Models and modeling are a major issue in science studies and in science education. In addressing such an issue, we first propose an epistemological discussion based on the works of Cartwright (1983, 1999), Fleck (1935/1979), and Hacking (1983). This leads us to emphasize the transitions between the abstract and the concrete in the modeling…

The purpose of this paper is to propose a new approach to research on gender differences in science that uses the work on expertise in science as a framework for understanding gender differences. Because gender differences in achievement and participation in the sciences are largest in physics, the focus of this review is on physics. The nature of…

A new method is introduced to study the behaviour of the falling spherical ball in a viscous liquid using the well known Stokes' law. Experimental results are compared with those obtained by numerical calculations. Upper limits on the size and mass of the spherical balls of different materials used in the experiment are presented. (Contains 5…

Two methods for measuring the Earth's magnetic field are described. In the former, according to Gauss, the Earth's magnetic field is compared with that of a permanent magnet; in the latter, a well-known method, the comparison is made with the magnetic field generated by a current. As all the used instruments are available off the shelf, both…

The typical elementary-school explanation of the difference between mass and weight goes something like the following: Mass is the amount of matter contained in an object. If you travel to the Moon, another planet, or anywhere far away from Earth, your mass doesn't change. Weight is how hard Earth pulls on you. When you travel to the Moon or…

The issue of why only particular isotopes of uranium and plutonium are suitable for use in nuclear weapons is analyzed with the aid of graphs and semiquantitative discussions of parameters such as excitation energies, fission barriers, reaction cross-sections, and the role of processes such as [alpha]-decay and spontaneous fission. The goal is to…

Described is a simple, cheap and versatile homemade windmill and electrical generator suitable for a school class to use to explore many aspects and practicalities of using wind to generate electrical power. (Contains 8 figures.)

What do the ideas of Daniel Bernoulli--an 18th-century Swiss mathematician, physicist, natural scientist, and professor--and your students' next landing of the space shuttle via computer simulation have in common? Because of his contribution, referred in physical science as Bernoulli's principle, modern flight is possible. The mini learning-cycle…

This paper presents the early investigations about the nature of sound of the Pythagoreans, and how they started a tradition that remains valid up to present times--the use of numbers in representing natural reality. It will touch on the Pythagorean notion of musical harmony, which was extended to the notion of universal harmony. How the…

Visualizations that adopt a first-person point of view allow observation and, in the case of interactive simulations, experimentation with relativistic scenes. This paper gives examples of three types of first-person visualizations: watching objects that move at nearly the speed of light, being a high-speed observer looking at a static environment…

The singularity of the exact electromagnetic fields is derived to include the "source terms" for harmonically oscillating electric (and magnetic) dipoles, so that the fields will be consistent with the full Maxwell equations with a source. It is shown explicitly, as somewhat expected, that the same [delta]-function terms for the case of static…

The 1935 debate opposing Einstein, Podolsky and Rosen to Bohr elicited so many comments and developments, both theoretical and experimental, until this day, that the main point at stake at that time can be overlooked by modern readers, especially students. This paper draws the reader's attention to the historical background of Einstein's paper and…

We study a system of two RLC oscillators coupled through a variable mutual inductance. The system is interesting because it exhibits some peculiar features of coupled oscillators: (i) there are two natural frequencies; (ii) in general, the resonant frequencies do not coincide with the natural frequencies; (iii) the resonant frequencies of both…

It has been argued that in higher education academic disciplines can be seen as communities of practices. This implies a focus on what constitutes identities in academic culture. In this article I argue that the transition from newcomer to a full participant in a community of practice of physicists entails a focus on how identities emerge in…

We study different ways of determining the mean distance (r[subscript n]) between a reference point and its nth neighbour among random points distributed with uniform density in a D-dimensional Euclidean space. First, we present a heuristic method; though this method provides only a crude mathematical result, it shows a simple way of estimating…