Scientists Find Most Earth-Like Planet Yet Discovered
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This is SCIENCE IN THE NEWS, in VOA Special English. I'm Faith Lapidus. And I'm Bob Doughty. On our program this week, we talk about a natural substance that makes people more likely to trust each other. We also answer a question about stuttering and describe treatments for the speech disorder. But first, space scientists report the discovery of what they call the most Earth-like planet ever found.
American scientists say they have discovered the smallest Earth-like planet ever observed outside our solar system. They announced their findings earlier this month at the National Science Foundation, near Washington, D.C.
The scientists made the discovery with one of the huge telescopes at the W.M. Keck Observatory in Hawaii. Each telescope stands eight levels tall and weighs more than three hundred metric tons.
The scientists describe the newly-discovered planet as a ball of rock made of the same materials as Earth. They also said the planet could have an atmosphere.
The scientists said the planet is more similar to Earth than anything ever observed. Yet it is very different. It is more than seven times the size of Earth and unable to support life. That is because the planet is extremely hot. Its surface temperature is between two hundred and four hundred degrees Celsius.
The scientists told reporters the planet orbits a star called Gliese Eight-Seven-Six. It is fifteen light years away from Earth in the group of stars known as Aquarius. The planet moves around the star once every two days. Gliese Eight-Seven-Six has two larger planets. They are closer in size to Jupiter, the largest planet in our solar system.
The scientists say the newly-discovered planet may be the first rocky planet ever found orbiting a star similar to our Sun. Three other rocky planets have been reported in other solar systems. But they orbit the remains of an exploded star, not a normal one.
The scientists said they do not know where the planet came from. But it is as small as can be found with current instruments. They also said improved instruments are planned in the next ten years. And they said the discovery suggests that more Earth-like planets will be found in the future.
Do you have trouble trusting people? Maybe your body needs more oxytocin. That is a hormone that some scientists say makes people more likely to trust each other.
Research scientists at universities in Switzerland and the United States recently tested the effects of oxytocin on a group of students. About one hundred eighty male students from the University of Zurich took part.
The researchers set up an investment game as part of the study. Some of the students were investors in the money game. Others were called trustees.
Investors and trustees were not permitted to communicate. Investors were given money. They were told any investment they made would be immediately worth three times more. But, they had to work with a trustee on each investment. And, the trustee had complete control of the money after the investment was made. So, a trustee could keep it all. Or give some back to the investor.
To make it even trickier, an investor could work with each trustee only once. So an investor had no experience of a trustee before working with him.
Before the games began some students were given oxytocin through their noses. Others breathed in a harmless substance, or placebo.
The researchers found that persons who received the hormone invested seventeen percent more than those who got the placebo. Forty-five percent of those in the oxytocin group invested all their money. That compared with twenty-one percent of the investors in the placebo group.
The researchers also reported that oxytocin only affected investors when they working with human trustees. The researchers say the effects of the hormone disappeared when the investors worked with computers as trustees.
Ernest Fehr of the University of Zurich led the study. He says increasing trust may be useful for people with social fears and the brain disorder autism.
There are new estimates of the number of Americans with the virus that causes AIDS. Government scientists say more than one million were living with the human immunodeficiency virus, or H.I.V. at the end of two thousand three. Health officials gave a report this month at the National H.I.V. Prevention Conference in Atlanta, Georgia.
The Centers for Disease Control and Prevention set a goal in two thousand one to cut the rate of new infections in half. That goal has not been met. But a C.D.C. official, Doctor Ronald Valdiserri, said researchers do think they are making progress.
Doctor Carlos del Rio of Emory University in Atlanta, however, suggested that prevention efforts have failed. He says there may be as many as sixty thousand new cases per year. In recent years, the number has been estimated at forty thousand.
Almost half of those infected are believed to be men who have sex with other men. And, experts say, almost half are black. People who are infected with H.I.V. often do not know it. There are no cures. But drug treatments can delay the progress of H.I.V. into AIDS. AIDS leaves a person defenseless against disease.
Researchers estimate that about forty million people worldwide are living with H.I.V. They estimate that every day more than eight thousand people die from conditions linked to AIDS.
About half of all people living with H.I.V. are women. And about half of new infections are in young adults.
Our question this week comes from Vietnam. Nguyen To Hieu would like to learn more about stuttering.
Stuttering is speech disorder. It also may be called stammering in some countries. Stuttering happens when the normal flow of speech is broken up. The speaker may repeat sounds or words. Or the speaker may have problems starting a word.
Some situations may cause people to stutter. For example, talking in front of a group might cause stuttering. Yet singing or speaking alone might not.
Experts estimate that more than three million Americans stutter. Stuttering affects people of all ages. But it is most common in children between the ages of two and six years. This kind of stuttering is called developmental stuttering. Children might stutter as they develop language skills, but they usually learn to speak normally once they are older.
Adults who stutter might have a form of stuttering called neurogenic. This means there are signal problems between the brain and the muscles and nerves that control speech.
Another kind of stuttering is called psychogenic. It is linked to the mental activities of thought and reasoning. This kind of stuttering is rare and can be found in individuals who have a mental illness or who experienced extreme mental pressure.
Medical experts do not know exactly why people stutter. They do know that stuttering may be common among members of the same family. Yet, the gene that is responsible has yet to be found.
Several treatments for stuttering do exist. Speech-language pathologists can provide help. They are trained to test and treat persons with voice, speech and language disorders. They can help people who stutter learn ways to improve their speech through special training. Speech-language pathologists also can help patients deal with the feelings that often come with such a disorder. When asked to speak, some people who stutter become easily frightened or shy.
Experts say it helps to be patient when talking with someone who stutters. When that person speaks, listen quietly. Also, it is important for parents of children who stutter to provide an easy home environment. Parents should be supportive of their children and not punish them for stuttering.
Many Americans who stuttered have become successful in work that requires public speaking. They include the actress Marilyn Monroe, actors Bruce Willis and James Earl Jones, and singer Carly Simon.
This SCIENCE IN THE NEWS program was written by Dana Demange, Cynthia Kirk, Nancy Steinbach and Caty Weaver. Cynthia Kirk was our producer. I'm Faith Lapidus. And I'm Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.