Researchers have demonstrated a prototype nanometer-scale generator that produces continuous direct-current electricity by harvesting mechanical energy from such environmental sources as ultrasonic waves, mechanical vibration or blood flow.

Based on arrays of vertically-aligned zinc oxide nanowires that move inside a novel “zig-zag” plate electrode, the nanogenerators could provide a new way to power nanoscale devices without batteries or other external power sources.

Scientists from the universities of Exeter and Cambridge have turned a textbook example of sexual selection on its head and shown that females may be more astute at choosing a mate than previously thought.

New research, funded by the Leverhulme Trust and published in Current Biology, shows that differences in the lengths of the long tail feathers possessed by male barn swallows are more about aerodynamics than being attractive. Female barn swallows favour mates with longer tails and the prominent male tail ‘streamers’ that extend beyond the tail were cited by Darwin as evidence of sexual selection. Now for the first time, scientists have tested this assumption and found that these ‘ornaments’ are in fact linked to natural selection.

In a galaxy far, far away, a massive star suffered a nasty double whammy. On Oct. 20, 2004, Japanese amateur astronomer Koichi Itagaki saw the star let loose an outburst so bright that it was initially mistaken for a supernova. The star survived, but for only two years. On Oct. 11, 2006, professional and amateur astronomers witnessed the star actually blowing itself to smithereens as Supernova 2006jc.

As the ancient Greeks were placing the last few stones on the magnificent theater at Epidaurus in the fourth century B.C., they couldn’t have known that they had unwittingly created a sophisticated acoustic filter. But when audiences in the back row were able to hear music and voices with amazing clarity (well before any theater had the luxury of a sound system), the Greeks must have known that they had done something very right because they made many attempts to duplicate Epidaurus’ design, but never with the same success.

New research by Iowa State University psychologists says it provides more concrete evidence of the adverse effects of violent video game exposure on the behavior of children and adolescents. 

Distinguished Professor of Psychology Craig Anderson, Assistant Professor of Psychology Douglas Gentile, and doctoral student Katherine Buckley share the results of three new studies in a book, "Violent Video Game Effects on Children and Adolescents" (Oxford University Press, 2007). It says it is the first book to unite empirical research and public policy related to violent video games.

Geophysicists at the University of Rochester announce in today’s issue of Nature that the Earth’s magnetic field was nearly as strong 3.2 billion years ago as it is today.

The findings, which are contrary to previous studies, suggest that even in its earliest stages the Earth was already well protected from the solar wind, which can strip away a planet’s atmosphere and bathe its surface in lethal radiation.