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Number 360, February 25, 1998 by Phillip F. Schewe and Ben Stein
ANTHROPIC COSMOLOGY. An anthropic argument is one which suggests that certain physical conditions, such as the oxygen content of the atmosphere or the Earth's distance from the Sun, are not inadvertently beneficial to intelligent life, but might actually be especially fine-tuned for life. This viewpoint has been slow to gain acceptance among scientists because anthropic logic seems to defy the arrow of time: was not the universe here long before man evolved? Yes, but there may be more than one universe (as some theories predict), or the universe we are in may have many domains, each with different physical parameters. And we would, according to these arguments, find ourselves in that domain that had just the right physics ingredients, just as cold-blooded reptiles thrive only in warm climates. Physicists at the Bartol Research Institute at the University of Delaware (contact Stephen Barr, 302-831-6883) and the University of Massachusetts (John Donoghue, 413-545- 1940) consider what the anthropic principle has to say not about atmospheric oxygen and Earth orbit, but about parameters of even more fundamental importance: the mass of the Higgs boson (the hypothetical particle that endows all other particles with mass), the cosmological constant (essentially the energy density of the universal vacuum), and the Planck mass (the energy scale---thought to prevail in the very early universe---associated with gravity, and the energy at which all known physical forces would have been equivalent). (V. Agrawal et al., Physical Review Letters, 2 March 1998.)
PROTON RADIOACTIVITY IN HIGHLY DEFORMED NUCLEI has been measured for the first time by a multinational team working at Argonne National Laboratory (Cary Davids, Argonne, 630-252-4062), offering insights into how the distorted shape of a nucleus can affect its radioactivity rates. A rare decay observed mainly in proton-rich isotopes of elements heavier than tin, proton radioactivity occurs when a nucleus ejects a single proton. Using Argonne's ATLAS accelerator to create holmium-141 and europium-131 nuclei, implanting them in a silicon-based detector, and measuring their rates of radioactivity and the energy of the emitted protons, the researchers noted that their data did not match the predictions of the standard theory of proton radioactivity, which assumes a spherically shaped nucleus. Their results only made sense when they used a newer model that allows them to consider the case in which the nucleus has a highly deformed shape, with a length approximately 1.5 times greater than its width (somewhat less distorted than "superdeformed nuclei" which have a ratio of about 2:1). Their data also allowed them to obtain experimental information on the lowest-energy state of a highly deformed nucleus. (Davids et al., Physical Review Letters, 2 March 1998; also see Physics News Preview)
NANO-CDs WITH 400 GBIT/IN2 DATA STORAGE DENSITY. Present compact disks have data storage densities that approach 1 Gbit/in2. IBM has tested disks with densities of 45 Gbit/in2, using electron lithography for writing 50-nm features, and a scanning-microscope proximal probe for read-back. Now, Peter Krauss and Stephen Chou (chou@ee.princeton.edu) at the University of Minnesota have achieved 10-nm features using nano- imprint lithography for writing and a proximal probe for reading. For such a nano-CD to be useful, however, more robust probe tips will have to be developed, along with multi-tip arrays for faster readout. (Applied Physics Letters, 24 November 1997.)
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