Futurehead.com

Members of Nasa's newest astronaut class, a group that includes the highest number of women since the program began more than 50 years ago, have been speaking about their selection.

The agency's 21st astronaut class, announced on Monday, includes four women and four men, who made it through a pool of 6,100 applicants, the largest ever. Those who make it through the program will have the opportunity to be on missions to the Earth's orbit, an asteroid and Mars.

"My parents are going to be excited. They know this has been a lifelong goal," said Tyler Hague, 37. "My brothers, as they always do, will give me a hard time."

Hague said it was his third time applying for the program. Since the program began in 1959, 330 people have made it through the selection process.

A team of researchers from the Nanoengineering Research Centre (CRNE) and the Department of Electronic Engineering at the Universitat Politècnica de Catalunya · BarcelonaTech (UPCn) has found a way to make the manufacture of crystalline silicon materials faster and more affordable. The results of their research have recently been published in the online version of the landmark journal Applied Physics Letters.

Ten years ago, few people would have heard of a social network. Today, Facebook, Twitter and LinkedIn permeate our lives. They show us how we are linked to each other and how we are more broadly placed within society.

What fascinates scientists is that the general properties of social networks seem to be invariant regardless of where they crop up. For example, one of the remarkable properties of social networks is their small world character. This means it is possible to go from one part of a network to any other part in a small number of steps (this is where the phrase 6 degrees of separation comes from).

That was entirely unexpected and counterintuitive when it was discovered in the 1960s by the American social psychologist Stanley Milgram. But it is as true today of Facebook and Twitter as it was of the society in which Milgram carried out his experiments.

Today,  P J Miranda at the Federal Technological University of Paraná in Brazil and a couple of pals study the social network between characters in Homer’s ancient Greek poem, the Odyssey. Their conclusion is that this social network bears remarkable similarities to Facebook, Twitter and the like and that this may offer an important clue about the origin of this ancient story.

Scientists have shown off their latest "invisibility cloak" by making a pet goldfish and a small cat vanish from plain sight.

The device is crude and unlikely to pass muster with the pupils of Hogwarts, but researchers said it marked a significant step forward in the science of the unseen.

In video footage of the device in action, a goldfish suddenly appears as it swims out of a cloak submerged in its tank. In another clip, the lower half of a cat disappears as it steps inside a cloak placed on a table.

Scientists led by Baile Zhang at Nanyang Technological University in Singapore created the cloaks from thin panels of glass that make objects invisible by bending light around them.

Though rudimentary - the devices only hide objects from certain angles, and in both cases the cloaks themselves were partially visible – they are better than earlier versions that worked only with polarised light, or with microwaves instead of the visible wavelengths that humans see in.