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Our World — 28 April 2007


This transcript is provided as a service; there may be some variation between it and the program as broadcast.

MUSIC: "Our World" theme

Straight ahead on "Our World," a planet is discovered outside our Solar System that might have water and life ... a new study finds sleep may boost our memory ... and students tackle the challenge of environmental sustainability:

MORRIS: "And a camel walks in circles and turns the wheel. The energy is transferred to vertical motion, which then pulls the water up through the column and transferred into a cistern that's used for drip irrigation."

Those stories, an online Encyclopedia of Earth, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

European astronomers this week reported finding the most Earth-like planet yet discovered outside our Solar System. It's a little bigger than Earth, and it's warm enough to support life, as we know it.

Almost all of the more than 200 other exoplanets discovered so far have been giants, more like Jupiter than Earth. But using sophisticated instruments at the European Southern Observatory in Chile, the astronomers discovered a planet with an estimated diameter only about one and a half times Earth's. It orbits much closer to its star than we orbit the Sun, but because its star is smaller and colder, astronomer Stéphane Udry says it likely harbors the essential ingredient of life.

UDRY: "This planet is very exciting because, at the distance of the planet from the star, we expect water to be present on the surface of the planet. And when you speak about water, you may speak about life."

Udry, who is based at the Geneva Observatory in Switzerland, is lead author of a paper describing the new find.

The new planet — known as Gliese-581c — is about 20 light years away in the constellation Libra, and there are at least two other planets orbiting the same star.

Researchers have a new clue about why some people lose their vision in old age and others do not. They found genes that are linked to an increase in the risk that macular degeneration will lead to blindness. As VOA's David McAlary reports, macular degeneration is the leading cause of blindness in people over age 55.

McALARY: Ten years ago, Harry Meyer began to notice his eyesight was fading.

MEYER: "I just realized that this old right eye was not doing what it should do."

McALARY: Harry's doctors found that he suffers from macular degeneration, the cause of vision loss in one of four people over age 75. The macula is part of the inner lining at the back of the eye called the retina, and it is responsible for central vision as opposed to peripheral or side vision. Degeneration means that the macula thins and in some cases bleeds.

But not everyone who has the disease loses vision, so researchers set out to learn why. They were led by physician Joanna Seddon at Tufts-New England Medical Center near Boston.

SEDDON: "We studied whether genetic and environmental factors are related to whether someone with this eye disease progresses to where they can no longer see other people's faces."

McALARY: To determine which risk factors lead to vision loss, Seddon's group tracked almost 1,500 macular degeneration patients for six years. Their work included analyzing the volunteers' genes from blood samples and is reported in the Journal of the American Medical Association.

SEDDON: "Common variations in two genes predict whether macular degeneration progresses to the advanced stages in visual loss."

McALARY: People with macular degeneration who had irregularities in either or both of two specific genes had two-and-a-half to seven times the increased risk of vision loss compared to those whose genes were normal. They also found behavioral factors play a role, specifically smoking and being overweight.

SEDDON: "If you had all the risk factors together, both genes plus being a smoker plus being obese, then all together that would increase your risk by nineteen-fold."

McALARY: Seddon says she believes that identifying these genes will lead to new ways of treating and preventing macular degeneration. David McAlary, VOA News, Washington.

Chances are you got some sleep last night. What you might not know is that those restful hours might have given you a memory boost. Health reporter Rose Hoban remembered to send in the story.

HOBAN: Sleep deprivation affects our ability to remember and perform complex tasks.

Harvard University neurologist Jeffrey Ellenbogen wondered if getting enough sleep had the opposite effect. So he had 48 people learn pairs of words in the evening.

ELLENBOGEN: "They had to learn combinations like blanket-baseball, lamp-chair and so forth. Then they went to sleep and then in the morning, we had them learn an entire new list of words right before recalling the list they had learned before they went to sleep."

HOBAN: Teaching the subjects another list of words in the morning was intended to distract them from remembering the words learned the night before.

Ellenbogen then took a different group of people and taught them a list of words in the morning. Both groups were tested on how well they remembered their lists later in the day.

