If you're an ordinary, law-abiding citizen in the UK, you can't own a gun.  So who owns them?  Criminals, of course, making crimes easier to commit.   But it isn't just organized crime and the assumption that gangs are most often at the root of gun crime in the UK is overstated, according to a study published today in Criminology and Criminal Justice.  In their paper, professor Simon Hallsworth and Dr Daniel Silverstone suggest that while gangs certainly exist, they are not involved in most illegal shootings.

In one of the largest studies examined, the Home Office conducted 80 structured interviews with young people involved with weapons, visiting UK cities with high levels of gun crime and penal establishments.

Is organic food better for you than conventional food?   It's the second most asked question we get here about food, the first being 'What is the difference between organic and inorganic food?  (Also Lee Silver's What is the meaning of "organic" (and inorganic) food?) 

A new study in Nature offers an explanation for the origin of dwarf spheroidal galaxies, one of the current puzzles in our understanding of galaxy formation.

Dwarf spheroidal galaxies are small and very faint, containing few stars relative to their total mass. They appear to be made mostly of dark matter - a mysterious substance detectable only by its gravitational influence, which outweighs normal matter by a factor of five to one in the universe as a whole.

Isaac Asimov's Three Laws of Robotics were immortalized in the short story "Runaround" in 1942.   In it he formalized the rules that all positronic robots must obey.

Two engineers think Asimov's laws need an update.

Scientists have been thinking increasingly about whether or not animals in the ocean might play a role in larger-scale ocean mixing, says John Dabiri, a Caltech bioengineer. Ocean mixing is the process by which various layers of water interact with one another to distribute heat, nutrients and gasses throughout the oceans.

"The perspective we usually take is how the ocean--by its currents, temperature, and chemistry--is affecting animals," says Dabiri, who, along with graduate student Kakani Katija, discovered the new mechanism.

The number of large-diameter trees that Yosemite National Park is famous far are on the decline, and warmer temperatures appear to be the culprit.

Their number have declined 24 percent in the park between the 1930s and 1990s. Scientists from the U.S. Geological Survey and University of Washington compared the earliest records of large-diameter trees densities from 1932 to the most recent records from 1988.