Cryptography and Computer Privacy
Computer systems in general and personal "data banks" in particular need protection. This can be achieved by enciphering all material and authenticating the legitimate origin of any command to the computer...
Features
The Role of the Heartbeat in the Relations between Mother and Infant
Most mothers exhibit a natural preference for holding their baby on the left side of their chest. There is reason to believe that the sound of the adult heart has a soothing effect on the infant...
Two-Dimensional Matter
Films only a molecule thick vapor-deposited on atomically clean, highly uniform crystal surfaces serve as physical analogues of theoretically ideal two-dimensional systems
Roots
The leaves of a plant gather the sunlight and carbon dioxide needed for photosynthesis; the roots gather the water and also the minerals that are essential not only to the plant but also to all animal life...
The Evolution of the Indian Ocean
A 75-million-year magnetic record in the floor of the Indian Ocean reveals how India was rafted northward for 5,000 kilometers before it collided with Asia. The encounter gave rise to the Himalayas...
Confirmation
For centuries investigators have been testing, confirming and disconfirming hypotheses by observation and experimentation. Yet the logic of the process is still far from being understood...
Galileo's Discovery of the Law of Free Fall
It has been thought that he erroneously assumed that the velocities of a falling body were proportional to distances. A new manuscript shows that he treated them correctly as being proportional to time...
The Infrared Receptors of Snakes
The snakes of two large families have sensitive organs that can detect the heat radiation emitted by their prey. The performance of these detectors is investigated with the aid of an infrared laser...
Departments
50 and 100 years ago, May 1973
Science and the Citizen, May 1973
- Letters
Letters to the Editors, May 1973
- Recommended
Books, May 1973
- Mathematical Recreation
Mathematical Games, May 1973
- Amateur Scientist
The Amateur Scientist, May 1973
- Departments
The Authors, May 1973
Bibliography, May 1973
