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MUSIC: "Our World" theme

Straight ahead on "Our World" ... celebrating a high-tech nail that could save property and lives ... making the Web usable for everybody ... and tracking the invisible universe ...
HOOPER: "We can look at stars, and we learn that these are moving really fast. And in order to be moving that fast, there must be a lot of mass in the galaxy. And it turns out there's something else there. And we call that dark matter."

Those stories, staying mentally alert in old age, and more.  I'm Art Chimes.  Welcome to VOA's science and technology magazine, "Our World."


Popular Science magazine has been showcasing the latest technology since 1872. For its December issue, Popular Science throws the spotlight on its Innovation of the Year. Associate Editor Joe Brown says he and his colleagues on the editorial board bypassed contenders such as the million-dollar Bugatti automobile, and human bladders grown in a laboratory, to choose ... a nail.

BROWN:  "It's a nail, yes. It's not just any nail, though."

Not just any nail, indeed. The Bostitch HurriQuake nail incorporates several design features so buildings constructed with it will survive storms and earthquakes.

BROWN:  "The guy who built it, Ed Sutt, has dedicated his life to designing a better nail. He was always obsessed with this one fact that the first point of failure on any kind of a structure in a hurricane or an earthquake is going to be the fasteners, the pieces that hold the pieces of wood together. Because wood's fairly flexible. Nails break."

Ed Sutt observed hurricane damage first hand in the Virgin Islands and in United States, where the dominant construction technique for houses and other small buildings includes nailing plywood wall and roof panels to a wood frame. It's also a common design around the world, including many areas where storms or earthquakes threaten structures.

Sutt and his team spent six years developing the new nail.

SUTT:  "The HurriQuake nail is a nail with unique features that delivers up to two times the resistance to wind uplift-type forces and up to 50 percent more resistance to earthquake-style forces.

To achieve those improvements, they re-thought the ordinary nail, adding barbs to the bottom of the shaft so it grips the wood and a spiral groove at the top to help it stay in place. The nail head itself is bigger than normal to prevent the nail from pulling through the wood.

The best part is that unlike some other ways of disaster-proofing a building, using these nails adds only a few dollars to the cost of a house.

Joe Brown of Popular Science said there were many worthy innovations this year.

BROWN:  "But across socioeconomic statuses, from country to country, the one item here that is accessible to rich and poor people, from any background, any country around the world, is this nail. This nail is going to be there to help keep their homes safe in natural disasters. And that's really important for us."

But like any good engineer, Ed Sutt says there's still room for improvement.

SUTT:  "Well, the HurriQuake's not done. And we're already working on the next generation nail to improve the basic properties. We hope to take just as large of a leap next time as well."

Engineer Ed Sutt, designer of the HurriQuake nail. He spoke with us from Bostitch headquarters in Connecticut.


HOBAN:  Worldwide, people are living longer. But many older people face both physical ailments and mental decline. As we hear from health reporter Rose Hoban, scientists are working at finding ways to keep people mentally fit as they age.

HOBAN:  A decade-long study indicates that giving seniors some cognitive training could slow the loss of memory and mental skill as they aged. Jeffrey Elias at the US National Institute on Aging is one of the top researchers.

ELIAS: "As people get older one of the things they worry about or are concerned about is how well they'll function in old age. And of all the things we do, both physically and mentally, I guess people are more concerned about their losses mentally, rather than physically."

HOBAN:  Researchers across the country recruited 2,800 participants over the age of 65 and divided them into four groups. One group was the control; they received no special intervention. A second group was given training in analytical reasoning and problem-solving skills, and another learned techniques to help them process visual information more quickly.

ELIAS:  "The last kind of training is the one that most people are concerned about or notice when they get older, which is memory. The idea there was to teach people strategies for organizing information, using personal images to remember information, to relax when you're trying to remember something, to relate it to something else." 

HOBAN:  Elias says, five years later, all the groups that received training had better mental function. But surprisingly, those in the memory strategies group had the least amount of improvement of the three trained groups.

Despite the different cognitive results, Elias says all of the trained groups reported better physical functioning during their every day Activities. The research was published in the Journal of the American Medical Association. I'm Rose Hoban.


