Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2008 May 17

Logarithmic Spirals
Image Credit: M101 - NASA, ESA, CFHT, NOAO; Typhoon Rammasun - MODIS, NASA
Comparison: Lawrence Anderson-Huang (Ritter Astrophysical Obs., Univ. Toledo)

Explanation: Uncomfortably close Typhoon Rammasun (right) and 25 million light-year distant galaxy M101 don't seem to have much in common. For starters, Rammasun was only a thousand kilometers or so across while M101 (aka the Pinwheel Galaxy) spans about 170,000 light-years, making them vastly dissimilar in scale, not to mention the different physical environments that control their formation and development. But they do look amazingly alike: each with arms exhibiting the shape of a simple and beautiful mathematical curve known as a logarithmic spiral, a spiral whose separation grows in a geometric way with increasing distance from the center. Also known as the equiangular spiral, growth spiral, and Bernoulli's spiral or spira mirabilis, this curve's rich properties have fascinated mathematicians since its discovery by 17th century philosopher Descartes. Intriguingly, this abstract shape is much more abundant in nature than suggested by the striking visual comparison above. For example, logarithmic spirals can also describe the tracks of subatomic particles in a bubble chamber, the arrangement of sunflower seeds and, of course, cauliflower.

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DIY brain therapy could halt migraines

A British team is to test a home "brain stimulation" method to short-circuit migraines before they become disabling.

Migraine is the most common neurological condition in the developed world. It affects over 15% of the UK population and is a more than just a headache; it can cause intense throbbing, visual disturbance and nausea and attacks can be so severe that sufferers have to take time off work.

Recently, a team at Ohio State University showed that zapping the brain with a magnetic field, using transcranial magnetic stimulation, TMS, can abort attacks as they start to develop, when sufferers see an "aura" , a disturbing pattern of zig zags, stars or flashes.

But the coil has to be applied to precisely the right part of the brain to be effective and now a simpler method to achieve the same effect, using two electrodes, is to be tested on migraine sufferers around the country by Prof Vince Walsh of the UCL Institute of Cognitive Neuroscience, Queen Square.

"We need to get brain stimulation into the home - you can't nip off to see your neurologist when you know you're going to have a migraine".

He will be discussing the method at the end of the month at a major conference of 300 researchers from around the world in London. The meeting is organised by the UCL institute with Magstim, the British company that pioneered TMS and is now developing stimulators that are easily portable and simple to use.

These new brain stimulators, called DC machines, introduce very weak electrical currents. But like TMS, DC also has the same effect of changing the "excitability" of brain cells, either damping down their reactivity or boosting it, which can change the way that the brain responds.

Although the prototype electrical stimulator costs around £5000, the hope is that the costs will fall as more are used. The device is much easier to use than TMS since it does not have to be precisely positioned over the correct brain region, which is currently done with a brain scanner.

The electrical version simply requires two electrodes, colour coded pink and yellow, to be put on head. Then a current passes between them, through the brain.

The method promises to have long lasting results for up to 90 minutes.

"This is a huge advantage of DC because TMS effects only last for a few minutes," says Prof Walsh, who expects the results of his trial next year.

The same techniques can help people cope with the aftermath of a stroke too. Both magnetic and electrical stimulation can sensitise the brain immediately before physiotherapy, so they can help a stroke patient to regain the ability to move a paralysed limb.

Recent trials suggest that the method is capable of improving speech and the ability to make arm and hand movements by making the brain more plastic, so areas spared by the stroke are coopted to take over from those that have been damaged.

"Patients can be helped to learn to grip cutlery, turn water taps, pout things - simple everyday abilities they may have lost after a stroke," he says. "The method helps the brain find new solutions. There is a wholly convincing study of the benefits with stroke in a trial at the National Institutes of Health in America," adds Prof Walsh.

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How a magnet turned off my speech

Words failed me. I stuttered as Prof Vincent Walsh turned off the speech centre of my brain for a few thousandths of a second to demonstrate the power of transcranial magnetic stimulation, a popular way to interfere with the most complex known object in the universe.

