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

Author Question: What is the Hubble constant essentially a measure of? a. the number of galaxies in the universe ... (Read 57 times)

ec501234

  • Hero Member
  • *****
  • Posts: 573
on: Jul 27, 2018
What is the Hubble constant essentially a measure of?
 
  a. the number of galaxies in the universe
  b. the expansion of the universe
  c. the age of the Milky Way galaxy
  d. the amount of dark matter in an average galaxy

Question 2

Why are interstellar absorption lines so narrow compared to the width of lines which originate in the photospheres of stars?
 
  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

juiceman1987

  • Sr. Member
  • ****
  • Posts: 316
Reply #1 on: Jul 27, 2018
Answer to Question 1

b

Answer to Question 2

Much of the interstellar gas is cold, and its density is very low. Because atoms in the ISM move slowly and collide only rarely, interstellar absorption lines are extremely narrow.


ec501234

  • Member
  • Posts: 573
Reply 2 on: Jul 27, 2018
YES! Correct, THANKS for helping me on my review

shailee

  • Member
  • Posts: 392
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

« previous next »
 

Did you know?

The most common childhood diseases include croup, chickenpox, ear infections, flu, pneumonia, ringworm, respiratory syncytial virus, scabies, head lice, and asthma.

Did you know?

In ancient Rome, many of the richer people in the population had lead-induced gout. The reason for this is unclear. Lead poisoning has also been linked to madness.

Did you know?

There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.

Did you know?

Immunoglobulin injections may give short-term protection against, or reduce severity of certain diseases. They help people who have an inherited problem making their own antibodies, or those who are having certain types of cancer treatments.

Did you know?

The average office desk has 400 times more bacteria on it than a toilet.

Gravitational Lensing of Extremely Distant Galaxies Gravitational Lensing of Extremely Distant Galaxies
Isotopes may be stable or radioactive depending on the arrangement and number of neutrons in the nuc Isotopes may be stable or radioactive depending on the arrangement and number of neutrons in the nuc
Norman Bel Geddes, with Dr. Otto Koller, Air Liner Number 4. Norman Bel Geddes, with Dr. Otto Koller, Air Liner Number 4.
A mini clamp-on digital multimeter can be used to measure alternator output and unwanted AC current ... A mini clamp-on digital multimeter can be used to measure alternator output and unwanted AC current ...
How to count for the correct number of significant digits How to count for the correct number of significant digits
Psychologists measure basic memory capacity Psychologists measure basic memory capacity
Video: Deglutition

For a complete list of videos, visit our video library