When the road is wet (there is a water layer on the road surface), the road marks become blurred and drivers are distracted. We discuss the contributing processes and identify which processes are dominant to the occurrence of this phenomenon. Modelling and a simple experiment demonstrate that the dominant processes are: (a) refraction of light by…

The incandescent bulb has been a useful tool for teaching basic electrical circuits, as brightness is related to the current or power flowing through a bulb. This has led to the development of qualitative pedagogical treatments for examining resistive combinations in simple circuits using bulbs and batteries, which were first introduced by James…

This paper presents an argumentation-based demonstration experiment to teach the light-matter interaction using an observable laser beam and vacuum pump. In the experiment, the concept of darkness was addressed using a virtual space environment created by gradually decreasing the pressure inside a quartz glass bell jar with a vacuum pump. This…

This article discusses two "magic tricks" in terms of underlying optical principles. The first trick is new and produces a "ghost" in the air, and the second is the classical real image produced with two parabolic mirrors. (Contains 2 figure and 6 photos.)

A fundamental issue in the design and the interpretation of experimental studies of perception relates to the question of whether the participants in these experiments could perform the perceptual task assigned to them using another feature, or cue, than that intended by the experimenter. An approach frequently used by auditory- and…

In the "The Science Study Series" book "The Physics of Television", it is stated that persistence of vision lasts for about a tenth of a second. This will be a notional figure just as 25 cm is taken to be the least distance of distinct vision. Estimates range from 1/8 to 1/16 s.

Historically, the bodily senses have often been regarded as impeccable sources of spatial information and as being the teacher of vision. Here, the authors report that the haptic perception of slope by means of the foot is greatly exaggerated. The exaggeration is present in verbal as well as proprioceptive judgments. It is shown that this…

A simple low cost demonstration experiment is performed using common apparatus in order to show various flexural patterns and to give a dynamical measure of Young's modulus. (Contains 4 figures.)

Some models of object recognition propose that items from structurally crowded categories (e.g., living things) permit faster access to superordinate semantic information than structurally dissimilar categories (e.g., nonliving things), but slower access to individual object information when naming items. We present four experiments that utilize…

Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.

Describes a perceptual illusion, the Janus mask, for use in introductory psychology demonstrations. Suggests using a motor or videotaped image to rotate the mask, giving the impression that the mask is following a moving observer or oscillating. Recommends the illusion to show that perception is usefully conceptualized as hypothesis testing. (DK)

Previous reports have demonstrated that the comprehension of sentences describing motion in a particular direction (toward, away, up, or down) is affected by concurrently viewing a stimulus that depicts motion in the same or opposite direction. We report 3 experiments that extend our understanding of the relation between perception and language…

This article examines how the human visual system represents the shapes of 3-dimensional (3D) objects. One long-standing hypothesis is that object shapes are represented in terms of volumetric component parts and their spatial configuration. This hypothesis is examined in 3 experiments using a whole-part matching paradigm in which participants…

In this article, we detail how to produce two inexpensive micromanipulators that offer high precision (approximately 25 micrometers) along a single axis of movement. The more expensive of the designs provides improved versatility along multiple axes. Both manipulators offer substantial savings over commercially available micromanipulators with…

Four experiments are reported exploring whether distractor pictures activate their phonological properties in the course of speech production. In Experiment 1, participants were presented with two pictures and were asked to name one while ignoring the other. Distractor pictures were phonologically related, semantically related or unrelated to the…