Tag Archives: light

Environs, Technica

Let the Sunshine In

A ingeniously simple and elegant idea brings sunshine to a small town in Norway.

From the Guardian:

On the market square in Rjukan stands a statue of the town’s founder, a noted Norwegian engineer and industrialist called Sam Eyde, sporting a particularly fine moustache. One hand thrust in trouser pocket, the other grasping a tightly rolled drawing, the great man stares northwards across the square at an almost sheer mountainside in front of him.

Behind him, to the south, rises the equally sheer 1,800-metre peak known as Gaustatoppen. Between the mountains, strung out along the narrow Vestfjord valley, lies the small but once mighty town that Eyde built in the early years of the last century, to house the workers for his factories.

He was plainly a smart guy, Eyde. He harnessed the power of the 100-metre Rjukanfossen waterfall to generate hydro-electricity in what was, at the time, the world’s biggest power plant. He pioneered new technologies – one of which bears his name – to produce saltpetre by oxidising nitrogen from air, and made industrial quantities of hydrogen by water electrolysis.

But there was one thing he couldn’t do: change the elevation of the sun. Deep in its east-west valley, surrounded by high mountains, Rjukan and its 3,400 inhabitants are in shadow for half the year. During the day, from late September to mid-March, the town, three hours’ north-west of Oslo, is not dark (well, it is almost, in December and January, but then so is most of Norway), but it’s certainly not bright either. A bit … flat. A bit subdued, a bit muted, a bit mono.

Since last week, however, Eyde’s statue has gazed out upon a sight that even the eminent engineer might have found startling. High on the mountain opposite, 450 metres above the town, three large, solar-powered, computer-controlled mirrors steadily track the movement of the sun across the sky, reflecting its rays down on to the square and bathing it in bright sunlight. Rjukan – or at least, a small but vital part of Rjukan – is no longer stuck where the sun don’t shine.

“It’s the sun!” grins Ingrid Sparbo, disbelievingly, lifting her face to the light and closing her eyes against the glare. A retired secretary, Sparbo has lived all her life in Rjukan and says people “do sort of get used to the shade. You end up not thinking about it, really. But this … This is so warming. Not just physically, but mentally. It’s mentally warming.”

Two young mothers wheel their children into the square, turn, and briefly bask: a quick hit. On a freezing day, an elderly couple sit wide-eyed on one of the half-dozen newly installed benches, smiling at the warmth on their faces. Children beam. Lots of people take photographs. A shop assistant, Silje Johansen, says it’s “awesome. Just awesome.”

Pushing his child’s buggy, electrical engineer Eivind Toreid is more cautious. “It’s a funny thing,” he says. “Not real sunlight, but very like it. Like a spotlight. I’ll go if I’m free and in town, yes. Especially in autumn and in the weeks before the sun comes back. Those are the worst: you look just a short way up the mountainside and the sun is right there, so close you can almost touch it. But not here.”

Pensioners Valborg and Eigil Lima have driven from Stavanger – five long hours on the road – specially to see it. Heidi Fieldheim, who lives in Oslo now but spent six years in Rjukan with her husband, a local man, says she heard all about it on the radio. “But it’s far more than I expected,” she says. “This will bring much happiness.”

Across the road in the Nyetider cafe, sporting – by happy coincidence – a particularly fine set of mutton chops, sits the man responsible for this unexpected access to happiness. Martin Andersen is a 40-year-old artist and lifeguard at the municipal baths who, after spells in Berlin, Paris, Mali and Oslo, pitched up in Rjukan in the summer of 2001.

The first inkling of an artwork Andersen dubbed the Solspeil, or sun mirror, came to him as the month of September began to fade: “Every day, we would take our young child for a walk in the buggy,” he says, “and every day I realised we were having to go a little further down the valley to find the sun.” By 28 September, Andersen realised, the sun completely disappears from Rjukan’s market square. The occasion of its annual reappearance, lighting up the bridge across the river by the old fire station, is a date indelibly engraved in the minds of all Rjukan residents: 12 March.

And throughout the seemingly endless intervening months, Andersen says: “We’d look up and see blue sky above, and the sun high on the mountain slopes, but the only way we could get to it was to go out of town. The brighter the day, the darker it was down here. And it’s sad, a town that people have to leave in order to feel the sun.”

A hundred years ago, Eyde had already grasped the gravity of the problem. Researching his own plan, Andersen discovered that, as early as 1913, Eyde was considering a suggestion by one of his factory workers for a system of mountain-top mirrors to redirect sunlight into the valley below.

