Universe Expanding: Is Gravity a Consequence?

In summary, the expansion of the universe is not like a balloon expanding and it is the fabric of space itself that is expanding. Gravity is a fundamental force caused by the curvature of space-time, and it is not affected by the volume or density of objects. The expansion of the universe and the presence of gravity are not directly related, but the distance between objects does affect the strength of gravity. The analogy of placing the universe on a plane like the surface of a balloon does not change anything, as the moon would still appear to be getting smaller due to the expansion of the universe, not because of its acceleration. As scientists continue to study these concepts, we gain a deeper understanding of the universe we live in.
  • #1
amaruq
16
2
As the universe expands...

Is it that we are more on the surface of a balloon, so the expansion is similar for us as it is for our most distant material counterparts? If this is the case than is gravity a consequence of matter resisting time (since the ?big bang or something?)

As we expand (say, like a balloon) away from the 'beginning' could gravity be the result of something of large mass taking more time to get moving than something of less... thus space/time gets bent around it as the universe accelerates? Then say there are 2 objects, one occupies a large volume at low density, and one with a small volume/ high density but both have the same mass are traveling in space/time... would the large volume object exerts a small force of gravity over a greater amount of space, and the small volume object exerts a great amount of gravity over a smaller amount of space? I know gravity is dependent on 2 things. Mass, distance.

Then if the universe was NOT expanding nor contracting, would there even be gravity? Would matter even be able to sustain itself, or would it diffuse into oblivion? I don't think a static universe is even possible... It has to be in a state of motion to exist. TinyTim explained to me a long time ago that the moon would appear to be getting smaller if gravity was due to acceleration/expansion, but if you place the universe on a plane like the surface of a balloon, does this change? why/why not?
 
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  • #2


I can say that your understanding of the expansion of the universe and the role of gravity in it is not entirely accurate. Let me try to address your questions one by one.

Firstly, the expansion of the universe is not like a balloon expanding. It is the fabric of space itself that is expanding, and it is not expanding into anything. This means that there is no center or edge to the expansion, and everything in the universe is moving away from everything else. This is known as the Hubble's Law.

Secondly, gravity is not a consequence of matter resisting time. Gravity is a fundamental force of nature that is caused by the curvature of space-time due to the presence of mass or energy. This means that objects with more mass will have a stronger gravitational pull, regardless of their speed or acceleration.

Thirdly, the concept of volume and density is not relevant when it comes to gravity. Gravity is solely dependent on the mass and distance between objects. So, a large object with low density will have the same gravitational pull as a small object with high density, as long as their masses are the same.

Fourthly, the expansion of the universe and the presence of gravity are not directly related. Even in a static universe, gravity would still exist. However, the expansion of the universe does affect the strength of gravity over large distances. This is because as the universe expands, the distance between objects also increases, resulting in a weaker gravitational pull between them.

Lastly, the analogy of placing the universe on a plane like the surface of a balloon does not change anything. The moon would still appear to be getting smaller because it is actually moving away from us due to the expansion of the universe, not because of its acceleration. The curvature of space-time caused by gravity would still be present in this scenario.

In conclusion, the expansion of the universe and the role of gravity are both complex concepts that cannot be fully explained through simple analogies. As scientists, we continue to study and explore these phenomena to gain a deeper understanding of the universe we live in. I hope this helps clarify some of your questions.
 

What is the current understanding of the expanding universe?

The current understanding of the expanding universe is based on the theory of the Big Bang, which states that the universe began as a singularity and has been expanding ever since. This expansion is driven by the force of gravity, as well as other unknown factors such as dark energy.

How does gravity affect the expansion of the universe?

Gravity plays a crucial role in the expansion of the universe. It is the force that pulls matter together, causing the formation of galaxies and other large structures. However, on a larger scale, gravity also acts as a resistance to the expansion of the universe, slowing it down over time.

Is gravity the only force responsible for the expansion of the universe?

No, gravity is not the only force that affects the expansion of the universe. There are other unknown factors, such as dark energy, that also play a role in the expansion. In fact, scientists believe that dark energy may be responsible for the accelerating expansion of the universe.

How does the concept of dark energy relate to the expansion of the universe?

Dark energy is a hypothetical form of energy that is thought to make up a large portion of the universe. It is believed to have a repulsive effect on matter, causing the expansion of the universe to accelerate. Its exact nature is still unknown and is a subject of ongoing research in the field of cosmology.

What implications does the expanding universe have for the future of our universe?

The expanding universe has significant implications for the future of our universe. If the expansion continues to accelerate, it is possible that the universe will continue to expand at an increasing rate, eventually leading to the "heat death" of the universe. However, there are also theories that suggest the expansion may eventually slow down and reverse, leading to a "Big Crunch" in which the universe collapses back in on itself.

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