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MUSIC: Our World themeStraight ahead on "Our World" ... another setback for the Space Shuttle ... Lions versus people in Tanzania ... and the telescopes of Mauna Kea..
Astronomy in paradise, sex and the computer science graduate, and more... I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Officials with the U.S. space agency, NASA, said Thursday it will probably be March 2006 before the space shuttle is launched again.
Earlier, they said the shuttle might go into space as soon as next month.
The problem is that large pieces of foam insulation broke off the shuttle's big external fuel tank during Discovery's launch in late July. There was no significant damage, but it was a major disappointment for NASA. A similar piece of flyaway foam damaged the shuttle Columbia in 2003, causing the spacecraft to burn up on its return to Earth.
After two and a half years, NASA thought it had fixed the problem with the foam insulation.
The space agency is still committed to finish construction of the international space station and to retire the shuttle fleet by 2010. At a news conference Thursday, NASA chief Michael Griffin said the aim is to view each shuttle mission, each launch, as a process.
GRIFFIN: "We're going to work each mission through the process, being as careful as we can, as deliberate as we can, but with the intent, of course, to go fly. We're going to use the shuttle system between now and then to assemble the space station. We believe that absent major problems, we believe that we can essentially complete the assembly of the space station with the shuttle fleet in the time that we have remaining. And that's what we're going to try to do."
Mr. Griffin's comments came one day after the space agency's management and processes were highly criticized.
The critics were members of the Stafford-Covey Task Group, an independent panel charged with advising NASA on the resumption of human space flight. Their final report, released Wednesday, concludes that NASA has done much to reduce the risk of going into space, although shuttle flights, it says, will always be risky.
But the Task Group's minority report is highly critical of NASA's management. It cites weak leadership, failure to establish and enforce adequate performance standards, the use of presentation graphics instead of proper engineering reports, and a pervasive lack of accountability. In its summary, the minority report says "NASA leadership often did not set the proper tone, establish achievable expectations, or hold people accountable for meeting them."
A new international study of computer science degrees earned by women shows large disparities from country to country, with some surprising results.
Women in all 21 industrialized countries surveyed were under-represented among university graduates in computer science. But if you think you can guess which countries would have the most women getting computer science degrees, you might be surprised at some of the leaders in female participation, including Turkey, South Korea and Ireland.
As expected, women were generally over-represented in traditionally-female disciplines such as education and generally under-represented in engineering and the sciences. Sex segregation persists, even where legal barriers to study have been eliminated, leading the study's sociologist authors to look for other explanations.
One interesting discovery, says co-author Maria Charles of the University of California, San Diego, is that girls may be more likely to pursue non-traditional careers in countries where they don't have a choice.
CHARLES: "Some of the countries where women are best represented in these historically male-type fields are countries where there are requirements that both boys and girls take math up until, you know, the 11th or 12th grade level. Or there are tests that are carried out, and those individuals who perform at a given level on the test are tracked into these math or technical fields, irrespective of their gender."
It's precisely that lack of choice, she says, that helps account for the higher representation of women in computer science programs in Ireland, Turkey and South Korea.
When young women do have greater choice, Professor Charles says, social pressures often lead them to choose a more traditional degree program rather than the challenging and well-paid computer science field. And that choice can affect the nation as a whole.
CHARLES: "There is, in many different countries, a lot of concern about the availability of scientists -- computer science experts, engineers, natural scientists. So there is, in that sense, a concern about just more individuals in these fields. And an obvious pool of individuals is women, who are, at least in the most industrialized countries, in many cases over-represented in higher education."
Maria Charles and her co-author, Karen Bradley of Western Washington University, presented their study at a meeting of the American Sociological Association.
A growing number of people in Tanzania are being attacked by lions, resulting in the stepped-up killing of these endangered animals. Wildlife researchers discuss the problem this week in the journal Nature. More from VOA's Jessica Berman.