The industrialist eventually abandoned the plan for want of adequate technology, but soon afterwards his company, Norsk Hydro, paid for the construction of a cable car to carry the long-suffering townsfolk, for a modest sum, nearly 500m higher up the mountain and into the sunlight. (Built in 1928, the Krossobanen is still running, incidentally; £10 for the return trip. The view is majestic and the coffee at the top excellent. A brass plaque in the ticket office declares the facility a gift from the company “to the people of Rjukan, because for six months of the year, the sun does not shine in the bottom of the valley”.)

Andersen unearthed a partially covered sports stadium in Arizona that was successfully using small mirrors to keep its grass growing. He learned that in the Middle East and other sun-baked regions of the world, vast banks of hi-tech tracking mirrors called heliostats concentrate sufficient reflected sunlight to heat steam turbines and drive whole power plants.He persuaded the town hall to come up with the cash to allow him to develop his project further. He contacted an expert in the field, Jonny Nersveen, who did the maths and told him it could probably work. He visited Viganella, an Italian village that installed a similar sun mirror in 2006.

And 12 years after he first dreamed of his Solspeil, a German company specialising in so-called CSP – concentrated solar power – helicoptered in the three 17 sq m glass mirrors that now stand high above the market square in Rjukan. “It took,” he says, “a bit longer than we’d imagined.” First, the municipality wasn’t used to dealing with this kind of project: “There’s no rubber stamp for a sun mirror.” But Andersen also wanted to be sure it was right – that Rjukan’s sun mirror would do what it was intended to do.

Viganella’s single polished steel mirror, he says, lights a much larger area, but with a far weaker, more diffuse light. “I wanted a smaller, concentrated patch of sunlight: a special sunlit spot in the middle of town where people could come for a quick five minutes in the sun.” The result, you would have to say, is pretty much exactly that: bordered on one side by the library and town hall, and on the other by the tourist office, the 600 sq ms of Rjukan’s market square, to be comprehensively remodelled next year in celebration, now bathes in a focused beam of bright sunlight fully 80-90% as intense as the original.

Their efforts monitored by webcams up on the mountain and down in the square, their movement dictated by computer in a Bavarian town outside Munich, the heliostats generate the solar power they need to gradually tilt and rotate, following the sun on its brief winter dash across the sky.

It really works. Even the objectors – and there were, in town, plenty of them; petitions and letter-writing campaigns and a Facebook page organised against what a large number of locals saw initially as a vanity project and, above all, a criminal waste of money – now seem largely won over.

Read the entire article here.

Image: Light reflected by the mirrors of Rjukan, Norway. Courtesy of David Levene / Guardian.

Idea Soup

Heavenly Light or Neuronal Hallucination

Many who have survived near-death experiences recount approaching a distant light as if closing in on the exit from a dark tunnel. Is it a heavenly light beckoning us towards the eternal afterlife in paradise? Perhaps, there is a simpler, scientific explanation.

From the Washington Post:

It’s called a near-death experience, but the emphasis is on “near.” The heart stops, you feel yourself float up and out of your body. You glide toward the entrance of a tunnel, and a searing bright light envelops your field of vision.

It could be the afterlife, as many people who have come close to dying have asserted. But a new study says it might well be a show created by the brain, which is still very much alive. When the heart stops, neurons in the brain appeared to communicate at an even higher level than normal, perhaps setting off the last picture show, packed with special effects.

“A lot of people believed that what they saw was heaven,” said lead researcher and neurologist Jimo Borjigin. “Science hadn’t given them a convincing alternative.”

Scientists from the University of Michigan recorded electroencephalogram (EEG) signals in nine anesthetized rats after inducing cardiac arrest. Within the first 30 seconds after the heart had stopped, all the mammals displayed a surge of highly synchronized brain activity that had features associated with consciousness and visual activation. The burst of electrical patterns even exceeded levels seen during a normal, awake state.

In other words, they may have been having the rodent version of a near-death experience.

“On a fundamental level, this study makes us think about the neurobiology of the dying brain,” said senior author and anesthesiologist George A. Mashour. It was published Monday online by the Proceedings of the National Academy of Sciences.

Near-death experiences have been reported by many who have faced death, worldwide and across cultures. About 20 percent of cardiac arrest survivors report visions or perceptions during clinical death, with features such as a bright light, life playback or an out-of-body feeling.

