【慢】PlanetariumsTakeViewersonaTripThroughSpace.doc

STEVE EMBER: Im Steve Ember.BARBARA KLEIN: And Im Barbara Klein with EXPLORATIONS in VOA Special English. A planetarium is a theater with a rounded ceiling onto which images of the stars and planets are projected. Planetariums give educational shows about astronomy and what you can see in the night sky. Today, we tell about the past, present, and future of planetariums. And, we visit the Albert Einstein Planetarium at the Smithsonian National Air and Space Museum in Washington, D.C.(MUSIC)STEVE EMBER: Since ancient times, humans have worked on ways to understand and represent the movement of the stars and planets. Experts credit the Greek astronomer Archimedes with developing the earliest known device to show the daily movement of the planets. He lived more than two thousand years ago. These mechanical devices that show the relative placement and movement of the planets and moons are sometimes called orreries. Over the centuries, scientific thinkers worked to develop these devices and improve their accuracy and complexity.The words orrery and planetarium were once used interchangeably. Today, the world planetarium generally means a theater inside a dome.BARBARA KLEIN: The earliest planetarium that is still working today is in the Netherlands, although the device is actually an orrery. It was built by a man named Eise Eisinga starting in seventeen seventy-four. It took him seven years to build this moving device inside a room in his house. All the planets move at the same speed as the real planets in our solar system. So, it takes one year for Earth to move around the sun and about twenty-nine years for Saturn to do so. Eisinga made his device out of wood, metal nails, a clock and nine weights.planetarium-friesland.nlThe oldest working planetarium was built by Eise Eisinga in the Dutch town of FrankstonOther versions of early planetariums were large globes. People could sit inside them. Holes were cut into the walls of these globes to represent stars.STEVE EMBER: A group of German engineers and scientists helped develop the modern planetarium between nineteen ten and nineteen thirty. The creators of the Deutsches Museum of science and technology in Munich wanted to build a planetarium. So, they asked the Carl Zeiss company in Germany to help with this plan. This company was known for making scientific equipment such as microscopes.It took engineers at Zeiss several years to invent a new planetarium technology. The complex mechanical device they made projected light through star plates of film that contained images of thousands of stars. Public viewings of the first Zeiss planetarium projector began in nineteen twenty-three.BARBARA KLEIN: Soon, other cities in Europe and later in the United States began ordering planetarium devices from Zeiss. An American business leader named Max Adler learned about these planetariums and traveled to Germany to see one for himself.He was so amazed with the Zeiss device that he donated the money for a planetarium to be built in his native Chicago, Illinois.Adler Planetarium in Chicago was the first modern planetarium in the United States The Adler Planetarium was the first modern planetarium in the United States. It opened its doors to the public in nineteen thirty. Planetariums soon opened in Philadelphia, Pennsylvania; Los Angeles, California and New York City.STEVE EMBER: Planetarium technology continues to evolve and improve to this day. But what if you live far away from a city with a planetarium?Dan Neafus helps supervise the Gates Planetarium at the Denver Museum of Nature and Science in Colorado. He says new technologies are helping to connect planetariums with viewers in other areas. There are relatively few digital planetariums around the world. But this technology could bring space education and the experience of a planetarium show to more people through the use of a computer and Internet connection.(MUSIC)BARBARA KLEIN: The Loch Ness Production company in Colorado makes shows, images and music for the planetarium community. The company also gathers facts about planetariums around the world. It says there are over one thousand five hundred planetariums in the United States. Many kinds of organizations have planetariums. They include museums, science centers, universities, schools and even astronomy clubs. Some planetariums have domes that measure over twenty meters, while others are much smaller.STEVE EMBER: Some planetariums use film projections. More technologically advanced planetariums use digital systems controlled by computers. Digital technologies offer planetariums many choices. These theaters can show movies about space. Or, these planetariums can serve as classrooms where live interactive presentations take place. For example, astronomers can guide viewers on a trip around the universe using image databases with real information about the placement of stars and planets.BARBARA KLEIN: The Smithsonian National Air and Space Museum in Washington, D.C. has both a digital system and a projector system made by the Carl Zeiss company.This Zeiss Model VI was a gift to the museum from West Germany in honor of the United States two hundred year anniversary. Last week, we attended a live show called The Stars Tonight. Astronomer Bill Dedmond showed visitors the night sky as the season changes from summer to fall.BILL DEDMOND: See, thats how night sky is supposed to look. You can see thousands of stars when you are away from the city light pollution. You can even see this bright band of light here all the way across the sky. What is that bright band of light?KIDS: The Milky Way!BILL DEDMOND: OK, Excellent!STEVE EMBER: Bill Dedmond talked about the groups of stars or constellations in the night sky. He pointed out an important constellation, the Big Dipper. If you can find this group of stars, you can easily find the North Star, or Polaris. Mr. Dedmond also gave viewers a tour of the planets.BILL DEDMOND: Our galaxy contains a couple hundred billion stars and we know there are about one hundred twenty-five billion other galaxies. Just incredible how many stars there are.BARBARA KLEIN: Speaking of stars, one of the Air and Space Museums planetarium shows is called Journey to the Stars. The movie is presented by actress Whoopi Goldberg. It tells about the life of a star using our sun as an example.WHOOPI GOLDBERG: The first stars changed everything, combining hydrogen and helium into new elements such as oxygen and carbon. Then supernovas blasted these elements into space, supplying ingredients for stars and planets to come. And though it may sound incredible, your body actually contains about a teaspoons worth of this stuff formed thirteen billion years ago by the very first stars.STEVE EMBER: The movie describes the many stages in the life of a star. Some stars known as super giants are about a thousand times bigger than our sun.The movie Journey to the Stars is very helpful not only because it tells interesting facts about stars and space. The movie helps viewers get a better idea of the extraordinary size and volume of space and the huge number of stars within it. This sense of size is hard to understand by just reading a book. The planetarium makes it feel as if you are observing, moving through and exploring A scene from the Smithsonians planetarium show Black Holes: The Other Side of InfinityBARBARA KLEIN: Another show at the Smithsonians planetarium is called Black Holes: The Other Side of Infinity. Black Holes are not actually holes. They are extremely massive concentrations of matter. The actor Liam Neeson narrates the movie.LIAM NEESON: How do you find something that hides in the dark? You have to look for its tell-tale signs. Swifts instruments are designed to record bursts of high energy radiation. Gamma rays dont penetrate Earths atmosphere, but out here in space, Swifts view of them is front row center. They erupt when a black hole is born. That happens when a large star dies in a blaze of glory called a super nova.STEVE EMBER: It takes a lot of work to produce a good planetarium movie. Experts at the Denver Museum of Nature and Science made the Black Holes movie. They worked with movie producers, computer experts, astronomers, astrophysicists and other professionals. Their film is scientifically correct and also a lot of fun to watch. Many images in the movie are based o