Is Spacetime Flat? Answers to Orbit Questions

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    Flat Spacetime
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Discussion Overview

The discussion centers around the nature of spacetime, specifically whether it is flat or curved, and how this relates to the behavior of objects in orbit. Participants explore theoretical implications, visual representations, and the concept of multiple universes in relation to spacetime geometry.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants assert that spacetime is not flat, suggesting that if it were, the universe would be in a steady state and empty.
  • Others argue that while spacetime itself is not flat, the three-dimensional slices of spacetime, referred to as "space," appear roughly flat based on current observations.
  • One participant proposes that if spacetime were absolutely flat, it would lead to the existence of multiple universes, which they believe is not the case, but they think it is close to flat.
  • A later reply challenges the idea of multiple universes, questioning whether Einstein discussed such concepts in relation to flat spacetime.
  • Another participant clarifies that Minkowski space represents flat, uncurved spacetime in the context of special relativity.
  • Visual representations of spacetime are discussed, with some participants suggesting that two-dimensional analogies can be misleading and proposing alternative ways to visualize spacetime.

Areas of Agreement / Disagreement

Participants do not reach consensus on whether spacetime is flat or curved, with multiple competing views presented throughout the discussion.

Contextual Notes

There are unresolved assumptions regarding the definitions of flatness and curvature in spacetime, as well as the implications of these concepts on the existence of multiple universes.

Quds Akbar
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Is space-time flat and if the answer is yes then how can objects orbit vertically and diagonally(since gravity is the warping of space-time)? Or does it exist from all sides?
 
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Spacetime is not flat.
 
Space-time itself is not flat. If it were totally flat, the universe would be in a steady state, (well, if it were totally flat everywhere, it would also have to be empty) which it is not. The 3-D slices of space-time, which we call "space" is roughly flat as far as we can tell. This is the statement that the curvature parameter found in the FLRW metric is roughly 0.
 
Spacetime is definitely not flat. The two dimensional analogies you might see on television and on documentaries are misleading.

The two dimensional visual representation is this:
geodetic.jpg


So just try picturing it better like this, instead:
illus_3dspace1.jpg
 
Space-time isn't flat,
If spacetime is absolutely flat, then if you were to set off in a rocket ship and travel in a single direction, you would eventually get to the universe that's just like the one you're in now, but where you got up an hour later this morning, or where Michael Jackson is still alive. And if you continued on this journey, eventually you would start getting to the other universes with basic physical laws, the other universes of the multiverse. What I believe is It's close to Flat, But not absolute flat

3D of Space Combine with 1D of Time to Form Malinowski space
200px-World_line.svg.png


Einstein in his book talked about this, Should read it..
 
CaptCoonoor said:
Space-time isn't flat,
If spacetime is absolutely flat, then if you were to set off in a rocket ship and travel in a single direction, you would eventually get to the universe that's just like the one you're in now, but where you got up an hour later this morning, or where Michael Jackson is still alive. And if you continued on this journey, eventually you would start getting to the other universes with basic physical laws, the other universes of the multiverse. What I believe is It's close to Flat, But not absolute flat

3D of Space Combine with 1D of Time to Form Malinowski space
200px-World_line.svg.png


Einstein in his book talked about this, Should read it..

What? I don't think Einstein talked about multiple universes to which you could travel if space-time is flat...
 
CaptCoonoor said:
3D of Space Combine with 1D of Time to Form Minkowski space

You've misunderstood what you read. Minkowski space is the flat uncurved spacetime of special relativity.
 
Matterwave said:
What? I don't think Einstein talked about multiple universes to which you could travel if space-time is flat...
I meant he talked abut Minkowsi space and lorentz transformation
 
What is the book called?
 
  • #11
We visualize space-time in a two dimensional (flat) image, because it's easier to understand that way.
If you stack an infinite amount of those two dimensional space-time fabrics above and below one another, like stacking plates; then you have what would be the the space-time we have around us.
 
  • #12
You may wish to search the forum for similar questions. This one has been answered more than once.
 
  • #13
This one is for Phinds:
teaching_physics.png
 
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  • #14
Lamdbaenergy said:
illus_3dspace1.jpg
Cool graphic, but isn't it curved the wrong way? Does the purple object have negative mass?
 

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