All Questions
99
questions
81
votes
17
answers
59k
views
How exactly does curved space-time describe the force of gravity?
I understand that people explain (in layman's terms at least) that the presence of mass "warps" space-time geometry, and this causes gravity. I have also of course heard the analogy of a blanket or ...
- 913
21
votes
5
answers
6k
views
How does "curved space" explain gravitational attraction? [duplicate]
They say that gravity is technically not a real force and that it's caused by objects traveling a straight path through curved space, and that space becomes curved by mass, giving the illusion of a ...
- 2,172
21
votes
6
answers
4k
views
Better explanation of the common general relativity illustration (stretched sheet of fabric)
I've seen many science popularisation documentaries and read few books (obviously not being scientist myself). I am able to process and understand basic ideas behind most of these. However for general ...
- 313
161
votes
6
answers
55k
views
Why would spacetime curvature cause gravity?
It is fine to say that for an object flying past a massive object, the spacetime is curved by the massive object, and so the object flying past follows the curved path of the geodesic, so it "appears" ...
- 1,926
36
votes
8
answers
6k
views
Does the curvature of spacetime theory assume gravity?
Whenever I read about the curvature of spacetime as an explanation for gravity, I see pictures of a sheet (spacetime) with various masses indenting the sheet to form "gravity wells." Objects ...
- 6,044
48
votes
9
answers
29k
views
Why is the gravitational force always attractive?
Why is the gravitational force always attractive? Is there another way to explain this without the curvature of space time?
PS: If the simple answer to this question is that mass makes space-time ...
- 1,772
70
votes
2
answers
9k
views
Is spacetime flat inside a spherical shell?
In a perfectly symmetrical spherical hollow shell, there is a null net gravitational force according to Newton, since in his theory the force is exactly inversely proportional to the square of the ...
- 2,163
11
votes
3
answers
11k
views
Gravitational time dilation at the earth's center
I would like to know what happens with time dilation (relative to surface) at earth's center .
There is a way to calculate it?
Is time going faster at center of earth?
I've made other questions ...
- 2,909
47
votes
15
answers
8k
views
Why does the speed of an object affect its path if gravity is warped spacetime?
I think I understand the idea of thinking about gravity not as a force pulling an object towards another object but instead a warping of space so that an object moving in a straight line ends up ...
- 579
1
vote
2
answers
3k
views
Bowling ball on a rubber sheet analogy - what pulls the ball down [duplicate]
Possible Duplicate:
Does the curvature of spacetime theory assume gravity?
Since I read Cosmos long ago, I see the same analogy about the balls rolling on a rubber sheet used to explain how ...
- 113
13
votes
4
answers
7k
views
Can a black hole be explained by Newtonian gravity?
In the simple explanation that a black hole appears when a big star
collapses under missing internal pressure and huge gravity, I can't see
any need to invoke relativity. Is this correct?
- 1,436
12
votes
6
answers
6k
views
The Fabric of Space-time?
I am not an academic in anyway, just someone interested in the story that is our universe. So my apologies if this isn't a well thought out inquiry.
I've been struggling with a concept for some ...
- 137
9
votes
2
answers
15k
views
Visualizing gravity in 3D
We've all seen the depiction of gravity bending space downwards, and so attracting objects into the dent it creates, cf. e.g. this and this Phys.SE posts. That's intuitive and makes a lot of sense, ...
- 415
9
votes
2
answers
4k
views
What does it mean for objects to follow the curvature of space?
In science documentaries that touch on general relativity, it is often said that gravitational pull isn't an actual a pull (as described by classical physics), but rather one body travelling in a ...
- 719
17
votes
2
answers
5k
views
Space falling faster than light after it falls inside the event horizon of a black hole?
Typing my question directly so people know what I am asking, afterwards providing background and context.
Q: What does it mean when space is falling, faster than light?
(I am specifically wondering ...
- 398