Does Mass determine our depth in the fabric of space?

Click For Summary

Discussion Overview

The discussion revolves around the concept of mass and its relationship to the structure of space, particularly whether mass creates a "dent" in space and how this affects the positioning of celestial bodies within a gravitational framework. Participants explore theoretical implications of mass, gravity wells, and the influence of black holes on the universe's structure.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions if mass creates a depth in the fabric of space, suggesting that less massive objects might be found at higher depths.
  • Several participants challenge the notion of a "fabric" of space, arguing it is a poor heuristic and that the concept of depth is misleading.
  • There is a discussion about whether all celestial bodies are within a single gravity well or if there are super gravity wells created by denser bodies.
  • Participants discuss the influence of nearby mass on gravitational effects and trajectories, particularly in relation to the Sun and Earth.
  • Black holes are proposed as significant factors in the structure of the universe, but their role in galaxy formation and their mass relative to galaxies is debated.
  • Questions arise regarding the formation of supermassive black holes and the limitations of current understanding about their growth and influence.
  • One participant suggests the possibility of black holes being remnants of older universes, which is met with a strong rebuttal emphasizing the need for systematic study of cosmology.

Areas of Agreement / Disagreement

Participants express a range of views, with some agreeing on the limitations of the "fabric" analogy while others maintain differing interpretations of gravitational influences and cosmic structure. The discussion remains unresolved on several points, particularly regarding the implications of mass and the nature of black holes.

Contextual Notes

Participants acknowledge the complexity of gravitational interactions and the challenges in applying simplified models to the universe as a whole. There are references to the need for a deeper understanding of cosmology and the limitations of current theories.

  • #31
genphis said:
so the singularity to inflation describing space being simultaneously created during expansion is not correct?, are all galaxies moving away at the same rate?

Do a google search for "Hubble's Law". The further away the galaxy, the faster it's moving away.
 
Physics news on Phys.org
  • #32
Mister T said:
Do a google search for "Hubble's Law". The further away the galaxy, the faster it's moving away.
will do thanks for your time guys, i have a lot to think about kind regards to you all
 
  • #33
genphis said:
so the singularity to inflation describing space being simultaneously created during expansion is not correct?

No. As I said before, that's a pop science description.

Also, if you are looking at the inflation era (which, btw, might not have begun with an initial singularity--we don't know how it began at this point), there were no galaxies then. The only "thing" in the universe was the field driving inflation; that was what was "expanding" (but working out what that term actually means in this context is somewhat complicated since the field is not an "object" or made of "objects" in the ordinary sense).

genphis said:
are all galaxies moving away at the same rate?

No, because they're not all at the same distance from us. The rate of recession we observe for a galaxy depends on its distance from us.
 
  • Like
Likes   Reactions: genphis
  • #34
PeterDonis said:
No. As I said before, that's a pop science description.

Also, if you are looking at the inflation era (which, btw, might not have begun with an initial singularity--we don't know how it began at this point), there were no galaxies then. The only "thing" in the universe was the field driving inflation; that was what was "expanding" (but working out what that term actually means in this context is somewhat complicated since the field is not an "object" or made of "objects" in the ordinary sense).
No, because they're not all at the same distance from us. The rate of recession we observe for a galaxy depends on its distance from us.
is this to say that the galaxies formed statically in the field and they are moving relative to the fields expansion?
 
  • #35
genphis said:
so the only uniform direction relates to the expansion of the universe ? thank you for clearing up some of the fog in my thoughts
No, it does not. There IS no "uniform direction" for the expansion of the universe. Again, if this were the case it would imply a preferred frame of reference and there is no such thing.

I recommend the link in my signature
 
  • Like
Likes   Reactions: genphis
  • #36
genphis said:
is this to say that the galaxies formed statically in the field and they are moving relative to the fields expansion?
What field?
 
  • #37
phinds said:
What field?
"The only "thing" in the universe was the field driving inflation; that was what was "expanding" (but working out what that term actually means in this context is somewhat complicated since the field is not an "object" " peterdonis mentioned this i assumed he was talking about the higgs field ?
 
  • #38
genphis said:
"The only "thing" in the universe was the field driving inflation; that was what was "expanding" (but working out what that term actually means in this context is somewhat complicated since the field is not an "object" " peterdonis mentioned this i assumed he was talking about the higgs field ?
Hm ... OK, I'm not sure about that but Peter knows WAY more than I do. I think then that the answer to your question "is this to say that the galaxies formed statically in the field and they are moving relative to the fields expansion?" is no. In fact I'm not even clear that the question makes any sense.

