Is 1D Space a Subspace of 2D Space in Physics?

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Discussion Overview

The discussion revolves around the relationship between different dimensional spaces in physics, specifically whether 1D space can be considered a subspace of 2D space, and how this concept extends to higher dimensions, including 3D and 4D spaces (spacetime). Participants explore the implications of these relationships in the context of vector spaces and physical properties.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether 1D space in physics can be viewed as a subspace of 2D space, and extends this inquiry to 3D and 4D spaces, suggesting a desire to understand the application of vector space properties in physical contexts.
  • Another participant asserts that if n < m, then n-dimensional space can be considered a subspace of m-dimensional space, providing an example to illustrate this point.
  • A different participant clarifies that while there are isomorphisms between 1D and 2D spaces, 1D space is not strictly a subspace of 2D space, emphasizing the distinction between isomorphism and subspace relationships.
  • One participant notes that physics in a plane can be viewed as a superposition of physics on two lines, while also cautioning about the differences in metrics when discussing special relativity in 4D spacetime.

Areas of Agreement / Disagreement

Participants express differing views on whether lower-dimensional spaces can be considered subspaces of higher-dimensional spaces. There is no consensus on the definitions and relationships between these spaces, indicating an ongoing debate.

Contextual Notes

The discussion includes assumptions about dimensionality and the nature of subspaces, which may depend on specific definitions and contexts in mathematics and physics. The implications of these relationships are not fully resolved, and participants express varying interpretations.

gianeshwar
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Please excuse me for my less knowledge. I always tried to physically visualise mathematics facts.
My first question is " Is 1D space of physics a subspace of 2D space of physics and so on...
So in this way our 3D space is a subspace of 4 D space(spacetime).
Can I imagine applying all properties of vector space applicable in physical world?
My study of Advanced Algebra is still in infancy.
Please let me know if my question is irrelevant.
Thank you all in advance.
Please reply so that I start further discussion related to Advanced Algebra. I want to master it.

In classical mechanics some process can be defined in terms of generalised coordinates like density , temperature , location , time and so on...
Now a space is defined with independent dimensions density,temperature,location, time and suppose colour.
Is space generated by density, temperature and location a subspace of above space.
Is it embedded in the above space?
Can I have two different subspaces of five dimensions of the above space?
 
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If n < m, then n dimensional space can be considered a subspace of m dimensional space.
Example: Let{(x,y,z)|x,y,z real} be a 3 dimensional space. Then {(x,y,a)|x,y real, a fixed} is a 2 dimensional subspace for each value of a.

I think this should help you with the second question. You can have as many subspaces as you want.
 
Notice the difference between your question "Is 1D space of physics a subspace of 2D space of physics and so on... So in this way our 3D space is a subspace of 4 D space(spacetime)."

and mathman's response "If n < m, then n dimensional space can be considered a subspace of m dimensional space."

Strictly speaking, no, 1D space is NOT a subspace of 2D space and 3D space is not a subspace of 4Dspace. Points in 1D space can be designated by a single number, a, while points in 2D space are designated by pairs of numbers, (x, y). But we can associate the point, a, with the pair (a, 0) so there is an "isomorphism" between 1D and a subspace of 2D. This is NOT the same as saying 1D is a subspace itself because there are many different such "isomorphisms" or assignments: a with (0, a) or with (a, a) or (a, ma) for fixed m, etc.
 
Thank you dear friends!
 
To a large extent physics in the plane can be considered a super position of physics on two lines. However, be careful. Special relativity with physics in 4 D (Space-time) is like physics in conventional four dimensions except the metric is different. The interval in special relativity is (often): sqr root(x squared + y squared + z squared - time squared).
 

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