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VOA慢速英语-SCIENCE IN THE NEWS - Archeological Dig Area in the

时间:2008-10-16 06:34:57

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(单词翻译)

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty1.

VOICE TWO:
 
Northern Lights seen near Palmer, Alaska last year

And I'm Barbara Klein. On our program this week, we will tell about the mystery of the aurora2 borealis, better known as the Northern Lights. We will also tell about an archeological dig in the southeastern United States. The project continues to surrender secrets of some very early Americans.

(MUSIC)

VOICE ONE:

For many centuries, people have looked with wonder at the Northern Lights. These mysterious lights often brighten the night sky in countries near the North Pole. The Northern Lights are also called the aurora borealis. An aurora is a natural burst of light that can be seen with the unaided eye. An aurora over the South Pole is called the aurora australis, or Southern Lights.

Auroras appear as large areas of moving light. They are often green, red or purple in color. Some auroras can extend across the sky for thousands of kilometers.

VOICE TWO:

Scientists have long known that auroras are caused by a storm of magnetic energy high above the Earth's surface. But scientists have been debating exactly what forces in nature cause these storms to create the colorful lightshows.

Recently, researchers working for the American space agency said they found the answer by using five of the agency's satellites. The researchers say the Sun's and Earth's electromagnetic fields normally move past one another in different directions. But when enough energy builds between the two fields, they separate and reconnect themselves in a new shape.

This reconnection releases a huge amount of electrical current in the Earth's magnetosphere. The researchers say the reconnection happens about one hundred twenty-nine kilometers away from the planet. That is about one third of the distance to the moon.

VOICE ONE:

The five satellites were launched last year as part of the American space agency's THEMIS project. THEMIS is a word the agency uses to represent Time History of Events and Macroscale Interactions During Substorms.

The researchers were able to directly observe the magnetic substorms using both the satellites and twenty ground observatories3. The observatories are in Canada and the American state of Alaska.

Every four days, the satellites lined up half way between the North and South Poles to record observations. Equipment on the ground helped to identify when and where a substorm was forming. Other devices measure the auroral4 light from particles moving along Earth's magnetic field. Their observations of six months ago confirmed that magnetic reconnection leads to substorms.


VOICE TWO:

The researchers say there is still more to be discovered about substorms. The Northern Lights are exciting to watch. However, the forces responsible for them can damage satellites, guidance systems and radio communication. They are also a possible threat to air travelers and astronauts.

Scientists hope that more investigation5 will lead to better methods of predicting substorms, both to protect equipment and lives.

(MUSIC)

VOICE ONE:

You are listening to the VOA Special English program SCIENCE IN THE NEWS. With Barbara Klein, I'm Bob Doughty.

(MUSIC)

VOICE ONE:

A college student recently found two ancient stone objects in the American state of South Carolina. He made the discovery during an archeological dig in an area known as the Topper Site.

The student, Matthew Carey, found the objects just a short distance from each other. They appear to have been buried together. University of South Carolina archeologist Albert Goodyear said the objects could be cutting tools. But he believes they look like the heads of spears or long knives. Mister Goodyear said they seem to be about eleven thousand years old.

Earlier archeological work at the Topper Site may have uncovered evidence of a settlement from as early as fifty thousand years ago.

VOICE TWO:

The Topper Site got its name from a local man. Years ago, David Topper told Mister Goodyear about a place he might find interesting near the Savannah River. A chemical company owns the land. The company lets the scientists work on the huge site each spring. The Topper Site covers an area measuring more than thirty thousand square meters.

Digging begins when the local wild-turkey-hunting season ends. Each May, Albert Goodyear leads volunteers for five weeks in uncovering the site's mysteries. The volunteers are scientists, teachers, students, and anyone else who likes to explore the past. They dig by hand. It is hard, painstaking6 work. But most scientists would say the site is well worth the hard work it requires.

VOICE ONE:

Mister Goodyear first began working near the place that would become the Topper Site in the nineteen eighties. He led a team searching for objects belonging to the Clovis people. Most scientists at the time believed that these people were the first settlers in the Americas.

The name "Clovis" came from an area near Clovis, New Mexico. Evidence of the people was found there. Scientists had long believed that human beings first entered North America across a land bridge from what is now Russia and Alaska. They thought these first Americans arrived about eleven or twelve thousand years ago. But in the late twentieth century, some researchers began to question that theory.

VOICE TWO:

Several discoveries became especially important in disputing the belief. Among the most important ones were findings at the Monte Verde Camp in Chile. Scientists began finding ancient artifacts there beginning in nineteen seventy-six. The artifacts included a piece of meat that had lasted many centuries. It might have been from an ancient animal similar to a modern elephant.

The findings at Monte Verde showed that humans were in South America about thirteen thousand years ago. Experts said that was about one thousand years before the Clovis people could have traveled there.

