Straight ahead on "Our World" ... Global warming and the threat of mass extinction ... an Internet service clashes with amateur radio operators ... and protecting buildings when fire approaches ...

SABO: "And with the smoke and flames you couldn't tell whether my home was in there or not, and then when it cleared the house was still standing there and there was no damage to it whatsoever."

He's talking about firegel. Those stories, reaching for the stars on our Website of the Week, and more. I'm Art Chimes. Welcome to the 400th edition of VOA's science and technology magazine, "Our World."


A new survey from Yale University this week highlights Americans' concerns about climate change.

More than 70 percent of those surveyed are convinced that global warming is happening, and almost as many believe human activities are entirely or partly responsible. Almost two-thirds said global warming is an urgent threat requiring immediate and drastic action. On the other hand, they strongly oppose carbon taxes that would, for example, increase the price of gasoline.

Climate change is not just a story in today's headlines, though. It's part of the history of the planet. Due in part to the unprecedented scale of human industry, we may be seeing the climate changing faster than it has in the past, but Earth's history is full of warming and cooling periods.

In a new book, Under a Green Sky, author Peter Ward examines the link between earlier periods of climate change and mass extinctions that have wiped out as many as 90 percent of the species on the planet. VOA's Rosanne Skirble reports.

SKIRBLE: Peter Ward has spent a career studying fossils. He specializes in catastrophic mass extinctions from the earth's ancient past ? what scientists call the Big Five.

WARD: "And the Big Five are those [mass extinctions] that killed off at least 50 percent of the species on earth, and one of them, the Permian, may have killed off 90 percent of the species on earth."

SKIRBLE: Ward, a University of Washington paleontologist, details the causes and consequences of these events in Under a Green Sky. He says most scientists embrace the idea that a giant asteroid hit the earth around 65 million years ago, hastening the demise of the dinosaurs.

WARD: "We have all this dust going in the air. The earth goes through a global blackout. We have falling meteors coming back from the impact sites setting all the forests on fire. We have sulfur going into the atmosphere coming back as sulfuric acid, acidifying the ocean, acid rain in the lakes. There are just any number of kill mechanisms."

SKIRBLE: But asteroids do not explain the other mass extinctions. For that, Ward and others have found evidence in the fossil record that prolonged volcanic activity spewed huge amounts of carbon dioxide and other gases into the atmosphere.

WARD: "It was as if, at every one of these mass extinctions, there was short-term rapid increase in carbon dioxide, and CO2 does something that we know that it does, it causes rapid global warming. High C02 increases greenhouse temperatures on the planet, which it did."

SKIRBLE: Over thousands of years the spike in CO2 and the resulting worldwide heat wave had nasty consequences. Winds ceased, ocean currents died, and most marine life vanished from too much heat and too little oxygen.

WARD: "These warm anoxic oceans up at the surface produced blooms of hydrogen sulfide-producing bacteria. Enough of that went into the atmosphere to kill land animals and land plants and cause the ozone to disappear as well."

SKIRBLE: Records show that environmental change began to accelerate when atmospheric CO2 hit 1,000 parts per million. Today's levels are one third of that and rising.

WARD: "You look at all the dead species in the earth's past and it has happened! It happened through raising carbon dioxide. It will happen if we do not somehow control CO2 rise in the atmosphere.

SKIRBLE: But all is not hopeless. Ward does see some positive signs in the fight against global warming.

WARD: "Most people are now educated as to what it is and almost everyone knows that it has to do with carbon dioxide and that we have to slow that down. There is half the battle right there."

SKIRBLE: Ward is also encouraged that people are beginning to make changes in their daily lives and demanding action from their leaders. He hopes his book helps readers put the current state of the earth into historical perspective.

WARD: "That we are on a planet that has violent convulsions and that we humans are playing with nature in such a way that we could recreate what were some really awful times in earth's history. That we really tinker with the earth's atmosphere at our peril."

SKIRBLE: As Peter Ward writes in Under a Green Sky, If we needlessly destroy this world, it is unlikely we will find another to replace it. I'm Rosanne Skirble.


