Features
Were Fundamental Constants Different in the Past?
Atomic physics, nuclear physics, and cosmology enable physicists to probe changes in the fine-structure constant over time scales ranging from a few years to nearly the age of the universe - Keith A. Olive and Yong-Zhong Qian
R-Process Nucleosynthesis in Supernovae
The heaviest elements are made only in cataclysmic events. Finding out whether supernovae are cataclysmic enough requires extensive astronomical observation and sophisticated computer modeling - John J. Cowan and Friedrich-Karl Thielemann
Shallow-Water Acoustics
Extracting a signal from noise can be complicated, especially along a coastline filled with marine life, shipping lanes, undersea waves, shelves, and fronts that scatter sound - William A. Kuperman and James F. Lynch
Reference Frame
Whence the force of F = ma? I: Culture shock - Frank Wilczek 
Letters
An American Physics Instructor in Botswana
Quantum World Is Only Smoke and Mirrors
An Early Route to MHV Tree Amplitudes
Suárez a Father of South American Astronomy
Naming a Name in H- Spectroscopy
Search & Discovery
Attosecond Bursts Trace the Electric Field of Optical Laser Pulses
The familiar textbook sketch of light's oscillating electric field can now be drawn directly from measurements.
New All-Electrical Measurement Schemes Can Detect the Spin State of a Single Electron
Spin-to-charge conversion improves prospects for semiconductor-based quantum information processing.
Intense X-Shaped Pulses of Light Propagate Without Spreading in Water and Other Dispersive Media
The nonlinear interaction of light with matter can imbue optical pulses with surprising and potentially useful properties.
Issues & Events
Special Report: Presidential Candidates Speak Out on Science Policies
Physics Today continues a tradition that begun in 1976 by asking Bush and Kerry nine questions covering a range of science topics. Their answers, sometimes direct and sometimes vague, show fundamental differences on several key issues.
NASA Bows to Pressure to Save Hubble
In a turnaround, NASA may extend the life of the Hubble Space Telescope by servicing it robotically. But doubts remain over the feasibility of such a mission, and over how NASA would pay for it.
Panel Chooses Superconducting Option for the International Linear Collider
For more than a decade, competing international collaborations have devoted intensive R&D to two different RF accelerating technologies for the next linear collider. Now, at last, the community has settled on one of the competing technologies
Physicists Get First Take at Science Fiction Film
Primer, which was named this year's dramatic award winner at the Sundance film festival, may be the first film to be marketed through physics conferences.
Japan Funds New Cosmic-Ray Detector in Utah
The new Telescope Array (TA) in Utah will combine fluorescence and scintillation detection methods used in earlier experiments to resolve a discrepancy in the observed rates of ultrahigh−energy cosmic rays.
Business Leaders Urged to Heed Global Warming Science
The greenhouse effect "is real and intensifying," according to a stark "executive action report" issued by the Conference Board, a New York-based nonprofit, nonpartisan business organization that does economic research for major corporations and other businesses.
News Notes
Money for UCF; Labs merge publications.
Web Watch
Molecular Expressions Photo Gallery; Alloy Database; Energy Levels of Hydrogen and Deuterium.
Meetings
AVS to Assemble in Anaheim
Books
The Herschel Partnership: As Viewed by Caroline, M. Hoskin, and
Caroline Herschel's Autobiographies, edited by M. Hskin (reviewed by N. Byers)
Bose-Einstein Condensation, L. Pitaevskii and S. Stringari (reviewed by A. Leggett)
Probability Theory: The Logic of Science, E. T. Jaynes (reviewed by R. Baierlein)
Introduction to Cosmology, B. Ryden (reviewed by B. Partridge)
Fields, Flows and Waves: An Introduction to Continuum Models, D. F. Parker (reviewed by J. Casey)
Surface Science: An Introduction, K. Oura, V. G. Lifshits, A. A. Saranin, A. V. Zotov, and M. Katayama (reviewed by J. T. Yates Jr)
An Analog Electronics Companion: Basic Circuit Design for Engineers and Scientists, S. Hamilton (reviewed by L. Rubin)
Galaxies and the Cosmic Frontier, W. H. Waller and P. W. Hodge (reviewed by J. Irwin)
Evolution of Networks: From Biological Nets to the Internet and WWW, S. N. Dorogovtsev and J. F. F. Mendes (reviewed by A.-L. Barabási)
New Books
New Products
Focus on Photonics and Imaging
We Hear That
Bjorken, Callan Win Dirac Medal
AAPT Bestows Honors
In brief
Obituaries
Victor John Emery
Mario Iona
Edwin Albert Power
Peter Wootton
Job Opportunities
