In this issue:
"Is the Universe Leaking Energy?": One of science's most fundamental laws does not apply to the universe as a whole.
"DNA Drugs Come of Age": New vaccines and medicines offer hope for fighting HIV, influenza, and other maladies.
"War of the Machines": Robots are bringing about the most profound transformation of warfare since the advent of the atom bomb.
"How Babies Think": Babies' and young children's cognitive abilities far surpass those that psychologists once believed.