All Questions
17
questions
5
votes
2
answers
2k
views
Is it the mass that bends spacetime, or is it the gravity?
I had understood that mass bends spacetime and that curvature generates gravity, but I have recently read that what bends spacetime is gravity.
Which comes first? Does the mass generate gravity, and ...
- 173
5
votes
4
answers
1k
views
Connection between spatial, temporal, and spacetime curvature?
There is an innumerable quantity of questions and answers on this site about spatial, spacetime, and temporal curvature. None of these answer my question.
Unfortunately, many use the terms in ...
- 29k
0
votes
2
answers
65
views
Is the light escaping from a massive star held back a bit by the pull of gravity, or by the warping of spacetime near it? [duplicate]
In The Universe in a Nutshell chapter 4, Hawking explains the warping of spacetime according to general relativity.
Near a massive but ordinary star, spacetime is warped such that the light emitted ...
-3
votes
1
answer
74
views
When does the warping of space time peak during the very early universe?
If gravity is a separate force and has taken its current form by 1 Plank time, then the very small 1 Plank length space-time must be warped beyond description according to General Relativity, or is it?...
- 131
-5
votes
1
answer
72
views
Could gravitational waves give an illusion of an expanding universe? [closed]
Could the effect of “expanding” gravity (gravitational waves spreading at the speed of light) as it travels through space (and therefore becomes less local) red-shift all EM waves and thus give us ...
0
votes
1
answer
253
views
Are physicists still ignorant of the existence of real singularities?
(1) Is the gravitational singularity (or space-time singularity) the same as the black hole singularity?
(2) The wikipedia page says
Physicists are undecided whether the prediction of ...
- 61
0
votes
2
answers
81
views
Is the universe expanding?
If spacetime is curved by object with mass, just like the sun curves space time and so makes the planets orbit around it and will eventually in time make them crash towards it then shouldn't the ...
-2
votes
1
answer
199
views
Could dark energy and gravity be explained as same phenomenon?
I have watched VSouce video on gravity. The idea is that gravity pulling it is just lots of mass bending space-time, and natural direction of movement becomes moving towards the mass, and since we ...
- 1,125
2
votes
1
answer
158
views
Isn't A Singularity Inevitable Given Infinite Time?
I am not a physicist but this is a question I've been trying to find the answer to for years and no answer I've been given has satisfied me.
It's my understanding that gravity affects all matter all ...
- 123
2
votes
1
answer
510
views
Why doesn't the universe collapse under its own gravity?
Is the reason the universe doesn't collapse into itself due to gravity because there is an infinite amount of bodies in infinite space, therefore there is an infinite amount of gravitational pull on ...
- 21
2
votes
1
answer
102
views
Hubble bubble and the shell theorem?
According to the Hubble bubble theory a local void could explain deviations of the Hubble constant for measurements in close vicinity to out local group compared to the global Hubble constant and ...
1
vote
2
answers
914
views
Is this a reasonable explanation for "the universe is finite but unbounded" which seems to be contradictory at first sight? [closed]
[Editorial note: I'm going to revise this question according to the suggestions made in comments and answers during the next few days. Thank you all for your valuable hints.]
There's the "ant on a ...
- 199
1
vote
0
answers
70
views
As space-time expands between two stars, what happens to the gravitational potential energy seemingly lost as U~1/r => ZERO.?
As the space-time between two stars grows (the accelerating expansion of the universe) the gravitational potential energy between two stars is reduced as 1/r -> ZERO (r is the distance between stars).
...
3
votes
2
answers
3k
views
How does critical density affect the expansion of the universe if gravity is the curvature of space-time?
From what I know there are three scenarios about the end and expansion of the universe that all depend on the concept of critical density:
If the matter of our universe is above critical density, the ...
- 453
0
votes
2
answers
280
views
What would have been the story of the Universe if there was no mechanism to produce massive fundamental baryonic particles? [duplicate]
Thanks for those of you who took their time answering my problem but it seems that there is a misunderstanding between us. Most answers are based on the assumption of Electroweak symmetry breaking ...
- 1,290