Galileo speculate on the origin of the planets.

The planets were formed in a particular place. From that place they were released at a constant acceleration until they reached their present speeds and distances from the Sun. This cosmogony required the special intervention of the Demiurge, who put each planet into a circular orbit at the moment it reached the speed it was destined to orbit forever. In this section, we show how we solved this problem with students by calculating the law of gravity.

Keywords:

history of science, teaching Nature of science, NOS, early cosmology