BERMAN: In the past decade, there has been an upward trend in Tanzania in the number of rural people being killed by lions, according to Craig Packer, a professor at the Department of Ecology, Evolution and Behavior at the University of Minnesota.
PACKER: "In the early 1990s, there might be an average of 30 or 40 cases per year, and now we are well above 100. And we think that ultimately this has to do with the fact that the human population in Tanzania has grown so much that there just far fewer resources for the wild lions that live outside the [conservation] parks."
BERMAN: The country's population has grown rapidly, from 23 million in 1988 to more than 34 million in 2002. Mr. Packer says this has reduced the amount of land and natural prey that is available to lions in the wild.
In the study reported in Nature, Mr. Packer and colleagues looked at the distribution of man-eating attacks, which appear to occur most often during the harvest period between March and May. An analysis showed that half of the attacks occurred in four districts in southern Tanzania, between the capital, Dar es Salaam, to the border with Mozambique.
Mr. Packer says in those areas there is very little natural prey for the lions, but heavy populations of bushpigs, animals that are crop pests.
Mr. Packer says the bushpigs pillage the crops at night. So, it is common for farmers wanting to protect their fields to sleep in them. Unfortunately, that puts them at risk for being attacked by lions.
PACKER: "Once the lions learn that they can take human flesh for food, they can become very aggressive and they can become very adventurous. And instead of just taking victims from agricultural fields, they will actually go into villages; they will break into peoples' houses; they will pull people out of bed."
BERMAN: Once there has been an attack, lions are often hunted down and killed.
Tanzania has the largest number of lions in the world, and researchers propose protecting some of the country's dwindling population of 12,000 cats by keeping bushpigs away from crops.
One strategy includes protecting fields by digging ditches that the bushpigs cannot cross.
Researchers also note that people hunted by lions are usually alone, so they should try to stay together in groups.
The investigators say the safety and well-being of humans come first. But they conclude resolving the conflict between humans and lions must be a top priority if animal conservation efforts are to be successful. Jessica Berman, VOA News, Washington.
Time again for Our World's Website of the Week, and this week's offering is really several websites all rolled up in one. The ECHO project uses the Internet to preserve and present the history of science and technology, and to serve as a laboratory for innovation in a very new field.
ECHO's Dan Cohen says the project has several missions, including —
COHEN: "Providing a centralized resource for studying the history of science and technology online. So we have a research center that catalogues, annotates and reviews more than 5,000 sites on the history of science, technology and industry. We also have a collecting center, which is an aid to those who would like to collect the recent history of science, technology or any other topic online."
The site also includes a Tools section, with a variety of software products to help create an attractive and engaging website.
You could spend hours browsing through those 5,000 or so science history websites listed at echo.gmu.edu. Many are prepared by universities, museums, and other established institutions. But others are the online creations of self-declared specialists with no formal training or credentials in history. Dan Cohen is a history professor at George Mason University, where ECHO is located. And he says some academic historians view that sort of democratizing of history as a threat. But the historians at ECHO don't see it that way.
COHEN: "We like the idea of the ability of anyone to post something online. It's meant, for instance, in the case of something like Wikipedia that there are historical topics that are covered in Wikipedia that no historian in academia is willing to cover. And yet these are topics that are covered online."
Wikipedia.org is a user-written encyclopedia that we featured here on Our World, in one of our very first Websites of the Week.
To help users get involved in building their own history-related websites, ECHO provides a variety of web-based tools.
COHEN: "So for instance to collect history online we have something called the survey builder. We have something called the web scrapbook that allows you to store all kinds of things -- images, text, web pages. We have a poll builder that allows you to add online polls to your site. And we have a note-taking application called Scribe."
So whether you just want a well-indexed guide to some of the Internet's most interesting websites on the history of science, or whether you want to build your own website, surf on over to echo.gmu.edu, or get the link from our site, voanews.com/ourworld.
MUSIC: Roy Eldridge: "Little Sir Echo"
You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.
