# Gravity as consequence of universe expansion. A speculation.

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Blade runner, Feb 24, 2008.

1. ### Blade runnerRegistered Senior Member

Messages:
3
I would like to drop an idead about the nature of the force of gravity. First I will state some well-known facts, then I will suggest an explanation and finally a hint for the way it might be proved correct.

Facts:

1. Analysis of the spectrum of light from galaxies reveals a shift towards longer wavelengths proportional to each galaxy's distance in a relationship described by Hubble's law indicating that space-time is undergoing a continuous and uniform expansion (Wikipedia). The longer its distance from us, the faster the speed it moves away from us.

This fact is usually exemplified with the simile of two points on the surface of an expanding balloon, moving apart from each other as it is inflated.

The pull of gravity is usually explained as the fall of objects down a slope in a surface warped (sunk) by more massive objects (simile of the balls on an elastic surface) falling towards a bigger ball down the subsidience the latter creates. Now, this model describes very well HOW objects move in space because of gravity, but not WHY, since they should not fall in abscence of other forces, no matter how big the subsidience is.

2. Apparently the most recent observations claim that this expansion is accelerating.

Going back to the simile of the balls on an elastic surface, they could fall towards each other’s holes if this elastic surface was accelarating upwards. Let’s imagine that the whole set of balls on an elastic surface is in a lift or elevator travelling upwards with an increasing speed. Its very acceleration would make the balls warp the surface they are on and the lightest balls would fall towards the heaviest.

And here comes my speculation:

Imagine the elastic surface (two dimensions) of a sphere or globe (three dimensions) is a simile of our universe (three spatial dimensions) as a surface of a hypersphere (four dimensions) which is expanding at an accelerating speed.

That accelarating expansion (like a tour dimensions balloon being blown) make the objects placed on its surface sink warping it. The more massive the objects, the deeper the warp and as a result lighter objects fall into them.
This would explain gravity in an easier way than nowaday’s speculations where gravitons (not founded) or masses placed in other dimensions are needed to provoke its effects in our universe. (In my opinion, the latter theory implies an endless series of masses pulling from equally endless dimensions...)

How could we possibly prove this theory right?

I suppose we could by comparing the value of the acceleration of the expansion of the universe (I ignore it) and the Gravitational Constant (G = 6.67 × 10-11 N • m2/kg2 ). But that is too far away from my capabilities. I drop the idea for cleverer ones.

To sum up, gravity would simply be the result of the warp of the space, caused by the inertia of the mass placed in it and as a consequence of its accelerating expansion. Namely, in a universe with no expansion there would be no gravity and objects would not be attracted to each other. With a zero expansion the Gravity Constant G would be zero. Going back to the simile, if the lift or elevator stopped accelerating, the balls would stop pressing on the elastic surface.

I would appreciate any comments.

to hide all adverts.
3. ### shalaykaCows are special too.Registered Senior Member

Messages:
201
This is an interesting visualization and conclusion. I am also of the belief that the cosmological repulsion can be seen to be a source for the other forces (if you consider them to be echoes in a sense).

There are some journals out there that deal primarily with philosophical issues such as these. For what it's worth, I think you should try to write this up in a paper and expand on it. You never know, there may be more people who agree with your point of view. Your style is also nice to read. You lay out the points you wish to make and let the reader make up their own mind, without calling Albert Einstein a doofus or whatnot.

Please Register or Log in to view the hidden image!

to hide all adverts.
5. ### kanedaActual CynicRegistered Senior Member

Messages:
1,334
I don't see how expansion would change the depth an object would sink into the surface of the hypersphere unless it changed it's surface density. The objects do not move but the space between them increases (it is alleged) as the hypersphere expands. Example. Imagine the universe at 3 billion years old. From it's imaginary centre, imaginary needles are put going through galaxies in the universe. 10 billion years later, the imaginary needles still impale those same galaxies which are now much further out (not allowing for non-expansion motion of said galaxies).

to hide all adverts.
7. ### GequalsaRegistered Member

Messages:
1
Black Mountains

Gravity is the physical manifestation of an expanding universe. It's the displacement that gives the appearance of gravity. Imagine a box and a planet both expanding. The box expands towards the planet and the planet expands towards the box. They can't occupy the same space, so they are both being moved from their original positions. To an outside observer the box appears to be sitting on the planet "pulled" by the planet's gravity. The expansion of everything, gives the impression of everything being pulled by gravity towards everything else.

