Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement…

Second article in a series describing basic physics phenomena observed at home on an ordinary day. Described is a "pinhole" camera effect caused by a lowered window shade. (SL)

Described are 15 events that take place during a physics olympics at a Michigan high school. These events are planned with the idea of involving the older students in designing and presenting projects to ninth graders, and involving the latter in a day of outdoor participation. (SA)

This final article in the series on the fine-beam cathode-ray tube presents: (1) additional investigations; (2) an alternative method for the electron e/m and synchrotron radiation; and (3) two challenges to students (in a dialogue format) together with a lengthy discussion on synchrotron radiation sources. (DH)

Presents a collection of suggestions, ideas, and reminiscences relating the first-day classroom activities of 13 different teachers at high schools and colleges. (YP)

Proposes a method to estimate the number of civilizations which may exist in the universe. Reviews attempts which have been made to contact these bodies. (CP)

Described are the events and results of the Physics Olympics held in February, 1976, at Indiana University of Pennsylvania. Included are highlights of various events. (SL)

Discusses the use of an overhead projector for the deflection of a vertical image to a screen. Describes three demonstrations: magnetizing of a steel ball bearing and paper clip; convection currents of a hot liquid within a cold liquid; and oscillation of concentrated salt solution into fresh water. (YP)

Describes the result of dropping objects of similar size and shape but of differing weight through air. Compares ideas on motion of Galileo and Aristotle. (GH)

Describes a method of making simple transmission gratings by photographing the interference fringes generated by an interferometer. (SL)

Examines (in the form of a hypothetical dialog between a teacher and a student) the nature of the mantle and the spectral content of the glow which lights up both beam and mantle. These phenomena are associated with excitation of helium gas in the presence of electromagnetic and electrostatic fields. (JN)

Describes a physics laboratory for college students, in which the students participate in a firsthand noninertial experience. The equipment and problems are described. (SA)

A relatively simple opto-electronic setup is described that utilizes a cadmium sulphide (CdS) photoconductive cell to detect resonance of a stretched vibrating string or wire. The display may be either an oscilloscope or a frequency counter. Also describes an inexpensive socket for flanged-base light bulbs. (JN)

Lasers are useful for demonstrating ray optics, especially in large classrooms where a well-defined, easily-viewed ray is essential. Described is a simple device that converts any laser to a projection oscilloscope (or laser spirograph). Suggestions for using the device (including demonstrating Lissajous figures and conic sections) are provided.…