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MUSIC: "Our World" theme
Straight ahead on "Our World" ... Just eight planets now in the Solar System, say astronomers, as a new definition leaves out Pluto ... a new way to get stem cells ... and how demographic trends are shaping our world ...
HAUB: "'Listen! We can't find workers. We haven't had enough babies and now we can't find workers.' So they will have to have to come from some place and that's going to have to come from outside the country."
Those stories, ocean dead zones, and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Pluto — since 1930 the ninth planet in our Solar System — was demoted this week. The International Astronomical Union, which gets to decide these things, voted Thursday on a new definition of a planet, and Pluto did not make the cut.
Meeting in Prague, the astronomers agreed that a planet is something that orbits the Sun, is big enough that its gravity has pulled it into a spherical shape, and has swept its orbit clear of other objects.
That last part is what doomed Pluto, which orbits among numerous other bodies known as Trans-Neptunian Objects.
Also, a planet cannot be a satellite of another body.
BINZEL: "A new definition was necessary because astronomers are discovering many, many Pluto-like objects out in the outer Solar System, and we simply needed to know what to call them."
Prof. Richard Binzel of the Massachusetts Institute of Technology was on the committee that had drafted a definition that would have included Pluto and, potentially, many other objects as planets.
Binzel's earlier definition, which he explained here on "Our World" last week, would have also embraced the asteroid Ceres, Pluto's own moon, Charon, and a recently-discovered object officially called 2003 UB 313, but widely known as Xena, which was hailed at the time as a 10th planet.
PENNER: "Good evening, I'm Gloria Penner. Astronomers at Palomar Observatory have discovered an object they believe is the 10th planet in our Solar System. ..."
There was a lot of media attention last year when astronomers in California announced the discovery by Mike Brown and his colleagues. But even though his discovery will join Pluto as a second-tier dwarf planet, Brown says the new classification makes sense.
BROWN: "If you started from scratch, and you looked at the Solar System, if you were flying in from Outer Space, you would very quickly realize that there are eight really large objects in the Solar System, and you would put those into one category and use one word to describe them, whatever your world would be. All of the other objects in the Solar System are much smaller. So it's very clear that from any point of vies, the eight planets now are these special objects."
The new planet definition effectively divides Solar System objects into three groups: planets, of which there are now eight; dwarf planets, a group that now includes Pluto; and small Solar System bodies — asteroids and the like.
The terminology is, perhaps, a bit confusing. Dwarf planets are a separate category, not a subcategory of planets.
The definition applies only to our Solar System, and doesn't deal with the increasingly numerous objects known to orbit around distant stars.
The decision to strip Pluto of its status as a full-fledged planet comes at an awkward time for school teachers, as the academic year is just beginning. Textbooks already printed will continue to refer to nine planets of the Solar System. But high school physics teacher John Whitsett, who is the president elect of the National Science Teachers Association, says this week's decision provides what educators like to call a "teachable moment."
WHITSETT: "The real positive piece of this is, it becomes a point where teachers can then really demonstrate that science is constantly changing, and that it is not facts, that it's a problem-solving process and that we're constantly having to modify our body of knowledge based upon the information that we come up with later."
The final word goes to British astronomer Michael Rowan-Robinson. During discussion before Thursday's vote, he stressed that the focus should not be on the label attached to any one object in the Solar System.
ROWAN-ROBSINSON: "We have to put everything in a positive light, that we've learnt new things, that there are new objects being discovered. So I think we all, whatever the past history of this process, we have to support this motion overwhelmingly, I think, and then we have to go away and sell it in a very positive way. The glass is filling. The fact that Pluto's being demoted is not so important."
A different space story, now. Astronomers say they have proven the existence of dark matter, an elusive form of matter believed to be much more abundant in the universe than the ordinary stuff we can see. VOA's David McAlary reports that detection came when the scientists observed two massive clusters of galaxies colliding.
McALARY: Until now, dark matter was just a hypothesis. It was first proposed more than 70 years ago to explain why some galaxies that moved through space at an unusually rapid speed did not fly apart. Scientists suggested that some unseen type of matter exerted enough gravitational pull to keep them together.
But University of Arizona astronomer Douglas Clowe says the notion of unseen matter has been discomforting.
