Five-fold symmetry is considered to be impossible in crystallography for the same reason that pentagonal tiles do not exist - it is not possible to cover a floor or wall simply using tiles with five sides of all the same length.

The only way around the problem is to use other geometrical shapes to fill in the gaps, a principal used by the builders of mosques as long ago as the 15th century. The complex ornamental structure was "rediscovered“ by mathematicians last century.

Roger Penrose demonstrated a pattern named the Penrose Parquet, which achieves complete coverage following simple rules using two periodically repeating geometrical forms.

The Centre for Epidemiological Studies into Sexually-Transmitted Diseases and AIDS in Catalonia (CEEISCAT) started a pioneering study in Spain in 2005 to look into the prevalence of sexually-transmitted diseases (STDs) among female sex workers (SWs). The objective was to monitor the rates of infection with both HIV and other diseases over time, as well as the prevalence of risky behavior. 

Following on the heels of 'missing links' in the popular media earlier this month, you might expect that research on mice carrying a "humanized version" of a gene believed to influence speech and language will have references to cartoons and mice that talk.

In reality, it's nothing so outrageous but the research can still teach us about our evolutionary past - even if the mice don't speak.

Two things men believe; first, women like them more when they are taken and second, a woman's relationship status influences her interest in the opposite sex. 

At least that second part appears to be true.   

In a new study, women both with and without sexual partners showed little difference in their subjective ratings of photos of men when considering such measures as masculinity and attractiveness.   However, the women who did not have sexual partners spent more time evaluating photos of men, demonstrating a greater interest in the photos. No such difference was found between men who had sexual partners and those who did not.

NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole.

This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate.

A new study carried out at the University of Leicester reveals that an alternative to oil could be found in ancient sea deposits dating to 300 million years ago.

Shale gas sourced in mudstones in shallow water seaways could provide the future alternative to fuel modern society in the wake of demands to find new energy sources, according to the doctoral research.

These mudstones, now exposed across central and northern England, contain up to 14% carbon.