World Oil Production
There is only a finite amount of oil and there are limits to the rate at which it can be recovered. Sometime before the year 2000 the decreasing supply of it will fail to meet the increasing demand
Volume 238, Issue 3
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Features
Heavy Leptons
The class of elementary particles of matter that includes the electron and the muon has a new member: the tau. It may be the first in a sequence of charged heavy leptons
The Electronic Telephone
One of the few components of the telephone system that has been little touched by the revolution in electronics is the instrument itself A telephone based on integrated circuits is in the offing
The Surface of Mars
The Viking spacecraft have provided an unparalleled view of it from orbit and from the ground, adding much evidence on how it has been shaped by volcano, meteorite impact, water and wind
The Flow of Energy in a Forest Ecosystem
Life on the earth is sustained by the finite amount of solar energy that is fixed by green plants. Quantitative study of the energetics of a forest has shown how this energy is partitioned and controlled
How Cells Make ATP
The prevailing theory is the "chemiosmotic" one. Light or oxidation drives protons across a membrane; then the energy-rich compound ATP is formed as the protons flow back through a complex of enzymes
The Combinatorial Mathematics of Scheduling
What is the best way to organize work so that it is finished in the shortest possible time? Discoveries in mathematics and computer science reveal the values and limits of various scheduling methods
Pieter Bruegel the Elder as a Guide to 16th-Century Technology
The great Flemish artist had a deep interest in the scientific concepts and the machines of his time. As a result many of his works offer rare glimpses of practical knowledge 400 years ago