Changing fine structure constant, packing spheres tighter, and mimicking complex birdsongs

Is the Fine Structure Constant truly constant?

J. K. Webb, J. A. King, M. T. Murphy, V. V. Flambaum, R. F. Carswell, and M. B. Bainbridge

Phys. Rev. Lett. 107, 191101 (2011)

One of the most cherished principles in science - the constancy of physics – apparently may not be true. A new study, using data from the world's largest optical telescopes, suggests that one of the four fundamental forces of Nature, electromagnetism - measured by the so-called fine-structure constant and denoted by the symbol alpha - seems to vary across the Universe. The discovery, if confirmed, has profound implications for our understanding of space and time and violates one of the fundamental principles underlying Einstein's General Relativity theory. The continuous drift in alpha may also imply a much larger universe than our observable patch, possibly infinite and also offer a natural explanation for a question that puzzled scientists for decades: why do the laws of physics seem to be so finely-tuned for the existence of life?

New way to pack marbles and buckyballs

Ho-Kei Chan

Physical Review E (forthcoming)

Spherical objects inside a cylinder can now be packed more efficiently than ever. With a suitable template, the densest packings can surprisingly be obtained from a very simple deposition procedure. The findings will have a broad range of applications in physics, from the macro- to the nano-scale, and also in commercial packaging.

Separating the instrument from the instructions in complex birdsong

Yonatan Sanz Perl, Ezequiel M. Arneodo, Ana Amador, Franz Goller and Gabriel B. Mindlin

Physical Review E (forthcoming)

Behavior emerges from the interaction between a nervous system and a peripheral bio-mechanical device executing those instructions. In that perspective, how much of the complexity is coded in the driving commands, and how much results from the design of the physical device? New research delves into the song the Zebra finch to test the hypothesis that much of its acoustic complexity is due to the nonlinear nature of the avian vocal organ. A version of the song created with simple numerical model, and compared with direct measurements of the physiological parameters driving the vocal organ, shows that simple instructions can closely mimic the peculiar and acoustically rich song of the Zebra finch. The research suggests that the design of a bird's vocal instrument is crucial to creating distinctive birdsongs, in much the same way that identical notes played on a piano and violin sound very different.

Source: American Physical Society