VOA慢速英语--于亚利桑那州生物圈2号实验25周年

25 Years Later: Biosphere¹ 2 Lives On

An unusual scientific experiment ended 25 years ago when eight people walked out of a miniature Earth called Biosphere 2.

Biosphere 2 is a collection of large, connected buildings in the American state of Arizona. The buildings are made mainly of steel and glass.

The experiment began in September 1991 when the eight individuals entered Biosphere 2. A crowd watched as the four men and four women were secured inside. The event received a lot of media attention in the United States and across the world.

Biosphere 2 was designed to test whether human beings could survive in a closed environment, one that aimed to create conditions similar to those found in nature. The miniature Earth had a man-made rain forest, desert, grasslands² and even a small ocean.

Technology provided air flow, water and temperature controls. Water supplies and air were cleaned and reused. The eight people grew vegetables, rice and other foods they needed to survive. Farm animals were used to provide meat, eggs and milk.

The eight test subjects, called “Biospherians,” faced a few unexpected problems during the experiment. Low oxygen levels were discovered and began to affect the group’s health. A decision was made to pump in additional oxygen. The group was also not able to produce as much food as expected.

But all of them were able to complete the survivability test, which ended in September 1993. By then, the Biospherians had divided into two opposing groups. They had split under the pressures of sharing a small space and disagreements over the direction of the project.

The decision to provide oxygen from the outside world led to criticism of the $150 million project. Some members of the scientific community called the experiment a failure because the closed environment was supposed to be self-sustaining.

In 1994, another experiment was launched with a new group of subjects after improvements were made to Biosphere 2. But it had to be stopped six months later because of disputes over administration and financing issues. The ownership of Biosphere 2 then changed several times over the years.

Today, the University of Arizona operates the buildings as a scientific research center for controlled studies. Researchers from around the world can now use the facility to carry out experiments.

Joaquin Ruiz is a geologist³ with the University of Arizona and director of Biosphere 2. He told the Associated Press the controlled settings can help researchers to complete experiments in a more predictable environment.

Among the users of Biosphere 2 have been researchers from the Global Institute for Water Security at Canada’s University of Saskatchewan. They studied how plants in the small rainforest deal with water intake⁴ without risking harm to the environment.

Scientists from the University of Hawaii have carried out experiments on a miniature coral reef without hurting real corals in the Pacific Ocean.

Christopher Field is the director of the Stanford Woods Institute for the Environment. He told the AP he thinks Biosphere 2 has developed into a valuable, modern scientific tool.

“You have to separate it from what it was originally to see its worth today,” Field said. He added that Biosphere 2’s controlled environment provides “a powerful way to help us understand the way the world works.”

Jane Poynter was a member of the first Biosphere 2 group. She told the AP she thinks the current operators of the project “have been doing a really great job” at developing “strong foundations” for science. She added: “Twenty-five years after we came out, it’s still very forward-looking.”

I’m Bryan Lynn.

Words in This Story

miniature – adj. very small

self-sustaining – adj. able to survive without outside help

reef – n. a line of rocks or sand at or near the surface of the sea

originally – adv. in the beginning; when something first existed

foundation – n. an underlying basis or principle for something

1 biosphere   

n.生命层，生物圈

参考例句：

• The entire biosphere was becoming more transparent.整个生物圈越来越透明。
• The impact of modern technology on the biosphere is evident worldwide.现代技术对生物圈的影响在全世界是明显的。

2 grasslands   

n.草原，牧场( grassland的名词复数 )

参考例句：

• Songs were heard ringing loud and clear over the grasslands. 草原上扬起清亮激越的歌声。 来自《现代汉英综合大词典》
• Grasslands have been broken and planted to wheat. 草原已经开垦出来，种上了小麦。 来自《简明英汉词典》

3 geologist   

n.地质学家

参考例句：

• The geologist found many uncovered fossils in the valley.在那山谷里，地质学家发现了许多裸露的化石。
• He was a geologist,rated by his cronies as the best in the business.他是一位地质学家，被他的老朋友们看做是这门行当中最好的一位。

4 intake   

n.吸入，纳入；进气口，入口

参考例句：

• Reduce your salt intake.减少盐的摄入量。
• There was a horrified intake of breath from every child.所有的孩子都害怕地倒抽了一口凉气。