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Interesting solution. I have a theory in my head for years now. It is probably wrong, but here it comes: In an infinite universe the total amount of gravity t

by ranulo 3y ago

Interesting solution. I have a theory in my head for years now. It is probably wrong, but here it comes: In an infinite universe the total amount of gravity that affect us in one point in space is defined by the event horizon if we assume that gravity travels with light speed. Every atom in the universe has a very small influence on us. But this event horizon expands with light speed all the time. I wonder if this could lead to very small but permanent increasing gravitational pull from all directions at once. In other words, and increasing inflation.

I_Am_Nous 3y ago
Sort of like a pair of ice climbers, where one climbing up and securing themselves allows the other climber to safely climb higher. Eventually we can't see the ice climbers anymore, but that doesn't mean they aren't still helping each other climb higher.
_boffin_ 3y ago
it grow. we grow?
jprete 3y ago
Increasing gravitational force would result in a contracting universe, not an expanding one, I think.
- pdonis 3y ago
  "Gravitational force" doesn't work for describing the dynamics of the universe as a whole. What would result in a contracting universe is a large enough density of matter (about a factor of 20 larger than the actual density in our universe if we just look at ordinary visible matter). But this does not mean "increasing gravitational force". As I have pointed out in other posts upthread, the "gravitational force" on a given piece of matter due to the rest of the matter in the universe (if we leave out local influences, like our solar system or galaxy for us here on Earth) is zero. This is true regardless of the current state of expansion or contraction.
yodon 3y ago
You're on the path to coming up with Mach's Principle[0]. [0] https://en.m.wikipedia.org/wiki/Mach%27s_principle https://en.m.wikipedia.org/wiki/Mach%27s_principle
kabouseng 3y ago
The force of gravity is reduced by the inverse square of the distance (newton's law). Thus as space expands, and matter red shift away from us, the force of gravity reduce over time. The maximum force of gravity was just after the big bang.
- pdonis 3y ago
  All of this is wrong. Newtonian gravity does not work for describing the universe as a whole. As I pointed out in response to the GP upthread, the "force of gravity" on us due to the overall matter distribution of the universe is zero.
ReptileMan 3y ago
Does this account for all the extra space being created - from what I have understood from "always right" youtube videos - parts of the universe are moving away from us with speed greater than the speed of light (or more precise the space between the points is increasing at rate higher than C, no actual movement is being done)
- pdonis 3y ago
  > Does this account for all the extra space being created As I have pointed out upthread, the GP's "theory" is not correct, so it doesn't account for anything. "Expansion of space" is just a consequence of the overall spacetime geometry of the universe, which is due to its overall average matter distribution (and to dark energy, which is what is causing the expansion to accelerate).
pdonis 3y ago
I don't know what theory of gravity you are trying to use, but it isn't the correct one. In our actual model of the universe, using the correct theory of gravity, the "total amount of gravity" affecting us (or any point) from the rest of the universe (i.e., once we factor out local influences like our solar system and our galaxy) is zero. That is because the average matter distribution in the universe is the same in all directions from us, so the "gravity" from it cancels out. The average matter distribution in the universe affects its overall rate of expansion over time, but this is not the same as the kind of "gravity" you are thinking of. Also, while our universe does have a cosmological horizon (due to accelerating expansion), this horizon does not work the way your hypothetical "event horizon" does. In short, your "theory" is not even wrong, because it doesn't even start from a correct underlying theory of gravity.
- mxkopy 3y ago
  > That is because the average matter distribution in the universe is the same in all directions from us, so the "gravity" from it cancels out. Can't gravity have an infinitesimally small effect, which means this matter distribution has to be perfectly balanced for its gravity to cancel out to zero at some point?
  - unsupp0rted 3y ago
    I don't think we know how small of an effect gravity can have over a large distance. Is there a lower Planck-like limit?
    - mxkopy 3y ago
      From my (complete lack of) understanding, it’s unlikely that spacetime is discrete, so maybe not.
    - pdonis 3y ago
      > Is there a lower Planck-like limit? Only in speculations that we have no way to test now or in the foreseeable future. We are many, many orders of magnitude away from being able to probe spacetime on such scales.

by ranulo 3y ago

I_Am_Nous 3y ago

Sort of like a pair of ice climbers, where one climbing up and securing themselves allows the other climber to safely climb higher. Eventually we can't see the ice climbers anymore, but that doesn't mean they aren't still helping each other climb higher.

