About Planetariums

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I’m Steve Ember. And I’m 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.

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.

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.

Other versions of early planetariums were large globes. People could sit inside them. Holes were cut into the walls of these globes to represent stars.

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.

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.

Another show at the Smithsonian’s 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. Swift’s instruments are designed to record bursts of high energy radiation. Gamma rays don’t penetrate Earth’s atmosphere, but out here in space, Swift’s 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.”

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 on complex mathematical calculations about space gathered by scientists.

Next week, the ‘Imiloa Astronomy Center in Hawaii will host a six-day ‘Imiloa Fulldome Film Festival. Museum and planetarium professionals from around the world will be able to watch some of the latest movies available for digital planetarium theaters.

The ‘Imiloa Astronomy Center is part of the University of Hawaii at Hilo. The center’s planetarium has the world’s first three-dimensional planetarium system. Viewers wear special glasses to experience this effect. The Astronomy Center is an example of how technologies will continue to change and improve experiencing the night sky in planetariums of the future.

This program was written and produced by Dana Demange. I’m Steve Ember. And I’m Barbara Klein. You can comment on this program at voaspecialenglish.com. Join us again next week for EXPLORATIONS in VOA Special English.