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 82 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?

There are actually 60 minerals, 16 vitamins, 12 essential amino acids, and three essential fatty acids that your body needs every day.

Did you know?

Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.

Did you know?

Eat fiber! A diet high in fiber can help lower cholesterol levels by as much as 10%.

Did you know?

The use of salicylates dates back 2,500 years to Hippocrates’s recommendation of willow bark (from which a salicylate is derived) as an aid to the pains of childbirth. However, overdosage of salicylates can harm body fluids, electrolytes, the CNS, the GI tract, the ears, the lungs, the blood, the liver, and the kidneys and cause coma or death.

Did you know?

Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.

The male reproductive system, sagittal section showing the organs of the system and their relation t The male reproductive system, sagittal section showing the organs of the system and their relation t
Solar Neutrino Experiment Solar Neutrino Experiment
Schematic of a typical electronic throttle control (ETC) system. Note that terminal #5 is always ... Schematic of a typical electronic throttle control (ETC) system. Note that terminal #5 is always ...
How to solve a linear system by the substitution method How to solve a linear system by the substitution method
Effect of “Moral Restraint” in the Malthusian Model Effect of “Moral Restraint” in the Malthusian Model
A chemical reaction is run in which 447 Joules of work is done by the system and A chemical reaction is run in which 447 Joules of work is done by the system and
Video: What are Strong & Weak Acids and How they're different?

For a complete list of videos, visit our video library