The World Wide Web has been around for more than a decade, and in many ways it has a profound impact on democratizing the flow of information. There is still a "digital divide" that keeps disadvantaged people offline, but for one group, having access to the Web doesn't necessarily translate into an ability to use its resources. People with physical disabilities face major challenges in using the Web. A report commissioned by the U.N. this month found only three of 100 top global websites surveyed are fully usable by all. VOA's Adam Phillips has more on the problem and what is being done to solve it.

PHILLIPS:  Although many governments have passed laws mandating that public places be made accessible to the disabled, equal access to cyberspace has lagged far behind. Judy Brewer, the director of the Web Accessibility Initiative at the World Wide Web Consortium, which sets technical standards for the Web, says things must change.

BREWER:  "There is so much valuable information on the Web right now, whether its educational or employment-related, health-related, government services, community activities ? and people with disabilities need to be able to access all of that information in order to have all the opportunities and the same ability to participate as people without disabilities."

PHILLIPS:  Brewer says that just as there are many kinds of disabilities, there are many ways to help the disabled access the Web. 

BREWER:  "If somebody has a hearing disability they would need captioning for the audio. If somebody had a physical disability ? let's say you can't use your hands ? there are actually many different ways. One of them would be voice recognition software, so you are essentially talking to your computer. All these different kinds of specialized software we can call 'assistive technology.'"


PHILLIPS:  That's a computer-generated voice reading the USA Today newspaper's homepage to Marc Grossman, a sales representative at the American Foundation for the Blind in New York City.

He is using screen reading software to translate the specialized code embedded in the text and images on every Web page into synthetic speech.

Grossman says this particular form of assistive technology has been a boon to the visually impaired. But he adds that many websites are still difficult to use.. For example, the software readers often "speechify" too much extraneous information, describing all of the graphic elements on a web page, such as advertisements, commonly placed within news articles.

GROSSMAN:  "If you are designing for people, you want them to catch certain information, like a headline. But here I am, I have no way of finding the headlines. [SYNTHESIZED VOICE] Could you tell me what that was? Who knows what that is? Something about a car, but I don't know what it means. You might as well just turn it off because if you're getting gibberish, it's just as bad as not getting any information at all."

PHILLIPS:  The irony, according to David MacDonald, a web developer at E-ramp, a Canadian firm specializing in accessible websites, is that writing the computer code to accommodate the needs of the disabled is quite easy to do.

MACDONALD:  "It's inexpensive. The biggest problem is in cognitively getting their head around that they want to do it. For one thing, it's the right thing to do.  Moreover, thought, you are really looking at increasing your client base. There are about 40 million people with disabilities in the United States and North America, for that matter."

PHILLIPS:  That number includes people with relatively minor disabilities, such as senior citizens who want large print, and the color blind, who cannot interpret web pages that use color cues to convey meaning. 

Change seems to be coming slowly, but surely. Rules requiring basic accessibility are being considered by many governments, and the disabled themselves are becoming better organized and more vocal in their demands for a World Wide Web that is accessible to all. I'm Adam Phillips in New York.


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

This is our last Website of the Week for 2006, and I have to report that our selection this week has gone to the birds.

SOUND: Mottled Wood Owl (Strix ocellata)

ANDERSON:  "Well, the Macaulay Library is a collection of video and audio sounds from animals - mostly birds - from around the world."

Mike Anderson is an assistant curator at the Macaulay Library at Cornell University in Ithaca, New York, online at  It used to be called the Library of Natural Sounds, which is perhaps a better description of this amazing collection of audio and video recordings, which includes some 7,000 different kinds of birds, representing more than two-thirds of all known species.

In many cases there are multiple recordings of the same species, which is a real help for researchers.

ANDERSON:  "Birds sound different across their range. There are some birds that live from the northern point in Alaska all the way down to Tierra del Fuego in Argentina, like the house wren and some others. And in some parts of their range they may sound different than others. So it's worthwhile in having a larger sample size to document any amount of variation across the species distribution."

Along with the actual recordings, the library documents where each recording was made and when, plus what the bird was doing at the time, the weather, and so on.