Scientists are one step closer to more accurate forecasts of space weather. It's a different kind of weather than we're used to here on earth, but it's still weather. Magnetic storms on the sun can spew highly-charged radiation out into space, with damaging consequences on earth. As we hear from VOA's David McAlary, data from two satellites are helping scientists do a better job of predicting potentially dangerous changes in space weather.
McALARY: At one time, scientists thought the space between Earth and Sun was a vacuum. But we now know that the sun fills it with gusts of hot, electrically charged atomic particles called the solar wind. Sometimes this wind blows hard. When the Sun's outer layer is very active, it hurls nearly one-third of its gaseous matter outward at supersonic speeds.
The U.S. government's oceans and atmosphere agency, NOAA, has a Space Environment Center to monitor these discharges. The center's director, Ernest Hildner, says intense solar emissions are not dangerous to people on the ground, but can be a hazard to airplane occupants and astronauts. They can also shut down satellites, power networks, communications, and other technical systems.
HILDNER: "When the Sun has a storm, an eruption of plasma and magnetic field, it smacks the Earth's magnetic field and it causes difficulties to our technological systems. That is what we think of as space weather."
McALARY: Scientists have long known that solar storms are generated internally by the sudden release of magnetic energy rising to the surface. Like a tightly twisted rubber band, the Sun's magnetic fields can suddenly snap into a new shape. Researchers have tried to predict solar storms by focusing on these magnetic patterns. But this method is not very reliable because they know that electrical currents must also be present. But how are they linked to magnetic fields to power large flares?
New satellite data have provided answers to U.S. government scientists and colleagues from the aerospace firm Lockheed Martin.
They have revealed that magnetic fields merging at different angles to each other are the most likely to produce a flare. Lockheed Martin physicist Karel Schrijver says this interaction creates more electrical current than normally associated with a magnetic field.
SCHRIJVER: "We learned to recognize that it had to come up in the wrong orientation, off with the alignment of what was already there, twisted, and come up, in fact, in such a way that it suggested to us that the field that came up was itself carrying new electrical currents into the atmosphere."
McALARY: To discover this, Mr. Schrijver and his government colleagues compared magnetic maps of the sun from the U.S.-European SOHO spacecraft with Sun surface images from the American TRACE satellite.
He says scientists can now predict which magnetic fields will turn into solar flares with 90-percent accuracy about two days before an outburst.
McALARY: The findings still do not permit forecasts of precisely when a flare will erupt, only whether one is likely to, much as the buildup of snow on a mountain increases the chance for an avalanche. The director of solar studies at the U.S. space agency, Richard Fisher, says refinement of the research will improve predictions.
FISHER: "This is quite useful for spaceflight operations and flight planning. We have been able to understand where it is likely to have a flare and what the size is likely to be. We can also tell when it is not very likely. This has considerable value."
McALARY: The findings are published in the Astrophysical Journal. David McAlary, VOA News, Washington.
Usually on Our World we present the latest scientific discoveries, or introduce you to scientists talking about their work. This time, we visit a place where scientists do their work ... a dormant volcano in Hawaii that is the world's highest island mountain. With clear, dry and pollution-free air, it's an outstanding place for astronomers to work. VOA's Rosanne Skirble reports paid a visit.
SKIRBLE: Astronomers must compete for observation time on Mauna Kea. Tourists are welcome anytime to hike up the 4,205-meter summit or to join a guided caravan tour that departs from the Mauna Kea Visitors Center, about two-thirds of the way up the peak at 2,800 meters. This is where guide Erik West hands out some basic advise:
WEST: "You do need a 4-wheel drive vehicle and there are some health and safety issues. You cannot have any heart or respiratory problems, be under 16 years of age or have scuba dived in the last 24 hours."
Erik West readies drivers for the trek up.
WEST: "Alright, do you have your vehicle already in 4-wheel drive low? All set to go and you played with your gas tank and got set? Alright."
SKIRBLE: One behind the other, the cars follow a steep gravel road that switches back and forth for during the 45-minute drive. The sedges gradually give way to a barren landscape of lava rock and cinder cones.
