Origami: Complexity in Creases (Again)
by Robert J. Lang
The burgeoning field of mathematical origami provides a theoretical basis for some beautiful art, and a hands-on approach to some nasty math problems.
Viruses, Viruses, Viruses
by David Baltimore
They're in the news every day-flu, HIV, SARS, bioweapons. And many of the discoveries of molecular biology were made with viruses. What, exactly, are they?
The Tunnel of Samos
by Tom M. Apostol
A new theory on how the ancient Greeks dug a two-sided tunnel through a mountain and met up perfectly in the middle.
Obituaries: William H. Pickering; J. Beverley Oke