While people like Peter Ward are worried about the fate of the planet, others are just trying to get through the day as they suffer from pain. Whether it's a simple headache or the agony of some forms of cancer, people will go to great lengths to avoid pain. But as we hear from health reporter Rose Hoban, a new survey finds that many around the world cannot avoid it, and needlessly experience pain ? especially while they're dying.

HOBAN: Steven Connor is a doctor whose work focuses on palliative care.

CONNOR: "Palliative care is care that is focused on relief of pain and symptoms in those facing life-threatening conditions. The aim is to try to improve the quality of life of those with limited amount of life left, so that physical, psychological, social, and spiritual concerns are all addressed."

HOBAN: Connor works with the National Hospice and Palliative Care Organization in the U.S., one of many groups around the world that focus on treating patients at the end of life and relieving their discomfort. He says the new survey on the state of pain relief around the world reveals some grim statistics.

CONNOR: "In 80 percent of the world's cancer patients have no access to any pain relief whatsoever and that many countries in the developing world have no analgesics at all to relieve any pain, let alone access to health care in general."

HOBAN: Connor says part of the problem is that many countries have restrictions on pain medications ? regulations passed in times when lawmakers were more worried about addiction to opiates such as morphine than they were about pain relief.

But Connor says in the past few decades, doctors have developed the science of pain relief. He says no one needs to live or die in pain. And his organization is working with some African countries on amending laws to allow for importation of more pain medications.

CONNOR: "It's a complex problem. You can change the law and make pain-relieving drugs available, but you still have to train physicians and other clinicians in how to prescribe and administer the drugs. And that takes considerable amount of time and resources. We expect it to take three years to work on this particular project in both East and West Africa, and we've made progress in several countries."

HOBAN: Connor says it's fairly easy to train health professionals to administer pain-relieving drugs, and the doctors he works with are happy that they can provide relief to their patients. Connor says he hopes the new survey will highlight the problem of unnecessary pain and let people know that relief for the dying is possible. I'm Rose Hoban.


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

This week it's a website where you can help astronomers track a major problem clouding their observations, while learning about the stars and how human activity is affecting one of the oldest of all sciences.

WARD: "The Great World Wide Star Count is a student and family activity, where we're asking people all the way around the world to go outside and look at their night sky and measure the amount of light pollution."

Dennis Ward is an astronomer at the University Corporation for Atmospheric Research in Colorado, home of the Great World Wide Star Count at

Star Count is real science, but you don't have to be an experienced skywatcher to take part. Just follow the instructions on the website; they're available in at least six languages. They explain how to identify the constellations Sagittarius in the southern hemisphere and Cygnus in the north.

WARD: "And they have a series of charts that show what that constellation might look like under the different amounts of light pollution, the different limiting magnitude of the sky. And all we're asking people to do is just compare their view of that constellation with one of seven charts that are in this activity guide."

No matter where in the world you are, Starcount wants your observations, but Ward is especially interested in reports from the Southern Hemisphere. And you can submit more than once, at different times or from different places. Results will be available at the end of the two-week observation period.

WARD: "After the campaign is over, in mid-October, all the data that everyone around the world has been collecting, we'll make that available to everyone so they can do their own analysis. We'll have it available in spreadsheets and text files, and even some mapping formats. We'll have step-by-step guides on how to do that."

Dennis Ward says the plan is to make the star count an annual event, so changes in light pollution can be tracked over time.

The Great World Wide Star Count ends on October 15th, so hurry over to, or get the link from our site,

MUSIC: Stefan Scaggiari ? "Swinging On A Star"

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


Fire can destroy everything in its path ? trees, homes, entire communities. Firefighters do everything they can to save homes ? but if the fire gets too intense they have to retreat. Fire gel is a new tool in their arsenal, used as a last ditch effort save homes about to be overwhelmed by advancing flames. Charles Michael Ray has this story from South Dakota.

RAY: In one hand, Gordon Sabo is holding a blowtorch. He's covered the index finger on his other hand with about a half a centimeter of what looks like hand lotion.

SABO: "Yeah, we're going to take this torch... and go ahead and light the torch and put this torch right against our finger."

RAY: Sabo casually holds the blue flame of the torch on his gel-covered finger.