For decades, the library housed its collection on disks and later, on tape. Now they are making this unique archive available on their website. So far, only about one-third of the recordings are online in digital format, but more are becoming available all the time.

Anderson says the Macaulay Library website attracts a wide range of users.

ANDERSON:  "We have researchers who appreciate the large sample size of any one particular species that they may be working on. We have educators coming in to use our website, looking to play a sound of a cardinal for their class. Or we have conservationists coming to determine what all of the birds in a particular forest in Africa sound like so that they can then do monitoring and such."

Mike Anderson of the Macaulay Library at Cornell University. You can listen and view their recordings online at, or get the link from our site,

MUSIC:  "Lullaby of Birdland" - Manfredo Fest

You're listening to VOA's fine-feathered science and technology magazine, Our World. I'm Art Chimes in Washington.


We Americans famously drive to work, drive to shop, even drive for fun. All that driving helps drive demand for gasoline and other imported petroleum products. Many motorists put "gasahol" in their tank ? a fuel blended of gasoline and ethanol, an alcohol fuel based on corn. But rather than an edible crop like corn, some scientists ? and politicians like President Bush ? think we should be looking at other kinds of biomass as a fuel source. VOA's Ted Landphair says researchers are looking at switchgrass, a wild plant that thrives in much of mid-America.

LANDPHAIR:  Millions of Americans are already driving cars powered principally by ethanol made from corn, or biodiesel made from soybeans.  But switchgrass ? a perennial with thick, hard stems that grows up to three meters tall ? may have more long-term potential as a fuel source. 

Charles Taliaferro, an Oklahoma State University emeritus professor of agriculture, has helped breed high-yielding varieties of the tenacious grass.

TALIAFERRO:  "It's environmentally friendly. It grows on non-crop soils where corn and other row crops cannot be produced. It has relatively high production biomass capability with minimal fertilizer and water." 

LANDPHAIR:  The corn, from which most ethanol is made today. must be planted annually on farmland with rich soil, and they're in constant demand as food sources. Meanwhile, not even cattle go out of their way to munch on brittle switchgrass. Whatever its source, that ethanol is a bit less powerful than gasoline, which is one reason why a bit of gasoline is mixed into most ethanol formulas. 

Danielle Bellmer, an associate professor at Oklahoma State University's School of Biosystems and Agricultural Engineering, says sugar can be extracted from cellulose in the switchgrass plant. That is turned into fuel, though the process is by no means easy.
BELLMER:  "Years of research have gone into hydrolysis, as it's called. Specific enzymes are required to break the cellulose down into sugar." 

LANDPHAIR:  Creating protein-based enzymes that can break down coarse grasses costs a lot more than coaxing sugar out of the starch in corn or soybeans. But the cost has been steadily dropping, and the time may be near when it's commercially viable to turn switchgrass into fuel.

BELLMER:  "Harvest the grass, chop it up, put it into a fermenter where there are enzymes, allow the enzymes to work and break down the cellulose into sugar, and then add yeast, which will convert the sugar into ethanol."

LANDPHAIR:  The latest research at Oklahoma State University includes work on a different approach that uses switchgrass to create what's called "grassahol." The entire plant, diced into bits, is burned at high temperatures in a device called a gasifier. This produces carbon monoxide, carbon dioxide, and hydrogen gases that are bubbled through a bioreactor, where micro-organisms convert them into ethanol.  As an engine fuel, it's about 85 percent as efficient as gasoline.

BELLMER:  "In exchange for the lower fuel mileage, you have to consider benefits to the environment and to our economic system in America. So we're supporting ourselves if we buy our own fuel, as opposed to supporting countries around the world. And it's a sustainable fuel."

LANDPHAIR:  Millions of hectares of switchgrass once swayed and whistled in the wind across the North American heartland.  Over two centuries, farmers plowed much of it under to plant edible corn, wheat, and soybeans.  But if today's successful research leads to actual grassahol production, wide swaths of the great tallgrass prairie could make a triumphant return. I'm Ted Landphair.


The more we know about how the world around us works, the stranger it all seems to be. Physicists have even named a subatomic particle the "strange quark."  In a universe where most of the matter is invisible and virtually undetectable, sometimes the temptation is just not to bother trying to understand modern physics.

