Science and Technology Week

BMW Produces Hydrogen-Powered Cars, Deorbit of Mir Causes Concern for Pacific Rim Residents, Foot-and-Mouth Outbreak Leads to Slaughter of Livestock

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

ANN KELLAN, HOST: High speed on hydrogen. Will this be the filling station of the future?

Also, will the Mir de-orbit endanger people on Earth? And finding clues to the first humans in North America. Those stories and more are just ahead on SCIENCE & TECHNOLOGY WEEK.

Hello, and welcome. I'm Ann Kellan.

A month ago, most people not in the livestock business had barely heard of foot-and-mouth disease. Now, it's making headlines around the world. The recent outbreak in Britain has led to the slaughter of hundreds of thousands of animals in an effort to stop the spread of the disease.

You may wonder why officials think it's necessary to kill the animals, and why healthy animals can't just be vaccinated against the virus. David George explains some of the complications dealing with foot-and-mouth.

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DAVID GEORGE, CNN CORRESPONDENT (voice-over): Why are they burning all those cows in Europe? It's to stop the spread of an animal disease that doesn't kill animals.

CORRIE BROWN, UNIVERSITY OF GEORGIA: It's not a disease of any significant mortality.

GEORGE: And it poses no threat to people.

BROWN: It's not considered to a zoonotic disease, that is, not a disease that's readily transmissible to humans.

GEORGE: Even so, foot-and-mouth is a devastating disease. It gets its name from causing blisters on the mouths and feet of animals with cloven hooves: pigs, goats, sheep, cows, and the like.

The real damage occurs inside. Infected animals stop giving milk and don't gain weight for about three weeks.

BROWN: In any country with an industrialized system of agriculture, three weeks of lost production is all it takes to wipe out profits.

GEORGE: But you'd think with profits at stake, there would be a vaccine or something.

BROWN: There is a vaccine, and it's used in outbreak situations to create a sort of fire wall around the outbreak.

GEORGE: However, once the outbreak is contained, all the animals involved, even the ones that got the vaccine, end up being killed anyway.

BROWN: The problem is that once you use the vaccine, you can't distinguish which animals have had the disease and which animals have been vaccinated.

GEORGE: Any country that does vaccinate against foot-and-mouth disease loses its designation as a foot-and-mouth-disease-free nation.

BROWN: No country would trade with us knowing that we had serologically positive animals, because it would mean we would have no system for detecting an outbreak.

GEORGE: The United States hasn't had a case of foot-and-mouth disease since 1929, but the University of Georgia's Corrie Brown says, in the current crisis, a North American outbreak may not be a matter of if, but when. And then...

BROWN: We figured an outbreak that spread to any extent would probably cost $2 billion to clean up and probably $20 billion in lost trade.

GEORGE: Brown says 17 percent of American jobs are related in some way to agriculture.

BROWN: It's $800 billion in exports. To put a big dent in that would have reverberating effects through the economy.

GEORGE: So that's why Europe is killing and burning so many cattle.

BROWN: That's the only way to contain the outbreak.

GEORGE: The carnage isn't just about cows. It's the economy.

David George, CNN, near Athens, Georgia.

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KELLAN: President Bush says he will not restrict emissions of carbon dioxide from power plants. That's a change from what he promised during his campaign.

Government figures show more than a third of the carbon dioxide emissions in the U.S. comes from power plants. Mr. Bush told Congress he doesn't want those emissions regulated, partly because of rising energy costs, and partly because CO2 is not considered a pollutant under the Clean Air Act.

The move outraged environmentalists, concerned about carbon dioxide's role as a greenhouse gas, which could lead to global warming. And coincidentally, a new study in the journal "Nature" this week claims to have found direct evidence of the greenhouse effect. Satellite data shows over a 27-year period, the atmosphere absorbed increasing amounts of energy, thanks in large part to increasing concentrations of carbon dioxide. The study did not address whether the Earth's climate is actually getting warmer.

An important part of the whole energy and environment debate is, of course, the automobile. Many automakers are looking for nontraditional fuels that could cut pollution or reduce our appetite for gasoline. One of them, German auto giant BMW, is pinning its hopes to hydrogen.

Rick Lockridge reports from Munich, Germany.

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RICK LOCKRIDGE, CNN SCIENCE CORRESPONDENT (voice-over): The hydrogen-powered car of the future, according to BMW: zero emissions and a respectable zero-to-60. Hey, the company believes its customers want to save the planet as much as anyone, they just want to do it from the passing lane.