CLOWE: "Astronomers have long been in the slightly embarrassing position of having to explain their observations using something that we didn't know actually existed."
McALARY: But that has changed as the result of work Clowe and colleagues have done with the U.S. space agency's orbiting Chandra x-ray telescope. They have witnessed the collision of two massive clusters of galaxies, an impact so great that it has split normal and dark matter apart. This made it easier for them to detect dark matter by measuring its gravitational force apart from the gravity of the normal, observable matter in the stars and hot gases of the clusters.
CLOWE: "This provides the first direct proof that dark matter must exist and must make up the majority of the matter in the universe."
McALARY: The two galaxy clusters passed through each other at an incredible speed of 16 million kilometers per hour. As they did, the bulk of the luminous matter in the two clusters, which is in the form of hot gases, bumped into each other and slowed down. But the dark matter sailed ahead because it does not interact with normal matter the same way.
The researchers could tell the dark matter was there because the Hubble Space Telescope and large ground telescopes showed that its huge gravitational force bent light coming from distant objects behind it. This distortion, called gravitational lensing, magnified the objects, making them appear larger than if dark matter's gravity had been absent.
CARROLL: "The great news about this is that it is the once and for all the case that you can say dark matter does exist."
McALARY: This is Sean Carroll, a cosmologist at the University of Chicago who was not involved in the observations. He says particle physics laboratories around the world are trying to capture dark matter in an effort to determine its properties.
CARROLL: "So there absolutely is a new particle that physicists get to go out there and find. That's great news because it tells theorists what to think about -- to think about models for dark matter -- and experimentalists what to do to go out there and look for that particle."
McALARY: Before this latest finding, some astronomers had proposed an alternative to dark matter. They suggested that ordinary matter's gravity might be stronger on the massive scale of galaxies and galaxy clusters. But Douglas Clowe says the new work shows that gravity's force is the same everywhere. David McAlary, VOA News, Washington
Scientists at a U.S. biotechnology company have announced a new method of extracting stem cells from an embryo so as not to damage the embryo.
The new procedure was developed by Robert Lanza and his colleagues at Advanced Cell Technology.
LANZA: "We've tested these cells in various animal models and shown that the differentiated replacement cells that we have generated are actually functional, and again we have also studied these, and we have shown that these cells appear to be normal in all respects."
Stem cells are at a primitive stage of development where they have the potential to be transformed into any kind of cell in the body. Many researchers say they could be used as a treatment for Parkinson's, Alzheimer's and other conditions.
Lanza's paper was published Thursday in the journal Nature. In a Nature podcast, he described the procedure, which is similar to a technique used to test for genetic disorders in in vitro fertilization.
Until now, embryonic stem cells were removed using a process that destroyed the embryo. That created ethnical concerns for some, including the Bush administration, which has imposed severe limitations on stem cell research, despite the potential benefits.
Lanza says that the embryos used in his lab went on to develop normally, despite having a cell extracted at a very early stage.
LANZA: "We have shown that we cannot only generate stem cells without destroying the embryo, but that that remaining embryo also has the potential to go on to create a healthy hatching blastocyst."
That assurance, however, seems unlikely to end the debate surrounding the use of embryonic stem cells.
Time again for our Website of the Week, when we showcase interesting and innovative online destinations. This week it's a site that uses an colorful interface to help you learn about the toxic risks in everyday life, and how you can protect yourself.
SZCZUR: "Tox Town is a website about commonly-encountered toxic substances, health and environment, and it illustrates where there are everyday locations where you might find toxic chemicals, and also it will point out some of the impacts associated with the environmental hazards."
That's Marti Szczur of the National Library of Medicine, which produces Tox Town at toxtown.nlm.nih.gov.
Tox Town presents cartoon-like pictures of a city, a farm and other environments, with lots of features to click on — such as schools and rivers and factories — and get links to possible hazards, as well as related issues.
The links include resources, such as government health and safety agencies. And since Tox Town is produced by the National Library of Medicine, it assures the high quality of the information.
SZCZUR: "And as a library we actually have gone in and very carefully selected some of the resources that would be the most useful and are highly reliable."
Take a walk along a city street in Tox Town, for example. There's a sandwich shop, with information about food safety and second-hand smoke, and a hair salon, where the dangers include a variety of toxic chemicals. Marti Szczur suggested stopping at the dental office on the same block.