P.S. Normally mass in the universe is shown on a grid warping space into valleys or holes. A better representation is mountains.

8. ### SaquistBannedBanned

Messages:
3,256
I agree Blade runner I think Gravity is part of the expansion of space

Or rather I think Gravity is the force of matter RESISTING the expansion of space which is why gravity and accleration have similar effects.

9. ### temurman of no wordsRegistered Senior Member

Messages:
1,330
Of course there is a connection since the expansion is explained by the general relativity. But which is the cause of the other must be very subtle if not meaningless. I mean just by some speculation on the surface you cannot conclude anything here.

10. ### SaquistBannedBanned

Messages:
3,256
I think the speculation inspires new possibilities and new thinking.

11. ### damnsteinRegistered Member

Messages:
1
spot on

I think Bladerunner is spot on. I first saw that pool table analogy of a mass deforming a 2D space when I was in high school. I realized the analogy only worked because gravity was pressing the mass downwards. But the analogy was trying to explain gravity, so there was a missing element.

Please Register or Log in to view the hidden image!

An ant crawling on the surface of a ballon expanding at constant rate would experience deceleration, because the surface of the balloon moves away from its center slower as you blow the ballon up.

So for a universe expanding at constant rate, the correct analogy would be an ant crawling on the inside of an expanding ballon.

If surface tension of the balloon remains constant during expansion, the deceleration of the ballon surface would need to be constant in order for the gravitational constant "G" to remain constant. However we all know that a ballon's surface tension increases in accordance with Hooke's law when one inflates the balloon.

In this case, the deceleration would have to increase with expansion in order for G to remain constant.

But does Hooke's law apply to the universe, or does the 3D surface tension of the universe remain constant?

Please Register or Log in to view the hidden image!

If the expansion of our 3D space in the 4th dimension is indeed accelerating, it may be acclerating at precisely the rate needed to maintain the deceleration of 3d space corresponding to our observed Gravitational Constant.

If instead our situation corresponds to ants crawling on the OUTSIDE of the balloon, the acceleration of the universal expansion needs to be great enough that the 4D motion of 3d space also accelerates as the universe expands.

Seems like a tall order to me! But I know nothing. :shrug:

12. ### gluonBannedBanned

Messages:
512
Earlier today, it occured to me that the expansion of space has nothing to do with the effect of gravity for two reasons.

1) Originally, gravity as according to Einsteins theory of relativity did not even include an expanding universe. His model was static and therefore, matter and gravity, acceleration and curvature, distortions and energy can all survive without the aid of expansion.

2) That even now with spacetime expanding at many times the magnitude of c=186,350 mph, matter isn't affected. You would imagine that if the superluminal expansion of the universe where to have any reason to the cause of gravity, you would expect some kind of back-reaction, but we see none. This means that the matter contained within spacetime is not moving at superluminal speeds, but are instead being dragged along with the fabric of spacetime itself. So the faster-than-light expansion has no consequence over gravity, or its effects, nor should one moving slower.

13. ### John ConnellanValued Senior Member

Messages:
3,636
Bladerunner: am I right that with your theory, if the universe were to later contract, gravitation force would be repulsive?

14. ### EndLightEndThis too shall pass.Registered Senior Member

Messages:
1,301
No because even on contraction there is still positive acceleration.

What I think your trying to ask is if the universe decelerates would the gravitational force weaken?

15. ### quantum_waveContemplating the "as yet" unknownValued Senior Member

Messages:
6,625
Keep in mind that popular cosmology not only doesn't give us the "why" of gravity, it doesn't give us the "why" of expansion. What your theory suggests is that though we don't know the cause of expansion, we can attribute the cause of gravity to it.

