Gravity as consequence of universe expansion

AI Thread Summary
The discussion proposes a new explanation for gravity, linking it to the accelerating expansion of the universe. It suggests that as the universe expands, massive objects warp space-time, causing lighter objects to fall towards them, akin to balls on an elastic surface in an accelerating lift. This model aims to simplify the understanding of gravity without relying on unproven concepts like gravitons or extra dimensions. The author hints at a method to validate this theory by comparing the universe's expansion rate with the Gravitational Constant. Ultimately, the theory posits that without expansion, gravity would not exist, emphasizing the relationship between space-time dynamics and gravitational forces.
Blade Runner
Messages
2
Reaction score
0
I would like to suggest an explanation of 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 accelerating upwards. Let’s imagine that the whole set of balls on an elastic surface is in a lift or elevator traveling 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 accelerating 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...)

Hint to a method to check this speculation:

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.
 
Astronomy news on Phys.org
This is not, as I am sure you understand, a new idea. Unfortunately, an analogy is not a theory. It has been shown that the no assumed "elasticity" of the space-time surface that would be warped can result in the observed gravitational force.
 
Thanks a lot HallsofIvy. Could you recommend me any author or article too learn more about this topic?
 
Blade_Runner, this article has a similar idea, in that the expansion is causing gravity by a shadowing effect. It's not a mainstream idea, as you can imagine.

http://arxiv.org/abs/gr-qc/0108026v1
 
Interesting idea, especially since the faster an object is moving the more mass it has(as shown in GR) hence it would have a stronger gravitational field. Is this thinking correct anyone?
 
TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better? In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
Thread 'Could gamma-ray bursts have an intragalactic origin?'
This is indirectly evidenced by a map of the distribution of gamma-ray bursts in the night sky, made in the form of an elongated globe. And also the weakening of gamma radiation by the disk and the center of the Milky Way, which leads to anisotropy in the possibilities of observing gamma-ray bursts. My line of reasoning is as follows: 1. Gamma radiation should be absorbed to some extent by dust and other components of the interstellar medium. As a result, with an extragalactic origin, fewer...
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
Back
Top