Scientific American Magazine

Ecologists' warnings of an ongoing mass extinction are being challenged by skeptics and largely ignored by politicians. In part that is because it is surprisingly hard to know the dimensions of the die-off, why it matters and how it can best be stopped

The most massive telescopes known to humanity sit not on earthly mountaintops but in deep space. They are gravitational lenses, once mere curiosities, now one of the most important tools in astronomy

The difficulties of childbirth have probably challenged humans and their ancestors for millions of years-- which means that the modern custom of seeking assistance during delivery may have similarly ancient roots

Legislators are spending billions to reduce class sizes. Will the results be worth the expense?

The antiviral era is upon us, with an array of virus-fighting drugs on the market and in development. Research into viral genomes is fueling much of this progress