“There’s hundreds of thousands of people reporting these experiences,” Borjigin said. “If that experience comes from the brain, there has to be a fingerprint of that.”

An unanswered question from a previous experiment set her down the path of exploring the phenomenon. In 2007, Borjigin had been monitoring neurotransmitter secretion in rats when, in the middle of the night, two of her animals unexpectedly died. Upon reviewing the overnight data, she saw several unknown peaks near the time of death.

This got her thinking: What kinds of changes does the brain go through at the moment of death?

Then last year, Borjigin turned to Mashour, a colleague with expertise in EEG and consciousness, for help conducting the first experiment to systematically investigate the brain after cardiac arrest. EEG uses electrodes to measure voltage fluctuations in the brain caused by many neurons firing at once. A normal, awake brain should show spikes depending on what types of processing are going on; in a completely dead brain, it flat-lines.

When the heart suddenly stops, blood flow to the brain stops and causes death in a human within minutes. A likely assumption would be that, without a fresh supply of oxygen, any sort of brain activity would go flat. But after the rats went into cardiac arrest, Mashour and his colleagues observed the opposite happening.

Read the entire article here.

Image courtesy of Discovery.

BigBang, Environs

Circadian Rhythm in Vegetables

The vegetables you eat may be better for you based on how and when they are exposed to light. Just as animals adhere to circadian rhythms, research shows that some plants may generate different levels of healthy nutritional metabolites based the light cycle as well.

From ars technica:

When you buy vegetables at the grocery store, they are usually still alive. When you lock your cabbage and carrots in the dark recess of the refrigerator vegetable drawer, they are still alive. They continue to metabolize while we wait to cook them.

Why should we care? Well, plants that are alive adjust to the conditions surrounding them. Researchers at Rice University have shown that some plants have circadian rhythms, adjusting their production of certain chemicals based on their exposure to light and dark cycles. Understanding and exploiting these rhythms could help us maximize the nutritional value of the vegetables we eat.

According to Janet Braam, a professor of biochemistry at Rice, her team’s initial research looked at how Arabidopsis, a common plant model for scientists, responded to light cycles. “It adjusts its defense hormones before the time of day when insects attack,” Braam said. Arabidopsis is in the same plant family as the cruciforous vegetables—broccoli, cabbage, and kale—so Braam and her colleagues decided to look for a similar light response in our foods.

They bought some grocery store cabbage and brought it back to the lab so they could subject the cabbage to the same tests they gave their model plant, which involved offering up living, leafy vegetables to a horde of hungry caterpillars. First, half the cabbages were exposed to a normal light and dark cycle, the same schedule as the caterpillars, while the other half were exposed to the opposite light cycle.

The caterpillars tend to feed in the late afternoon, according to Braam, so the light signals the plants to increase production of glucosinolates, a chemical that the insects don’t like. The study found that cabbages that adjusted to the normal light cycle had far less insect damage than the jet-lagged cabbages.

While it’s cool to know that cabbages are still metabolizing away and responding to light stimulus days after harvest, Braam said that this process could affect the nutritional value of the cabbage. “We eat cabbage, in part, because these glucosinolates are anti-cancer compounds,” Braam said.

Glucosinolates are only found in the cruciform vegetable family, but the Rice team wanted to see if other vegetables demonstrated similar circadian rhythms. They tested spinach, lettuce, zucchini, blueberries, carrots, and sweet potatoes. “Luckily, our caterpillar isn’t picky,” Braam said. “It’ll eat just about anything.”

Just like with the cabbage, the caterpillars ate far less of the vegetables trained on the normal light schedule. Even the fruits and roots increased production of some kind of anti-insect compound in response to light stimulus.

Metabolites affected by circadian rhythms could include vitamins and antioxidants. The Rice team is planning follow-up research to begin exploring how the cycling phenomenon affects known nutrients and if the magnitude of the shifts are large enough to have an impact on our diets. “We’ve uncovered some very basic stimuli, but we haven’t yet figured out how to amplify that for human nutrition,” Braam said.

Read the entire article here.

Art

Berlin’s Festival of Lights

Since 2005 Berlin’s Festival of Lights has brought annual color and drama to the city. This year the event runs from October 12-23, and bathes light on around 20 of Berlin’s most famous landmarks and iconic buildings. Here’s a sampling from the 2010 event:

[div class=attrib]For more information on the Festival of Lights visit the official site here.[end-div]