KLAUS PEHR, BMW ENGINEER: The feeling for our customers will be the same in the future. They have a high-powered car. They have the same performance of the car that they are used to.

LOCKRIDGE: Now, BMW is taking its clean car fleet on the road: from Dubai to Brussels, Milan to Los Angeles, the 7-series sedans will show off their 12-cylinder, 200-horsepower engines -- top speed 140 miles per hour. The H-cars can also burn regular gasoline if they need to, but hydrogen as a fuel is perfectly clean. The only tailpipe emissions: water and steam.

PEHR: We take water, make hydrogen out of it, and burn it to water again.

LOCKRIDGE: The car also gets its electrical power from hydrogen: solid-state fuel cells in the trunk. It's a different technology, but the fuel's the same -- hydrogen. Yes, it's expensive and complicated to produce, but it's also essentially limitless.

PEHR: We think hydrogen is the energy carrier of the future, the only one.

LOCKRIDGE: You make liquid hydrogen by using electricity to strip the hydrogen molecules out of ordinary water, but that's not as easy as it sounds, and then you have to store the liquid hydrogen at minus 423 degrees Fahrenheit, or it starts to evaporate.

UNIDENTIFIED MALE: This here is our "Yellow Submarine."

LOCKRIDGE: This refueling depot at the Munich airport, the only one like it in the world, uses NASA technology to store liquid hydrogen for the H-cars and gaseous hydrogen for a small fleet of airport buses.

(on camera): As filling stations go, this one's fairly Spartan. You can't buy a soft drink, although you can wash your windshield.

(voice-over): Since liquid hydrogen is so volatile, the driver is not permitted to pump his own. Instead, a robot with a laser scanner looks for the car's fill-up valve and locks on.

UNIDENTIFIED MALE: The control system knows it is a BMW 7- series.

LOCKRIDGE: The hydrogen tank on the BMW is heavily reinforced. Crash tests indicated little chance of an explosion or fire. Still, when remembering hydrogen-fueled vehicles of the past, the Hindenburg disaster, the Challenger explosion come to mind. And one might wonder: do I want to ride around on top of a tank of rocket fuel?

ULRICH WAGNER, LUDWIG MAXIMILIAN UNIVERSITY: Well, I don't want to paint any horror scenarios, but if you look at the other conventional energy carriers, we also had a lot of accidents in the past.

LOCKRIDGE: Professor Ulrich Wagner say that the world will solve any hydrogen handling problems, because it must.

WAGNER: Whether this will happen in 30 years, or 40 years, or 50 years, but it will happen.

LOCKRIDGE: And what'll make it happen, proponents say, is a growing concern for the environment, especially in Europe, and a growing awareness that the world has a lot more water than it does oil.

For SCIENCE & TECHNOLOGY WEEK, I'm Rick Lockridge.

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KELLAN: Later in the show, high-tech treasure hunting under the ocean. And up next: the remains of the Mir space station are supposed to crash harmlessly in the ocean next week, but could they land on a populated area instead?

(COMMERCIAL BREAK)

KELLAN: Astronomers have new evidence that the early universe was teeming with supermassive black holes. NASA's orbiting Chandra X- Ray telescope has been focusing on small areas of space, taking long exposures, some lasting more than a week. Now, It captured images of the faintest X-Ray sources ever recorded, showing distant galaxies as they existed 12 billion years ago.

The data show that giant black holes were much more active in the past, and astronomers say there are billions of them out there. Black holes are small points that are so dense, their gravity prevents even light from escaping.

We're about to see the end of an era in space exploration. The Mir space station is scheduled to come down to Earth next week. Now even though most of it will burn up on the way, as much as 30 tons could survive re-entry. Could any of it land near you?

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KELLAN (voice-over): Even though Russians will control much of Mir's reentry, and its target is huge -- 380,000 square miles of unpopulated south Pacific waters -- no manmade object this big has ever come down before. So what are the chances it could land on your head?

COL. NORMAN BLACK, U.S. SPACE COMMAND: I'll say two point zero billion chance to one that you're going to get struck by this thing.

KELLAN: Odds are, pieces of the station will rain down, far from land and from populated areas. And according to its operators, Mir is carrying no hazardous materials. Still, aiming the 140-ton station is no easy task.

JOHN LOGSDON, GEORGE WASHINGTON UNIVERSITY: The odds are it's going to be OK, but the odds aren't 100 percent. There is some risk in this.

KELLAN: Of the many variables, Mir's orbital path.

LOGSDON: The orbit it has carries it over 85 percent of the world's population, over most of the major cities of the world except Moscow.