_boffin_ 3y ago

it grow. we grow?

jprete 3y ago

Increasing gravitational force would result in a contracting universe, not an expanding one, I think.

pdonis 3y ago
"Gravitational force" doesn't work for describing the dynamics of the universe as a whole. What would result in a contracting universe is a large enough density of matter (about a factor of 20 larger than the actual density in our universe if we just look at ordinary visible matter). But this does not mean "increasing gravitational force". As I have pointed out in other posts upthread, the "gravitational force" on a given piece of matter due to the rest of the matter in the universe (if we leave out local influences, like our solar system or galaxy for us here on Earth) is zero. This is true regardless of the current state of expansion or contraction.

yodon 3y ago

You're on the path to coming up with Mach's Principle[0]. [0] https://en.m.wikipedia.org/wiki/Mach%27s_principle https://en.m.wikipedia.org/wiki/Mach%27s_principle

kabouseng 3y ago

The force of gravity is reduced by the inverse square of the distance (newton's law). Thus as space expands, and matter red shift away from us, the force of gravity reduce over time. The maximum force of gravity was just after the big bang.

pdonis 3y ago
All of this is wrong. Newtonian gravity does not work for describing the universe as a whole. As I pointed out in response to the GP upthread, the "force of gravity" on us due to the overall matter distribution of the universe is zero.

ReptileMan 3y ago

Does this account for all the extra space being created - from what I have understood from "always right" youtube videos - parts of the universe are moving away from us with speed greater than the speed of light (or more precise the space between the points is increasing at rate higher than C, no actual movement is being done)

pdonis 3y ago
> Does this account for all the extra space being created As I have pointed out upthread, the GP's "theory" is not correct, so it doesn't account for anything. "Expansion of space" is just a consequence of the overall spacetime geometry of the universe, which is due to its overall average matter distribution (and to dark energy, which is what is causing the expansion to accelerate).

pdonis 3y ago

I don't know what theory of gravity you are trying to use, but it isn't the correct one. In our actual model of the universe, using the correct theory of gravity, the "total amount of gravity" affecting us (or any point) from the rest of the universe (i.e., once we factor out local influences like our solar system and our galaxy) is zero. That is because the average matter distribution in the universe is the same in all directions from us, so the "gravity" from it cancels out. The average matter distribution in the universe affects its overall rate of expansion over time, but this is not the same as the kind of "gravity" you are thinking of. Also, while our universe does have a cosmological horizon (due to accelerating expansion), this horizon does not work the way your hypothetical "event horizon" does. In short, your "theory" is not even wrong, because it doesn't even start from a correct underlying theory of gravity.

mxkopy 3y ago
> That is because the average matter distribution in the universe is the same in all directions from us, so the "gravity" from it cancels out. Can't gravity have an infinitesimally small effect, which means this matter distribution has to be perfectly balanced for its gravity to cancel out to zero at some point?
- unsupp0rted 3y ago
  I don't think we know how small of an effect gravity can have over a large distance. Is there a lower Planck-like limit?
  - mxkopy 3y ago
    From my (complete lack of) understanding, it’s unlikely that spacetime is discrete, so maybe not.
  - pdonis 3y ago
    > Is there a lower Planck-like limit? Only in speculations that we have no way to test now or in the foreseeable future. We are many, many orders of magnitude away from being able to probe spacetime on such scales.