Muscle Sounds
Contracting muscle generates distinct sounds that are not heard only because the human ear is insensitive to low frequencies. Such sounds are now studied for their possible usefulness in science and medicine
Stories by Gerald Oster
Auditory Beats in the Brain
Slow modulations called binaural beats are perceived when tones of different frequency are presented separately to each ear. The sensation may show how certain sounds are processed by the brain
Phosphenes
Seeing stars is seeing phosphenes, subjective images generated within the eye and brain rather than by light from outside. They presumably reflect the neural organization of the visual pathway
The Chemical Effects of Light
Visible light triggers few chemical reactions (except in living cells), but the photons of ultraviolet radiation readily break chemical bonds and produce short-lived molecular fragments with unusual properties
Density Gradients
Devices incorporating this simple concept have recently found application In fields as diverse as solid-state physics, the manufacture of plastics and the chemistry of the genetic code
Moiré Patterns
They are produced when figures with periodic rulings are made to overlap. A study of their basic properties reveals that they can illuminate many problems of scientific interest
Polyethylene
The simplest polymer bids fair to become the Commmonest. Until recently it could be synthesized only at very high pressures. Now with the aid of catalysts it can be made at low pressure