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 98 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?

About 100 new prescription or over-the-counter drugs come into the U.S. market every year.

Did you know?

Adults are resistant to the bacterium that causes Botulism. These bacteria thrive in honey – therefore, honey should never be given to infants since their immune systems are not yet resistant.

Did you know?

The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

For pediatric patients, intravenous fluids are the most commonly cited products involved in medication errors that are reported to the USP.

This jumping spider's main ocelli (center pair) are very acute. This jumping spider's main ocelli (center pair) are very acute.
A passenger train crosses Stony Creek Bridge in the Rocky Mountains in 1878. Railroads were importan A passenger train crosses Stony Creek Bridge in the Rocky Mountains in 1878. Railroads were importan
The first step in hoisting a vehicle is to properly align the vehicle in the center of the stall. The first step in hoisting a vehicle is to properly align the vehicle in the center of the stall.
A normally worn spark plug that has a tapered platinum-tipped center electrode. A normally worn spark plug that has a tapered platinum-tipped center electrode.
Criteria for Trauma Center Designation Criteria for Trauma Center Designation
Injuries That Benefit from Burn Center Care Injuries That Benefit from Burn Center Care
Video: Glucose Evaluation Procedure

For a complete list of videos, visit our video library