Some cosmologies are now playing with the idea that expansion and entropy have not always been occuring. Reverse entropy is suggested in the cyclical model by using gravity to reverse expansion. Your theory would not allow a big crunch to form due to gravity and would preclude such reverse entropy. That would mean we are in eternal expansion which I have seen referred to as eternal inflation cosmology.

One distinction with eternal inflation is that there had to be a zero volume infinitely dense beginning at a point in time in the past. This is the something from nothing universe that defies the conservation of energy.

That brings me to the question, is there any expenditure of energy in your view of how gravity works?

Last edited: Jan 12, 2009
16. ### John ConnellanValued Senior Member

Messages:
3,636
I took him to mean that positive acceleration = gravitational force. However the nature of the force depends on the nature and direction of the acceleration.

I am not asking this because I think he has stated himself that there would be no gravity without some form of acceleration

17. ### markl323Registered Senior Member

Messages:
166

Interesting speculation although I have a couple of questions:

1) According to general relativity, the spacetime distortion caused by the mass of an object forces lighter objects to move closer to it from all directions (it doesn't matter where the smaller object is, above, below, left or right of the object). This is how it is proposed I believe. However, if the spacetime distortion is now caused by the movement of an object, then it is no longer the same in all direction. Using the expanding balloon example with the object pressing against the inside surface of the balloon, I would imagine that the spacetime distortion created by this can only allow smaller objects inside the balloon to fall to it but not objects outside of the balloon. And that this time of spacetime distortion might even repluse objects outside of the balloon. I don't think this has been observed?

2) If the universe is expanding at an accelerated rate, wouldn't the pulling force between 2 objects get stronger each second? This would mean the moon would get closer to the earth every second but I don't think we are seeing this?

18. ### John ConnellanValued Senior Member

Messages:
3,636
But the pulling force will be constant if the acceleration is constant. That's what I got out of the theory :shrug:

19. ### BenTheManDr. of Physics, Prof. of LoveValued Senior Member

Messages:
8,967
The point is that the expansion is SO much weaker than gravity on small scales that it isn't even measurable. For example, if this were true, why do we have to look at the most distant supernovae to tell that the universe is expanding? Why not just look at the moon?

20. ### John ConnellanValued Senior Member

Messages:
3,636
Well, it's very hard to compare expansion with gravity since they measured are totally different units! Who's to say that just because we can't measure it locally with our tools here on earth that it isn't enough to cause gravity via the theory proposed by OP?

21. ### D HSome other guyValued Senior Member

Messages:
2,257
The OP has not posted a theory. It is just a metaphysical rant, and it will remain so until the OP develops the underlying mathematics.

22. ### Paul6144Registered Member

Messages:
2
Here is a suggestion for someone to develop the underlying mathematics from OP.

Could we, by quantum calculations demonstrate that the expansion of the universe is directly proportional to the resultant of all energy expended by gravity?

The principle is as follows;

On the first day of BigBang, a state of pure energy has been transformed, among other things, into matter. This mash of pure energy, cooling down and transforming in all kinds of components, such as matter, dark matter and dark energy causes the expansion of our universe and continue inflating.

With the standard model in mind, one of these components or particles could be continuously emitted by all atoms in all directions, causing the expansion of dark energy. This could be directly proportional to the expansion of the universe.

As far as gravity is concerned; these components, when released or emitted, free up a physical space that must be replaced by something else because there is no absolute vacuum. This effect causes contraction of all physical space simultaneously, or space-time. Neighbourhood masses must therefore replaced the void created by the resultant of emitted components, same as the Bernoulli Effect on the airplane’s wings.

If these interactions are made at the Planck scale but inversely proportional in amounts, the result could match that of the gravitational attraction.

The gravity would not be an attraction force but some kind of Bernoulli Effect that affect the masses in the expansion of the universe caused by the emissions of these particles.

One could calculate the strength of a gravitational field according to the result of amplitude as per quantum calculation for the amounts of these particles that goes through a quantity of space time.

What are those particles? Maybe we have enough information to go backward and calculate what it shall be. Nevertheless, this thinking of adapting quantum mechanics to include gravity (since it would not be a force) worth spending few hours of calculations for someone that has the knowledge and time to do so.