SZCZUR: There's a dentist which, when you roll over it — they all have sound effects and the one, when you roll over the dentist, gives you that horrible drill sound, but it entices you to go in and take a look at information related to chemicals in a dental office and the lab."
Tox Town has a full range of everyday toxic hazards, and advice on how to avoid them, at toxtown.nlm.nih.gov, or get the link from our site, voanews.com-slash-ourworld.
MUSIC: "Bagpipe Blues" - Rufus Harley (1936-2006)
And you're listening to VOA's non-toxic science and technology magazine, Our World. I'm Art Chimes in Washington.
The world population reached 6.6 billion this year, up from six billion in 1999. By 2025, researchers expect nearly eight billion people will be living on the planet. And, as VOA's Rosanne Skirble reports, 99 percent of those new inhabitants will be in developing countries.
SKIRBLE: Three million migrants are moving from poor countries to wealthier ones each year, and increasingly, their destination is a neighboring country. Those statistics come from an annual demographic snapshot of global population numbers and trends, produced by the Population Reference Bureau.
Rachel Nugent, an economist with the research group, points to the population shifts that are occurring now from Bangladesh to Indian or from India, Egypt and Yemen to the Persian Gulf. She says people are moving within the developing world for the same reasons they migrate to wealthier nations.
NUGENT: "People from very poor countries going to less poor countries, people fleeing wars and conflict, people responding to population pressures because in some countries still they are very densely populated, and they often have high population growth. Those people need to go somewhere, and they often are going looking for jobs."
SKIRBLE: Migration from Guatemala to Mexico is one such example.
NUGENT: "And many Guatemalans go to Mexico, probably 25,000 a year that stay and 100,000 a year that go back and forth. And that is a pretty high proportion of the Guatemalan population."
SKIRBLE: The United Nations projects that by 2050, the population of Europe — now at 750 million — will fall by 75 million. And Japan — home to 128 million people — will lose 16 million. Population Reference Bureau senior demographer and survey author Carl Haub says a shrinking population is a threat to economic health.
HAUB: "The number of young people in many European countries is half the size of their parents' generation. So what you see today are the corporations, the health care system saying, 'Listen! We can't find workers. We haven't had enough babies and now we can't find workers.' So they will have to have to come from some place and that's going to have to come from outside the country."
SKIRBLE: The World Population Data Sheet also notes that although the prevalence of HIV/AIDS is lower than previously estimated, it remains catastrophically high in some sub-Saharan African countries. There is also disappointing news about efforts to increase access to sanitation and safe drinking water, as called for by the United Nations. Rachel Nugent says that issue is one of several new environmental indicators in this year's survey.
NUGENT: "We can see that in rural areas in the developing world and in some parts of Africa and Asia we don't have high rates of access to sanitation. That needs to be addressed. The other one is the percentage of land that is protected, which means protected for wildlife, for plant biodiversity, protected for the indigenous and other populations that live nearby."
SKIRBLE: Report author Carl Haub says the easy-to-read World Population Data Sheet is designed to raise awareness among the public — and public officials.
HAUB: "The numbers are there, and it's always a question of whether politicians will pay any attention to them. I think the some of the problems with making the projections [is that] they are too far in the future. And, a politician probably doesn't want to look past the next election."
SKIRBLE: Haub says that is something that they [the politicians] will have to get over. I'm Rosanne Skirble.
The U.S. ocean research agency NOAA has added four deep-sea sensors off the Alaska coast to its tsunami warning network.
The four buoys are part of the DART system — DART for Deep-ocean Assessment and Reporting of Tsunamis. It's designed to give advance warning of tsunamis before they reach shore.
The DART network is now about half-finished. The full system will include 39 buoys in the Caribbean, the Atlantic, and around the Pacific rim.
Tsunamis are caused by undersea earthquakes. A global seismic network can pick up signs of an earthquake. But not all undersea quakes produce tsunamis. The National Weather Service regional director in Alaska, Laura Furgione, says that's where the DART buoys come in.
FURGIONE: "So the warning's likely going to already be out prior to the DART buoy giving us the information, if there has been a tsunami or not, so again this is one piece of the puzzle. We have to have the tsunami warning system in place so we can get the message out. The DART buoys allow us to then verify if there has been a tsunami or not, and possibly the height of the wave."