DIY brain therapy could halt migraines Sitting in the basement of a lab in Queen Square, London, where the nation's greatest concentration of brain surgeons can be found, I am told to recite a nursery rhyme as a way to see if the experiment has worked. Watch as Roger Highfield's speech is turned off For this remarkable demonstration of how to boggle a brain, the professor is wielding what looks like a giant black key against my head. I am reciting a nursery rhyme as he moves the coil about and delivers a high powered pulse, signified by snapping noise, a twitch on my scalp and an unpleasant, though pain free, nervy feeling in my mouth. Prof Walsh is shifting the coil around the left side of my head, hunting for the speech area of my brain, named Broca's area after the 19th century doctor. Disconcertingly for me (Prof Walsh seemed unconcerned), he had difficulty finding my Broca's and only succeeded after he called for a bigger coil to be used, as powerful magnetic pulses were delivered through my skull by his colleague, Dr Neil Muggleton.

I was reciting Humpty Dumpty and hoping that all the Queens Square's neurologists and all the Queens neurosurgeons would not have to put my brain back together again.

Finally he located my Broca's and the train of pulses stopped me in my tracks. I wanted to recite the rhyme but stumbled and stuttered as my speech area was disabled.

Intriguingly, I could still sing Humpty Dumpty as he buffetted my Broca's: it turns out that singing is controlled by the right side of the brain, the opposite hemisphere to the one he stimulated.

"That is why you can sing but not talk."

This is also why some people with stroke can sing sentences, even though they cannot speak.

The first practical demonstration of TMS was made 23 years ago by Prof Anthony Barker at the University of Sheffield.

Since then, it has become a relatively simple, non-invasive, and painless way to interfere with the workings of the brain, though there is a risk of epilepsy.

Many scientists now use it for basic research. Some have used it to induce electrical changes in the brain's temporal lobes, which have been linked with religious belief, because some sufferers of temporal lobe epilepsy seem to experience hallucinations that bear a striking resemblance to mystical experiences of holy figures.

Many doctors believe it has a role in helping a damaged brain to heal.

TMS offers a kinder alternative to electroconvulsive therapy, the treatment of last resort for people with severe depression who do not respond to drugs.

Others have used it to treat severe epilepsy, and there are efforts to use it to quieten the voices heard by schizophrenics and to track nerve development in infants.

A few even believe that it could actually enhance cognitive skills.

Prof Allan Snyder, at the University of Sydney believes TMS can act as "a creativity-amplifying machine".

But Prof Walsh is highly sceptical. "Brain stimulation does not release hidden talents and when it is used to improve things in patients, it comes at the cost of blocking some nerve pathways to encourage others."

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Examples of Fibonacci Numbers in Nature

In mathematics, the limit of Fibonacci series is called as Golden Ratio. This ratio is approximately equal to 1,618. In nature, one can come across this ratio in many areas of art and science.

I kept on researching over it on the net and wanted to see them by naked eyes. Everything I read was completely true and the realm was really amazing. This is a list of Fibonacci numbers in nature. I believe that some of the facts will astonish you.

The distribution of seeds in sunflower is spiral. The seeds of the sunflower spiral outwards in both clockwise and counterclockwise directions from the center of the flower. The number of clockwise and counterclockwise spirals are two consecutive numbers in the Fibonacci sequence.

The shells of the snails follow the Fibonacci sequence. In the same way, the shells of the nautilus follow the same rule. The only difference between these two is that nautilus' shells grow in a three-dimensional spiral, whereas snails' shells grow in a two-dimensional spiral.

Pine cones are one of the well-known examples of Fibonacci sequence. All cones grow in spirals, starting from the base where the stalk was, and going round and round the sides until they reach the top.

Another notable example is human body.In human body, the ratio of the length of forearm to the length of the hand is equal to 1.618, that is, Golden Ratio. Another well-known examples on human body are:

1. The ratio between the length and width of face
2. Ratio of the distance between the lips and where the eyebrows meet to the length of nose
3. Ratio of the length of mouth to the width of nose
4. Ratio of the distance between the shoulder line and the top of the head to the head length
5. Ratio of the distance between the navel and knee to the distance between the knee and the end of the foot
6. Ratio of the distance between the finger tip and the elbow to the distance between the wrist and the elbow

The same sequence exists on the leaves of poplar, cherry, apple, plum, oak and linden trees.