Who’s up for the challenge?

Please Register or Log in to view the hidden image!

23. ### JukriSRegistered Senior Member

Messages:
210
Funny

There is no drawing force at all!

When particle is new, is hot/density and that particle time is slowly!

Thats why new particle dont emit energy fast and that why is not giving kinetic energy for expanding atoms nucleus!

When particle is old, is not so hot/density and time is not so slowly and thats why particle emit energy fast. Thats why particle giving kinetic energy for expanding atoms nucleus!

thats why we stay earth skin with out gravity, you know!

thats why you can see old light who is redshifting!

Not, because space expanding!

space dont expanding or curving/bending at all!

You say, space start expanding faster same time when quasars born!

You can see how energy start expanding faster and you say, space start expanding faster?

It is funny!

Because there born quasars, there start moving more energy between expanding photons and that energy get photons expanding faster!

it is onesimpleprinciple com, nothing else, you know!

Space dont expanding at all!

Energy expanding in space who dont expanding!

Also photons expanding and emit expanding energy and with that energy, expanding photons pushing themselfs far away same way what photons wexpanding!

thats why old light it is redshifting!

You cant see, heard, taste, smell or feel space1

You cant make any test with space!

There is no drawing force at all!

Only force is pressure!

We can explain everything with change of pressure!

All the phenomens can be explained by one force and this force is the pressure. (Don´t forget the power of thought! You also can move yourself by the power of thought! Quite right. You get yourself to move with the help of the muscles . You so you send message of your brains to your muscles and you get yourself to move? What is power/force of this thought, which get you to move there where you want?).

We can describe by people what happens in the atomcores all the time. For example one thousand people can go to the space and curl up close to each other. Now we have made an energyconsentration of people that covers a certain spot of the space. We know that the biggest part of the atoms is empty space. Also between people there exists empty space that does not expand or curve.

Now these people can begin to straighten or in other words to open up and this way they push themselves away from each other. One can observe the hardest pressure in the middle of this human energyconsentration and people who locate in the middle must do an enormeous job so that they woun´t
flatten in the centre. These people in the centre sweat the most. This is excactly the same thing that happens without gravitation for example in the centre of the earth and in the centre of the sun.

The density of the human energyconsentration reduces and the people push themselves away from the centre of the human energyconsentration. Now for a little while we can observe a phenomen of gravitation without a drawing force (that actually does not exist) on the surface of the human energyconsentration.

In my opinion the space does not expand or curve. If it would expand, could you describe how does the space expand?

It is easy to describe how the energy all the time turns into a less dense energy in the atomcores, so I think that it is time to forget all about the magical expanding and curving of the space. You can also forget all the spare spacedimentions, the dark substance and the dark energy.

So the space does not expand or curve!

The atomcores expand and open up expanding electrons and expanding photons and they beam their expanding energy as waves away from themselves. This is how it goes!

When you look at the galaxy, you can understand that the energy inside the galaxy is denser than outside the galaxy. If you look at a star, you can understand that energy inside the star is denser than outside the star. This way you will know for sure that the energy inside the atomcore is denser than outside the atomcore. It is not difficult to understand that the energy inside the protons / neutrons is denser than outside of them and the energy inside the qvarks is denser than outside the qvarks and so on...

It it also easy to realize that outside the visible universe the is an area, where is really much more energy than the visible universe has all together and the energy some where out there is much denser than than it is in a visible universe. Still in that area far away from the visible universe there is no centre point where the energy would be denser than outside it.

That three-dimentionally expanding energyconsentration that bems energywaves with the nature of the galaxies, is formed also from separate three-dimentionally expanding energyconsentrations ect. And so the smaller separate energyconsentrations we talk about, the denser and denser the
energy is all the time.

So the atomcore does not have a centre point, where the energy would be denser than outside it. There is no centre point also at the universe, outside which the energy would be less denser.

Because the MOVEMENT takes place towards a less dense area, then the visible universe MOVES as an entity away from that one point that is really far away from the visible universe and where the energy is much denser than it is in a visible universe.