A slightly different version of General Relativity

[SapphireSpire]

General relativity describes gravity as a curve in space-time.  In a curved space-time, an object moving in a straight line and at constant speed will, in normal space, appear to accelerate along a curved path.  So curved space-time is equivalent to the accelerated shrinking of normal space over time.

How then can an object have a constant volume while the space it's in is constantly shrinking?
In order for matter to keep it's volume, either:

       1. space is flat and gravity is the curving or shrinking of something other than space.

            ...or

       2. all matter is expanding at precisely the same rate as the space around it is shrinking.

Last I check, subatomic particles have no volume, they're just points of mass. Therefore the volume of an object is just space and a high concentration of electric fields.

If matter is expanding than it's because the electric fields within the atoms and molecules are expanding- meaning they're increasing in scale, not energy.

Edited October 9, 2017 by SapphireSpire

[Strange]

1 minute ago, SapphireSpire said:

So curved space-time is equivalent to the accelerated shrinking of normal space over time.

Is it?

2 minutes ago, SapphireSpire said:

How then can an object have a constant volume while the space it's in is constantly shrinking?

I guess you are thinking of tidal forces / spaghetiffication? In that case, as an object is stretched it also gets thinner and the volume remains constant.

This page has a good overview of the mathematics of GR: http://math.ucr.edu/home/baez/einstein/ (which one can follow, without knowing all the math).

[studiot]

37 minutes ago, SapphireSpire said:

General relativity describes gravity as a curve in space-time.  In a curved space-time, an object moving in a straight line and at constant speed will, in normal space, appear to accelerate along a curved path.  So curved space-time is equivalent to the accelerated shrinking of normal space over time.

How then can an object have a constant volume while the space it's in is constantly shrinking?
In order for matter to keep it's volume, either:

       1. space is flat and gravity is the curving or shrinking of something other than space.

            ...or

       2. all matter is expanding at precisely the same rate as the space around it is shrinking.

Last I check, subatomic particles have no volume, they're just points of mass. Therefore the volume of an object is just space and a high concentration of electric fields.

If matter is expanding than it's because the electric fields within the atoms and molecules are expanding- meaning they're increasing in scale, not energy.

 

I have to say that this seems to me to be a classic case of the Chinese Whisper Theorem applied to the Handbook of pocsci.

[John Cuthber]

"A slightly different version of General Relativity"

So, that's slightly different from the one that gives the right answers...

[Vmedvil]

On 10/9/2017 at 9:57 AM, SapphireSpire said:

General relativity describes gravity as a curve in space-time.  In a curved space-time, an object moving in a straight line and at constant speed will, in normal space, appear to accelerate along a curved path.  So curved space-time is equivalent to the accelerated shrinking of normal space over time.

How then can an object have a constant volume while the space it's in is constantly shrinking?
In order for matter to keep it's volume, either:

       1. space is flat and gravity is the curving or shrinking of something other than space.

            ...or

       2. all matter is expanding at precisely the same rate as the space around it is shrinking.

Last I check, subatomic particles have no volume, they're just points of mass. Therefore the volume of an object is just space and a high concentration of electric fields.

If matter is expanding than it's because the electric fields within the atoms and molecules are expanding- meaning they're increasing in scale, not energy.

No,  space cannot be flat or you wouldn't see time dilation. 

All matter is not contracting at the same rate or they would all have the same velocity, which they do not.  The space is shrinking, expansion of space is constant throughout the entire universe. 

Subatomic particles do have volume, take half the diameter or size then do the sphere volume equation you will find they do, this makes them non point mass.

"Therefore the volume of an object is just space and a high concentration of electric fields." Yes, and a resounding NO, there are many fields not just electric, if they were just electric then you would only have charge in the universe, which we don't find just a single force which is not even general relativity at this point, take that up with QCD and QED.

That is still dark energy, it could have never have been just charge, charge does not expand the universe just increase density of space whether (+,- )(+,+)(-,-) The magnitude of the field is positive or negative the vector not the energy increasing or decreasing potential difference not positive or negative energy.

The Universe just isn't that simple is the reason why this system fails to explain it, even classical mechanics is not that simple to have a single form. 

Edited October 15, 2017 by Vmedvil

[Dutailly]

Actually in Relativity there are 2 different theories : one addresses the geometry of the universe, the other one gravitation.

The General relativity Geometry is based on simple facts. i) To locate an event you need 4 coordinates, in a chart (whatever it is, it is conventional) : 2 for space location, 1 for time location.  So the right representation of the universe is with a 4 dimensional manifold. For any observer the "space" corresponds to the event to which it has assigned a given time. This is a folliation of the universe in 3 dimensional hypersurfaces. ii) There is a breakdown of symmetry : time is not measured with the same units and protocols than space. There should be some universal constant relating both : x=ct. iii) The Principle is causality is the same for all observers. This implies the existence of a bilinear form - the metric - which is not euclidean, the Lorentz metric, which is the physical part of the geometry. It changes from a point to another. iv) The main property of material bodies - including the observers - is that they occupy a single point at any time. So they travel along a world line in the universe. The tangent to their world line is a quantity which has an absolute meaning : it does not depend on an observer.  There is a unique (up to an origin) parameter t such that the world line x(t) has a given tangent. This is the proper time, which is also the biological time of any observer. The issue is then "at what rate clocks of different observers run ?" The basic assumption is that the 4 dimensional velocity of an observer (and any material body) is the same. A simple computation shows that the Lorentz length of the velocity is null, the spatial speed is such that v=ct. And from there we get the usual formulas, which hold for any observer using an orthonormal basis, without involving the speed of light, train or whatever.

The assumption about the "expanding universe" involves only the metric : the container does not change, only the metric. This is an assumption about cosmology. And of course a material body, be it a particle or a star, does not change, only the geometric measures.

The Einstein's theory of gravitation is distinct. It is based on 2 assumptions. i) Material bodies follow geodesics. So we need to define a geodesic, and this is done through the metric. ii) The metric is defined, through a classic implementation of the Principle of Least Action using the scalar curvature. So only the metric is involved. This is a beautiful, consistent, theory, but it does not account for the motion of stars in the Galaxy. The usual answer of lazzy physicists is to say that it requires a new mystery (good for the media) : dark matter. Actually the Einsitein's theory of gravitation denies the existence of a gravitational field. Einstein, and many others, tried to adjust the theory, but it needs one way or another to give up the central role given to the metric.

 

 

[studiot]

4 hours ago, Dutailly said:

The metric is defined, through a classic implementation of the Principle of Least Action using the scalar curvature.

Indeed, but for which model of GR?, the original simple one, or one of the many rewrites over the 20th cnet or the 2008 one after Connes?

[Country Boy]

"General relativity describes gravity as a curve in space-time.  In a curved space-time, an object moving in a straight line and at constant speed will, in normal space, appear to accelerate along a curved path.  So curved space-time is equivalent to the accelerated shrinking of normal space over time. "

You are misunderstanding "accelerate".  An object that is either speeding up or slowing down is "accelerating".  Even an object moving around a curve at constant speed is "accelerating".  It does NOT follow that "normal space" is shrinking.