You are currently previewing the NEW Scientific American site. Tell us what you think or view the old site

Skip to main content


What Is a Planet?

The controversial new official definition of "planet," which banished Pluto, has its flaws but by and large captures essential scientific principles

By Steven Soter

The Power of Riboswitches

Discovering relics from a lost world run by RNA molecules may lead to modern tools for fighting disease

By Jeffrey E. Barrick and Ronald R. Breaker

The Mississippi's Curious Origins

A mountain range once separated the continental interior of the U.S. from the Gulf of Mexico. Some clever geologic sleuthing has revealed how that barrier was breached, allowing the river to reach the Gulf

By Roy B. Van Arsdale and Randel T. Cox

Is Ethanol for the Long Haul?

Ethanol could displace gasoline, but it won't pay off until we find a way to distill cornstalks, not corn

By Matthew L. Wald

Evolved for Cancer?

Natural selection lacks the power to erase cancer from our species and, some scientists argue, may even have provided tools that help tumors grow

By Carl Zimmer

Better Ways to Target Pain

Improved understanding of the chemical pathway on which aspirin and Vioxx act may lead to analgesics with fewer side effects

By Gary Stix


Purchase To Read More

Already purchased this issue? Sign In to Access
Select Format

Starting Thanksgiving

Enter code: HOLIDAY 2015
at checkout