Linked Questions

1
vote
2answers
5k views

If the universe is 3D, how is space-time like a “fabric”? [duplicate]

I have been taught that space-time should be viewed as a fabric and that objects with a large gravitational influence indent that fabric. My question is, if the singularity of a black-hole punctures ...
44
votes
8answers
22k 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 ...
28
votes
6answers
5k 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 which are ...
8
votes
6answers
3k 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 ...
10
votes
3answers
2k 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 ...
8
votes
2answers
10k 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, ...
8
votes
5answers
1k views

How can I vizualize and understand curved spaces in general relativity?

I'm taking a basic physics class and the teacher described space with a special table that has curves and black holes etc. He would throw a metal ball down onto it and the class would watch it circle ...
-1
votes
1answer
2k views

Is the structural similarity between atoms ( smallest) and universe (biggest) a conincidence. Or there can a reason for this beyond imaginations

Is the structural similarity between atoms ( smallest) and universe (biggest) a coincidence? Or there can a reason for this beyond imaginations? It seems like, if one starts travelling out from atoms....
1
vote
2answers
5k views

What is the Fabric of Spacetime? [duplicate]

I always get the analogy of the pretend sun on a piece of cloth pulling everything down such as the image attached below: But What I never really understood is what IS that piece of cloth. Like is it ...
1
vote
2answers
2k 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 ...
5
votes
2answers
758 views

Demonstration of General relativity

I've been trying to at least roughly understand gravitation in general relativity, but so far I haven't found a demonstration which I'd find satisfactory. The most common demonstration is ...
5
votes
2answers
702 views

Is the popular explanation given for gravity in General Relativity misleading? [duplicate]

In most popular explanations of General Relativity, both in print and film/television, gravity is demonstrated using an example of a 2 dimensional plane being flat, then when putting a heavy object in ...
6
votes
2answers
265 views

Ricci scalar and General Relativity cartoon pictures

In many cartoon pictures trying to explain general relativity, there is usually a massive object embedded in a "spacetime mattress" and heavier the object, deeper it sinks. However, what is actually ...
0
votes
1answer
1k views

2D space-time curvature [closed]

Actually, why is the space-time curvature considered 2D plane. As 2-D dimensional space-time curve is used to explain why moon revolves around the earth stating because the massive objects wraps the ...
2
votes
2answers
2k views

Curvature of spacetime as a real thing?

I get the curvature tensor in General Relativity, it is “just” math. Does space-time REALLY curves as a tangible thing, or is Einstein proposing a mathematical abstraction? More naively, please allow,...

15 30 50 per page