Inside Boxes Research Articles

The integration of knowledge and experimentation strategies in understanding a physical system

AbstractThis study investigated how people integrate different kinds of knowledge in coming to understand the functions of components of a physical system. Twenty‐three undergraduates worked on a hypothesis‐testing task in which they constructed test circuits to decide the identity of electrical components hidden inside boxes. The students' problem‐solving was driven by qualitative causal models that included ideas about cause and effect, task demands, and functions of circuits and circuit components. There was a hierarchy of four causal models, with higher levels representing increasing understanding and supporting increasingly successful problem solution. These causal models were associated with characteristic experimentation strategies, including strategies for generating evidence, interpreting evidence, and managing memory requirements. Some of these strategies followed directly from the causal model a student held, whereas others appeared to be more general. The level of understanding a student eventually attained about this physical system was a function of both domain knowledge and proficiency in experimentation strategies.

Suspected Infanticide in the Starling

Suspected Infanticide in the Starling

The stark effect for the hydrogen atom inside boxes with paraboloidal surfaces

Hypervirial relationships and perturbation theory are used in order to obtain analytic approximate expressions for the energy levels of the hydrogen atom in a paraboloidal box in an electric field.

Prey recognition learning by red spitting cobras, Naja mossambica pallida

Eleven ingestively inexperienced red spitting cobras (Naja mossambica pallida; 4 weeks old) failed to respond to food items (neonatal mice, Mus musculus, and live lizards, Sceloporus undulatus). Live prey were inside clean plastic boxes that were placed into snake cages for 5 min. Rate of tongue flicking and number of biting attacks were recorded. The cobras were then offered neonatal mice (but not lizards), and gradually, these prey were accepted. By the end of the 5th week, all snakes had eaten at least one mouse. From this time until the snakes were 10 months old, mice were offered once each week, and most snakes ate each week. Prey recognition tests were conducted again (at 10 months), and the snakes responded to mice but not to lizards (Anolis carolinenesis). It is concluded that increased response to mice between the 1-month and 10-month tests was not based on increased predatory motivation and/or acclimation to the laboratory, because these factors should also produce increased response to lizards. Accordingly, it seems probable that experience with mice resulted in the acquisition of stimulus control by mouse-derived cues over snake predatory behavior (i.e., prey recognition learning).

Hypervirial perturbative treatment of the hydrogen atom inside boxes with paraboloidal surfaces

The hypervirial perturbative method (HPM) is applied to study the behavior of the hydrogen atom within paraboloidal boxes with impenetrable walls. Numerical results obtained from an analytical closed formula are compared with those reported previously by Ley-Koo and Rubinstein from a numerical procedure.

The hydrogen atom inside boxes with paraboloidal surfaces

The Schrödinger equation for the hydrogen atom inside boxes defined by pairs of confocal, coaxial and mutually intersecting paraboloidal walls is solved exactly using parabolic coordinates. The energy eigenvalues and eigenfunctions for the lowest states of the system are determined numerically for such boxes, having different sizes and shapes. Also, the isotropic and anisotropic components of the hyperfine splitting are evaluated.