Furgione says the DART system is especially designed to give warning of tsunamis that can travel thousands of kilometers, triggered, for example, by an earthquake in Alaska.
FURGIONE: "And we can have hours of advance warning before it hits the Hawaiian islands and then on down into the Southern Pacific."
Furgione stressed that while the technical warning system is important, getting the word out when a tsunami is detected won't save lives unless people know what to do - which is basically, get to high ground inland, as quickly as possible.
Scientists just back from a research cruise are reporting "a wave of death" in the Pacific Ocean off America's Northwest Coast. Underwater sea life is literally suffocating from lack of dissolved oxygen. And recently, beachcombers in the region have reported several unusual fish kills. As Tom Banse reports from the coastal village of Taholah, in Washington State, scientists are not sure what to make of the phenomenon.
BANSE: Researchers could scarcely believe the most recent oxygen readings they recorded in waters off the central Oregon Coast. They're near zero a short distance off shore. So scientists deployed an underwater camera to look with their own eyes.
CHAN: "It was really quite shocking, to be honest. We were all huddled in the cabin of the research vessel staring at multiple video monitors."
BANSE: Oregon State University marine ecologist Francis Chan describes evidence of a "silent killer."
CHAN: "Shapes started coming into focus and we were seeing what looked to be dead worms -- fairly good sized worms. Then we started coming upon piles and piles of dead Dungeness crabs. We didn't see one living fish all day long."
TEXT: This is the fifth year in a row a so-called "dead zone" has appeared off the Oregon Coast. But Chan says this one appears to be more severe and more extensive than any before.
At the end of July, crabbers off the Washington coast started pulling up pots of dead crabs. Then thousands of dead fish washed ashore at the Quinault Indian reservation, even further north.
SHARP: "I grew up in this village and community and I don't ever recall seeing this sort of thing on the beach. It was very disturbing to see that much on our coastline."
BANSE: Quinault Nation president Fawn Sharp says tribal crabbers and beachcombers noticed two waves of fish kills. But now the ocean off the coastal reservation seems back to normal.
SHARP: "We were hoping that is was just a short-term, not a long-term problem or phenomenon that's killing our seafood. But now it's gone. So hopefully, the good Lord willing, it's run its course."
BANSE: Obviously, scientists have a major mystery to unravel.
BRANCATO: "Part of the picture we're missing, is how long has this been going on, how often does it happen, and how much of the population does it affect. It might be that it's been occurring over time and the populations do fine with this periodic occurrence."
BANSE: Marine biologist Mary Sue Brancato monitors coastal beaches for the Olympic Coast National Marine Sanctuary. She's kneeling on the sand in bright yellow rubber overalls counting tiny creatures on the beach.
BRANCATO: "Do you have anything to record yet?"
BANSE: Seasonal winds drive some coastal currents. When the wind slackens or changes direction, it can disrupt the water circulation. Then you have the potential for an underwater 'dead zone.' Oregon State's researchers suspect that the disrupted ocean currents could be a sign of global warming. But for now, Brancato of the Marine Sanctuary remains cautious.
BRANCATO: "I think that would be fascinating to understand better and I think over the long-term that is exactly what we want to do."
BANSE: Oregon marine ecologist Francis Chan notes the "dead zones" vary in size and severity. He says nothing can be done about the phenomenon except study it.
CHAN: "This is really an immense event. It's sort of like a heat wave. There's very little you can do but ride it out."
TEXT: Mostly it's scientists riding this wave in the Pacific Northwest. Elsewhere, the ripples have touched more people, more broadly. For example, dead zone occur off Namibia in the South Atlantic, off Peru in the Pacific and west of India in the Arabian Sea. In those areas, fishermen face reduced catches — and economic losses — when fish and prawns flee the oxygen-starved waters. Then the impact extends far beyond the water line. For Our World, I'm Tom Banse in Taholah, Washington.
MUSIC: "Our World" theme
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Voice of America
Washington, DC 20237 USA.
Faith Lapidus is our editor this week. Eva Nenicka is our technical director. And this is Art Chimes, inviting you to join us online at voanews.com/ourworld or on your radio next Saturday and Sunday as we check out the latest in science and technology...in Our World.