This is SCIENCE IN THE NEWS in VOA Special
English. I'm Shirley Griffith.
I'm Bob Doughty. Today we tell about two
recent inventions that have helped to save lives. We will also tell about the people who
Most cars have seat belts as part of
their equipment. Seat
belts protect drivers and passengers in case of accident. They also reduce the effect of a crash on the
body. Safety experts estimate that the
restraining devices save more than four thousand lives a year in the United States alone. Worldwide, some experts,
say the devices have protected up to a million people.
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first seat belt was said to have been created in the eighteen hundreds by
George Cayley of England. He is
remembered for many inventions, especially for early "flying machines."
United States first recognized the invention of an automobile seat belt in
eighteen forty-nine. The government gave
a patent to Edward J. Claghorn of New York City so that others would not copy
his invention. Claghorn called the
device a Safety-Belt. It was said to
include hooks and other attachments for securing the person to a fixed
Other inventors followed with different versions of the
seat belt. But more than one hundred
years passed before the current, widely used seat belt was developed. It resulted from the work of a Swedish
engineer, Nils Bohlin. His three-point,
lap and shoulder seat belt first appeared on cars in Europe fifty years
was born in Sweden in nineteen twenty. After completing college, he designed seats for the Swedish aircraft
industry. The seats were built for the
pilot to escape from an airplane in case of disaster. Bohlin's work with planes showed him what
could happen in a crash at high speed. In nineteen fifty-eight, Bohlin brought that
knowledge to the Swedish car manufacturer Volvo. He was the company's first chief safety
At the time, most safety belts in cars
crossed the body over the abdomen. A
buckle held the restraints in place. But
the position of the buckle often caused severe injuries in bad crashes.
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Nils Bohlin recognized that both the upper and lower
body needed to be held securely in place. His invention contained a cloth strap that was
placed across the chest and another strap across the hips. The design joined the straps next to the hip.
Volvo was the first automobile manufacturer to offer
the modern seat belt as a permanent addition to its cars. It also provided use of Nils Bohlin's design
to other car-makers.
The Swedish engineer won
many honors for his seat belt. He
received a gold medal from the Royal Swedish Academy of Engineering Sciences in
nineteen ninety-five. He died in Sweden
in two thousand two.
is another invention that has saved many people from serious injury and
death. Kevlar is a fibrous material with
qualities that make it able to reject bullets. Added to clothing, the material protects
security officers and soldiers across the world.
fibers form a protective barrier against gunfire. Bullets lose their shape when they strike
Kevlar. Those bullets look like
mushrooms, and do not enter the body. Most threats to police and security officers come from handguns. They wear Kevlar vests to protect the upper
body. Soldiers wear more extensive
clothing protected with Kevlar against heavier ammunition.
Kevlar might not have been invented had Stephanie
Kwolek been able to seek a career in medicine. From childhood, she wanted to be a doctor. But she lacked the money for a medical
Today, thousands of people are glad that Stephanie Kwolek
became a research chemist. In that job,
she developed the first liquid crystal polymer. The polymer was a chemical product that formed the basis for Kevlar.
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Kwolek was born in nineteen twenty-three in New Kensington, Pennsylvania. As a child, Stephanie loved science. Later, she studied chemistry and other
sciences at a Pennsylvania college now known as Carnegie Mellon
She got a job with the DuPont chemical company in
nineteen forty-six. It was the beginning
of a career with the company that lasted about forty years.
the nineteen sixties, Dupont already had produced materials like nylon and
Dacron. The company wanted to develop a
new fiber. Stephanie Kwolek was part of
a DuPont research group that asked to work on its development.
At the time, she was searching for a way to make a
material strong enough to use on automobile tires. If tires could be improved, automobiles would
need less fuel. Miz Kwolek needed a new
way to make stiff, resistant fibers for the job.
experiments for the project were supposed to produce a clear substance similar
to a thick syrup. Instead, what
Stephanie Kwolek produced was unexpected. It was a liquid that looked cloudy or milky. She said she might have thrown it out. But she decided to let it sit for
Recently, she told VOA that she was
warned the liquid could never complete a required process. The process calls for the chemical to be pushed
through the small holes of a spinneret. She
remembers that the man operating the device at first refused to accept her material. He probably suspected it had solid particles that
would block the holes. However, after
awhile he said he would try it. She says
she thinks he was tired of being asked, or might have felt sorry for her.
That person must have been surprised when the substance
passed the test. It returned from the
laboratory with more firmness than anything Stephanie Kwolek had made before.
Kwolek did not tell anyone that she had produced something new and strong. She said she was afraid there might have been
a mistake. Repeated testing, however, did
not find anything wrong. She and her group
worked to improve the discovery. DuPont
first manufactured large amounts of Kevlar in nineteen seventy-one. The material is found today in hundreds of
products from sports equipment to window coverings.
the years, Stephanie Kwolek has received many awards. Her honors include membership in the National
Inventors Hall of Fame. Today she says
she loved her long career in chemistry. She
says that considering the times, she was lucky to get the job.
Getting Kevlar placed in protective clothing resulted
mainly from the work of Lester Shubin and Nicholas Montanarelli. Mister Shubin was educated in chemistry. He worked for the United States Army in the
nineteen seventies. At the time, Mister Montanarelli
was an Army project director. He was trained
in engineering and psychology.
The two Americans were working at the Aberdeen Proving
Ground in Maryland. They were searching
for a way to protect people in public life from gunfire. Mister Montanarelli knew about DuPont's recently
developed fiber, and the two men decided to test it.
men fired handguns at several materials protected by Kevlar. The material changed the shape of the bullets. It seemed a good candidate to help defend
police officers and soldiers.
Mister Shubin was
able to gain financial help for a field experiment. Thousands of police officers in many cities began
to wear the vests. But Mister
Montanarelli said it was difficult to get companies to make them. The companies feared legal action if the
vests should fail.
Then came December, nineteen seventy-five. A gunman shot at a policeman in Seattle, Washington. One bullet hit the officer's hand. But a bullet fired very close to the
policeman struck his chest.
The officer survived. The bullet did not enter his body. He felt good enough to protest being kept in
a hospital that night to make sure all was well. The incident helped get manufacturers to stop
worrying about legal action. They began
making the vests.
Today, about three thousand
people are members of the Kevlar Survivors' Club. DuPont and the International Association of
Chiefs of Police organized the exclusive club. All the members have escaped injury or death because long ago, a chemist
named Stephanie Kwolek produced something unexpected.
SCIENCE IN THE NEWS was written by Jerilyn Watson. Our producer was Brianna Blake. I'm Bob Doughty.
And, I'm Shirley Griffith. Join us again next week for more news about science
in Special English on the Voice of America.