Gravity & Spacetime Curvature: Have I Understood?

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Discussion Overview

The discussion revolves around the understanding of gravity and spacetime curvature, exploring the conceptual framework of how objects move through spacetime and the implications of curvature on their trajectories. Participants are examining theoretical aspects and visual representations of these concepts.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant proposes that when spacetime is not bent, objects move straight up the y-axis through time, suggesting two assumptions about motion: either all things want to move the shortest distance to the next point in time or they move at 90 degrees relative to the curvature of space.
  • Another participant questions whether spacetime is curved relative to the object itself, noting that their own vertical movement does not seem to change the curvature from their perspective.
  • Concerns are raised about the visualization of curvature, with one participant expressing confusion over how the curvature is represented around a planet and its implications for understanding gravitational effects.
  • Participants express a desire for clearer visual aids, such as 2D representations of spacetime, to better grasp the concepts discussed.

Areas of Agreement / Disagreement

The discussion reflects multiple competing views and uncertainties regarding the nature of spacetime curvature and its implications for gravity. Participants do not reach a consensus on their understanding of these concepts.

Contextual Notes

Participants express limitations in their understanding based on visual representations and conceptual explanations, indicating a need for further clarification and exploration of the topic.

slibbfalusken
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When spacetime is not bent the two objects, red ball and blue ball, will move strait up the y-axis as they move through time. (Space is x and time is y).
Spacetime1.png

Now I've made the assumption that either a) All things want to move the smallest possible distance to the next point in time or b) all objects move 90 degrees relative to the rotation (Curvature) of the space in their coordinates. These two assumptions give the same result. As you can see in the picture below the blue ball is now heavy and has curved space significantly. Where the red ball is the time is now pointing a bit to the left. As the two objects move through time they will now meet in one point.
Spacetime2.png

Is this what gravity is or have I missunderstood it? If not I'd be really glad if someone could show me a 2d picture of spacetime and how it actually works.
 
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slibbfalusken said:
If not I'd be really glad if someone could show me a 2d picture of spacetime and how it actually works.



 
But is spacetime really curved relative to the object itself? If I jump 1 meter up and down spacetime, in relation to me, is not going to change right? That video only makes sense to me if light or something travels next to a star or something and changes its path due to it actually traveling so far that the change in spacetime angle matters.

Also that curvature is weird. Is the planet supposed to be at the bottom? How on Earth is the curve spaced around it? I just can't picture it.

Hm if I go in from another angle I perhaps can see the point. The planet makes, from the apples perspective, the next frame in time slightly bended a few degrees. Though this can't really be imagined from an outsider perspective.

So, I don't think I fully understood just by watching those videos. I mean, I see why the ball is moving down but I don't understand the curvature itself.
 
slibbfalusken said:
So, I don't think I fully understood just by watching those videos.
Try the links in the video description of the second video (on youtube).
 

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