This topic contains a solution. Click here to go to the answer

Author Question: Discuss the discovery of galaxies, and the scientific debate that led astronomers to identify them ... (Read 32 times)

nelaaney

  • Hero Member
  • *****
  • Posts: 560
Discuss the discovery of galaxies, and the scientific debate that led astronomers to identify them as distant clouds of billions of stars.
 
  What will be an ideal response?

Question 2

A certain type of atom can only absorb certain wavelengths.
 
  a. True
  b. False
  Indicate whether the statement is true or false



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

ebe

  • Sr. Member
  • ****
  • Posts: 320
Answer to Question 1

In the middle 1800s, astronomers were first able to build telescopes large enough to see galaxies clearly. Due to their nebulous appearance and spiral shape, they were called spiral nebulae.There was disagreement over whether galaxies were within our own galaxy, or distant objects outside of our galaxy. Astronomical technology was not sensitive enough to resolve the issue until the early 1900's. In 1920, Edwin Hubble was able to use a telescope much larger than its predecessors and more sensitive photographic techniques to take more detailed pictures of galaxies.Hubble's images showed individual stars in nearby galaxies. More importantly, Cepheid variables could be seen, and their period measured. The measurement of the period of the Cepheids allowed astronomers to calculate their distance, which was clearly outside of the Milky Way.

Answer to Question 2

True




nelaaney

  • Member
  • Posts: 560
Reply 2 on: Jul 27, 2018
Excellent


billybob123

  • Member
  • Posts: 336
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

 

Did you know?

Methicillin-resistant Staphylococcus aureus or MRSA was discovered in 1961 in the United Kingdom. It if often referred to as a superbug. MRSA infections cause more deaths in the United States every year than AIDS.

Methicilli ...
Did you know?

Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.

Did you know?

Colchicine is a highly poisonous alkaloid originally extracted from a type of saffron plant that is used mainly to treat gout.

Did you know?

Stevens-Johnson syndrome and Toxic Epidermal Necrolysis syndrome are life-threatening reactions that can result in death. Complications include permanent blindness, dry-eye syndrome, lung damage, photophobia, asthma, chronic obstructive pulmonary disease, permanent loss of nail beds, scarring of mucous membranes, arthritis, and chronic fatigue syndrome. Many patients' pores scar shut, causing them to retain heat.

Did you know?

Children of people with alcoholism are more inclined to drink alcohol or use hard drugs. In fact, they are 400 times more likely to use hard drugs than those who do not have a family history of alcohol addiction.

For a complete list of videos, visit our video library