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Stop the Flow of Junk Mail

Junk mail is a triple threat: It tries your patience, jeopardizes your identity and spoils the environment. But without too much effort, you can give yourself peace of mind and an uncluttered mailbox.

Register with the Direct Marketing Association to remove your name from its national mailing list. The service is free if you register online, or $1 by mail.

Reject preapproved offers from credit card companies by visiting http://https://www.optoutprescreen.com or calling 888-567-8688.

Sign up free at http://www.catalogchoice.org, and the site will do the grunt work to get you off mailing lists for catalogues you don't want.

Pay a $20 annual fee, and GreenDimes will remove your name from catalogue and other direct-mail lists, plus plant up to 10 trees.

For $41, 41pounds.org -- named for the weight in junk mail the average adult receives each year -- will contact several dozen direct-mail companies on your behalf. In addition, $15 of your fee goes to your choice among the group's nonprofit affiliates.

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Alaska hunters fret about polar bear ruling

By Brian Harris

BARROW, Alaska (Reuters) - The U.S. decision to list polar bears as a threatened species has indigenous Alaskans like Aalak Nayakik worried that hunting the animals they rely on for food and warmth could be banned.

Standing on the edge of the receding sea ice-shelf offshore from Barrow, some 350 miles north of the Arctic Circle, Nayakik, a member of the Inupiat peoples who have inhabited northern Alaska for centuries, says polar bears are a staple food for his family.

"I like to eat bear meat almost every winter, can't go without it," he said. "It is almost like taking the cow away from the white folks."

The Bush administration's ruling on Wednesday left residents of the northernmost point in the United States uncertain about how their lives and customs will change.

Nayakik, who uses polar bear fur for his family's bedding, said news of the listing has him wondering if hunts will lead to sanctions or jail time.

He estimates that about 20 bears a year are killed by authorized Inupiat hunters in the Barrow area.

"The Inupiat have hunted the polar bear for years, not necessarily for trophy matters but for food, and the hide itself is used for clothing materials," said Barrow Mayor Michael Stotts.

"It is considered a delicacy. It is considered an honor in the Inupiat tradition to be able to capture and have a polar bear," he said.

The bears live only in the Arctic and depend on sea ice as a platform for hunting seals. The U.S. Geological Survey said two-thirds of the world's polar bears -- some 16,000 -- could be gone by 2050 if predictions about melting sea ice hold true.

THINNER ICE, AND LESS OF IT

In announcing the government's decision, Interior Secretary Dirk Kempthorne acknowledged that human-caused greenhouse gas emissions contributed to the global warming that has damaged the bears' habitat.

It is something that Barrow is all too familiar with.

"There is less (ice) and it's thinner. It is not really thick like it used to be," Nayakik, 47, said as he stood at the edge of the ice. "It is going to melt right away."

The new protection was not accompanied by any proposals to address climate change or drilling in the Arctic for the fossil fuels that spur the climate-warming greenhouse effect.

Throughout Barrow, a mostly native community of 4,500 people, there was fear that residents would shoulder an undue amount of the burden to protect the polar bear.

"Everyone needs to worry about it," said Nayakik's son Charlie, 14.

Television host Jeff Corwin, who was in Barrow filming a segment on polar bears for his "Animal Planet" show, said it would be unfair to leave Barrow solely responsible for protecting the polar bear.

"These are the iconic, apex pinnacle predator of these lands," he told Reuters. "I don't think one remote community can or should be saddled with responsibility for that species. It should be shared."

(Editing by Daisuke Wakabayashi, Mary Milliken and Xavier Briand)

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Two-mile-high urban termite mound to house planet's swarming humanity

"We’ve seen a whole slew of gigantic, volcano shaped, city-in-a-building towers, each promising to be the largest building in the world. First it was the wacky X-Seed design for Tokyo, and then even Norman Foster got into the game with his proposal for the massive ‘Crystal Island’ development in Moscow.

