A map of lines and metallic circuit connections by the American Telephone and Telegraph Co., 1891

When the Weather Service Spied on Americans

The United States National Weather Service began as part of the military, with a mandate to serve the interests of federal officials and business owners.
Composite image of Dmitri Mendeleev, a periodic table, and the Milky Way galaxy

How Far Does the Periodic Table Go?

Efforts to fill the periodic table raise questions of special relativity that “strike at the very heart of chemistry as a discipline.”
Nuclear test

How Nuclear Tests Spawned Environmentalism

It's been 55 years since the Nuclear Test Ban Treaty. The massive amounts of fallout in the decade previous to the Treaty taught us a lot about the interconnected planet we live on.
Charles Hatfield, the rainmaker, checking some equipment. (Copyright Bettmann/Corbis / AP Images)

When San Diego Hired a Rainmaker a Century Ago, It Poured

After Charles Hatfield began his work to wring water from the skies, San Diego experienced its wettest period in recorded history.