When referring to named objects, speakers can choose either a name ("mbira") or a description ("that gourd-like instrument with metal strips"); whether the name provides useful information depends on whether the speaker's knowledge of the name is shared with the addressee. But, how do speakers determine what is shared? In 2…

A simple apparatus is described which serves as a materials testing laboratory. Bolts are placed in it and subjected to tensile and torsional stress while being tightened. The tensile and torsional stress and strain can be measured, which enables the determination of several mechanical properties of the bolt material, including Young's…

The construction of a voltaic pile (battery) is a simple laboratory activity that commemorates the invention of this important device and is of great help in teaching physics. The voltaic pile is often seen as a scientific toy, with the "pile" being constructed from fruit. These toys use some strips of copper and zinc inserted in a piece…

Typical commercial solar panels consist of approximately 60 individual photovoltaic cells connected in series. Since the usual Kirchhoff rules apply, the current is uniform throughout the circuit, while the electric potential of the individual devices is cumulative. Hence, a solar panel is a good analog of a simple resistive series circuit, except…

In our teaching practice, we find that a large number of first-year university physics and chemistry students exhibit some difficulties with applying Newton's third law to fluids because they think fluids do not react to forces. (Contains 1 table and 3 figures.)

Gas exchange in animals is ultimately diffusion based, generally occurring across dedicated respiratory organs. In many aquatic amphibians, however, multiple modes of gas exchange exist, allowing for the partitioning of O[subscript 2] uptake and CO[subscript 2] excretion between respiratory organs with different efficiencies. For example, due to…

Children have a difficult time in generalizing among changes in background context. We examined the role of two processes that may aid in generalizing category labels in new contexts. In this study, 2-year-old children were taught novel object categories in one type of contextual condition and were tested for category generalization in a new…

We present a number of simple demonstration experiments recorded with high-speed cameras in the fields of gas dynamics and thermal physics. The experiments feature relatively slow combustion processes of pure hydrogen as well as fast reactions involving oxy-hydrogen in a stoichiometric mixture. (Contains 4 figures.)

With the recent discovery of a new particle at the CERN Large Hadron Collider (LHC) the Higgs boson could be about to be discovered. This paper provides a brief summary of the standard model of particle physics and the importance of the Higgs boson and field in that model for non-specialists. The role of Feynman diagrams in making predictions for…

People's moods can influence moral judgment. Such influences may arise because moods affect moral emotion, or because moods affect moral thought. The present study provides evidence that, at least in the footbridge dilemma, moods affect moral thought. The results of two experiments are reported in which, after induction of positive, negative, or…

Creativity has become a hot topic in education. From President Barack Obama to Amazon's Jeff Bezos to "Newsweek" magazine, business leaders, major media outlets, government officials, and education policy makers are increasingly advocating including student creativity in the curriculum. But without a clear understanding of the nature of creativity…

From the first year of life, imitative learning readily occurs in contexts where a demonstrator directly interacts with infants (i.e., "interactive contexts"), and at least by 18 months, imitation will also occur in third-party or observational contexts where infants witness a demonstration by another person that is not directed at them. However,…

In Study 1, 72 internet documents containing creationism, ID (intelligent design), or evolution content were selected for analysis. All instances of proof cognates (the word "proof" and related terms such as "proven", "disproof", etc.) contained within these documents were identified and labeled in terms of the manner in which the terms were used.…

A simple and cheap laboratory class is proposed to illustrate the lethal effect of UV radiation on bacteria and the operation of different DNA repair mechanisms. The class is divided into two sessions, an initial 3-hour experimental session and a second 2-hour analytical session. The experimental session involves two separate experiments: one…

The majority of adolescent risk taking occurs in the presence of peers, and recent research suggests that the presence of peers may alter how the potential rewards and costs of a decision are valuated or perceived. The current study further explores this notion by investigating how peer observation affects adolescent risk taking when the…