Concept explainers
Group Discussion: Sharing the Sky. Astronomers around the world are fond of saying “we all share the same sky.” Gather in groups of two to four students to discuss the meaning of this statement.
a. Give each group member a chance to describe the similarities and differences you would expect between the sky you see during a 24-hour period and the sky seen by someone on the opposite side of the world, or on the other side of the equator.
b. Discuss whether you think that people making independent studies of the sky in different locations would come to simi-lar conclusions about how the universe works. Would their conclusions be more accurate if they share perspectives with people from other places? Why or why not?
c. Discuss whether the skies that people saw 2000 years ago differ in any significant ways from the skies we see today.
d. Do you think that people living 2000 years from now will have experiences of the sky that are similar to your own? Why or why not?
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Essential Cosmic Perspective
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