Is Spacetime Flat? Answers to Orbit Questions

In summary, the conversation is about whether space-time is flat and how objects can orbit in different directions if gravity is the warping of space-time. The conclusion is that space-time is not completely flat, but the 3D slices of space-time are roughly flat. Minkowski space is the flat, uncurved spacetime of special relativity, which was discussed by Einstein in his book. The conversation also mentions the concept of multiple universes and how space-time can be visualized in a two-dimensional image. There is also a discussion about a graphic of stacked two-dimensional space-time fabrics and the possibility of negative mass.
  • #1
Quds Akbar
124
6
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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  • #2
Spacetime is not flat.
 
  • #3
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.
 
  • #4
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
 
  • #5
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..
 
  • #6
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...
 
  • #7
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.
 
  • #8
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
 
  • #9
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
 
  • Like
Likes phinds
  • #14
Lamdbaenergy said:
illus_3dspace1.jpg
Cool graphic, but isn't it curved the wrong way? Does the purple object have negative mass?
 

Related to Is Spacetime Flat? Answers to Orbit Questions

1. Is spacetime really flat?

Spacetime is a concept in physics that combines the three dimensions of space and the dimension of time into a single four-dimensional continuum. Whether it is truly flat or not is a matter of debate among scientists. Some theories, such as general relativity, suggest that spacetime is curved by the presence of mass and energy, while other theories propose that it is indeed flat.

2. How does the curvature of spacetime affect orbiting objects?

The curvature of spacetime plays a crucial role in the motion of orbiting objects. According to general relativity, the presence of massive objects, such as planets or stars, curves the spacetime around them. This curvature causes smaller objects, like satellites, to follow curved paths around the larger objects, rather than traveling in straight lines.

3. Can we observe the curvature of spacetime?

While we cannot directly observe the curvature of spacetime, we can indirectly measure its effects on objects, such as the orbit of planets and stars. Scientists also use gravitational lensing, where the light from distant objects is bent by the curvature of spacetime, to study the effects of spacetime curvature.

4. Is spacetime flat in all directions?

In general relativity, spacetime is described as being locally flat, meaning that in small regions of space it appears to be flat. However, on a larger scale, the presence of massive objects can cause spacetime to become curved in certain directions. This means that spacetime is not completely flat in all directions.

5. How does the concept of spacetime curvature relate to the concept of gravity?

In general relativity, the concept of spacetime curvature explains the phenomenon of gravity. Instead of being a force between objects, gravity is described as the curvature of spacetime caused by the presence of mass and energy. This curvature determines the paths of objects, including the motion of planets and the orbit of the moon around the Earth.

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