True or False: Kids + Too Much TV = Less Ability to Learn?
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This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty. And I'm Barbara Klein. On our program this week, we tell about proposed changes to an important environmental law. We tell about the first look inside a comet in space. We also present some interesting questions about science. But first, does watching television harm a child's ability to learn?
All parents want their child to perform well in school. However, three new studies suggest this may not happen if the child watches too much television. The studies were published this month in the Archives of Pediatric and Adolescent Medicine.
Researchers at Stanford University in California and Johns Hopkins University in Maryland carried out one study. They examined the test scores of three hundred fifty students who were about eight years old.More than seventy percent of these students reported having a television in the room where they sleep. These students performed between seven and nine points lower on math, reading and language tests than students without televisions in their rooms.
Scientists at the University of Washington carried out the second study. They examined information on about one thousand eight hundred students. The researchers found that too much television before age three was linked to lower reading skills by age six. The study also found that six and seven-year-old children had poorer short-term memory if they had watched a lot of television in their earliest years. However, children who watched TV after age three seemed to be better able to sound out and say words.
Researchers at the University of Otago in New Zealand did the third study. They followed more than one thousand people born around nineteen seventy-two. They found that those who watched the most television between the ages five and fifteen were the least likely to finish high school and college by age twenty-six.
A report critical of the three studies also appeared in the Archives of Pediatric and Adolescent Medicine. Deborah Linebarger of the University of Pennsylvania helped write it. She said the studies measured only the time children spent watching television and not what programs they watched. Her research has shown that quality educational programs can help children learn.
A committee of the United States Congress is considering changes to a law meant to protect plants and animals from disappearing from Earth. Congress passed the Endangered Species Act in nineteen seventy-three. The law provides protection for more than one thousand kinds of plants and animals that are threatened with dying out.
Some groups say it is the strongest and most important wildlife protective legislation in the world. But a number of interest groups say the Endangered Species Act slows progress and economic growth.
Reports say the proposed changes call for stronger requirements for defining species as endangered. The change in description would limit the measures taken to protect them. Another change reportedly being considered would narrow the definition of protected living areas. These areas would be limited to places where a plant or animal now grows or lives. The law currently includes places where the plant or animal could live if its population grew.
Landowners, developers and builders are urging changes in the law. These critics say government and environmental groups unfairly restrict people's control over their own land. They say the landowner does not receive anything in return for limitations placed to protect wildlife.
Opponents also say the current law has not helped rescue many species. They charge that only one percent of protected species have been removed from the list of endangered wildlife. The rescued species include the Florida manatee, the Florida panther and the American bald eagle.
Some environmental activists agree that the law needs changing. But they say they fear its purpose may be lost in the rewritten legislation. They worry that changes could cause some animals and plants to die out forever.
American space agency scientists are getting their first look inside a comet. Earlier this month, NASA crashed its Deep Impact spacecraft into a comet called Tempel One. The crash took place more than one hundred thirty million kilometers from Earth.
NASA scientists say the Comet Tempel One may provide information about the development of the Solar System. Comets are made of ice, gas and dust. They are made of particles from the farthest and coldest areas of the Solar System that formed more than four thousand million years old.
NASA is studying the ancient matter inside the comet where material from the formation of the solar system remains generally unchanged.
Scientists are studying the photographs taken before, during and after the crash. They say a huge cloud of fine powdery material was released when the spacecraft crashed into the comet. The cloud shows that the comet is covered with the powdery material.
Deep Impact was launched into space in January. It traveled more than four hundred thirty million kilometers. The spacecraft was made of two parts. The larger part of the spacecraft was called the "flyby". It flew near the comet and took pictures of the crash. The smaller part of the spacecraft was called the "impactor". It separated from the spacecraft and crashed into the comet while traveling at about ten kilometers per second. The crash caused a great explosion of heat and light. The impactor was destroyed deep below the comet's surface when it crashed.
The spacecraft's three cameras took more than four thousand images. It will take experts some time to study all of the photographs and information gathered by the spacecraft. Who knows what secrets about the universe this comet will reveal.
American inventor Thomas Edison started Science magazine one hundred twenty-five years ago. Today, many important researchers publish their findings in Science. The magazine recently asked more than one hundred scientists what they thought were the most important unanswered questions facing science today. The magazine published a list of one hundred twenty-five questions in honor of its one hundred twenty-fifth anniversary.
The magazine chose the top twenty-five questions on the list. Some of these questions have interested people for years, such as: "How and where did life on Earth arise?" And "Are we alone in the universe?" Many scientists believe that we are not alone and that they may have an answer to this question in about twenty-five years. Other questions on the list are: "Why do humans have so few genes?" And "What genetic changes made us human?"
Another important question is: "How much can human lifespan be extended?" Some scientists believe people in the future will live more than one hundred years. Others say a person's lifespan is more limited. The Population Council says human lifespan has increased by more than fifty percent during the past one hundred years.
The scientists said they chose the top twenty-five questions for several reasons. They chose some questions because of the major effect the answers would have on society. These questions include: "Is an effective vaccine against H.I.V. possible?" "How hot will the world become because of greenhouse gases?" And "What can replace cheap oil – and when?"
You can learn more about the project at Science magazine's Internet web site. The address is www.sciencemag.org. Click on the one hundred twenty-fifth anniversary issue.
Now it is your turn to ask a question about science. If you have a question that we can answer, send an e-mail to [email protected] Please tell us your name and where you live. Or you can mail a question to VOA Special English, Washington D.C., two-zero-two-three-seven, U.S.A.
This Science in the News program was written by Jill Moss, Jerilyn Watson, Dana Demange and Cynthia Kirk, who was also our producer. I'm Bob Doughty. And I'm Barbara Klein . Join us again next week for more news about science in Special English on the Voice of America.