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365DaysDate: March 27, 2009

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Title: Observing the Sky: Pre-Telescope

Podcaster: Nancy Ross Dribin and Mark Webb of the Adler Planetarium

Organization: The Adler Planetarium

Description: Prior to the age of the telescope man still looked to the sky. This podcast will explore the stories of the stars and how the night sky was observed in past cultures.

Bio: The Adler Planetarium — America’s First Planetarium — was founded in 1930 by Chicago business leader Max Adler. The museum is home to three full-size theaters, including the all-digital projection Definiti® Space Theater, the Sky Theater which utilizes a Zeiss optical projector, and the Universe 3D Theater. It is also home to one of the world’s most important antique instrument collections. The Adler is a recognized leader in science education, with a focus on inspiring young people, particularly women and minorities, to pursue careers in science.

Today’s Sponsor: This episode of “365 Days of Astronomy” is sponsored by Beth Katz in honor of her Dad. As a naval aviator, he learned the navigational stars. He taught her and shared his love of the sky. Now she teaches her kids and scouts to find their way in the sky. Beth reminds everyone to look up and feel connected to each other, to history, and to the future.

Transcript:

Nancy
Welcome to a special edition of the Adler Planetarium’s Bi-weekly podcast, Adler Night and Day. The Adler Night and Day podcast provides listeners with a glimpse of what you can see in the night sky, as well as updates on recent solar weather and riveting conversation. For the 365 days of Astronomy, daily podcast of the IYA, we’ll be concentrating on the riveting conversation!

Without further ado, I’m your host Nancy…

Mark
And I’m Mark. And today we’re joined on Adler Night and Day by Dr. Bruce Stephenson, historian at the Adler Planetarium. Welcome Bruce.

Bruce
Well, I’m glad to be here!

Mark
Our modern day framework of the sky had to have started somewhere. What’s the story behind that?

Bruce
In the western world, our framework of the sky basically originated with the ancient Greeks in systematic star catalogs that survived from ancient Greece. The positions of the stars are described with reference to constellation figures in the sky. For example, the three stars in Orion’s Belt or the right eye of Hercules. From this it is clear that the Greeks already had a tradition that placed well-known figures in the sky.

Eastern civilizations, the most important of which is China, of course had their own ways of looking at the sky and developed their own constellations. Uh, it was quite different from the Greek constellations, there was less interest in pictures you could make by connecting stars and more interest in finding the cosmic order that corresponded to the social order on Earth. They knew what the ordering principles of human society were and hence they thought that they knew what the ordering principles of the heavens must be. Thus the emperor, around whom all of society revolved on Earth, corresponded to the celestial North Pole around which the heavens revolved.

Nancy
So you’ve mentioned constellations and studying the stars, prior to the invention of the telescope, our first optical tool for observing the night sky was our eyes. Uh, what would earlier cultures have seen when they looked up at the night sky?

Bruce
Well, of course they would have seen the night sky, it hasn’t changed that much. But what you’ve actually asked is a more interesting question than that. Uh, today’s most people’s knowledge of the night sky comes not from looking at it through telescopes. When we rewind back to pre-telescopic times we’re also stripping away a lot of other technology on which our knowledge today is based… television, the Internet, even podcasts like this one. Prior to all that technology of course, people had only their unassisted eyes to view the heavens… just like most of us today, but it is really important to point out a couple of things. First, their skies were much darker and less polluted than ours. If you’ve ever been under really dark sky, you’ll appreciate that the stars up there are astoundingly vivid. And second, most people prior to modern technology probably spent more time outdoors at night than most of us do today… There was no television to draw them indoors. It is difficult for a city-dweller in the 21st century to imagine how familiar how the night sky would have been to most people a thousand years ago. They saw those stars every night and they knew them.

Nancy
Where as, in Chicago for example, not so much seeing the night sky.

Mark
(Laughs) Not too much.

So, the Greeks and many other cultures looked up at the sky and they created constellations, what was the purpose behind that?

Bruce
Well, I don’t think there was a purpose… the human mind just does it. It automatically organizes all the huge amount of information that it receives from the senses and the eyes.

Mark
Huh…

Bruce
Otherwise it would be impossible for us to think or remember anything. And the way the human mind organized hundreds of stars scattered across the sky was obviously to break them up into small groups and associate each group with something that was familiar and easy to remember, something such as a river, or the head of a bull, or often it was human figure from mythology.

Nancy
So you mentioned earlier that, ah, they took these constellations and these pictures and tied them into the workings of life on Earth. What were some of the practical uses of the night sky for those pre-telescope cultures?

Bruce
Hmm… Practical?! Well, there was mythology, which doesn’t sound practical but was actually an essential part of life until we developed something equally robust to replace it as a way of organizing the world around us. Uh, mythology made people more comfortable with the sky and in turn the sky made it easier for the people to remember the mythology.
Another practical use was for farming, which obviously cannot succeed without some kind of calendar. When you plant your seeds, uh, you have to expect that they will receive sun and rain… uh, so that they can sprout and flourish. A, third important practical use was for navigation and long-distance travel in general. Over short-distances on land, you could rely on mountains or other landmarks to keep track of what direction you wanted to go. But over long distances or as soon as you go to sea and lose sight of your landmarks you need to be able to line up your travel with an unchanging direction. Now, the night sky isn’t the only way to do that. Uh, we know for instance, that Polynesian sailors were actually able to steer based on stable patterns in the waves and currents.

Nancy
Wow, that’s pretty cool!

Bruce
It is pretty cool, uh, it was amazing when they learned that the Polynesians were actually able to detect these stable patterns. But, the night sky is certainly one of the best ways of steering over long distances. The North Star of course has long provided a reference direction for navigator in the northern hemisphere.

Mark
Well, to use the night sky for navigation or farming would require familiarity with the cycles of the sky and that requires long-term observations what would happen if, ah, something disrupted those, ah, cycles… if there was a meteor shower or a comet or some other unforeseen event in the sky?

Bruce
Well, as you say the good thing about the night sky is its regularity. It changes, but it changes slowly, from night to night and it changes in predictable cycles, the month, the year… usually. Sometimes though, people have looked up and seen something unexpected in the night sky; and in the pre-technological world this was frightening. Even today people get frightened as we see every time something unusual happens up there. People want regularity in the night sky. So, events such as a meteor showers or comets scared the heck out of people. The intellectuals at the top of society, who for most of history were priests and scholars, reacted by interpreted the unnatural events as omens, which of course those intellectuals were qualified to explain. Today, even for those of us without telescopes, the night sky can be a potent and soothing source of regularity in our lives. It tells us every night that we are a part of something much bigger than our little problems here on Earth.

Nancy
Well, thank you Bruce for joining us today on this very special edition of Adler Night and Day.

Mark
Yes, thanks.

Bruce
Well, I’ve had a great time.

Nancy
Great! I’d also like to thank the listeners of the 365 days of Astronomy podcast. To listen to full episodes of Adler Night and Day, please visit www.adlerplanetarium.org/podcasts.

End of podcast:

365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by the New Media Working Group of the International Year of Astronomy 2009. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.