KELLAN: Some people in Japan don't like the sound of that. Mir's final orbit, if everything goes right, will pass over the Pacific rim.

UNIDENTIFIED FEMALE (through translator): Of course I'm worried. There's no assurance that it won't drop here.

UNIDENTIFIED MALE (through translator): Well, the Mir has to fall somewhere. There's not much we can do about it.

KELLAN: In Australia, you can even purchase space debris insurance. In 1979, NASA's Skylab missed its mark and pieces of Western Australia.

(on camera): Russian and U.S. official downplay the worry, saying since 1957, there have been more than 17,000 pieces of space junk that have fallen to Earth, with no reported injuries. But this time, they say, there's no margin for error.

(voice-over): Here's what could go wrong. If the rocket engine guiding Mir into the south Pacific quits halfway through its burn, debris could strike parts of Europe. If the engine quits even sooner, Mir could stay in orbit a lot longer, landing anywhere. Who's keeping track of its path? BRUCE BAUGHMAN, FEMA: We have a direct line with NORAD and U.S. space command.

KELLAN: FEMA has a plan of action, ready to go in the event it got word that debris was headed toward the U.S. It would put out a warning similar to those used to warn of severe weather. Once it starts coming down, you'll have less than an hour to react.

BAUGHMAN: I would say that it's probably a low probability. You know, the best thing to do is keep alert, listen, and if it looks like it's going to hit somewhere, we'll get the warning out to everybody, and then I think they should take whatever appropriate action that their local government recommends.

KELLAN: The size of the pieces, or how many will hit Earth, no one can predict. Specialists say it's like skipping rocks on water. You can aim it, but you can't pinpoint exactly where it's going to land.

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KELLAN: When we come back, what's holding up the widespread use of HDTV?

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KELLAN: U.S. broadcasters have five more years to switch over to digital television. When that happens, all of us will have to buy either new digital TV sets or set-top boxes that make our old sets capable of receiving a digital signal. In return, we'll get sharper pictures and richer sound.

David George returns with a status report on the transition.

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DAVID GEORGE, CNN CORRESPONDENT (voice-over): With the right kind of TV set, people in Raleigh, North Carolina can watch the clearest, sharpest, best-sounding television news broadcasts in the country. WRAL-TV is the first station to offer local news in HDTV, high definition television.

JAMES GRIFFIN, WRAL STATION MANAGER: The experience that the viewer gets in high definition television, both video and with sound is just extraordinary.

GEORGE: But so far relatively few Americans have even seen HDTV. Fewer than 200 of the country's 1,600 TV stations have spent the upwards of $2 million it costs to go digital. With few buyers, digital sets remain expensive.

That's in marked contrast to Great Britain, where digital receivers -- with their wide, theater-like screens -- are found in 30 percent of homes. Critics say the digital TV technical standard used in England and 40 other countries is superior to the one used in the United States. MARK HYMAN, SINCLAIR BROADCASTING: I barely rotated the antenna 15 degrees before the picture was lost.

GEORGE: Sinclair Broadcasting, owner and operator of 62 TV stations nationwide, says the current U.S. digital standard is so flawed, sets that use antennas might not be able to pick it up.

EDDIE FRITTS, NATIONAL ASSOCIATION OF BROADCASTERS: The problem with not being able to receive an over-the-air signal is that everyone who has a television set that uses an antenna as opposed to using cable or satellite, may never see broadcast television.

GEORGE: Sinclair is calling for more technical tests, but the nation's broadcasters seem to have made up their minds.

UNIDENTIFIED MALE: The industry has decided. We've selected a standard for free over-the-air television and we're moving forward.

GEORGE: But are things moving fast enough to meet that 2006 deadline?

GRIFFIN: I think that's probably a little too ambitious. It certainly is, considering how slow the industry is moving in terms of providing the service.

GEORGE: So, few people watch HDTV because in most of the country there isn't much on. Most broadcasters aren't rushing to convert to digital because few people are watching. It is a digital dilemma.

David George, CNN, Raleigh, North Carolina.

(END VIDEOTAPE)

KELLAN: Thanks, David. OK, now we'd like to hear your comments on our show. You can e-mail us at scitechweek@cnn.com. We can't promise to answer every e-mail, but somebody will definitely read it. And we really appreciate all you comments so far.

Coming up, a project that could change our ideas about how long humans have lived in North America.

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KELLAN: Who do you call if you want to find something that's lost on the bottom of the ocean? Well, there are just a few companies that can do that kind of search.

CNN's Elaine Quijano reports on one of them.