VOICE ONE:

In nineteen ninety-eight, Mister Goodyear and his team wanted to find more artifacts of the Clovis people. He planned a dig near the Savannah River. But the river had flooded the area he wanted to examine. So he decided7 to start digging nearby.

Today, he remembers how much he regretted the flood. He told V.O.A. that did not want to move his explorations. But the area proved a big surprise. The archeologist described it as the best thing that ever happened to him.

VOICE TWO:

The flood caused Mister Goodyear and his team to dig about a meter deeper than usual for Clovis artifacts. They found evidence of tools and extremely small stone particles or flakes8. The objects appeared older than those made or used by the Clovis people. The objects were found during the last two weeks of the Goodyear team's yearly research project.

Digging at Topper in the following years added to the artifact collection. The scientists found artifacts that appear to have come from times before the Clovis people.

VOICE ONE:

Four years ago, Mister Goodyear and his team found ancient plant material at the Topper Site. Shortly before the work was to end, they discovered black soil. The soil provided charcoal9, a material combining wood and other substances. Charcoal can be tested for age by a process called radiocarbon dating.

Tom Stafford of the Stafford Research Laboratories in Colorado arrived to take pieces of the charcoal. Months later, the test results were announced. They showed that the charcoal could be up to fifty thousand years old.

If correct, it would mean that the first settlement in the Americas took place many years earlier than had been thought. It could also mean settlers lived in North America fifty thousand years ago.

VOICE TWO:

Some experts do not accept that human beings made or used the most ancient objects found at the Topper Site. Some believe that the weather and the ages made these artifacts look like tools. And experts continue to disagree about when North America was settled.

Mister Goodyear and his team plan to continue digging. They hope to find more evidence of very early peoples in America. When next May comes, they will be again excavating10 at the Topper Site.

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS program was written by Jerilyn Watson and Brianna Blake, who also was our producer. I'm Bob Doughty.

VOICE TWO:

And I'm Barbara Klein. You can read and listen to our programs at voaspecialenglish.com. Join us next week for more news about science in VOA Special English.

 


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点击收听单词发音收听单词发音  

1 doughty Jk5zg     
adj.勇猛的,坚强的
参考例句:
  • Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质:脾气倔强,性格刚强。
  • The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。
2 aurora aV9zX     
n.极光
参考例句:
  • The aurora is one of nature's most awesome spectacles.极光是自然界最可畏的奇观之一。
  • Over the polar regions we should see aurora.在极地高空,我们会看到极光。
3 observatories d730b278442c711432218e89314e2a09     
n.天文台,气象台( observatory的名词复数 )
参考例句:
  • John Heilbron, The Sun in the Church: Cathedrals as Solar Observatories, 3-23. 约翰.海耳布隆,《教会里的太阳:教堂即太阳观测台》,第3-23页。 来自互联网
  • Meteorologists use satellites, land observatories and historical data to provide information about the weather. 气象学家使用卫星、上天文台和历史资料来提供有关天气的信息。 来自互联网
4 auroral mO0yQ     
adj.曙光的;玫瑰色的
参考例句:
  • This high result was interpreted to reflect previous aurora activity.这一高结果可以用以前的极光活动来解释。
  • The aurora is one of nature's most awesome spectacles.极光是自然界最可畏的奇观之一。
5 investigation MRKzq     
n.调查,调查研究
参考例句:
  • In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
  • He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。
6 painstaking 6A6yz     
adj.苦干的;艰苦的,费力的,刻苦的
参考例句:
  • She is not very clever but she is painstaking.她并不很聪明,但肯下苦功夫。
  • Through years of our painstaking efforts,we have at last achieved what we have today.大家经过多少年的努力,才取得今天的成绩。
7 decided lvqzZd     
adj.决定了的,坚决的;明显的,明确的
参考例句:
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
8 flakes d80cf306deb4a89b84c9efdce8809c78     
小薄片( flake的名词复数 ); (尤指)碎片; 雪花; 古怪的人
参考例句:
  • It's snowing in great flakes. 天下着鹅毛大雪。
  • It is snowing in great flakes. 正值大雪纷飞。
9 charcoal prgzJ     
n.炭,木炭,生物炭
参考例句:
  • We need to get some more charcoal for the barbecue.我们烧烤需要更多的碳。
  • Charcoal is used to filter water.木炭是用来过滤水的。
10 excavating 5d793b033d109ef3f1f026bd95b1d9f5     
v.挖掘( excavate的现在分词 );开凿;挖出;发掘
参考例句:
  • A bulldozer was employed for excavating the foundations of the building. 推土机用来给楼房挖地基。 来自《简明英汉词典》
  • A new Danish expedition is again excavating the site in annual summer digs. 一支新的丹麦探险队又在那个遗址上进行一年一度的夏季挖掘。 来自辞典例句

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