Why did Aristotle arrange the planets in this order?

  • Context: High School 
  • Thread starter Thread starter Glenn G
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around Aristotle's arrangement of the planets in the order of Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. Participants explore the reasoning behind this order within the context of Aristotle's geocentric model and observational limitations of his time.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that Aristotle's order may reflect his interpretation of the distance of celestial bodies from Earth, with the Moon being closest.
  • Another participant notes that the arrangement might have been influenced by the visibility of the Moon, Mercury, and Venus passing in front of the Sun, leading to their classification as inner celestial spheres.
  • A different viewpoint proposes that the Sun's position in the order could be due to its unique movement in the sky, suggesting it could serve as a demarcation between inner and outer planets.
  • One participant questions the reasoning behind placing the Sun fourth in the order, indicating a lack of clarity on Aristotle's rationale.
  • Another participant speculates that aesthetic considerations might have influenced the arrangement, particularly regarding the apparent wandering of the planets.

Areas of Agreement / Disagreement

Participants express differing interpretations of Aristotle's reasoning, with no consensus on why the Sun is placed fourth or the overall rationale behind the order of the planets.

Contextual Notes

Participants acknowledge the limitations of Aristotle's observational capabilities and the potential for misjudgment regarding the sizes and distances of celestial bodies.

Glenn G
Messages
113
Reaction score
12
Hi,
I'm interested to find out why he went with Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn as his order (in fact on one wiki page it has Sun as 2nd though this seems wrong). However the moon being so prominent in the sky and sun also followed by mercury and Venus as inner planets always observed relatively close into the sun would have seemed a reasonable assumption to him?

I've tried to search but can't find out why?

Regards,
G.
 
Astronomy news on Phys.org
Hi,

After having a quick read through of his description of the geocentric model, the only reasonable conclusion that I would come to would be that he interpreted that particular order being the order of distance from the Earth.

ie, the moon closest to Earth then the Sun, then Mercury, then Venus, then Mars etc..

It's obvious to us now that this isn't the case, but perhaps it wasn't obvious to Aristotle when observing these bodies.

For example, Aristotle not knowing that the planets are orbitting the Sun, and observing another planet in the solar system could lead him to misinterpret the distance to said planet.

This is my interpretation anyhow.

Hope it helps.
 
Hiya, yes that's why I said that would make sense but his actual suggested order was moon, mercury, Venus Sun etc. I can't see why he's put sun at 4th?
 
Well I suppose he could have misjudged the size of the planets and sun. But where have you read he placed the sun fourth if you don't mind me asking?
 
upload_2017-4-26_22-28-5.png
Hi again, there are a number of pictures like this.
upload_2017-4-26_22-31-16.png
I think it may have been that the moon (luna), mercury and venus were all observed, at some point, passing infront of the sun so must be on an inner celestial sphere?
 
This is just an informed guess.
Of all the bodies the Sun wanders the least in the sky. As such it seems in its own category. To make the model aesthetically pleasing you could either put it at the front in the back, or in-between some other two groups.
It can't be at the front, since solar eclipses are a thing (hence Moon is first).
Not at the back because... beats me. Unless the ancient Greeks could verify whether a planet can or cannot transit. (could they?)
But as a demarcation between two other groups, it works fine with the inner and outer planets (as we know them today). The inner ones wander less than the outer ones (and differently - no apparent retrograde motion), hence two nice groups of wanderers (gr. planetes) and the stately sun in-between.
Why the order of planets in each group such as it is - this again eludes me. It could be another aesthetic argument about how much of wandering a planet should do.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 16 ·
Replies
16
Views
5K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 10 ·
Replies
10
Views
5K
Replies
17
Views
4K
  • · Replies 34 ·
2
Replies
34
Views
8K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K