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STEVEN SAINT-AMOUR, R.O.V. SPECIALIST: In the next 20 years, whatever we want to find can be found.

ELAINE QUIJANO, CNN CORRESPONDENT (voice-over): Including a 2,000-year-old Greek shipping vessel, found off the coast of Cyprus. A Maryland-based underseas exploration company made that discovery and many more.

UNIDENTIFIED MALE: We come around 15 degrees 4035, over.

QUIJANO: For 15 years, the Nauticus corporation has scoured the ocean floor looking for sunken objects: Ship wrecks, submarines, even downed planes.

THOMAS DETTWEILER, EXPEDITION LEADER: If you want it back, this is the only way you're going to get it.

QUIJANO: But to get it, researchers spend months and sometimes years narrowing down a search area before even catching a glimpse of the ocean.

Once at sea, the search begins by dropping sonar equipment into the water and dragging it along the ocean bottom.

SAINT-AMOUR: We call it mowing the lawn, we just have to keep going path after path after path for day after day.

QUIJANO (on camera): After they find their target, the operation shifts here to this control room where a pilot uses this joystick to control the remote-operated vehicle and identify what they found.

DETTWEILER: If there's no other means of doing that, divers are really only good to about 200 feet on a practical sense.

QUIJANO (voice-over): Worldwide, less than 10 companies do this type of exploration, but each day advances in technology open up a sea of possibilities, and soon many more sunken treasures could be discovered.

For SCIENCE & TECHNOLOGY WEEK, I am Elaine Quijano.

(END VIDEOTAPE)

KELLAN: When did the first humans arrive in North America? Well, the current theory suggest a group called the Clovis people arrived around 11,500 years ago. But there are hints out there of an earlier human presence, and archaeologists are trying to track them down.

Tony Clark reports.

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TONY CLARK, CNN CORRESPONDENT (voice-over): This peaceful, shady cove, bubbling with fresh water springs, nestled between limestone hills and low flat-lying prairie was, archaeologists say, a frequent stopping place for perhaps the first humans to inhabit North America.

MICHAEL COLLINS, UNIVERSITY OF TEXAS: These little flat spots were here in the past. They would dry out in the dry months when the water table went down, and this would just be a nice, flat, little, grassy, shady spot, just ideal for camping. CLARK: The conventional theory is humans first came to the Americas across a land bridge from Asia about 11,500 years ago, the so-called Clovis people.

But the discovery of a site 1,000 years older in South America has raised questions about that theory, and started archaeologist Michael Collins on a quest to find evidence of pre-Clovis people in North America.

COLLINS: We see hints, whispers that maybe there are some earlier cultural remains there, can't say if for sure yet.

CLARK: What Collins has found is an artifact-rich site where Clovis people apparently returned again and again.

COLLINS: Which is different than the usual idea of nomadism, where for a week or so they were here and then they would pick up, and the next night when they came home, it was at another place, and stay there for a week or so, and then move on.

CLARK: How do archaeologists know Clovis people were here?

DAVID MELTZER, SOUTHERN METHODIST UNIVERSITY: The Clovis occupation is marked by these very, very distinctive projectile points or spear points.

CLARK: And one of the best materials for making those spear points is the stone found at this site.

MICHAEL EDWARDS, TEXAS A&M UNIVERSITY: So what they come to the site and they find the raw material, which was the Edwards chert, they would then flake this down to various stages, you know, to the point where eventually they produced something like this.

CLARK: The Texas site has also provided examples of the ingenuity of the Clovis people, like this long serrated stone.

COLLINS: The wear that shows up here under high power magnification can only be produced by cutting meat. This is the original serrated steak knife, maybe for mammoth stakes, I don't know.

CLARK: Also found: stone etchings that scientists believe must have been done by people. Last month, Marty Fransell (ph) found three.

UNIDENTIFIED FEMALE: You sit and look at it and think, yeah, that is exactly what it is.

CLARK: Yet, the thing Collins wants most find, continues to elude him.

COLLINS: Before our investigation of that site ends, we have to know as surely as we can whether there is, or is not, evidence for pre-Clovis at that site.

CLARK: And if there is, such a finding could rewrite history. For SCIENCE & TECHNOLOGY WEEK, I'm Tony Clark.

(END VIDEOTAPE)

KELLAN: Stay tuned. Thanks for joining us. I'm Ann Kellan.

Next week: protecting the wildlife riches of a vast Brazilian wetland, a new approach is designed to please both conservationists and land owners. That's coming up on the next SCIENCE & TECHNOLOGY WEEK. We'll see you then.

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