COMPUTING SCIENCE

A Lucid Interval

Brian Hayes

Brian Hayes on the pluses and minuses of interval arithmetic, an error-controlling alternative to familiar floating-point computation

SIGHTINGS

DNA in Action

Felice Frankel

Felice Frankel on a historic glimpse of life's machinery in action—the first electron micrograph of genes during transcription

MARGINALIA

We Are All Africans

Pat Shipman

Pat Shipman reviews the mounting evidence that the first modern humans evolved in Africa

ENGINEERING

Hotel Design *

Henry Petroski

Henry Petroski explores the inevitable compromises of design, using Edinburgh's Point Hotel as an example

SCIENCE OBSERVER

First in Flight?

David Schneider

Were the Wright brothers really the first human beings to fly?

Gaul in the Family

Greg Ross

An English geneticist constructs an evolutionary "tree" of European languages

"Black" and "White" Not Quite Right

Christopher R. Brodie

In Brazil, racial appearances can be deceiving

LETTERS TO THE EDITOR

Suspension of Belief

Political Science

Timely Argument

Set Photons for 'Mail'

Worm's-Eye View

From the President