The Hydrogen Economy
A case is made for an energy regime in which all energy-sources would be used to produce hydrogen, which could then be distributed as a nonpolluting multipurpose fuel
Features
How the Immune Response to a Virus Can Cause Disease
The body's defense mechanism may not always be beneficial. In many cases the very process that should combat a virus is itself a cause of the damage associated with a viral disease
The Omnivorous Chimpanzee
Observation of chimpanzees in the wild indicates that they not only eat plant foods but also hunt, kill and eat other mammals. Moreover, they display a well-developed pattern of sharing meat...
Mars from Mariner 9
The first spacecraft to go into orbit around another planet provides evidence that Mars is just beginning to heat up internally. Systems of channels and gullies suggest erosion by water or some other agent...
The Control of Sensitivity in the Retina
Interactions among nerve cells keep the response range of the system in register with ambient illumination, enabling the retina to form a high-contrast neural image over a broad range of light conditions...
Judaism at the Time of Christ
Traditionally Judaism is regarded as a unified set of beliefs. New evidence indicates that between 200 B.C. and A.D. 100 its expressions were remarkably diverse, and some were even pagan...
Conduction Electrons in Metals
Inside crystals electrons and atoms act collectively to create waves described as quasiparticles. They help to determine whether a crystal is an insulator, a semiconductor, a conductor or a superconductor...
Snow Crystals
The classic finely branched hexagonal crystal is only one of an almost infinite variety of shapes. Each form depends on the history of the snow crystal as it grows in a cloud
Departments
50 and 100 years ago, January 1973
Science and the Citizen, January 1973
- Letters
Letters to the Editors, January 1973
- Recommended
Books, January 1973
- Mathematical Recreation
Mathematical Games, January 1973
- Amateur Scientist
The Amateur Scientist, January 1973
- Departments
The Authors, January 1973
Bibliography, January 1973
