Andrew Chaikin

FOCAL POINTSomber ImpressionsNot since the incept: ment five years L triggered as much ings of a Malcontent" in thi page 364. California amateur offers one rebuttal here, and other readers' responses car Letters to the Editor on pag

The Iron SunJames R. Graham, Lawrence Berkeley Laboratory, CaliforniaIRON is the dead-end elettient. Its atomic nucleus is the most tightly bound, unable to yield energy by either fission or fusion reactions. It is the ultimate ash of nuclear fires.The formation of iron sounds the death knell of...

Ulugh Beg's Forgotten ObservatoryErnest W. Piini, San Jose Astronomical AssociationThe Persian Empire once stretched into what is now the southern Soviet Union, and there, at the ancient city of Samarltand, many crossroads met. Famous travelers once walked there, including Marco Polo's father...