Tanzania’s Hadza group sheds light on ancient social networks

Long before Facebook made it possible to share photos of your breakfast with hundreds of friends and let them know just how you feel about your latest parking ticket, humans were forming social networks with essentially the same structure people use today.

A team of researchers has mapped out the relationships among a remote group of 205 hunter-gatherers in Tanzania who live as humans did about 10,000 years ago and found that their social networks are very much like ours, even in the absence of the complicating factors of megacities, cellphones and the Internet.

The researchers found that individuals who are willing to cooperate prefer the company of other cooperative people and that free riders tend to stick to their own kind as well. The results appear in Thursday’s edition of the journal Nature.

“These networks of primitive cultures are not that different from the kinds of networks that exist in modern society,” said Stanley Wasserman, a statistician at

Two-million degrees Fahrenheit.

That is temperature produced by a new laser beam, according to the U.S. Department of Energy’s SLAC National Accelerator Laboratory.

The department, which on Wednesday announced the successful experiment of the fastest and purest x-ray laser pulses ever achieved, said the laser could achieve temperatures as hot as 3.6 million degrees Fahrenheit — hotter than the sun’s corona. Scientists say the laser beam is billion times brighter that any other man-made X-ray source, making it the brightest entity ever created.

The laser, known as the Linac Coherent Light Source or LCLS, is the first of its kind able to actually penetrate inside solid matter, according to research scientists. Using ultra-short wavelengths of its X-ray light, the laser ramps up the temperature by focusing its rapid-fire pulses from the beam on a piece of aluminum foil thinner than spider’s silk. Scientists said the result of the experiment was the creation of a material known as hot dense matter.

“The LCLS X-ray laser is a truly remarkable machine,” said Sam Vinko, a postdoctoral researcher at Oxford University and the paper’s lead author. “Making extremely hot, dense matter is important scientifically if we are ultimately to understand the conditions that exist inside stars and at the center of giant planets within our own solar system and beyond.”

Scientists have long been able to create plasma from gases and study it……………. continues on The State Column