Number 195, September 20, 1994 by Phillip F. Schewe and Ben Stein NEUTRON STAR MASSES , at least for binary systems consisting of two neutron stars, seem to lie in a relatively narrow range. Lee Samuel Finn of Northwestern (708-491-4568) has studied the observations made of four such systems and found that with high statistical certainty the eight neutron star masses all fall within a range of 1.3 and 1.6 solar masses. Finn works only with this small sample of double neutron star binaries (only a few more are known in addition to the four he considered) because their tight mutual orbit affords a more precise mass determination than for other systems---isolated neutron stars or those in orbit around white dwarfs or other stars. Finn expects that the apparent restriction in the neutron star mass range (for which there is no theoretical explanation) will help in the eventual interpretation of catastrophic events in which binary partners spiral in toward each other. Events of this type will be sought by the Laser Interferometer Gravitational Wave Observatory. (Lee Samuel Finn, Physical Review Letters, 26 September 1994.) A MAGNETIC FORCE MICROSCOPE (MFM) produces images of a superconductor's surface through the detection of the force between a magnetic cantilever-mounted probe tip and the sample, which tries to repel magnetic fields. The MFM technique can attain a spatial resolution of 20 nm, which is not as good as is possible with a scanning tunneling microscope (STM). However, since it senses a much larger volume of the sample at any one moment, MFM is not nearly as sensitive as STM to surface cleanliness or order. This might make MFM a better tool than STM for characterizing superconductor surfaces. The MFM can also image non- superconductor materials. As a demonstration, a team of scientists at the University of Texas and Park Scientific Instruments (Sunnyvale, CA) has used their MFM device to image magnetic structures in VHS tape at room temperature, at 77 K, and at 6 K. (C.W. Yuan et al., Applied Physics Letters, 5 Sept. 1994.) TOYS WASHED OVERBOARD in a Central Pacific storm are helping oceanographers study the pathways of ocean currents. In January 1992, 29,000 small plastic bath toys fell from a foundering ship into the sea. Curtis C. Ebbesmeyer of Evans Hamilton, Inc. (Seattle) and W. James Ingraham of the National Oceanic and Atmospheric Administration have coordinated computer simulations with the actual recovery of some of the toys all along the Alaskan coast in the two years since the event. The same scientists performed a similar operation a few years before when 61,000 Nike shoes spilled from a boat into the Gulf of Alaska. (Eos, 13 Sept. 1994.) PROTONS MAY NOT BE SPHERICAL . This is the conclusion of Berthold Schoch at the ELSA accelerator in Bonn, Germany. ELSA shoots electrons at energies up to 1.2 GeV at protons in order to study the proton shape and its excited states without actually shattering it. This type of research explores the middle ground between particle physics, which regards a nucleus as a bunch of quarks held together with gluons, and nuclear physics, which normally views the nucleus as a collection of neutrons and protons held together by mesons. This work will soon be aided by the advent of the Continuous Electron Beam Accelerator Facility (CEBAF) in Virginia, where construction is almost complete. (Science News, 27 Aug.)