"Well now, architect Eugene Tsui is taking the gigantic volcano tower concept to a whole new eco level, by taking design inspiration from the natural world. His new design for the Ultima Tower – a 2-mile high Mt Doom-esque structure - borrows design principles from trees and other living ystem to reduce its energy footprint. We are always intrigued by architecture that uses biomimicry – the borrowing of principles from nature’s designs - and Tsui’s concept for this towering, ultra-dense urban development has certainly captured our attention with its thought-provoking design. (((Also, it looks completely insane... or at least it makes Frank Lloyd Wright's nuclear-powered "Mile-High" look like a piker.)))

"Population growth rates and rural-urban migration are creating a trend of chaotic urbanization that brings environmental, economic and social challenges. Within the next 7 years, 22 megacities across the globe are expected to have populations that exceed 10 million people, according to the UN. The Ultima Tower is an innovative green design concept proposed to resourcefully use earth’s surface and allow sustainable distribution of resources within a dense urban setting.

"Designed to withstand natural calamities, (((good idea))) Ultima Tower is highly stable and aerodynamic. Rather than spreading horizontally the structure rises vertically from a base with a 7,000 foot diameter - inspired in part by the termite’s nest structures of Africa, the highest structure created by any living organism..."

(((After that it just gets weirder. Though it's interesting to see that finally, in 2008, the world's most ferociously ambitious architectural notions are green.)))

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Pandas Sensed China Quake Coming?

In the minutes before a massive earthquake shook central China on Monday, captive pandas near the epicenter began acting strangely, according to an eyewitness account released today. (Watch video.) The observation, made by a British tourist who had been watching the pandas at the famous Wolong National Nature Reserve near Chengdu, mirrors previous accounts of animals "sensing" disasters before they occur.

Diane Etkins told the Associated Press that the pandas "had been really lazy and just eaten a little bit of bamboo, and all of a sudden they were parading around their pen.

"Looking back they must have sensed something was wrong."

(Read: "Can Animals Sense Earthquakes?" [November 11, 2003].)

Etkins and 30 other Britons were evacuated to the provincial capital of Chengdu after the magnitude 7.9 earthquake devastated the remote mountainous region, toppling towns and killing more than 19,000 people.

Twelve Americans, part of a tour of China sponsored by the conservation group WWF, were also visiting the breeding center when the earthquake hit. All of the tourists survived the quake, WWF confirmed to National Geographic News on Wednesday.

"It certainly was a surreal experience going through a 7.9 … earthquake surrounded by 25 pandas all sort of reacting to that as well," one of the Americans, Robert Liptak, told the Associated Press.

The 86 captive adult pandas were unharmed by the disaster, and an unknown number of cubs were moved to a safer location in Shawan, a main town in Wolong.

Odd Behavior

Accounts abound of both domesticated and wild animals behaving oddly before major natural disasters.

In 2005, elephants screamed and ran for cover and zoo animals rushed into their shelters before a tsunami struck Sri Lanka and India.

The giant waves killed more 150,000 people in a dozen countries, yet few animals were reported dead—suggesting that the animals reacted early to the impending disaster, experts said. Animals have extraordinary sensory perceptions that exceed those of humans, said Diana Reiss, a professor at Hunter College in New York who studies animal cognition.

For instance, many animals can see and hear beyond human capabilities. Snakes can feel seismic waves from their burrowing prey. And some scientists have found that elephants may even be able to "hear" through their feet, Reiss said.

Many of these highly developed senses developed as survival tools in the wild, Reiss said.

"It would be important for animals to use as many cues in the environment as possible to predict an impending disaster," she told National Geographic News.

However, Reiss warned about reading too much into the apparent strange behavior of the Wolong pandas.

"These are interesting observations, but to really determine whether they are responding to something seismic … we would have to know more about what their normal behavior is," she added.

Marc Brody, president of the U.S.-China Environmental Fund (USCEF), works on panda conservation.

"I would think that animals certainly have a stronger sense of perception than humans in terms of their natural environment," he said. "When I think of a panda and their four broad feet on the ground, one would think they feel tremors before we do."

