Is There Truly an Inside and Outside?

  • Context: High School 
  • Thread starter Thread starter ddjj77
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the concepts of "inside" and "outside," particularly in relation to physical objects like pipes and closed surfaces. Participants explore whether these terms have real meaning in physical reality or if they are merely conceptual. The conversation touches on philosophical implications, scientific definitions, and the nature of boundaries in both classical and quantum contexts.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • Some participants question whether "inside" and "outside" exist as tangible realities or are merely conceptual frameworks.
  • One participant emphasizes that science does not require exact definitions, suggesting that ambiguity in defining boundaries can be acceptable.
  • Another participant argues that there is a clear distinction between inside and outside for closed surfaces in 3D Euclidean space, asserting that mathematical definitions provide clarity.
  • Several participants note that from a quantum mechanical perspective, the concept of an exact border may not hold, which complicates the discussion of boundaries.
  • One participant humorously suggests asking one's heart to determine the inside of a person, indicating a more philosophical approach to the question.
  • Another participant highlights the importance of understanding the distinction between inside and outside in the context of physical laws, such as Gauss's law.

Areas of Agreement / Disagreement

Participants express differing views on the nature of "inside" and "outside," with some asserting clear definitions while others emphasize ambiguity and conceptual interpretations. The discussion remains unresolved, with multiple competing perspectives present.

Contextual Notes

Participants acknowledge that definitions may depend on the context, such as mathematical versus physical interpretations. The discussion also reflects on the limitations of language in conveying precise scientific concepts.

Who May Find This Useful

This discussion may be of interest to those exploring philosophical questions in physics, the nature of boundaries in mathematics, or the implications of quantum mechanics on classical concepts.

ddjj77
Messages
64
Reaction score
4
Are there any such locations in reality as "Inside" and "outside" anything, except as concepts?
We say "Inside a circle," while circles exists only as concepts.
Specifically, is there an inside of me?
Or, is there an inside to a 1" OD x 3/4" ID x .000001" L pipe?
Is there an inside to a similar pipe that's a mile long? Where exactly is the border between the inside and outside of the pipe?
 
Physics news on Phys.org
An important coming-of-age realization is that not everything is black and white. Another is that this does not rob "black" and "white" of all meaning.
 
  • Like
Likes   Reactions: Chestermiller, DrClaude and Khashishi
ddjj77 said:
Where exactly is the border between the inside and outside of the pipe?
To do science, we need to get rid of the word 'exactly'. Science is not exact. It does not need to be, and attempts to be exact only hinder progress.

Consider Newtonian mechanics. It is not exactly correct, but it is enormously useful. We have replaced it with Einstein's theory of gravity. We do not expect that to be exact either, since we know it is incompatible with quantum mechanics, yet it is more accurate than Newtonian mechanics, and useful in even more situations. One day we expect Einstein's theory will be replaced by something even better, which will later on be replaced by something better again, and so on.

Turning to the pipe. When you zoom right in, ambiguity arises about exactly what the border of the pipe is. Indeed, from a quantum mechanical perspective, there is no such thing as the exact border of the pipe. Fortunately, we don't need to identify an exact border, so the fact that the question has no answer doesn't matter.

For most purposes, if the pipe wall's thickness is approx h and the pipe has radius approx R to the approx outer wall of the pipe, we can work by simply assuming that all points of distance less than R - 1.001 h from the pipe's approx centre are inside the pipe and all points of distance more than R + 0.001h are outside it.
 
  • Like
Likes   Reactions: Chestermiller
andrewkirk said:
Turning to the pipe. When you zoom right in, ambiguity arises about exactly what the border of the pipe is. Indeed, from a quantum mechanical perspective, there is no such thing as the exact border of the pipe. Fortunately, we don't need to identify an exact border, so the fact that the question has no answer doesn't matter.

Good points. Thanks.
 
The inside of this thread is closed for Moderation. Hopefully we can figure out what to do with it inside of a day...
 
  • Like
Likes   Reactions: Chestermiller, phinds and Asymptotic
After a Mentor discussion, the thread is re-opened. Thanks for your patience.
 
I think there is a clear distinction between inside and outside for closed surfaces in 3D euclidean space.
 
ddjj77 said:
Specifically, is there an inside of me?
Ask your heart :smile:
 
andrewkirk said:
When you zoom right in, ambiguity arises about exactly what the border of the pipe is. Indeed, from a quantum mechanical perspective, there is no such thing as the exact border of the pipe. Fortunately, we don't need to identify an exact border, so the fact that the question has no answer doesn't matter.
This reminded me of
 
  • #10
I actually do not understand the problem with this whole thing.

"Inside" is defined as a region encompassed by a closed boundary. When you have a spherical shell, there is no ambiguity on where "inside" the sphere is, since one volume is bounded by a closed surface, the other isn't.

Note that this is more math than physics, and I'm sure there are clear and unambiguous set of definitions for this. And we use such math in many instances. In Gauss's law, you'd BETTER know the difference between inside a closed surface versus outside of it.

Zz.
 
  • Like
Likes   Reactions: davenn

Similar threads

  • · Replies 63 ·
3
Replies
63
Views
5K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 14 ·
Replies
14
Views
9K
  • · Replies 18 ·
Replies
18
Views
12K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K