This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: The _______________ time is the amount of time it took light to travel from a celestial object to ... (Read 67 times)

c0205847

  • Hero Member
  • *****
  • Posts: 531
on: Jul 27, 2018
The _______________ time is the amount of time it took light to travel from a celestial object to Earth.
 
  Fill in the blank(s) with correct word

Question 2

Why are reflecting telescopes cheaper to build than refracting telescopes?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

kthug

  • Sr. Member
  • ****
  • Posts: 332
Reply #1 on: Jul 27, 2018
Answer to Question 1

lookback
look-back

Answer to Question 2

Mirrors are much less expensive than lenses because light reflects off the front surface; therefore, only the front surface of a mirror needs to be made with a precise shape. Lenses are much more difficult to manufacture than a mirror of the same size. The interior of the glass must be flawless and pure, and must be made of two different kinds of glass requiring four precisely ground surfaces. Refracting telescopes larger than 1 m would be prohibitively expensive.


c0205847

  • Hero Member
  • *****
  • Posts: 531
Reply #2 on: Jul 27, 2018
Thank you!


kthug

  • Sr. Member
  • ****
  • Posts: 332
Reply #3 on: Jul 27, 2018
Always glad to help...


« previous next »
 

Did you know?

In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.

Did you know?

The oldest recorded age was 122. Madame Jeanne Calment was born in France in 1875 and died in 1997. She was a vegetarian and loved olive oil, port wine, and chocolate.

Did you know?

Green tea is able to stop the scent of garlic or onion from causing bad breath.

Did you know?

In 2010, opiate painkllers, such as morphine, OxyContin®, and Vicodin®, were tied to almost 60% of drug overdose deaths.

Did you know?

The familiar sounds of your heart are made by the heart's valves as they open and close.

Excitation of isolated chlorophyll by light. Excitation of isolated chlorophyll by light.
The biochemical reactions of near-infrared light The biochemical reactions of near-infrared light
When young infants hold objects for a long period of time they eventually become habituated to them. When young infants hold objects for a long period of time they eventually become habituated to them.
Elizabeth Murray, Just in Time. Elizabeth Murray, Just in Time.
The steps in the hearing process. (1) Sound waves enter the outer ear and travel through the ear ... The steps in the hearing process. (1) Sound waves enter the outer ear and travel through the ear ...
In the retina, there are two types of light receptor cells: Rods are sensitive to differences in lig In the retina, there are two types of light receptor cells: Rods are sensitive to differences in lig
Video: Five phases of cardiac cycle & Atrial contraction

For a complete list of videos, visit our video library