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

Author Question: If they existed, and if they were watching, a civilization at the center of the Milky Way could have ... (Read 60 times)

ghost!

  • Hero Member
  • *****
  • Posts: 560
on: Jul 27, 2018
If they existed, and if they were watching, a civilization at the center of the Milky Way could have detected our first TV signals by now.
 
  Indicate whether the statement is true or false

Question 2

Explain how we estimate that there are about 50-100 billion galaxies in the observable universe.
 
  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

tandmlomax84

  • Sr. Member
  • ****
  • Posts: 323
Reply #1 on: Jul 27, 2018
Answer to Question 1

FALSE

Answer to Question 2

Obviously it's impossible to count so many galaxies one by one, but by observing a small part in detail, we can extrapolate to get the total number. As an example, the Hubble deep field shows thousands of galaxies in a very small angular area of the sky (about equal to the size of a grain of sand held at arm's length). Multiplying the number of galaxies by the ratio of the angular area of the entire sky to the angular area of the deep field then gives an estimate of the total number of galaxies in the observable universe.


ghost!

  • Hero Member
  • *****
  • Posts: 560
Reply #2 on: Jul 27, 2018
Thank you!


tandmlomax84

  • Sr. Member
  • ****
  • Posts: 323
Reply #3 on: Jul 27, 2018
Always glad to help...


« previous next »
 

Did you know?

Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.

Did you know?

As many as 28% of hospitalized patients requiring mechanical ventilators to help them breathe (for more than 48 hours) will develop ventilator-associated pneumonia. Current therapy involves intravenous antibiotics, but new antibiotics that can be inhaled (and more directly treat the infection) are being developed.

Did you know?

According to the CDC, approximately 31.7% of the U.S. population has high low-density lipoprotein (LDL) or "bad cholesterol" levels.

Did you know?

Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.

Did you know?

Most women experience menopause in their 50s. However, in 1994, an Italian woman gave birth to a baby boy when she was 61 years old.

Bow shock formed by the magnetosphere of LL Orionis (center) as it collides with the Orion Nebula fl Bow shock formed by the magnetosphere of LL Orionis (center) as it collides with the Orion Nebula fl
Vision with macular degeneration is experienced with an inability to focus in the center of the visu Vision with macular degeneration is experienced with an inability to focus in the center of the visu
To keep the foot under the center of gravity, the biped’s femur is angled from hip to knee. The quad To keep the foot under the center of gravity, the biped’s femur is angled from hip to knee. The quad
Statistics Center (07/2016) Statistics Center (07/2016)
A horizontally opposed engine design helps to lower the vehicle’s center of gravity. A horizontally opposed engine design helps to lower the vehicle’s center of gravity.
The responses of an on-center cell to contrast. The responses of an on-center cell to contrast.
Video: Heart sounds

For a complete list of videos, visit our video library