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Author Question: Why were telescopes with very large, thin mirrors not built 50 years ago? What will be an ideal ... (Read 172 times)

londonang

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on: Jul 27, 2018
Why were telescopes with very large, thin mirrors not built 50 years ago?
 
  What will be an ideal response?

Question 2

Stars of spectra type K have strong Balmer lines.
 
  a. True
  b. False
  Indicate whether the statement is true or false


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Kimmy

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

Because a large thin mirror will sag under its own weight, the optical shape of a large thin mirror must be controlled by computer-driven thrusters, using a technique called active optics. This technology was not available 50 years ago.

Answer to Question 2

False


londonang

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Reply #2 on: Jul 27, 2018
Thanks


Kimmy

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Reply #3 on: Jul 27, 2018
Welcome :)


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