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

Author Question: Describe the Ptolemaic model of the solar system. How did Ptolemy account for the apparent ... (Read 98 times)

tichca

  • Hero Member
  • *****
  • Posts: 554
on: Jul 27, 2018
Describe the Ptolemaic model of the solar system. How did Ptolemy account for the apparent retrograde motion of the planets?
 
  What will be an ideal response?

Question 2

Using an orbit size of 8 kpc, and a period of 225 million years, the mass of our Galaxy is found to be closest to
 
  A) 106 solar masses.
  B) 108 solar masses.
  C) 1010 solar masses.
  D) 1011 solar masses.
  E) 1012 solar masses.


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Ptupou85

  • Sr. Member
  • ****
  • Posts: 334
Reply #1 on: Jul 27, 2018
Answer to Question 1

Although Ptolemy's model was an Earth-centered model of the solar system, it was sufficiently accurate to remain in use for 1,500 years. His model used the ancient idea that all motions in the heavens must be perfect circles. Therefore, the planets moved on circles that orbited on larger circles around Earth. This circle upon circle motion accounted for the apparent retrograde motion of the planets. Ptolemy carefully selected sizes for the circles to reproduce the motions seen in the sky. He also placed Earth slightly off-center to improve model predictions even more.

Answer to Question 2

D


tichca

  • Hero Member
  • *****
  • Posts: 554
Reply #2 on: Jul 27, 2018
Both answers were spot on, thank you once again


Ptupou85

  • Sr. Member
  • ****
  • Posts: 334
Reply #3 on: Jul 27, 2018
Great! Please up vote :D


« previous next »
 

Did you know?

Medications that are definitely not safe to take when breastfeeding include radioactive drugs, antimetabolites, some cancer (chemotherapy) agents, bromocriptine, ergotamine, methotrexate, and cyclosporine.

Did you know?

More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.

Did you know?

Studies show that systolic blood pressure can be significantly lowered by taking statins. In fact, the higher the patient's baseline blood pressure, the greater the effect of statins on his or her blood pressure.

Did you know?

Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.

Did you know?

Nearly all drugs pass into human breast milk. How often a drug is taken influences the amount of drug that will pass into the milk. Medications taken 30 to 60 minutes before breastfeeding are likely to be at peak blood levels when the baby is nursing.

A hypothetical model of the process of cell-wall expansion. A hypothetical model of the process of cell-wall expansion.
Disorders and Diseases of the Digestive System Disorders and Diseases of the Digestive System
How the Wernicke-Geschwind model works in a person who is responding to a heard question and reading ... How the Wernicke-Geschwind model works in a person who is responding to a heard question and reading ...
Effects of Earth’s Changing Orientation: Solar Angle Effects of Earth’s Changing Orientation: Solar Angle
Lymphatic system vessels and the flow of lymph. Lymphatic system vessels and the flow of lymph.
The Autonomic Nervous System The Autonomic Nervous System
Video: Inflammation Animation

For a complete list of videos, visit our video library