Tells the story of an experiment conducted by Galileo and proves that a light pebble and a heavy rock travel with equal speed when dropped from the same distance and touch the ground at the same time. Indicates the importance of open-mindedness and tolerance. First published in 1939. (YDS)

Discusses challenges in teaching lasers and optical communications to engineers, including the prohibitive cost of laboratory experiments, and describes the development of a computer-based photonics simulation experiment module which provides students with an understanding and visualization of how lasers can be modulated in telecommunications.…

Presents an experiment testing three wing angles, swept-back, straight, and swept forward, to determine which of them produces the most lift in a low speed tunnel. (YDS)

Explains the theory of thin layer electrophoresis, hazards related to the apparatus, and how to conduct an experiment. (YDS)

By nose poking a lighted key, rats obtained food pellets on either a variable- interval schedule of reinforcement or a schedule that required an average of four additional responses after the end of the variable-interval component (a tandem variable-interval variable-ratio 4 schedule). With both schedule types, the mean variable interval was…

We tested the impact of associative strength and retrieval heuristics in false source memory. We arranged 12-item associative lists in descending order of backward associative strength to a critical non-presented item and then split them into 6-item sub-lists at the median. High- and low-strength sub-lists were correlated with presentation source.…

Trees burst with color in the northern states. Autumn leaves dust the ground. Painting the fall landscape is nothing new. Teachers have been doing it in classrooms for decades. The approach, however, can make the difference between whether the fall landscape is simply painting for fun, or a real learning experience. Students learn best when they…

Most introductory optics lab activities begin with students locating the real image formed by a converging lens. The method is simple and straightforward--students move a screen back and forth until the real image is in sharp focus on the screen. Students then draw a simple ray diagram to explain the observation using only two or three special…

Previous research has shown that rats increase their rate of responding for 1% sucrose reinforcement in the first half of the session if food-pellet, rather than 1% sucrose, reinforcement will be available in the second half (i.e., positive induction). Four experiments investigated whether this induction effect would be changed by altering the…

Epoxide chemistry is widely used in organic synthesis and regularly discussed in organic chemistry textbooks. An experiment to generate dimethyldioxirane in situ from acetone using Oxone is explained.

The experiment describes the regioselective synthesis of a stereodefined push-pull alkene from inexpensive chemicals. Important concepts in organic chemistry, such as resonance theory and role of solvent polarity on formation of intra- and intermolecular hydrogen bonds, which affect the configuration of the double bond in predictable way are…

A survey of progress made over the past ~30 years (1970 - 2004) to improve the reliability of surface analyses by XPS is presented. The basic principles of XPS are very simple yet there is considerable complexity in designing experiments, interpreting data, and analyzing the results for the many different modes of operation and many different…

An experiment that highlights the role electrochemistry plays in the fabrication of nanoscale structures is presented. The movement and alignment of the nickel nanowires were observed, when manipulated using magnetic fields through the lens of an optical microscope using common magnets to alter the applied magnetic field.

An experiment is presented that introduces students to nanotechnology through the preparation of nanoparticles and their visualization using transmission electron microscopy (TEM). The experiment familiarizes the students with nonaqueous solvents, biphasic reactions, phase-transfer agents, ligands to stabilize growing nanoparticles, and bidentate…

The technique for producing quantum-sized zinc oxide (ZnO) particles is much safer than a technique that used hydrogen sulfide gas to produce cadmium sulfide and zinc sulfide nanoparticles. A further advantage of this method is the ability to sample the solution over time and hence determine the growth kinetics.