SCIENCE IN THE NEWS(在线收听

SCIENCE IN THE NEWS
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Broadcast: Tuesday, July 13, 2004

VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And I'm Sarah Long. Coming up: scientists demonstrate a possible way to make faster computers in the future.

VOICE ONE:

What to do about some ancient Native American ruins.

VOICE TWO:

And the World Health Organization urges people to be careful with traditional medicines.

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VOICE ONE:

Scientists have made a big move in the transport of matter. Two teams say they transported the properties of one atom to another without the use of any physical link. The process is called teleportation.

 
They made it look easy.
Back in the nineteen-sixties, the "Star Trek" television series made the process look easy. There, you stepped into a transporter. Your body de-materialized. Then it came back together someplace else. To return, you could simply radio the ship's chief engineer and say: "Beam me up, Scotty!"

In real life, nothing about teleportation is simple, not even the scientific description. In the minds of physicists, to teleport is to move quantum states between atoms. The quantum state of an atom describes its physical properties. These are properties like energy, magnetic field and movement.

Scientists have demonstrated teleportation with particles of light. But this was the first demonstration with atoms.

VOICE TWO:

The two teams that did the experiments are from the United States and Austria. The American team is from the National Institute of Standards and Technology in Boulder, Colorado. The Austrians work at the University of Innsbruck. The two teams worked independently. But they jointly published their findings in the magazine Nature.

The scientists used different kinds of atoms in their experiments. The American team used laser beams to teleport the properties of an atom of beryllium, a kind of metal. The team in Austria used a calcium atom. All the atoms were ions. This means they had an electric charge.

In both cases the teams used three ions. We will call them A, B and C. The teams set up magnetic traps that held the ions in place. Then the scientists began a process called entanglement. Entanglement links the quantum states of atoms.

The scientists linked A with B. They also linked A with C. These relationships created a system. Any change to one ion produced a change in the others. The goal was to teleport the properties of B to C. The scientists did this in three steps. These were entanglement, measurement of A and B and correction to C to permit the teleportation to happen.

VOICE ONE

So ion C took on the properties of ion B. But not completely.

This is one reason you will not be traveling by teleportation anytime soon. Humans would probably want a guarantee of one-hundred percent reproduction at the other end. And a human being would mean a lot more information to gather and send than a single atom.

The scientists say they cannot imagine such use of teleportation. But their work does offer great possibilities for the future of information technology. It could help in efforts to build a quantum computer. Such a computer would be faster and more powerful than any we now use.

VOICE TWO:

Quantum properties of atoms are not like the world we normally observe. For example, scientists are able to create a special condition where ions can be in two places at once. Ions can also hold information representing more than one number at once.

And scientists have known for many years that two ions can be entangled. Such atoms can be made to affect each other even when they are separated. Albert Einstein had a name for this kind of effect. The great physicist called it "spooky action at a distance."

We talked about teleportation with Laura Ost [OH-st] in the news office at the National Institute of Standards and Technology. She noted that teleportation does not physically move matter. It only moves the properties of one particle to another. This could be faster than physically moving particles inside a device like a quantum computer.

But the only way to teleport is to destroy the particle being teleported. If the particle were not destroyed, then you would be copying. And scientists say there is no copying in the quantum world.

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VOICE ONE:

In the American West, the public has gotten its first look at the ruins of an ancient people who lived in what is now the state of Utah. Officials recently showed reporters the area where the Fremont Indians lived about a thousand years ago.

 
Waldo Wilcox in the remains of an ancient Indian pit house.
A cattle ranch owner named Waldo Wilcox had protected the ruins for the last fifty years. The land was part of his property. He permitted some researchers to visit. But mostly he kept the ruins a secret. Mister Wilcox is now in his seventies. He finally sold the property into the public trust. The state of Utah now owns the land. But Mister Wilcox says he still worries that the ruins will be destroyed or stolen by people who want a piece of history.

The state wants to prevent this and still permit people to learn about the Fremont culture.

The ruins are spread over thousands of hectares of land in the high desert about two-hundred kilometers southeast of Salt Lake City. Only one dirt road leads into the area.

Scientists have found where the Indians stored grain in the sides of mountains. There was still maize inside. They have found arrows used a thousand years ago. They have also found human remains, examples of rock art and pieces of pottery. Fifteen years ago, Mister Wilcox himself discovered the remains of a small village built on an edge of a mountain.

VOICE TWO:

 
Thousand-year-old artwork.
Scientists say the ruins may offer answers to questions about the Fremont Indians. Scientists do know that the people hunted animals and gathered plants for food. But no one knows what happened to them. The Indians left the place now known as Range Creek about eight hundred years ago.

The ruins show that the Fremont Indians built homes from stone. They painted and carved designs in rock walls. They built stone containers for corn and beans.

Waldo Wilcox, the former owner of the land, is not the only one worried about the future of the ancient ruins. Some local Indian leaders want to make sure that tribal ways are honored as the area is studied. They are especially worried about the human remains that have been found.

Utah officials say they do not know how many remains are still at Range Creek. But they say they are sure that Native Americans will be involved in decisions about the future of the area.

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VOICE ONE:

The World Health Organization says people need more information about how to safely use traditional medicines. The W.H.O. now has guidelines to suggest ways for public health officials to develop that information. The health agency is part of the United Nations.

The W.H.O. says up to eighty percent of people in developing countries depend on traditional medicines. More and more people in wealthy countries use them too. But the W.H.O. notes that just because products are natural does not always mean they are safe. It says reports of bad reactions have increased sharply in the last few years.

In China, for example, about ten-thousand harmful drug reactions were reported in two-thousand-two. There were just four-thousand cases reported between nineteen-ninety and nineteen-ninety-nine.

Traditional medicines are made from plants, animal products and minerals. The health agency says they remain largely outside government control.

VOICE TWO:

In most countries, traditional medicines can be purchased without a doctor's order. Sometimes they are prepared by friends or by the patients themselves. The W.H.O. says this situation raises concerns about the quality of treatments and the lack of professional supervision.

Under the new guidelines, traditional healers would have to be skilled. And the public would have to be informed about how and where to report problems.

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VOICE ONE:

SCIENCE IN THE NEWS was written by Caty Weaver, Nancy Steinbach and Jill Moss. Cynthia Kirk was our producer. This is Bob Doughty.

VOICE TWO:

And this is Sarah Long. Join us again next week for more news about science, in Special English, on the Voice of America.

  原文地址:http://www.tingroom.com/voa/4/science/17790.html