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Author Question: Suppose it turns out that one in 1 million stars has a planet that at some point in its history is ... (Read 47 times)

Tirant22

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on: Jul 27, 2018
Suppose it turns out that one in 1 million stars has a planet that at some point in its history is home to an advanced civilization. Then the total number of civilizations that have arisen in our galaxy would be closest to ________.
 
  A) 40,000 B) 400,000 C) 40 D) 4,000 E) 400

Question 2

Is Hubble's tuning fork diagram a real evolutionary tool? Why?
 
  What will be an ideal response?


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dajones82

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Reply #1 on: Jul 27, 2018
Answer to Question 1

B

Answer to Question 2

No, galaxies are not progressing from round ellipticals to flatter spirals over time. Observational evidence seems to indicate that collisions and tidal interactions between galaxies are commonplace and may be the main physical process driving galaxy evolution.


Tirant22

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Reply 2 on: Jul 27, 2018
:D TYSM

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Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

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