And yet, for many people ? curious youngsters and those long out of school ? the "curiouser and curiouser" world of modern physics is wondrously exciting.

Physics researcher Dan Hooper has a new book out, called Dark Cosmos, that tries to present the wonders of dark matter and dark energy to non-specialists.

We reached him at his office at the Fermi National Laboratory in Illinois.

HOOPER:  "Well,for quite some time now we've known that most of the mass of our  universe is in some sort of non-luminous form, something that appears invisible to our telescopes. We know it's there because of its influence of gravity. Now, imagine a planet going around the Sun in our Solar System. The reason the planet stays in orbit is because, as it spins around the sun, the gravity from the sun pulls it in and keeps it in that orbit. So you can tell from the speed that this planet moves around the Sun, how heavy the star ? the Sun ? must be in order to hold it in its orbit. So we can do the same thing with our whole galaxy, Milky Way. And when we do that, we can look at stars going around the center of the galaxy, and we learn that these are moving really fast. And in order to be moving that fast, there must be a lot of mass in the galaxy. And it turns out most of that mass is not in stars. There's something else there, some big part. And we call that dark matter."

Q:  Well, that's dark matter. What about dark energy?

HOOPER:  "Dark energy is a much more baffling mystery to us at this time. We don't really understand what it is, and we've only recently discovered that it exists at all. And we have a lot more progress that needs to be made before we can really say much more definitively about it. The reason we know dark energy is there - well, to understand that you have to go back all the way to Einstein. So when Einstein published his general theory of relativity, his  equations show that it was actually possible that space itself could expand or contract with time. So when you looked at Einstein's equations you would lead yourself to believe, from looking at them just at face value, that either the universe should be getting bigger but at a slower-and-slower rate, or it should be contracting. And sometime later, Edwin Hubble and others measured that it was in fact expanding, and it was a great confirmation of his theory.

"Now, all that was turned on its head, however, back in 1998 and 1999 when astronomers observed for the first time that the universe was not only expanding, but expanding faster and faster and faster. There is one way you can get Einstein's equations to predict an accelerating expansion rate of the universe, and that's to include something called dark energy. And we're just beginning to understand it at this point in time."

Q:  Dark matter. where is this stuff hiding?

HOOPER:  "So let's do an experiment. You hold up your hand and if you could ? you can't ? but if you could, you could count numbers of dark matter particles passing through it every second. They're everywhere. And in particular our galaxy is basically a big, giant cloud of dark matter. So, ordinary matter, like planets and stars and things, tend to clump together, right? Dark matter is much more diffuse than that. It doesn't collect, clump together quite as much."

Q: We call it empty space, but it's just more empty than the rest of space. 

HOOPER:  "That's right. There's no such thing as real empty space."

Q  How did this stuff, which makes up 95 percent of the universe, how did it escape detection for so long?

HOOPER:  "If we look around at the normal objects in our room or in our car or in our world, these objects are remarkably easy to infer the presence of, to detect. I can pick them up, I can touch them, I can see them, I can smell them. I can feel them. Now, imagine a particle, some sort of exotic kind of matter, that simply doesn't allow you to interact with it in this way. It can pass through your hand without you knowing it. For that matter, these things can pass through the entire Earth without knowing it. And it makes it very hard to study.

Q: You write that skepticism is one of the most important qualities a scientist can have. Why is that?

HOOPER:  "Well I think what I say is that if it weren't for skeptics, the status quo, or the scientific perspective of one particular  generation would just get frozen in time. So when Einstein came along, it was important that he was a skeptic of Newtonian physics, Isaac Newton's theory, because if he weren't a skeptic he may not have created his more perfect and more complete theory of gravity that we know as general relativity. Similar, if Isaac Newton hadn't been a skeptic of some of the dogma and doctrine that existed before him, that would have been frozen in as well. It's really critical that we ask ourselves what we know and what we don't know for sure, and really push these envelopes until we discover something new, something more complete."

Fermilab physicist Dan Hooper is the author of "Dark Cosmos," just published by Smithsonian Books.


MUSIC: "Our World" theme

That's our show for this week.  If you'd like to get in touch, 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 technology ... in Our World.