Many experimenters, starting with Ernst Mach in 1883, have reported that if a device alternately sucks in and then expels a surrounding fluid, it moves in the same direction as if it only expelled fluid. This surprising phenomenon, which we call "Machian propulsion", is explained by conservation of momentum: the outflow efficiently transfers…

In this paper, coupled pendulums with different lengths are studied. Through steel magnets, each pendulum is coupled with others, and a stepping motor is used to drive the whole system. To record the data automatically, we designed a data acquisition system with a CCD camera connected to a computer. The coupled system shows in-phase, locked-phase…

Children in classrooms and scientists in laboratories engage in similar activities: they observe, ask questions, and try to explain phenomena. Video conferencing technology can remove the wall between the classroom and the laboratory, bringing children and scientists together. Virtual experiences and field trips can provide many of the benefits of…

Demonstrations are used in chemistry lectures to improve conceptual understanding by direct observation. The visual aid described here is designed to demonstrate the change in state of matter with the change of temperature and the change of pressure with temperature. Temperature is presented by the rate of airflow and pressure is presented by…

This laboratory exercise introduces students to concepts in recombinant DNA technology while accommodating a major semester project in protein purification, structure, and function in a biochemistry laboratory for junior- and senior-level undergraduate students. It is also suitable for forensic science courses focused in DNA biology and advanced…

This paper analyses the real origin and nature of scientific errors against claims of science critics, by examining a number of examples from the history of electricity and optics. This analysis leads to a conclusion that errors are a natural and unavoidable part of scientific process. If made available to students, through their science teachers,…

We present a consistent series of activities, including experiments and basic computational studies, investigating the shape and optical properties of water drops in connection with novel technological devices. Most of the work can be carried out with simple teaching equipment and is well suited to undergraduate students. Firstly, we show how the…

Several reports on science education suggest that students at all levels learn better if they are immersed in a project that is long term, yielding results that require analysis and interpretation. I describe a 12-wk laboratory project suitable for upper-level undergraduates and first-year graduate students, in which the students molecularly…

This quantitative study investigated the relationship between Chemistry students' scientific epistemologies and their perceptions of the nature of laboratory inquiry. Seventy-two Advanced Level Chemistry students were surveyed. The students were sampled from twelve schools in three of Zimbabwe's nine administrative provinces. Students' scientific…

The substitution of petroleum-based fuels with those from renewable sources has gained momentum worldwide. A UV-vis experiment for the quantitative analysis of biofuels (bioethanol or biodiesel) in (petroleum-based) diesel oil has been developed. Before the experiment, students were given a quiz on biofuels, and then they were asked to suggest a…

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the…

Little more than half of college freshmen will get a degree, but initiatives are emerging to boost college completion. The gap between access and completion has put a new focus on ramping up retention--the percentage of freshmen who return to the same institution for a second year of college. And that's a task, observers say, for precollegiate…

An advanced undergraduate laboratory project is described that integrates inorganic, analytical, physical, and biochemical techniques to reveal differences in binding between cationic metal complexes and anionic DNA (herring testes). Students were guided to formulate testable hypotheses based on the title question and a list of different metal…

This article describes a project designed to extend sixth-form pupils looking to further their knowledge and skill base in physics. This project involves a quantitative analysis of the decaying amplitude of a metal plate oscillating in a strong magnetic field; the decay of the amplitude is used to make estimates of the strength of the magnetic…

Experimental data are analysed statistically to allow researchers to draw conclusions from a limited set of measurements. The hard fact is that researchers can never be certain that measurements from a sample will exactly reflect the properties of the entire group of possible candidates available to be studied (although using a sample is often the…