In a series of 3 experiments modeled after infant studies, 3- to- 6-year-old children's intuitive knowledge about support was assessed. Different objects were shown either sufficiently supported or not. Children had to predict whether a block would remain standing on a platform upon release or make perceptual judgments about the possibility of a…

Purpose: In this study, the authors aimed to determine how between-language interaction contributes to phonological acquisition in bilingual Spanish-English speaking children. Method: A total of 24 typically developing children, ages 3;0 (years;months) to 4;0, were included in this study: 8 bilingual Spanish-English speaking children, 8…

Reaching and grasping skills have been described to emerge from a dynamic interaction between intrinsic and extrinsic factors. The aims of the study were to investigate the effect of such intrinsic factors as age and Down syndrome on the development of reaching and grasping skills and on overall gross motor skill, and to test the influence of the…

This essay recounts Hermann von Helmholtz's trip to represent Germany at the International Electrical Congress in Chicago in 1893 as well as his reception by various members of the American scientific, technological, and cultural elite in several other American cities. In doing so, it seeks to portray something of the vitality of the youthful and…

This study proposes a multi-dimensional approach to investigate, represent, and categorize students' in-depth understanding of complex physics concepts. Clinical interviews were conducted with 30 undergraduate physics students to probe their understanding of heat conduction. Based on the data analysis, six aspects of the participants' responses…

This paper describes a very simple exercise using an inverted test tube pushed straight down into a column of water to determine the free-fall acceleration "g". The exercise employs the ideal gas law and only involves the measurement of the displacement of the bottom of the "diving bell" and the water level inside the tube with respect to the…

Even today, with all of the instant communication technologies available, we are still often unaware of all that happens in other parts of the world. In the middle of Europe, in the Czech Republic, physics teachers have created a couple of innovative conferences--or "workshops" might be a better term. Having attended two of each, I think…

In this paper, the time required for a tower block to collapse is calculated. The tower collapses progressively, with one floor falling onto the floor below, causing it to fall. The rate of collapse is found to be not much slower than freefall. The calculation is an engaging and relevant application of Newton's laws, suitable for undergraduate…

We present a simple one-dimensional quantum-mechanical model for a particle attached to a surface. It leads to the Schrodinger equation for a harmonic oscillator bounded on one side that we solve in terms of Weber functions and discuss the behaviour of the eigenvalues and eigenfunctions. We derive the virial theorem and other exact relationships…

Previous research has shown that young children make a perseverative, gravity-oriented, error when asked to predict the final location of a ball dropped down an S-shaped opaque tube (Hood, 1995). We asked if providing children with verbal information concerning the role that the tubes play, in determining the ball's trajectory would improve their…

Recent elaborations on cultural-historical activity theory (CHAT) (Engestrom et al., eds., "Perspectives on activity theory." New York: Cambridge University Press, "1999") and its relation to organizational theories have produced a theoretical amalgam of these earlier ideas, which allow for the exploration of learning in formal…

Solid modeling is widely used as a teaching tool in summer activities with high school students. The addition of motion analysis allows concepts from statics and dynamics to be introduced to students in both qualitative and quantitative ways. Two sets of solid modeling projects--carnival rides and Rube Goldberg machines--are shown to allow the…

The temperature dependence of the dielectric permittivity is taken into account to study the energy change in a capacitor that follows a cycle between a cold and a hot thermal reservoir. There is a net energy gain in the process that, in principle, can be transformed into usable work. The paper is simple enough as to be used with keen…

This paper deals with temperature variations over time of objects placed in a constant-temperature environment in the presence of thermal radiation. After a historical introduction, the paper discusses cooling and warming laws, by taking into account first solely object-environment energy exchange by thermal radiation, and then adding…

In this paper, canonical transformations generated by constants of motion in the case of the Kepler problem are discussed. It is shown that canonical transformations generated by angular momentum are rotations of the trajectory. Particular attention is paid to canonical transformations generated by the Runge-Lenz vector. It is shown that these…