The International Control of Disarmament
The widely acknowledged need for a separate United Nations agency-responsible for verifying and controlling disarmament agreements is intensified by the current impasse In bilateral "summit" talks
Features
The Structure of Emission Nebulas
An emission nebula is a cloud of interstellar gas that shines by its own light. Each kind of ion in it has a characteristic color, and three-color photography reveals how the ions are distributed
How Cilia Move
The hairlike organelles that propel swimming cells or move liquids over fixed cells are composed of sheaves of nlicrotubules. The cilia beat when the microtubules, powered by ATP, slide past one another
Nitrogen Fixation
Life requires nitrogen that has been "fixed" through combination with other elements. Thermodynamics imposes a constraint on all possible methods of fixation: invariably energy must be supplied
The Dimensions of Stairs
From antiquity to modern times stairways have been built by rules of thumb. A study of how people move and expend energy in going up and downstairs suggests a more rational approach to their design
Mimicry in Parasitic Birds
Various species of birds lay their eggs In the nest of another bird, which then incubates the eggs and feeds the young. The widow birds of Africa achieve this result by some remarkable feats of mimicry
The Coordination of Eye-Head Movements
The sequence of events in the nervous system that coordinates the movements of the eyes and the head in firating a visual target has been clarified by recent experiments with monkeys
The Excavation of a Drowned Greek Temple
Geological changes in the level of the Mediterranean shoreline have sublnerged a number of classical sites. The investigation of one of these shallow-water ruins suggests that they would all reward study
Departments
50 and 100 Years Ago, October 1974
Science and the Citizen, October 1974
- Letters
Letters to the Editors, October 1974
- Recommended
Books, October 1974
- Mathematical Recreation
Mathematical Games, October 1974
- Amateur Scientist
The Amateur Scientist, October 1974
- Departments
The Authors, October 1974
Bibliography, October 1974
