Feature

Making the Deuterium Fit the Big-Bang Theory

Test-Tube Babies in the Makings

Soviets and Americans Tackle Heart Disease

NAS Calls ’75 Standards Technologically Feasible

Why Stars Twinkle

Oily Seas and Plastic Waters of the Atlantic

The Asteroid Belt: Not as Much Material as Expected

Causes of Aggression

Environment Message: A Middle Path

The Chances of Contacting Extraterrestrial Civilizations Seem Poor

Front Matter

Films of the Week