Author Question: Why did Hubble conclude the universe must be expanding? What will be an ideal ... (Read 26 times)

casperchen82

  • Hero Member
  • *****
  • Posts: 540
Why did Hubble conclude the universe must be expanding?
 
  What will be an ideal response?

Question 2

When an electron in a hydrogen atom changes its spin from the same to the opposite direction as the proton, it
 
  A) absorbs a visible light photon.
  B) emits an X-ray photon.
  C) emits a radio wave photon.
  D) absorbs a radio wave photon.
  E) neither emits nor absorbs a photon.



mistyjohnson

  • Sr. Member
  • ****
  • Posts: 331
Answer to Question 1

He found the universe was not static, that the most distant galaxies showed us the highest recessional velocities and redshifts. He believed this was most easily understood by having all of spacetime itself expand, taking the galaxies with it.

Answer to Question 2

C



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The first monoclonal antibodies were made exclusively from mouse cells. Some are now fully human, which means they are likely to be safer and may be more effective than older monoclonal antibodies.

Did you know?

If you could remove all of your skin, it would weigh up to 5 pounds.

Did you know?

Elderly adults are living longer, and causes of death are shifting. At the same time, autopsy rates are at or near their lowest in history.

Did you know?

Excessive alcohol use costs the country approximately $235 billion every year.

Did you know?

The FDA recognizes 118 routes of administration.

For a complete list of videos, visit our video library