A Critical Time for Nuclear Nonproliferation
This month the parties to the nuclear nonproliferation treaty meet again to debate how well the agreement is working. The continuing arms buildup by the nuclear powers puts the treaty's future in doubt
Volume 253, Issue 2
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Features
The Adrenal Chromaffin Cell
This cell synthesizes, stores and secretes a complex mixture containing adrenaline, proteins and peptides. Studies of these processes elucidate mechanisms relevant to other secretory cells, which include neurons
The Scanning Tunneling Microscope
A new kind of microscope reveals the structures of surfaces atom by atom. The instrument's versatility may extend to investigators in the fields of physics, chemistry and biology
The Classical Vacuum
It is not empty. Even when all matter and heat radiation have been removed from a region of space, the vacuum of classical physics remains filled with a distinctive pattern of electromagnetic fields
The Mesozoic Vertebrates of Thailand
The northeastern part of the country holds a fossil record spanning more than 100 million years of vertebrate evolution. The record in turn helps to clarify the geologic history of southeastern Asia
Young Supernova Remnants
The remnants of recent stellar explosions in our galaxy are intense X-ray sources. An orbiting telescope has revealed their structure. One has a pulsar; others are expanding shells of shock-heated gas
The Antarctic Ice
On the average it is 2,200 meters deep; its climatic history is being learned through the analysis of deep cores. The bedrock of the continent has been mapped
Butterfly Engineering
Butterflies drink nectar, fly and bask in the sun to regulate their internal temperature. Underlying such life-sustaining functions are mechanisms that can be studied according to engineering principles