Growing a New Retina in a Dish

Wind power is becoming more and more popular, but one of the major reasons that it is so expensive is that the wind is not uniform. On some days the wind blows very slowly but on others it blows very hard or even worse provides vicious gusts. This means that you have to build a wind turbine that can survive the worst gusts which makes it far heavier than it has to be for 99% of its normal use. Most turbines can feather or change the angle of their blades in very high winds to avoid damage, but this can be too slow to avoid damage from a quick gust.

A group from Risø DTU in Denmark is working on a technology which may help. In the same way that you can change the amount of lift on a plane wing using flaps, or aerolons to control the plane, if you add a trailing edge flap to the wind turbine blade you can greatly alter the amount of lift it is producing and therefore the forces on the structure.

The big difference between a wind turbine blade and a wing is that an aeroplane is moveable and can be regularly maintained, where as wind turbines are usually in inaccessable places, and maintainance would stop them being economic anyway. This means that conventional mechanical flaps wouldn't work, so the group is working on flexible rubber or plastic flaps which can be activated by pumping air or hydraulic fluid into specially designed cavities at the rear of the flap.

As the flap is much lighter than the whole blade it can be activated far more quickly than the feathering system so it can adapt to individual gusts without a huge use of energy, which should enable wind turbines to be built lighter and therefore cheaper.

They have built laboratory models which are very promising, and the group is now moving onto building a real test wind turbine.

Manners maketh man, and a tidy street stops stereotyping - In a surprise finding from the Netherlands, researchers have discovered that choas and clutter cause people to be far more prejudiced than when things are kept tidy.

Writing in Science, University of Tilberg scientists Diederik Stapel and Siegwart Lindenberg took advantage of a strike by cleaners at Utrecht train station to test the impact of a messy environment on peoples' prejudices towards others.

Asking a mixture of white men and women to take part in a questionnaire, the researchers invited the participating commuters to sit on one of a line of six chairs, a seat at one of which was already occupied by either a white or black assistant. Unbeknown to the volunteers, the researchers were watching which seat in the row they elected to sit on.

When the station was messy at the height of the strike, the participants sat, on average, 50% further away from the already-seated individual compared with when the station was tidy - but only if he was black. When the already-seated individual was white, there was no difference between tidy and messy days and the participating commuters left an average of two empty seats between themselves and the person already sitting down.

The researchers then carried out a similar experiment in an affluent Dutch suburban street. On the first occasion the street was made to look scruffy, with paving slabs removed, a car parked on the pavement and a bike abandoned beside the road.

Passers-by were stopped and asked to fill out a survey asking questions about stereotyping; they were then given some money for taking part and then invited to donate some of it to a charity supporting minorities.

The researchers then returned the street to its formerly-orderly appearance and repeated the process. In the untidy setting, respondents were far more likely to display prejudiced behaviour and also donated significantly less money to the minorities charity than when the environment was tidy.

The researchers then went on to demonstrate that pictures of disorder and even information presented subconsciously in a disordered way could induce similar behaviours in study participants.

But why? Their explanation is that perceived disorder in a person's surroundings trigger a craving to create order, which includes using highly simplified categories and judgements to classify the world, which in turn trigger discriminatory behaviours.

This, they say, is a learning point for local councils and civil amenities providers, pointing out that "Signs of disorder such as broken windows, graffiti and scattered litter will not only increase antisocial behaviour, they will also automatically lead to stereotyping and discrimination.

Thus...investing in repair and renovation, and preventing that neighborhoods fall into disarray, may be relatively inexpensive ways to reduce stereotyping and discrimination."