<blockquote>
<p>If gravity is just matter traveling through curved spacetime, then wouldn’t something with no acceleration just act like it’s in outer space (just floating)?</p>
</blockquote>
<p>You have already answered your question, yes gravity is an effect of <strong>Spacetime curvature</strong>, it is the curvature of both space and time component that fully explains gravity. For a bit more understanding, remember that everything that has mass (or energy) curves spacetime, the time is the thing that causes acceleration, see the answers to this  <a href="https://astronomy.stackexchange.com/questions/48579/time-in-0-gravity-points/48584#48584">question</a> to get a clear view on time dilation. For a more intuitive understanding consider the following graphs:
<a href="https://i.sstatic.net/aWyFM.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aWyFM.png" alt="enter image description here" /></a></p>
<p>In the above graph where there is not curvature of spacetime and you are at rest, the axis of both time and space/ distance will be perpendicular, So if your are at rest, you will be staying at rest according to Newton's first law.</p>
<p>Now if there is a curvature in spacetime, there time dilation takes place, which will change the angle between your time axis and your space axis, this will give:
<a href="https://i.sstatic.net/CMfnl.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/CMfnl.png" alt="enter image description here" /></a></p>
<p>Now, you are not moving and not external force is acting on you, but since the angle between your time axis and space axis s changed, you will see that while you move in time you also move through space, this is the concept of gravitational acceleration according to general relativity. And the graph I showed here does not show you the acceleration, to see acceleration, just see that the angle between the two axis changes at every instant, which will give you a curved graph.</p>

CC BY-SA 4.0
2022-04-11T10:21:09.200Z
2022-04-11T10:21:09.200Z
Kavin Ishwaran
<p>General relativity explains that gravity is the curving of spacetime by massive objects. This makes sense, like when I throw a ball, it follows the curve of spacetime, which is towards the center of the earth.</p>
<p><strong>But what I’m struggling to understand is if something has no acceleration, why does it still fall towards earth?</strong> If gravity is just matter traveling through curved spacetime, then wouldn’t something with no acceleration just act like it’s in outer space (just floating)?</p>

CC BY-SA 4.0
2022-04-11T04:45:59.357Z
It’s not a proper answer but I once heard an argument that maybe already helps: everything is moving all the time through space-time because we are moving through time even when we are not moving through space.
Hartmut Braun
CC BY-SA 4.0
2022-04-11T05:02:42.407Z
Maybe this video helps. It doesn’t answer your actual question but it explains the “moving through spacetime“ aspect: https://youtu.be/A2JCoIGyGxc
Hartmut Braun
CC BY-SA 4.0
2022-04-11T07:19:15.367Z
I’m voting to close this question because there is only incidental astrophysical relevance, and this question already has a good answer on [physics.se]  Please go and see https://physics.stackexchange.com/questions/90592/better-explanation-of-the-common-general-relativity-illustration-stretched-shee to understand how the problems with the rubber sheet model of GR. And this comic https://xkcd.com/895/ for the difficulty in talking about General Relativity in any terms.
James K
CC BY-SA 4.0
2022-04-11T08:29:23.957Z
For a bit more maths, https://physics.stackexchange.com/questions/47379/what-is-the-weight-equation-through-general-relativity shows how to calculate the weight of an object using GR.
James K
CC BY-SA 4.0
2022-04-12T00:08:19.090Z
This is an excellent question. But you won't get any satisfying answer to it, unfortunately. You'll mainly be told, in ways both direct and indirect, that time is somehow the accelerant. Time though is of course not a thing; it can't move anything. And so, we're really left in a weird position here.
White Prime
CC BY-SA 4.0
2022-04-12T16:22:11.183Z
General relativity does a better job than does Newtonian mechanics regarding explaining what gravity **does**. Neither theory explains what gravity **is**.
David Hammen
CC BY-SA 4.0
2024-04-02T00:49:55.910Z
Also see https://physics.stackexchange.com/a/586854/123208
PM 2Ring
<gravity><astrophysics><general-relativity>
How does general relativity explain gravity?
Banana Jones
# How does general relativity explain gravity?

(Asked by: username_0 on 2022-04-11)

General relativity explains that gravity is the curving of spacetime by massive objects. This makes sense, like when I throw a ball, it follows the curve of spacetime, which is towards the center of the earth.

**But what I’m struggling to understand is if something has no acceleration, why does it still fall towards earth?** If gravity is just matter traveling through curved spacetime, then wouldn’t something with no acceleration just act like it’s in outer space (just floating)?

**Tags:** gravity, astrophysics, general-relativity
> **Comments:**
> **username_1**: It’s not a proper answer but I once heard an argument that maybe already helps: everything is moving all the time through space-time because we are moving through time even when we are not moving through space.  
> **username_1**: Maybe this video helps. It doesn’t answer your actual question but it explains the “moving through spacetime“ aspect: https://youtu.be/A2JCoIGyGxc  
> **username_2**: I’m voting to close this question because there is only incidental astrophysical relevance, and this question already has a good answer on [physics.se]  Please go and see https://physics.stackexchange.com/questions/90592/better-explanation-of-the-common-general-relativity-illustration-stretched-shee to understand how the problems with the rubber sheet model of GR. And this comic https://xkcd.com/895/ for the difficulty in talking about General Relativity in any terms.  
> **username_2**: For a bit more maths, https://physics.stackexchange.com/questions/47379/what-is-the-weight-equation-through-general-relativity shows how to calculate the weight of an object using GR.  
> **username_3**: This is an excellent question. But you won't get any satisfying answer to it, unfortunately. You'll mainly be told, in ways both direct and indirect, that time is somehow the accelerant. Time though is of course not a thing; it can't move anything. And so, we're really left in a weird position here.  
> **username_4**: General relativity does a better job than does Newtonian mechanics regarding explaining what gravity **does**. Neither theory explains what gravity **is**.  
> **username_5**: Also see https://physics.stackexchange.com/a/586854/123208  

---

## 1 answers

### Answer by username_6 on 2022-04-11. Score: 3 | Accepted answer

> If gravity is just matter traveling through curved spacetime, then wouldn’t something with no acceleration just act like it’s in outer space (just floating)?

You have already answered your question, yes gravity is an effect of **Spacetime curvature**, it is the curvature of both space and time component that fully explains gravity. For a bit more understanding, remember that everything that has mass (or energy) curves spacetime, the time is the thing that causes acceleration, see the answers to this [question](https://astronomy.stackexchange.com/questions/48579/time-in-0-gravity-points/48584#48584) to get a clear view on time dilation. For a more intuitive understanding consider the following graphs:
[![enter image description here](https://i.sstatic.net/aWyFM.png)](https://i.sstatic.net/aWyFM.png)

In the above graph where there is not curvature of spacetime and you are at rest, the axis of both time and space/ distance will be perpendicular, So if your are at rest, you will be staying at rest according to Newton's first law.

Now if there is a curvature in spacetime, there time dilation takes place, which will change the angle between your time axis and your space axis, this will give:
[![enter image description here](https://i.sstatic.net/CMfnl.png)](https://i.sstatic.net/CMfnl.png)

Now, you are not moving and not external force is acting on you, but since the angle between your time axis and space axis s changed, you will see that while you move in time you also move through space, this is the concept of gravitational acceleration according to general relativity. And the graph I showed here does not show you the acceleration, to see acceleration, just see that the angle between the two axis changes at every instant, which will give you a curved graph.


---