SABO: "That torch is about 15 times more intense than any forest fire will ever become."

Q: Now is you finger hot at all?

SABO: "No, at this point I can't feel anything."

RAY: The fire gel protecting Sabo's finger is a super-absorbent polymer ? it's 97 percent water ? and it's sticky. When sprayed on it will adhere to a wall for days at a time. It just needs to be periodically re-wet to remain active. Sabo has developed an applicator that mixes the gel with water right at the nozzle. It uses a pump that can be mounted to a pickup or fire truck.

Fire gel like this has been around since about 1996. A firefighter discovered disposable baby diapers ? unburned ? after a house fire, and wondered if their absorbent material would protect a structure, as well. It did.

But the fire-blocking gel he developed is only now becoming more widely used. So far, fire gel has had only limited use outside the U.S. ? although Greece has introduced the gel in the wake of the devastating fires there this summer.

South Dakota's top wild land firefighter, Joe Low, is convinced of its value. He says not only is the gel an effective tool in the effort to protect structures in the path of fire? it keeps firefighters safer.

LOW: What it does it allows them to get in and get the structures way a head of the flaming front and then get out of the area when the flaming front comes through, which is a safer operation.

RAY: The 'flaming front' is the wall of fire that can bear down at high speeds on homeowners. In the worse case scenarios, Sabo says, a fire can move at six meters per second. If the fire gets in the trees, flames can reach 75 meters high and spread nearly a kilometer wide.

SABO: "People think that you can stand there with your garden hose and squirt it at the fire and put the fire out [but] your water hose will evaporate before it ever gets close to the fire."

RAY: The 2003 Battle Creek fire in the Black Hills of South Dakota exhibited this kind of behavior. It was one of the region's largest and most intense burns of the last decade, and Gordon Sabo's house was in the path of the flames.

Just before the fire hit, Sabo took a gel applicator and sprayed down his own home. He then reluctantly had to retreat from the intense heat and hope for the best.

SABO: "I actually was watching the fire consume everything around my home, and with the smoke and flames you couldn't tell whether my home was in there or not, and then when [the smoke] cleared the house was still standing there and there was no damage to it whatsoever. And I said, OK, that's great, and we went after 14 of my neighbors homes and we saved all of those."

RAY: Gel trucks are seen as the last line of defense against an advancing fire. Sabo and his team are often called in as the rest of the fire crews are ordered out. They work close to the flames, but Sabo says the reward of saving someone's home is worth the risk.

SABO: "When people will stop their cars driving down the street and run over to us and hug us and shake our hands and thank us for what we do ? and that's the reward right there."

RAY: Gordon Sabo and his crew spent the summer fighting some of the biggest fires in the nation. They covered hundreds of homes in fire gel, many of which would not be standing today without their efforts.

For Our World, I'm Charles Michael Ray in Rapid City, South Dakota.


When consumers around the world hopped onto the Internet starting in the 1990s, most used dial-up modems, which converted data into sounds that could be sent over telephone lines designed for voice communication.

As websites became more complex, and people wanted to download or share pictures, music and video, dial-up became too slow, and users migrated to high-speed Internet connections. Today, about half of American homes have high-speed Internet service, usually either through cable TV or digital telephone lines. As for the rest, some are not interested or can't afford it, but many simply can't get broadband service for technical reasons.

One solution is to piggy-back Internet service over electric power lines. The technology works and is cost-effective, but as we hear from VOA's Kim Andrew Elliott, broadband over power lines, or BPL, can interfere with shortwave broadcasting and amateur radio transmissions that can be vital in emergencies.

ELLIOTT: Amateur radio is a hobby, but it also provides a public service is times of emergency, like Hurricane Katrina in 2005, when the electrical grid, telephone lines, cell phone networks, and the internet were all not available.


ELLIOTT:  Those of us who are into radio know that sound. It's an amateur radio QSO, or conversation. In most countries, amateur radio operators are licensed to operate low-powered transmitters as a hobby.

This amateur radio contact took place Wednesday from an outdoor exhibit here in Washington, next to the U.S. Capitol building. With an array of equipment running on batteries, generators and solar panels, it was a demonstration of how amateur radio can provide off-the-grid communications in a time of emergency.

