www.manythings.org/voa/scripts

SCIENCE IN THE NEWS #2115 - Digest

By StaffThis is Bob Doughty.And this is Sarah Long with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about the discovery of the wreck of an ancient Greek ship. We tell about a World Health Organization campaign against the disease epilepsy. And we tell about a new kind of plastic that repairs itself.

An American exploration company has found the wreck of an ancient Greek ship in a very deep area of the Mediterranean Sea. It may be the deepest ancient shipwreck ever found. The discovery questions a long-held belief that ancient sailors lacked skills needed to guide ships in open seas.

The magazine "Archeology" reports the discovery. The ancient ship lay more than three-thousand meters below the surface of the Mediterranean. The wreck was more than four-hundred-eighty kilometers from the island of Corsica. Scientists believe the ship is about two-thousand-three-hundred years old.The Nauticos Corporation of Hanover, Maryland discovered the wreck. The company was looking for an Israeli submarine that had disappeared more than thirty years ago. The Nauticos crew found the ancient ship two years ago. They kept the discovery secret until they had recovered the Israeli submarine.

Nauticos official Thomas Dettweiler said two company ships were searching for the Israeli submarine. He supervised the operation from a ship with sonar equipment. A sonar system uses sound waves to find and identify objects under the water. A second ship carried a vehicle for deep-sea searches.During the search, one ship's sonar began making strange sounds. Mr. Dettweiler thought this meant they had found the lost submarine. He ordered the other ship to send down the deep-sea vehicle to search.

But a video camera on the vehicle did not show a submarine. Instead, it showed many large clay containers lying on the bottom of the sea. These containers are called amphoras. Mr. Dettweiler was excited. He says he knew that the presence of about two-thousand amphoras meant they had discovered an important shipwreck. In ancient times such containers held wine, olive oil and other goods.

He also knew that scientists believe ancient trading ships stayed close to the coast. Scientists thought that sailors were afraid of open seas and deep water. So Mr. Dettweiler knew scientists would be very interested in the discovery.The Nauticos team sent their video and sonar studies to scientists at Texas A and M University in College Station, Texas. A scientist there says the ancient ship may have traveled in deep, open waters from Greece to Egypt.

The scientists believe the amphoras probably came from the Greek islands of Rhodes and Kos. The containers lie on top of each other. They cover the remains of the ship. A large metal container is among the amphoras. The experts believe this cauldron was used for cooking.The scientists hope to examine a piece of the cauldron. The condition of its metal could tell how the Mediterranean Sea and atmosphere have changed over the past two-thousand years.

Nauticos and the scientists hope to do more research in the area soon. Mr. Dettweiler believes four other ancient ships may be nearby. He says finding shipwrecks from different time periods could be especially important. It could be the first evidence of continued open-sea trading in the ancient world.

((MUSIC BRIDGE))You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Sarah Long with Bob Doughty in Washington.

((MUSIC BRIDGE))

The World Health Organization has announced projects in four countries as part of its campaign against the disease epilepsy. The countries are China, Argentina, Senegal and Zimbabwe.

The four projects will find out the number of people suffering from epilepsy. Medical experts will train health care workers to identify and treat patients with the disease.Epilepsy is a brain disorder in which nerve cells suddenly release a large amount of electrical energy. Victims react by suffering what are called seizures. They may close their eyes, fall down and move their muscles uncontrollably for a few minutes. Or they may appear confused for a few minutes or act strangely.

The World Health Organization says epilepsy is the world's most common brain disorder. At least fifty-million people suffer from it. Eighty-five percent of them live in developing countries. Two-million people develop epilepsy every year.The W-H-O says any kind of brain injury or disease can lead to epilepsy. It also says common causes of epilepsy in developing countries include poor care during childbirth and a lack of healthy food. There is no cure, but epilepsy can be treated. The W-H-O says up to eighty percent of the people with epilepsy could lead normal lives if they were treated.

The W-H-O says most epilepsy sufferers get no treatment. For example, its office in Latin America says five-million people in the area suffer epilepsy. It also says more than three-million of them are not treated. A recent study in thirty Latin American countries showed that none have national policies for epilepsy. In Africa, only one doctor for every four-million people is able to treat brain disorders.People with epilepsy fear that other people will find out they have the disease. The W-H-O campaign wants to educate the public about epilepsy. And it wants to improve the lives of those with the disease. Officials say their aim is to improve treatment, prevention and social acceptance of the disease.

((MUSIC BRIDGE))American scientists have developed the first material that repairs itself. The material is a form of plastic that has been engineered to fill breaks in its surface.

Plastics are used today in everything from airplane wings to hundreds of objects found in the home. Scientists wanted to find a way to make objects made of plastic last longer. The researchers hope their new discovery can be used to make objects that are difficult or impossible to replace.

The surface of plastic objects breaks over time. Very small breaks, or cracks, develop every time a plastic object is used. The researchers wanted to find out how to stop plastic from developing small cracks that grow, weaken and destroy it. The research team at the University of Illinois at Champaign-Urbana found an answer to the problem. They found the answer in the chemical structure of plastic itself.Plastic is made of small molecules called monomers. These monomers link together to form very long molecules called polymers. Polymers give plastic its ability to be shaped and its strength.

The research team found a way to make plastic that contains very small balloons filled with liquid. The liquid contains monomer molecules the building material of plastic. The team then created solid plastic that contains a special chemical. This chemical is called a catalyst. A catalyst is a substance that starts a chemical reaction.

The new plastic still cracks like common plastic. But, when it does, the monomer liquid is released and flows into the crack. The catalyst in the solid plastic then reacts with the liquid monomer. The chemical reaction between the liquid monomer and the catalyst creates polymer molecules that repair the break. The repaired plastic has seventy-five percent of the strength of undamaged plastic.The scientists say the new self-repairing plastic is not yet ready for production. But it has several possible uses. One could be in space vehicles where parts cannot be repaired or replaced. Another possible use might be in bridges. And it could be used in people, to replace bone joints that have become broken or damaged. These include knees or hips.

This SCIENCE IN THE NEWS program was written by Jerilyn Watson, Nancy Steinbach and Mario Ritter. It was produced by George Grow. This is Bob Doughty.And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.