How big is the Universe?

Actually galaxies also do move in regards to local gravitational forces as well, which is why you see some close by galaxies like Andromeda that are blue shift rather than red shifted. The local gravitational forces between our Milky Way and Andromeda are greater than the expansion forces of the expanding universe. However, this only works locally. The further we go out the faster the universe is expanding away from us. Like the balloon analogy if you put two dots really close to each they will not separate as much as if you put them on opposite sides of the balloon.The 2 dimensional skin of the balloon in this analogy represents the 4 dimensions of spacetime itself in which everything in our universe resides. That is probably what is hanging you up. You cannot see, touch, feel, or taste the 4 dimensions of spacetime so it is hard for you to conceptualize. However we can detect it through the behavior or objects in space; specifically, the gravitational effects (relativistic effects such as rotating frames of reference, time dilation, relavistic dynamics, etc) of objects upon other objects in space. This is the whole idea behind the Theory of Relativity (both Special and General) proposed by Albert Einstein.A good book to read that might shed some light on the matter for the average layman is 'The Fabric of the Cosmos: Space, Time, and the Texture of Reality' by Physicist Brian Greene. Edited by DevilsAdvocate, : No reason given.Edited by DevilsAdvocate, : correct misspellings and grammerEdited by DevilsAdvocate, : No reason given.

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One of the saddest lessons of history is this: If we've been bamboozled long enough, we tend to reject any evidence of the bamboozle. We're no longer interested in finding out the truth. The bamboozle has captured us. It is simply too painful to acknowledge -- even to ourselves -- that we've been so credulous. - Carl Sagan, The Fine Art of Baloney Detection"You can't convince a believer of anything; for their belief is not based on evidence, it's based on a deep seated need to believe." - Carl Sagan"It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." - Carl Sagan, The Demon-Haunted World

I believe the Big Bang Theory explains events that occur after T>0 but does not in itself explain the cause or origin of the spacetime itself.The origin/cause of the Big Bang is still being hypothesized though Hawkings predicts that our universe, the spacetime we exist in, did not have an origin meaining the concept of time itself cannot have a first cause. Cause and effect are concepts dependent on the concept of time and therefore time is unbounded i.e. it has no one point of origin, as Hawkings predicts. Therefore it makes no sense to say that spacetime had a beginning.There are other hypothesis/theories that state that our universe (not all of spacetime) had other types of origins i.e. spawned off from other universes (multi-world theory), is part of a large omniverse (the brane), is infinite progression of expansion and collapsing spacetime continuum, etc, or a combination of the above. As we digger deeper into reality we reveal many of these theories are interrelated and have hidden truths that apply.Just to add another perspective albeit a layman's perspective based on some very limited amount of knowledge.Edited by DevilsAdvocate, : No reason given.

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One of the saddest lessons of history is this: If we've been bamboozled long enough, we tend to reject any evidence of the bamboozle. We're no longer interested in finding out the truth. The bamboozle has captured us. It is simply too painful to acknowledge -- even to ourselves -- that we've been so credulous. - Carl Sagan, The Fine Art of Baloney Detection"You can't convince a believer of anything; for their belief is not based on evidence, it's based on a deep seated need to believe." - Carl Sagan"It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." - Carl Sagan, The Demon-Haunted World