Brody, who has received funding from the National Geographic Society, added that animals' general ability to hear at different sonic wavelengths may attribute to their early warning systems. (The National Geographic Society owns National Geographic News.)

Sybille Klenzendorf, director of species conservation for WWF, said "it's not an uncommon phenomenon for animals to get nervous when big storms or tsunamis come."

The Chinese earthquake is the "same sort of thing. [Animals feel] changes in the environment—vibrations that we don't feel."

Animals such as pandas are "more in tune with their sixth sense"—an ability humans probably had in the past, Klenzendorf said. "But we've lost that kind of sensitivity," she added.

Wild Pandas

The famed Wolong National Nature Reserve, which stretches for 772 square miles (2,000 square kilometers) across rugged mountain terrain of central China, includes the largest population of captive giant pandas in the world. (See photos of the Wolong pandas.)

More than 1,590 wild pandas also inhabit the reserve, and their fate is still unknown, China's state-run media agency, Xinhua, reported Thursday.

But USCEF's Brody said that those animals are likely unhurt in their native habitat.

Suzanne Braden, director of U.S.-based Pandas International, told the Associated Press on Monday that the wild pandas were probably fine.

"The wild pandas, they can sense things," she said.

"I'm sure they moved to higher terrain. But captive pandas do not have that luxury."

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Study: Will rising ocean submerge part of South Florida?

Sebring - Polar bears and their melting habitat sent a wake-up call to South Florida water managers Wednesday.

The same day the federal government added the polar bear to the endangered species list because of global warming, South Florida water managers agreed to take a yearlong look at how melting ice could raise sea levels that could claim the southern part of the state.

The South Florida Water Management District's long-term plans once anticipated the sea level rising about 1 foot by 2100, but more recent projections say the rise could be five times as much.

That could move the southern tip of Florida's mainland to the Tamiami Trail and submerge swaths of some of the most populated areas along the southeast coast.
From flooding to more saltwater seeping in and fouling drinking water supplies, climate change is an issue that needs more attention, said Jayantha Obeysekera, who will lead the district's global warming review.

"We cannot put up walls and stop the sea level," Obeysekera said. "Let's start looking at it [and] see what our vulnerabilities are."

On Wednesday, district officials called for spending $100,000 over the next year to study the threat of climate change.

The district, which has a $1.3 billion budget, might need to do more, governing board member Charles Dauray said.

Though Dauray said his skepticism about global warming remains, he also said a rise in the sea level could factor into decisions about whether to pursue seawater desalination plants and how to proceed with Everglades restoration.

"We might be coming to some pretty important forks in the road," Dauray said. "We better look at it pretty seriously."

Board member Michael Collins said $100,000 would be a good start until more is known about climate change.

"The data is all over the map," said Collins, who represents the Florida Keys.

Even if the worst-case scenario doesn't play out, a less dramatic rise in the sea level could create problems for South Florida, said Carol Ann Wehle, executive director of the agency.

If the sea level rises 2 feet, the vast system of drainage canals that relies on gravity to keep South Florida dry will not work, Wehle said. That would mean investing in pumps to push water out to sea, she said.

Saltwater from the ocean for decades has been seeping in and threatening freshwater wells near the coast. The district might need to consider creating new well fields farther inland, Wehle said.

In addition, the state and federal government are in the midst of a multibillion-dollar effort to restore water flows to the Everglades. Rising sea levels could mean changing those restoration plans, she said.

Climate change is the biggest challenge the district, and all governments, must face, board member Shannon Estenoz said.

"We don't have the luxury of waiting," Estenoz said.

Coincidently, the district's governing board on Wednesday met in Sebring, northwest of Lake Okeechobee, which Board Chairman Eric Buermann pointed out was once Florida's southern tip.

"It may be again," Buermann said.

Andy Reid can be reached at abreid@sun-sentinel.com or 561-228-5504

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Is the Polar Bears’ Predicament a Sign of Things to Come?

