Authors of physics textbooks frequently use the deflection of a thin, vertically falling water jet by a charged balloon, comb, or rod as a visually appealing and conceptually relevant example of electrostatic attraction. Nevertheless, no attempts are made to explore whether these charged bodies could cause visible deformation of a horizontal water…

The paper is a philosophical analysis of experimentation. The philosophical framework of the analysis is the interrogative model of inquiry developed by Hintikka. The basis of the model is explicit and well-formed logic of questions and answers. The framework allows us to formulate a flexible logic of experimentation. In particular, the formulated…

A Cartesian diver can be used to measure the surface tension of a liquid to a certain extent. The surface tension measurement is related to the two critical pressures at which the diver is about to sink and about to emerge. After sinking because of increasing pressure, the diver is repulsed to the centre of the vessel. After the pressure is…

In a total solar eclipse, the Moon completely covers the Sun, casting a shadow several hundred km wide across the face of the Earth. This paper describes observations of the 14 November 2012 total eclipse of the Sun visible from north Queensland, Australia. The edge of the umbra was captured on video during totality, and this video is provided for…

In 1974, Professor Eric Laithwaite demonstrated an unusually heavy gyroscope at a Royal Institution lecture in London. The demonstration was televised and can be viewed on YouTube. A recent version of the same experiment, together with partial explanations, attracted two million YouTube views in the first few months. In both cases, the gyroscope…

Vortex cannons have been used by physics teachers for years, mostly to teach the continuity principle. In its simplest form, a vortex cannon is an empty coffee can with a hole cut in the bottom and the lid replaced. More elaborate models can be purchased through various scientific suppliers under names such as "Air Cannon" and…

The experiment described here is fairly easy to reproduce and dramatically shows the magnitude of ambient air pressure. Two circular plates of aluminum are applied one against the other. How do you make their separation very difficult? With only the help of an elastic band! You don't have to use a vacuum pump for this experiment.

Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

In the theory of heat of the first half of the nineteenth century, heat was a substance. Mayer and Joule contradicted this thesis but developed different concepts of heat. Heat was a force for Mayer and a motion for Joule. Both Mayer and Joule determined the mechanical equivalent of heat. This result was, however, justified in accordance with…

Size exclusion chromatography is an important technique in the separation of biological and polymeric samples by molecular weight. While a number of laboratory experiments have been published that use this technique for the purification of large molecules, this is the first report of an experiment that focuses on purifying an unknown small…

This paper begins with an early measurement of the speed of sound in water. A historical overview of the consequent development of SONAR and medical imaging is given. A method of measuring the speed suitable for demonstration to year 10 students is described in detail, and an explanation of its systematic error examined.

Poly(vinyl alcohol) (PVA) precipitates in many kinds of aqueous salt solutions. While sodium sulfate, a coagulant for PVA fiber, precipitates PVA to yield a white rigid gel, coagulation of PVA with aluminum sulfate, a coagulant for water treatment, yields a slime-like viscoelastic fluid. One type of homemade slime is prepared under basic…

A small-scale wastewater cleaning plant is described that includes the key physical pretreatment steps followed by the chemical treatment of mud by flocculation. Water, clay particles, and riverside deposits mimicked odorless wastewater. After a demonstration of the optimization step, the flocculation process was carried out with iron(III)…

Dark matter makes up most of the matter in the universe but very little of a standard introductory physics curriculum. Here we present our construction and use of a spandex sheet-style gravity simulator to qualitatively demonstrate two aspects of modern physics related to dark matter. First, we describe an activity in which students explore the…

Thin film interference manifests itself in a wide range of visually pleasing situations in everyday life (in the colored effects caused by a drop of oil on water, in soap bubbles, etc.) and is also involved in important technical applications (semi-reflecting mirrors, anti-reflection lenses, etc.). Yet, despite its familiarity, high school…