ELLENBOGEN: "The wake group, the people that did their normal routine day were able to remember about 40 percent of the words. But the people who slept were able to remember about 75 percent so there was a very large difference between the ability to recall information after sleep compared to the ability to recall information after a normal routine waking day."

Ellenbogen says it's remarkable that the sleep group had better recall of words learned the night before than those who'd learned words that day, even after researchers tried to confuse the sleepers with new information.

ELLENBOGEN: "In fact what we think is really going on is that sleep leads to boosts in memory, but most people aren't aware of that boost unless you test it in the right way."

HOBAN: Ellenbogen will be presenting his research at the annual meeting of the American Academy of Neurology, taking place April 28–May 2 in Boston.

While we're on the subject of sleep, we recently found an interesting science question in the Our World mailbag.

Edzai Stanley Mungwariri writes from Harare, Zimbabwe, to ask about the difference between sleep and anesthesia. It's a good question, I think. Sometimes the process of anesthesia is described like sleep, and we talk about "waking up" after surgery.

But as we found out from Dr. Carol Ash, a board-certified specialist at the Sleep for Life center in Hillsborough, NJ, they're entirely different.

ASH: "There are two separate physiologic states, actually, and most people think of sleep and anesthesia as a state of unresponsiveness, and in truth there certainly is a certain extent of unresponsiveness in our behavior when we sleep, but in sleep you can reverse that unresponsiveness, unlike anesthesia, where external stimuli will not reverse that state. You have to essentially wait for the effects of the medications to wear off, so you can arouse the person."

You normally have to wait for anesthesia to run its course before the patient wakes up. Whereas with sleep, you can be awakened by your spouse rolling over, or by a loud alarm clock that always seems to go off too early.

In deep sleep it's said we're "dead to the world," but Ash says that, in contrast to anesthesia, sleep is actually a very active state.

ASH: "Sleep is restorative. Sleep is responsible for many physiologic functions, so you can see growth hormone being released at night. So it's actually not a process where you close your eyes and you got to sleep, and nothing is happening there. It's actually a very active state of being."

One of the biggest differences, of course, is that sleep is an entirely natural phenomenon, whereas Dr. Carol Ash explains that anesthesia is induced chemically, through the use of drugs typically injected or inhaled.

ASH: "So all of these different types of medications that we use to decrease consciousness cause the person to have less awareness of their surroundings and less reaction to external stimuli."

And that's a good thing since you probably won't want to respond to stimuli like a surgeon performing an operation.

For submitting an excellent question, we'll be sending Edzai Stanley Mungwariri a special VOA gift as our way of saying thanks. If you've got a question about science, technology or health, you can email it to us at, or listen for the postal address at the end of the show.

Time again for our Website of the Week, when we showcase interesting and innovative online destinations.

This time we've got probably the newest major site on the web, a tremendous new resource for anyone interested in planet Earth. Launched April 27th, the Earth Portal features the latest news about the environment, a forum for discussion, and the Encyclopedia of Earth, which already features more than 2,000 articles by experts in some 50 countries.

CLEVELAND: "What the Encyclopedia of Earth seeks to do is to provide authoritative information about all the relevant environmental issues of the day, that have been reviewed and vetted by experts, that is written for a general lay audience, and that is free and free of advertising."

Professor Cutler Cleveland of Boston University is the editor-in-chief of the Encyclopedia of Earth, part of the Earth Portal at

Four years in the making, the Earth Portal is a project of the Environmental Information Coalition. Senior member Peter Saundry highlights another feature: a continually updated news service called Earth News.

SAUNDRY: "We have partnered with the Environmental News Network — very high quality information about environmental news. We have an RSS feed from them, which feeds in the latest news. And then over here on the left, we have news articles that authors and topic editors in the encyclopedia have identified and sent to us, which you can click through and read about."

The third part of the Earth Portal is the forum, which is a place for dialog between visitors and the scientists and other experts who contribute to the encyclopedia.

SAUNDRY: "And they will post pieces on a daily basis on various topics. But we also invite the general public to participate, and you can post articles and comment on articles by the experts, and they get posted. And we already have a fledgling, ongoing dialogue between scientists writing the encyclopedia and the general public."

