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

Author Question: Changing minds: From the time the idea of dark matter was first proposed in the 1930s, it took ... (Read 146 times)

azncindy619

  • Hero Member
  • *****
  • Posts: 562
Changing minds: From the time the idea of dark matter was first proposed in the 1930s, it took nearly 50 years for astronomers to universally accept the existence of dark matter. Discuss the process by which that acceptance came about.
 
  What evidence was collected, and how was it checked?

Question 2

Order the interior layers of the Sun from the hottest to the coldest.
 
  A) radiation zone, core, convection zone, photosphere
  B) photosphere, convection zone, core, radiation zone
  C) core, radiation zone, convection zone, photosphere
  D) photosphere, convection zone, radiation zone, core



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Awesome

  • Sr. Member
  • ****
  • Posts: 280
Answer to Question 1

The idea was first proposed as an explanation for how galaxies in clusters had such high speeds relative to each other yet did not fly apart. Later astronomers also found that there was some unseen source of mass within spiral galaxies  the speed at which stars orbit does not drop off with distance, as would be expected if the only source of gravity was the stars and gas. A source of unseen mass in galaxies was further confirmed by measuring the high-speed random orbits of stars in elliptical galaxies. Dark matter in galaxy clusters was confirmed by the discovery of very high temperature intracluster gas (heated by moving under the influence of large amounts of unseen matter), and by gravitational lensing of clusters. It was only after the idea of dark matter was used to explain several more phenomena that it became generally accepted.

Answer to Question 2

C




azncindy619

  • Member
  • Posts: 562
Reply 2 on: Jul 27, 2018
YES! Correct, THANKS for helping me on my review


peter

  • Member
  • Posts: 330
Reply 3 on: Yesterday
:D TYSM

 

Did you know?

Increased intake of vitamin D has been shown to reduce fractures up to 25% in older people.

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

Did you know?

Bisphosphonates were first developed in the nineteenth century. They were first investigated for use in disorders of bone metabolism in the 1960s. They are now used clinically for the treatment of osteoporosis, Paget's disease, bone metastasis, multiple myeloma, and other conditions that feature bone fragility.

Did you know?

Asthma-like symptoms were first recorded about 3,500 years ago in Egypt. The first manuscript specifically written about asthma was in the year 1190, describing a condition characterized by sudden breathlessness. The treatments listed in this manuscript include chicken soup, herbs, and sexual abstinence.

Did you know?

Drug abusers experience the following scenario: The pleasure given by their drug (or drugs) of choice is so strong that it is difficult to eradicate even after years of staying away from the substances involved. Certain triggers may cause a drug abuser to relapse. Research shows that long-term drug abuse results in significant changes in brain function that persist long after an individual stops using drugs. It is most important to realize that the same is true of not just illegal substances but alcohol and tobacco as well.

For a complete list of videos, visit our video library