What Is the Importance of Understanding the 4th Dimension?

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Discussion Overview

The discussion centers on the significance of understanding the fourth dimension, particularly in relation to concepts from physics and popular media. Participants explore theoretical implications, analogies, and the relevance of higher dimensions in explaining physical phenomena.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the relevance of the fourth dimension, questioning whether it serves merely human curiosity or has practical implications in physics.
  • Another participant uses the film "Time Machine" to illustrate the concept of moving through the fourth dimension, suggesting it allows for movement beyond physical barriers.
  • A participant notes that a position-vs-time graph represents a four-dimensional mathematical space, contrasting it with simpler one-dimensional models.
  • One contributor explains that dimensions are numerical specifications for points in space, emphasizing the need for four dimensions to describe events in spacetime, as per Einstein's theory.
  • There is a discussion about the speculative nature of higher spatial dimensions, with some theories proposed but lacking experimental validation.
  • An analogy involving a two-dimensional being trapped in a circle is presented to illustrate how a fourth spatial dimension could allow movement outside of perceived boundaries.
  • A later reply challenges the feasibility of the time travel scenario presented in the film, indicating that the rock's movement would not align with the proposed fourth-dimensional escape.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation of the fourth dimension, with some agreeing on its theoretical implications while others remain skeptical about its practical relevance. The discussion does not reach a consensus on the importance or interpretation of the fourth dimension.

Contextual Notes

Some claims about the fourth dimension are speculative and depend on definitions that are not universally accepted. The discussion includes unresolved questions about the implications of higher dimensions and their experimental validation.

_Mayday_
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Hello, I am in the process of reading Black Holes, Wormholes & Time Machines and am somewhat confused, even though it is aimed at people like myself who have very little knowledge on the subject. I am reading about the 4th dimension now but I do not understand the relevance of researching into the 4th dimension or giving it a lot of thought. Jim Al-Khalilie, the author, has explained the fourth dimension as like being in a hollow sphere, and the fourth dimension would allow you to exit the sphere without getting any closer to any of the edges. What does knowing there is a fourth or second dimension universe mean? Is it just out of human curiosity or does it explain or help explain some theories. I'm really stuck here I am very interested in this subject, so do not think that I am saying it is useless because I have no idea really :-p

_Mayday_

If this is in the wrong part of the site please let me know so I don't do it again... :smile:
 
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A great example is the film "Time Machine" .. the time traveler is trapped inside a rock so he can not move but going forward on time (moving on the fourth dimension) he moves to a place where the rock has disappeared.

Real physics in 4-D implies no motion , perhaps 4 dimension exists or is just a physical artifact to describe nature, if we could 'see' in 4 dimension i believe that the mistery of QM and Relativity could be solved.
 
Note that a position-vs-time graph is a 4-dimensional "[mathematical] space".
In introductory physics, one often simplifies the discussion and considers only one-dimensional spatial motion (say, along a line)... which yields a position-vs-time graph that is 2-dimensional.
 
Are you clear on what "dimension" means? A dimension is just a number specifying a specific thing. To designate a specific point in space requires 3 numbers no matter what coordinate system you use- it is "three dimensional". Physicists study "events": things that happen at a specific place at a specific time. We require three numbers to specify the position in space and a fourth to designate the time. That is what Einstein meant when he said "Our universe is a four-dimensional space-time continuum.

It appears that the text you are referring to is talking about a possible 4th "space" dimension- that would be somewhat speculative. There are a number of theories that involve higher space dimensions but none of them have been shown to be experimentally "correct" (there isn't any question about a "second dimension"!).

The analogy with the hollow sphere is this- Suppose there existed a being that lived only in two dimesions- that could move about on a sheet of paper, that could move "up or down" or "left or right" but knew nothing about "vertical" direction. A circle containing that being would be a prison it could not get out of. But if the creature could move vertically, it would could move outside the circle. Similarly, if there were a fourth space dimension, a three dimensional person could move out of a hollow sphere.
 
mhill said:
A great example is the film "Time Machine" .. the time traveler is trapped inside a rock so he can not move but going forward on time (moving on the fourth dimension) he moves to a place where the rock has disappeared.
That wouldn't actually work if the rock is just moved rather than broken up into pieces. And that movie sucked. :smile:
 
HallsofIvy said:
Are you clear on what "dimension" means? A dimension is just a number specifying a specific thing. To designate a specific point in space requires 3 numbers no matter what coordinate system you use- it is "three dimensional". Physicists study "events": things that happen at a specific place at a specific time. We require three numbers to specify the position in space and a fourth to designate the time. That is what Einstein meant when he said "Our universe is a four-dimensional space-time continuum.

It appears that the text you are referring to is talking about a possible 4th "space" dimension- that would be somewhat speculative. There are a number of theories that involve higher space dimensions but none of them have been shown to be experimentally "correct" (there isn't any question about a "second dimension"!).

The analogy with the hollow sphere is this- Suppose there existed a being that lived only in two dimesions- that could move about on a sheet of paper, that could move "up or down" or "left or right" but knew nothing about "vertical" direction. A circle containing that being would be a prison it could not get out of. But if the creature could move vertically, it would could move outside the circle. Similarly, if there were a fourth space dimension, a three dimensional person could move out of a hollow sphere.

Thank you, that has certainly cleared things up.
 

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