As we reach the summit and park our vehicles, the complex of domed observatories suddenly looms like a garden of giant mushrooms across the horizon. Once on top we park. The air up here is cool as we walk toward the buildings, but our guide warns us that the air can also make you sick because it has 40 percent less oxygen than at sea level.
WEST: And, it has varying effects on people. If you start to feel dizzy, nausea, let someone know. We do carry oxygen with us. If you do need oxygen need to have oxygen, you do have to go down. That is the rule. You have to go down if you have to have oxygen.
SKIRBLE: The first large telescope was installed built on Mauna Kea in 1970. Since then, others followed.
WEST: There is a total of 13 groups of observatories. One of them — SMA [Submillimeter Array] — is actually eight different telescopes that operate together. There are 11 different countries that are involved with the telescopes up here and various universities. And over here we have the biggest telescopes — the 10-meter Keck telescopes. And, the reason that they keep getting bigger and bigger as technology allows is that we want to be able to collect as much light as possible up here. So the bigger you are, the more light you can see."
SKIRBLE: The twin Keck One and Keck Two are the world's largest optical and infrared telescopes. Their mirrors are divided into 36 hexagonal segments, which work together as a single piece of reflective glass. During the day Keck One is a sleeping giant of steel beams and silent gears closed inside a protective shell. Erik West says the real action begins at sundown:
WEST: "The dome weighs about 700 tons protecting this thing. Its goes up about 10 stories to the top of the dome and the whole mirror structure is about eight stories tall. The dome will open up and start rotating to where they need it and the mirror rotating to where they are going to be observing. And, throughout the night, if it is following an object, it will be moving very slightly to follow it as it moves across the sky. But there won't be anyone in here generally. They will be in the control rooms staying warm."
SKIRBLE: Over the years, astronomers have discovered new moons around Jupiter, taken pictures that help measure the expansion of the universe and have observed hundreds of small objects orbiting the Sun beyond past the orbit of the planet Neptune. Each movement, each gear, each wheel guiding these massive telescopes is remotely controlled. Astronomers review the data, not from an eyepiece, but from a desktop computer. This is where Rolf Kudritzki likes to work. He is the director of the Institute for Astronomy, which manages Mauna Kea. Rolf Kudritzki says that despite such sophisticated equipment, projects often fail; not every astronomer at Mauna Kea finds what they are looking for.
KUDRITZKI: "Because in modern astronomy we look at things that are barely detectable, extremely faint at the margin of feasibility all the time, because we are just pushing the frontier of our detections further and further away. So it is not always clear that such an observation will be successful."
SKIRBLE: Rolf Kudritzki says that compared to space telescopes, land-based observatories like those atop Hawaii's Mauna Kea mountain provide astronomers with less expensive observing time and a more diverse array of tools for observing the heavens. As we head back down the mountain, Mr. Kudritzki predicts confidently that the Mauna Kea observatories will continue to complement earth orbiting telescopes for many decades to come. So, at least for the foreseeable future, Mr. Kudritzki says, land-based telescopes will continue to play a major observational role in the universe. For now those observations are cheaper and equipment more flexible than those taken from space. I'm Rosanne Skirble.
Finally today, scientists in Singapore have developed a new kind of battery. They say it could be used in home medical test kits used, for example, by diabetics. It should be especially good for urine testing because, in fact, it is powered by urine.
The battery uses paper impregnated with copper chloride, sandwiched between layers of copper and magnesium. Researchers at Singapore's Institute of Bioengineering and Nanotechnology say it will be cheap to make and could be used in disposable devices to monitor health and identify possible kidney or liver disease.
MUSIC: Our World theme
That's our show for this week. We always like to hear from you. Tell us what you like about the program, or what you don't like. Email us at ourworld@voanews.com. Ourworld is all one word. Or the postal address is -
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Our World is edited by Rob Sivak, the editor who never sleeps. Our technical director is Gary Spizler. 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.