An exciting and brand-new addition to the web featuring high quality information about environmental science, written and edited by top scientists. Our Website of the Week is, or get the link from our site,

MUSIC: Paul Winter — "Aula de Matemática"

Your portal for science and technology news, this is VOA's Our World. I'm Art Chimes in Washington.

Most scientists agree that the world's climate is heating up, largely due to a rising concentration of "greenhouse gases" such as carbon dioxide, which are released into the atmosphere by burning fossil fuels. From New York, VOA's Adam Phillips looks at some experimental techniques for capturing carbon dioxide and storing it where it can no longer affect the earth's climate.

PHILLIPS: Several methods have been proposed to reduce the dangerous levels of carbon dioxide, or CO2, that have been pumped into Earth's atmosphere by coal-fired power plants, automobiles, industrial and residential buildings and other consumers of fossil fuel. We can use energy from alternative sources of energy, such as the wind or the sun. We can conserve fossil fuels.

Someday we may also employ so-called "carbon capture and storage" technologies, which literally trap, contain, and then store atmospheric carbon where it will have no impact on the climate.

Research efforts into carbon capture got a boost this week when Columbia University announced that Klaus Lackner, a professor of engineering and applied sciences, had developed a way to bind CO2 from normal air using an absorbent material that is both easier to use and less caustic than the sodium hydroxide that has been used in carbon capture experiments to date.

The ability to trap C02 from the air is not new technology, notes Ed Rubin, an engineering and public policy professor at Carnegie Mellon University. Rubin was also the lead author of the Special Report on Carbon Capture and Storage to the Intergovernmental Panel on Climate Change.

RUBIN: "NASA has been doing it in the space program for 30 years. That's how astronauts are able to breathe in spacecraft. So the technological ability to remove CO2 from the air is, I think, not in dispute."

PHILLIPS: What Rubin and some other experts do dispute is whether the carbon capture and storage process itself would be energy efficient, given current technology:

RUBIN: "Right now over half of the electricity nationally is coal, and that is a source of CO2. So you are kind of taking it out at one end and putting it in at the other end. And one of the key issues is what exactly is that tradeoff?"

PHILLIPS: Klaus Lackner and his colleagues acknowledge the drawback in their current method and want to meet it head on. One tactic they propose is to modify the process of prying the carbon dioxide from the "sorbent" air cleaner.

LACKNER: "We are therefore working on a separate process which uses heat. In that case we are controlling the process and we can collect the CO2 as well. We will then end up collecting one ton from the air and collecting another 0.2, 0.3 tons of CO2 from our process, and that combined CO2 is then sequestered."

PHILLIPS: Transporting carbon dioxide from where it is captured — at a power plant, say — to where it will be "sequestered" or stored can also be an expensive in purely financial terms, says Gavin Schmidt, a climatologist at the NASA Goddard Institute of Space Studies in New York City

SCHMIDT: "There are cheaper ways to reduce emissions either at the power stations or in cars or increasing energy efficiency. So the test of this new announcement will really come when it is shown to be "carbon dioxide efficient" — it doesn't generate more than it gains - and relatively cheap, so it can compete with other methods of reducing carbon dioxide emissions into the atmosphere."

PHILLIPS: Where to put the captured carbon is also a key question. Klaus Lackner is working on the storage problem as well.

LACKNER: "I'm involved right now in another project to inject deep below the ocean floor at a place where CO2 is denser than water, and therefore, if there were a fracture, the CO2 doesn't want to come up. It wants to go down."

PHILLIPS: The search for ways to offset the effects of fossil fuel consumption promises to get even more urgent in the years ahead, as rising world population and rising demand for energy seem likely, for now, to increase global use of coal and other carbon dioxide emitting fuels. Whether research into carbon capture and storage technology can keep pace is an open question. For Our World, I'm Adam Phillips.

Under an enormous white tent pitched a few hundred meters from the U.S. Capitol building in Washington, D.C., several hundred students with backgrounds in science, engineering, law, economics and architecture gathered this week at the 3rd Annual National Sustainable Design Expo. The event is a major showcase of student ideas for an environmentally sustainable future. VOA's Rosanne Skirble has the story:

SKIRBLE: The Environmental Protection Agency awards $10,000 to each college or university team with a winning idea. The teams then compete for six grand prize awards of 75,000 each. And these are pretty big ideas we're talking about.