I'm having a hard time figuring out what it is that you really want to know.
 
  • #39
genphis said:
is this to say that the galaxies formed statically in the field and they are moving relative to the fields expansion?

No. The galaxies did not form until long after inflation ended.

genphis said:
i assumed he was talking about the higgs field ?

No, I was talking about the inflaton field (note carefully the spelling), i.e., the field that drove inflation.
 
  • #40
PeterDonis said:
No. The galaxies did not form until long after inflation ended.
No, I was talking about the inflaton field (note carefully the spelling), i.e., the field that drove inflation.
so if the galaxies formed after inflation and inflation has ceased, i understand hence the question as to what is currently driving the galaxies away from us.
 
  • #41
genphis said:
so if the galaxies formed after inflation and inflation has ceased, i understand hence the question as to what is currently driving the galaxies away from us.
AGAIN, I suggest the link in my signature.
 
  • #42
genphis said:
what is currently driving the galaxies away from us.

Nothing. The expansion of the universe is not "driven" by anything. At the end of inflation, the universe was in a hot, dense, rapidly expanding state. It has continued expanding ever since because of inertia.

(Technically, dark energy provides a very tiny "force" that is causing the expansion to accelerate; but that's a tiny effect next to the inertia that I described above.)
 
  • #43
PeterDonis said:
Nothing. The expansion of the universe is not "driven" by anything. At the end of inflation, the universe was in a hot, dense, rapidly expanding state. It has continued expanding ever since because of inertia.

(Technically, dark energy provides a very tiny "force" that is causing the expansion to accelerate; but that's a tiny effect next to the inertia that I described above.)
does this allow gravity to counter the inertia or are we expanding to a cold none reactive universe?
 
  • #44
genphis said:
does this allow gravity to counter the inertia

I'm not sure what you mean. We've already discussed the existence of systems bound by gravity in the universe.

genphis said:
or are we expanding to a cold none reactive universe?

I don't know what you mean by this.

At this point it would be really helpful if you would give some references for where you are getting your understanding of basic cosmology.
 
  • #45
PeterDonis said:
I'm not sure what you mean. We've already discussed the existence of systems bound by gravity in the universe.
I don't know what you mean by this.

At this point it would be really helpful if you would give some references for where you are getting your understanding of basic cosmology.
sorry i meant to slow the expansion and counter the eventual entropy, my knowledge is from a bookcase of various books on physics and Astrophysics from penrose, hawkins, feynman, greene mostly covering quantum mechanics, relativity and special relativity cosmology is an area that is beginning to fascinate me more and more, thank you for your time and generosity of your knowledge
 
  • #46
genphis said:
... a cold none reactive universe?
I think you are referring to the 'heat death' scenario as the very long term future of the Universe.
As far as I know, that is the opinion of many experts, but by no means is it considered to be certain.
 
  • #47
genphis said:
i meant to slow the expansion and counter the eventual entropy

There are theoretical models in which the universe stops expanding at some point and starts recollapsing, but those models do not fit our observations.

genphis said:
my knowledge is from a bookcase of various books on physics and Astrophysics

Are any of them textbooks? I suspect not. If not, then you should be very cautious about trying to draw inferences from what you read. Pop science books, even the best of them, can't really teach you the actual physics. For that you need to study textbooks.
 
  • #48
genphis said:
I would like help understanding that if mass makes a dent in the fabric of space, does it mean celestial bodies are sitting at different depths in the fabric, and does that mean the less mass in an object you are then more likely to find it at a higher depth.

In Newtonian mechanics of celestial bodies gravity potential ##\phi## plays similar role with your dent. With usual boundary condition ##\phi=0## infinite far away, gravity potential near a celestial body is ##\phi<0##, deeper for heavier bodies. Also in Schwartzshild solution in relativity, ##g_{00}## plays the similar role with infinitely deep at the event horizon. Best.
 
  • #49
genphis said:
sorry i meant to slow the expansion

In the late 1990's astronomers observed that the expansion is accelerating. The term "dark energy" was introduced to provide a possible explanation. If your books are older than this they won't mention it. Prior to this time one of the big questions was whether or not the expansion was slowing and would eventually stop. Obviously that question is moot if the expansion is accelerating.

Not to be confused with dark matter, which was a term introduced much earlier to provide a possible explanation for galaxy rotation rates. That is likely mentioned in your books as it was introduced much earlier.
 
  • Like
Likes   Reactions: genphis

Similar threads

  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 13 ·
Replies
13
Views
747
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
4K