What has happened over the past couple of decades that has landed the mighty polar bear on the "threatened" list under the Endangered Species Act? Scientists believe that at least two-thirds of the world's polar bears will be gone within 40 years. The U.S. Geological Survey has confirmed that the biggest concern for the bears’ future is the shrinking Arctic sea ice, which is quickly reducing the size of the bear’s habitat. Heightened controversy over the status of the polar bear is tied to the fact that this is the first time a species has been considered for listing specifically because its habitat is threatened by global warming.

"This decision is a watershed event because it has forced the Bush administration to acknowledge global warming's brutal impacts," said Kassie Siegel, climate program director at the Center for Biological Diversity.

But some say the decision is just lip service and ignores the real issues. Rep. Edward J. Markey, D-Massachusetts, Chairman of the Select Committee on Energy Independence and Global Warming told CNN in that "After years of delay, the Bush administration was forced to face the reality that global warming has endangered the polar bear and that the polar bear needs to be placed on the Endangered Species Act. But the administration has also simultaneously announced a rule aimed at allowing oil and gas drilling in the Arctic to continue unchecked even in the face of the polar bear's threatened extinction. Essentially, the administration is giving a gift to Big Oil, and short shrift to the polar bear."

There are currently around 20,000 to 25,000 polar bears now in the Arctic wild. The polar bear population had actually been recovering since the late 1960’s thanks in part to another protective law, the Marine Mammal Protection Act. However, the “best scientific data available” from the U.S. Geological Survey and other organizations, indicates that bears’ luck is about to run out. They are now having an increasingly difficult time, which will only worsen. They are a species that is “likely to become endangered of extinction within the foreseeable future” due to the worrisome trends with Arctic ice. Overall, scientists believe the future is not a bright one for the bears.

In announcing the new threatened listing, Secretary of the Interior, Dirk Kempthorne, seemed to be feeling a little threatened himself. He was very quick to point out that the decision should not be "misused" to regulate global climate change. Kempthorne also quoted US President Bush on the matter trying to reemphasize the fact that the burgeoning oil and natural gas development in the region should not be blamed.

"Listing the polar bear as threatened can reduce avoidable losses of polar bears. But it should not open the door to use of the Endangered Species Act to regulate greenhouse gas emissions from automobiles, power plants, and other sources," said Kempthorne. "That would be a wholly inappropriate use of the ESA law. The ESA is not the right tool to set U.S. climate policy."

Kempthorne’s wording seemed to reflect concessions common to the overall climate debate. Beliefs about global warming seem to be largely split two ways. The vast majority of scientists believe the accumulated evidence indicating that global warming will have dire consequences to Earth’s diverse biology, but big industrial companies and lobbyists, along with a small minority of scientists, say it’s either nothing to worry about or it’s something we can’t do anything about either way.

Critics say that oil companies and industrial lobbyists are too quick to downplay human involvement in climate change say that they are primarily motivated by greed and that there stance is both short-sighted and dangerous. A “lets wait and see” attitude doesn’t cut it for many scientists who believe that without immediate and considerable action to stem the effects of man-made climate changes, it could quickly become too late.

According to the Intergovernmental Panel on Climate Change (IPCC) comprised of climate experts from around the globe, the Arctic Sea could be ice-free in the summer by as early as 2040, and that winter ice depth may shrink drastically. The IPCC also predicted that once global oil production peaks between 2008 and 2018 there will be a global recession. Once “Hubbert's” Peak is reached, global oil production will begin an irreversible decline, possibly triggering a global recession, food shortages and conflict between nations over dwindling oil supplies, the IPCC predicted last summer.

But for now it’s the Arctic that is really feeling the heat. According to a recent PBS report “there's no doubt the Arctic is warming. In fact, this extreme region has warmed faster than any other on earth, with the Arctic temperature increasing three to five times faster than the Earth as a whole over the past 100 years. Climate models predict that the Arctic will become an additional 7 to 12 degrees Fahrenheit warmer during the next century…With the Arctic experiencing the most rapid and severe climate change on Earth, the plants and animals that have evolved to survive in this extreme habitat come increasingly under threat. Like the canary in the coalmine, the Arctic can serve as our early warning sign of impending climate change. Observing the tumultuous change its inhabitants are experiencing can be a lesson to us about the changes in store for the rest of the world.”

Posted by Rebecca Sato

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