SKIRBLE: The Design Expo includes projects such as methods to produce fuel from algae, an affordable system to reduce chemical leaching from farmlands and a simple means to purify water using the sun.

Environmental engineering major Kim Morris stands beside a model of a simple rope water pump. Her team from the University of New Hampshire partnered with a non-profit organization in Niger to design and install the pump for a school garden in the West African country.

MORRIS: "You can see that it works with animal power. And a camel walks in circles and turns the wheel. The energy is transferred to vertical motion, which then pulls the water out through the PVC [plastic pipe] columns, which are located in the well, and they pull up the rope and washers which then pull up the water through the column and transferred into a cistern that is then used for drip irrigation."

SKIRBLE: Morris says the water pump not only made a difference in the daily lives of children in Niger, but also for her classmates at the University of New Hampshire.

MORRIS: "We were welcomed with open arms. And it is exciting to be able to transfer the knowledge that we we're learning [from] books in the classroom to something that is actually usable and applicable to something so far away in Africa."

SKIRBLE: Under another part of the tent, Katherine Game from Albion College in Michigan is peddling an exercise bike hooked to an electrical generator. Her team's Calories to Kilowatts project developed an on-campus education workout center.

GAME: "The program is set up so that college students who use the equipment keep track of how much energy they are generating, and they can only use that much energy at the end of a month. So they really see how much actual mechanical energy they're using when they work out."

SKIRBLE: Game says students quickly learn the difference between the energy requirements of a low wattage laptop computer and that of a high-powered hairdryer. She says project surveys confirm that students are getting the message.

GAME: "We've seen a significant increase in participants' knowledge of renewable energy sources. And we've also seen people rate their energy conserving behaviors. We've seen an increase of that as well in the surveys."

SKIRBLE: Other U.S. colleges have expressed interest in the Calories to Kilowatts program, and Game says next year her team plans to install a unit in an elementary school in Cameroon.

PARENT: Make those muscles work Katherine!

SKIRBLE: Nine-year-old Katherine lifts a bar on a rope attached to a pulley that simulates wave motion on the surface of the ocean.

SKIRBLE: Former navy diver Michael Raftery is an engineering student at Stevens Institute in Hoboken, New Jersey. His idea is to harness wave energy. His device would be anchored on the sea floor and attached by cable to a buoy on ocean's surface. Raftery says laboratory results have been promising.

RAFTERY: "The research tells us that we should be able to get somewhere in the 100 KW per unit power range when we scale it up to a full size ocean-going version off [the coast] of New Jersey."

Q: How do you think that this could be applied, not only in New Jersey, but perhaps in other places in the world.

RAFTERY: "I believe that we can lead the entire world in a resource that can replace all fossil fuel and nuclear power. A 400-kilometer by 400-kilometer area of sea surface can replace all of our existing energy demands."

SKIRBLE: Fiddle playing Appalachian State University graduate student Jeremy Ferrell stands next to a bus powered by bio-diesel fuel. He and his musical teammates were among the grand prize winners in last year's event with a project called Closing the Bio-diesel Loop. Given $75,000 by EPA to further develop and commercialize their idea, the students built an educational laboratory on campus that demonstrates sustainable bio-diesel production.

FERRELL: "We have an ecological machine that is treating the waste water that is produced in the manufacturing of [the bio-fuel]. That encompasses different people. There is outreach. We have been making soap as one of the by-products. There is a whole 'nother group of people that are interested in that. So really we find out that everybody has something to offer when it comes to bio-diesel and that there is a lot of room for involvement."

SKIRBLE: Ferrell says the adoption of these sustainable principles makes sense for the planet and for the economy. When he graduates next month he plans to recycle his award-winning engineering talents into a job with a local Boon North Carolina agency that promotes earth-saving initiatives. I'm Rosanne Skirble.

MUSIC: "Our World" theme

That's our show for this week. We're always interested in your comments. Email us at Or use the postal address -

Our World
Voice of America
Washington, DC 20237 USA.

Rob Sivak edited the program. Eva Nenicka is the technical director. And this is Art Chimes, inviting you to join us online at or on your radio next Saturday and Sunday as we check out the latest in science and Our World.