Scientific American Magazine

The U. S. may drill a hole to the Mohorovicic discontinuity between the earth's crust and the underlying mantle. The hole would provide priceless evidence on the earth's history and internal constitution

Where the birth rate of the U. S. was once fairly stable, practices of contraception have now made it a variable. How these practices affect population trends has been examined by a large-scale study

Experiments with specially distorted rooms reveal that the way in which we perceive the size and even the shape of others is powerfully influenced by our emotional relationship with them

Many plants have evolved natural mechanisms that keep their seeds "dormant" until the optimal time for sprouting. These mechanisms include chemical responses to light and rainfall

Pluto, our sun's most remote and mysterious planet, may once a satellite of Neptune. Current theories about its origin provide new clues to the genesis of the solar system

Although they lack internal controls, they can maintain a high temperature by their behavior. A lizard, for example, can raise its temperature by changing the position of its body in the sun

Crystals have different properties in different directions. Alignment of the crystal grains within a piece of metal can significantly alter its mechanical and magnetic behavior

Usually this small animal reproduces by budding, but it can also develop male and female organs for sexual reproduction. What factors determine which method of reproduction it uses?