That close to the seat of Congress, there must have been something political about this display. There was. The radio amateur community is supporting legislation that would protect their frequencies. Specifically the amateurs are concerned about a new technology called broadband over power line, or BPL, also called. Outside the United States, BPL is known as power line communications. Allen Pitts is the public relations manager for the American Radio Relay League, the national organization of amateur radio.

PITTS: "BPL is a scheme which is to put broadband signals on electrical power lines. The problem is that it turns those electric lines into antennas, and they actually radiate radio waves. There are places where it has been done successfully and has not caused interference, but there are many other places where it has caused massive harmful interference."

ELLIOTT:  The ARRL website provides this sound of interference to the amateur radio frequency 14335 kilohertz, heard while driving throughmonitored in Briarcliff Manor, New York, where a BPL system is now operating.


ELLIOTT:  That would be heard not only on the amateur frequencies, but also in the shortwave broadcast bands.

The companies that provide BPL say that they do not get many complaints about radio interference. And BPL has many advocates. The chairman of the Federal Communications Commission, Kevin Martin, said, "By encouraging the development of new technologies, such as BPL, we can best achieve the president's goal of universal broadband by the end of 2007."

So, aren't more households in the United States interested in broadband access than in amateur radio? Allan Pitts admits that's possible.

PITTS: "And BPL can be done without causing trouble. That's the key issue. We're not against BPL. We're against the interference, and it doesn't have to have it."

ELLIOTT: Now, Art, while the radio amateurs see a threat to shortwave caused by BPL, shortwave broadcast listeners see a threat caused by international radio stations going off shortwave.

CHIMES: Right, that seems to be happening all the time. I know a couple of years ago you were here in the studio and told us about Swiss Radio International. You had a tape of their last moments on the air. And now I gather another European broadcaster is giving up on shortwave.

ELLIOTT: Yes, the latest station to go off shortwave is RAI, the public broadcaster of Italy, and indeed they are going off all of their 25 languages plus Italian on shortwave, and dropping all those 25 languages on the Internet and satellite as well. Now, many of your listeners probably have heard this interval signal have heard this interval signal on their shortwave radios ?


? and I'm going to miss hearing that bird, which was the unique tuning signal for RAI Italy. I also managed to record the last day of RAI English broadcasting from RAI

RAI NEWSCASTER: "I would like to inform all our listeners that starting from tomorrow, Monday, October the first, RAI will end its shortwave news broadcasts."

CHIMES: And I think it's very interesting that you recorded that off the Internet.

ELLIOTT: Yes, I was cheating, although I did listen to RAI on shortwave that last day. But as shortwave goes, it was fading out by the time the English broadcast came on that evening of September 30.

Art, by the way, on October 1 another international broadcaster, NHK Radio Japan, dropped all of its German, Malaysian, Swedish and, ironically, Italian broadcasts, and it reduced shortwave transmissions in Japanese, English, French and Spanish.

CHIMES: It's a real pattern. And we should say, I guess, that VOA is not immune from this either.

ELLIOTT: No, VOA is among the stations that has cut back on shortwave.

CHIMES: Dr. Kim Andrew Elliott. He was for many years the host of Communications World here on VOA and currently works as an audience research analyst. Thanks for coming in, Kim.


And finally today, a little celebration as Our World marks its 400th show.

MUSIC: Original "Our World" theme

SIVAK: Welcome to Our World on VOA, a weekly look at developments in human technology and natural science. I'm Rob Sivak. Today, the continuing debate over genetically engineered crops. We'll get an Asian ..."

That's how we started back on February 5, 2000. Rob got promoted, and he now edits the show. Rosanne Skirble hosted Our World from March 2003 to April 2004, and she remains, of course, a regular contributor. And it's been my privilege to sit at this microphone for the past three and a half years. I like to tell people I have a great job ? I get to meet and talk with some of the smartest people around, and I learn something new every day. But I wouldn't be sitting in this studio if you weren't there, so thanks for listening. I hope we'll be in this together for a long time to come.

MUSIC: "Our World" theme

And that is 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.

This week's show was edited by Faith Lapidus. 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.