Space-Time Fabric: Understanding 3D & Time Together

In summary: Then you can imagine a universe with more dimensions (above and beyond the 3 we experience) and see how the curvature of that extra dimension affects space-time.
  • #1
gsingh2011
115
1
I don't understand how the space-time fabric works. I've seen videos where the sun is in the space-time fabric and it makes a ripple in it and the Earth revolves around this. This works fine if our universe was 2D, but what if there was something above the sun in that diagram? Basically, I'm confused on how you put 3D space along with a fourth dimension time in a 2D plane...
 
Physics news on Phys.org
  • #2
You are right, it is a really poor analogy and quite useless.
 
  • #3
gsingh2011 said:
I don't understand how the space-time fabric works. I've seen videos where the sun is in the space-time fabric and it makes a ripple in it and the Earth revolves around this.
This is a common misconception. In this analogy the fabric doesn't represent space-time, just reduced space (2D dimensions of it). It shows just the spatial curvature which has some effects on its own, but the main effect of gravitation (mass attraction), cannot be explained without the time dimension. Here are links to better visualizations:
http://www.relativitet.se/spacetime1.html
http://www.physics.ucla.edu/demoweb..._and_general_relativity/curved_spacetime.html
http://www.adamtoons.de/physics/gravitation.swf

gsingh2011 said:
This works fine if our universe was 2D,
Yes you have to imagine we live in an universe with less dimensions to understand this curvature visualizations by embedding. The illustrations are 3D, so a curved diagram in it can be 2D at max. The space-time diagrams linked above are not different that that aspect. They just use 1 space & 1 time dimension instead of 2 space dimensions.

gsingh2011 said:
but what if there was something above the sun in that diagram?
If there was something above the sun in that diagram, it would not be in our universe. The 3D dimensions of these illustrations are a virtual embedding space without physical meaning. It is needed to visualize curvature of the diagram.

This sun and Earth are actually not spheres above the fabric, but circles within the fabric in a space-space diagram, even if they are often shown as spheres.

gsingh2011 said:
Basically, I'm confused on how you put 3D space along with a fourth dimension time in a 2D plane...
Well you don't. You can only visualize 2 of the 4 space-time dimensions in a 2D diagram.
 
Last edited:
  • #4
gsingh2011 said:
I don't understand how the space-time fabric works. I've seen videos where the sun is in the space-time fabric and it makes a ripple in it and the Earth revolves around this. This works fine if our universe was 2D, but what if there was something above the sun in that diagram? Basically, I'm confused on how you put 3D space along with a fourth dimension time in a 2D plane...
The best way, I suppose, is to suppress two spatial dimensions and view space-time as 2-dimensional.
 

1. What is space-time fabric?

The concept of space-time fabric refers to the idea that space and time are not separate entities, but rather are interconnected and can be thought of as a fabric or fabric-like structure. This fabric is affected by the presence of mass and energy, causing it to curve and bend.

2. How does space-time fabric relate to Einstein's theory of relativity?

Einstein's theory of relativity states that the laws of physics are the same for all observers in uniform motion. This theory also introduced the concept of space-time fabric, where space and time are not absolute but rather are relative and interconnected. The curvature of space-time fabric explains the effects of gravity.

3. Is space-time fabric the same as the fabric of the universe?

No, space-time fabric is a concept used to explain the interconnectedness of space and time. The fabric of the universe, on the other hand, refers to the entire physical structure of the universe, including all matter, energy, and space-time fabric.

4. Can space-time fabric be seen or measured?

Space-time fabric cannot be seen or measured directly, as it is a theoretical concept. However, its effects can be observed and measured through experiments and observations, such as the bending of light around massive objects due to the curvature of space-time fabric.

5. How does space-time fabric impact our understanding of the universe?

Space-time fabric plays a crucial role in our understanding of the universe, particularly in explaining the effects of gravity and the behavior of massive objects. It also provides a framework for understanding the concept of time and how it is affected by the presence of mass and energy. The concept of space-time fabric has significantly advanced our understanding of the universe and continues to be an essential concept in modern physics.

Similar threads

  • Special and General Relativity
2
Replies
37
Views
2K
  • Special and General Relativity
Replies
29
Views
2K
  • Special and General Relativity
Replies
18
Views
2K
  • Special and General Relativity
Replies
16
Views
2K
  • Special and General Relativity
Replies
16
Views
5K
  • Special and General Relativity
Replies
16
Views
2K
  • Special and General Relativity
Replies
14
Views
4K
  • Special and General Relativity
Replies
3
Views
913
  • Special and General Relativity
Replies
29
Views
1K
  • Special and General Relativity
Replies
5
Views
1K
Back
Top