Travelling to the edge of the Universe, 4th Dimensional Time Travel

Click For Summary

Discussion Overview

The discussion revolves around the concept of traveling to the edge of the Universe and the implications of such travel in relation to dimensions, particularly the fourth dimension. Participants explore theoretical models of the Universe's shape and structure, including the idea of a 4D hypersphere and the nature of spatial and temporal dimensions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that if the Universe is finite, there may be an 'edge' or a point of wraparound, similar to a video game, though this remains speculative.
  • Others argue that the observable universe is always centered on the observer, suggesting that no matter how far one travels, they remain at the center of their observable universe.
  • One participant notes that if the Universe curves back on itself, it would require hundreds of billions of light years to observe such curvature, which current measurements suggest is not evident, indicating a nearly flat universe.
  • There is a distinction made between curvature in a fourth spatial dimension versus time, with some participants seeking clarification on this concept.
  • Another viewpoint suggests that it is impossible to reach the limits of the universe due to its expansion exceeding the speed of light.
  • Discussion includes the definition of a 4D hypersphere and its implications for understanding curvature in spatial dimensions rather than time.
  • Some participants express confusion regarding the existence of a fourth spatial dimension in our Universe, with a consensus that we currently understand our universe to have three spatial dimensions and one time dimension.
  • There are challenges to the expertise of participants, with some questioning the ability of others to answer fundamental physics questions.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of the Universe, the concept of dimensions, and the implications of travel within it. The discussion remains unresolved with no consensus on key points.

Contextual Notes

Limitations include the dependence on definitions of dimensions and curvature, as well as the unresolved nature of the Universe's structure and the implications of its expansion.

GetBent
Messages
3
Reaction score
0
There is no edge of the Universe. Alright, I kinda realize this, I'm not a layman.

However, nobody addresses what would happen if you traveled far enough. There's only a limited amount of matter out there and going off the theory that the volume of our Universe is finite, there's 'an edge' somewhere. Maybe not one that is reachable in 3D space however..

Say you're an adventurer, and you cataloged every piece of matter in existence after traveling for trillions of light years in one single direction. My question: Would you eventually 'wraparound' back to your original location, like in a video game, like Pac-Man?

Take the balloon model, imagine a 3d Balloon. On there is a 2D Plane. The 2D plane is the universe. We put circles with marker over it to represent galaxies and we inflate it. That's our Universe expanding from Dark Energy and yada yada (We all know this). Now we draw a straight line around the balloon. Though it's not a straight line to us, it is to the 2D inhabitants. In our 3D world, the line 'bends' across our 3D vector, where to the 2D inhabitants however, it's just a line going on and on in one direction.

Now apply that to the 3D Universe. Assuming the Universe is just one big 4D hypersphere: Using the model, as we travel in a straight line journey across the Cosmos in one direction, we'd be 'bending' across this 4th Dimensional vector, which is Time correct? So if we keep traveling, the 4th coordinate vector would increase, than slowly decease back to our original vector location, which would mean our Time is getting distorted. Would we eventually return to our original location, and would it happen because the side effect of Time Travel has made it feasible?
 
Astronomy news on Phys.org
The observable universe is always centered on the observer. No matter how far you travel, you are still at the center of your observable universe.
 
GetBent said:
Say you're an adventurer, and you cataloged every piece of matter in existence after traveling for trillions of light years in one single direction. My question: Would you eventually 'wraparound' back to your original location, like in a video game, like Pac-Man?

We don't know. It may or may not be true. We do know that if the universe does curve back on itself it must take hundreds of billions of light years at least. Otherwise we would see curvature already. Instead, measurements show a universe that is very close to being flat.

Now apply that to the 3D Universe. Assuming the Universe is just one big 4D hypersphere: Using the model, as we travel in a straight line journey across the Cosmos in one direction, we'd be 'bending' across this 4th Dimensional vector, which is Time correct?

No, this curvature would be in a 4th spatial dimension, not in time.
 
Drakkith said:
No, this curvature would be in a 4th spatial dimension, not in time.

Care to elaborate on what you mean by 4th 'spatial' dimension rather than just the 4th Dimension?
 
Its impossible to ever prove this one way or the other since the observable universe is expanding faster then c. Since its impossible travel faster then c we can never reach the limits of the universe even if we traveled for trillions of years.
 
  • Like
Likes   Reactions: 1 person
GetBent said:
Care to elaborate on what you mean by 4th 'spatial' dimension rather than just the 4th Dimension?

A 4d hypersphere by definition occupies four spatial dimensions. The curvature would be along the surface of the hyperesphere, not the time dimension.

http://en.wikipedia.org/wiki/Hypersphere
 
The fourth spatial dimension could for example be orthogonal, at right angles to, to all three of the dimensions we are so familiar with. All three, simultaneously...
 
..but the fourth 'spatial' dimension doesn't exist in our Universe correct?
 
GetBent said:
..but the fourth 'spatial' dimension doesn't exist in our Universe correct?

As far as we know, we live in a universe with three spatial dimensions and one time dimension, so no, it does not exist.
 
  • #10
I puzzled by this. You say you are a professional physicists, yet you seem to be unable to answer fairly basic questions about physics.
 
  • #11
HallsofIvy said:
I puzzled by this. You say you are a professional physicists, yet you seem to be unable to answer fairly basic questions about physics.

Huh?
 

Similar threads

Replies
14
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K