First time poster. Cool site.

When I heard that the expansion of the universe is accelerating, I wondered if it might be due to gravitational attraction between our universe and everything that surrounds our universe. I am sure that somebody thought of this and determined that it is impossible. But I can’t get anybody to explain why it is impossible.

Please destroy my theory, or make my day by saying that I may be onto something.

Here is a story that explains what I think might have happened.

We were inside a black hole from another universe.

Long ago, in a universe that surrounds ours, a black hole grew to contain nearly the mass of our universe. Then the last bit of our universe fell through the event horizon and exceeded the limit of a black hole’s capacity. A chain reaction unleashed the energy that created our universe. The explosion was a big bang.

In the universe that surrounds ours, the shock wave of the explosion created a much larger space that was nearly void of matter. Eventually the mass of our universe will collide with the mass of that universe. Our universe will end to become part of that universe. We will be assimilated.

Inside this black hole, in our universe, events progressed for about 14 billion years to become our here and now. On Earth, in the Sol system, in the Milky Way galaxy, a question puzzled theoretical physicists.

Why is the speed at which our universe expands increasing?

The story of our exploding black hole creates a situation that, in my mind, explains this acceleration:

Our universe is gravitationally attracted to the universe that surrounds ours. Someday, we will be united with our surrounding universe in a violent collision. Ever done a canon ball in a swimming pool? There is a moment when water is pushed away followed by a forceful crash of water collapsing the hole. Our big bang is like doing a cannon ball with the mass of our universe.

I suppose, if this were true, that there would only be one universe. If we experience the gravity, then we are in the universe to which we are drawn.

I like this theory because it supports my intuition that space and time are eternal in all directions. Ours may be one of countless bubbles rushing to join the surrounding universe. It also explains what caused the big bang.


OK. Now finish laughing and tear this theory apart.

If we have a uniform spherical shell of matter and a particle inside of it, what gravitational force does that particle experience? A calculation might show that it is attracted to he geometric center of the shell, even though none of the shell's matter occupies that point. You should check out the details of that question.

I was just sitting here thinking about why the universe's expansion might be accelerating. I found your post after a quick search to try and find a discussion regarding current theories being formulated since the recently published conclusions that the speed of the universe's expansion is accelerating as opposed to being constant.
I am not a physicist, but I like your theory and it could explain the acceleration data, expecially if the acceleration is constant or at least somewhat uniform. Your theory is much more scientific and logical than mine; but like you, I wonder if anyone else might consider, or already may have considered my wild hypothesis as a possibile reason for the acceleration.

My theory is that; like a tree grows faster in the summer because the environment in which it exists changes over time in a way that improves the conditions required to accelerate the tree's growth, our universe may also exist within an a much larger environment which also is not constant and in some way is currently improving the conditions for a spurt of growth for our universe ?

Pretty wild hypothesis, I know, but could this be another direction to explore ???

I was just sitting here thinking about why the universe's expansion might be accelerating. I found your post after a quick search to try and find a discussion regarding current theories being formulated since the recently published conclusions that the speed of the universe's expansion is accelerating as opposed to being constant.
I am not a physicist, but I like your theory and it could explain the acceleration data, expecially if the acceleration is constant or at least somewhat uniform. Your theory is much more scientific and logical than mine; but like you, I wonder if anyone else might consider, or already may have considered my wild hypothesis as a possibile reason for the acceleration.

My theory is that; like a tree grows faster in the summer because the environment in which it exists changes over time in a way that improves the conditions required to accelerate the tree's growth, our universe may also exist within an a much larger environment which also is not constant and in some way is currently improving the conditions for a spurt of growth for our universe ?

Pretty wild hypothesis, I know, but could this be another direction to explore ???

Well it could be so. But, as one physicist once remarked, there are hypotheses and hypotheses. He mentioned that all this is like writing fiction . It can become a theory only when it explains all things known and makes predictions about things unknown which can be verified.

Personally, to me the universe is everything i.e. all inclusive. So if there is another universe, it contradicts my understanding. I would prefer terms like galaxies, clusters, superclusters etc. for those 'universes'

This is like they once defined atom as the smallest indivisble unit of matter. Then came the electron proton and neutron but they continued calling it an atom and claimed it is divisible! This contradicts the original definition of the atom

If you mean that our universe originated from a black hole, then that makes sense. Our Universe would not "collide with" the out side bodies of that universe. If we originated from a black hole then our universe "branched out" in a new direction. In a way, that theory is the same and synonymous with the Inflation theory, as they both describe universes that branch off of each other due to the uncertainty theory.

No. That's impossible since it's meaningless to speak of things that surround our universe. Think of our surface of a sphere. Label that surface "the universe."All that exists is on that surface. That's why we call it the universe in fact. If someone were to ask you to point to a place that exists but which is not on that surface but lies outside it then you can see how that'd be a meaningless request.

If you are inside spherically symmetrical shell of matter, the net gravitational force of the shell on you is zero. That's a result from classical physics. So a fairy tale about the universe being pulled outward by matter surrounding it needs to explain why there would be any force to pull it apart.. We need to see some equations and calculations..