
Garrett Lisi Responds to Criticism of his Proposed Unified Theory of Physics

Garrett Lisi Responds to Criticism of his Proposed Unified Theory of Physics

Comet Bops Past Neptune Cleanly
Comet Hale-Bopp has been spotted beyond the orbit of Neptune, far enough from the sun to be without its dirty tail. John Matson reports


The Lost Galaxies
By the latest estimate, the observable universe contains 200 billion galaxies. Astronomers wonder: Why so few?

Recommended: The Fate of Greenland
Books and recommendations from Scientific American

Budget crunch mothballs telescopes built to search for alien signals

Underground Xenon100 experiment closes in on dark matter's hiding place

Paul Davies: Physics Could Help Fight Cancer
At a science and tech policy discussion, cosmologist Paul Davies talked about being recruited by the National Cancer Institute to study metastasis. Steve Mirsky reports

U.S. Collider Offers Physicists a Glimpse of a Possible New Particle
The soon-to-be-retired Tevatron collider has uncovered an unexplained signal that could be a previously unknown particle

How Cosmic Inflation Creates an Infinity of Universes [Video]

The Inflation Debate
Is the theory at the heart of modern cosmology deeply flawed?

The Origin of Life
A new analysis suggests lightning and volcanoes helped make life possible. David Biello reports

Antimatter of Fact: Collider Generates Most Massive Antinucleus Yet
The Relativistic Heavy Ion Collider has produced several nuclei of the antimatter counterpart to helium 4