Alpha and Omega

[Little Bang]

The Big Bang has been discussed at this site almost on a daily basis.We have heard many times that no one place can be the center of the universe. All who make that statement believe that the universe had a beginning( a BB). Now does that statement go to the fact that we cannot know for sure the shape of universe? If there was a beginning then some where there must be a central point where the universe began. What was the make up of the BB? Was it an explosion of radiation, quarks and anti-quarks or something even smaller than quarks? What is your opinion?

[pgrmdave]

The Big Bang is not an 'explosion' of matter, but rather an expansion of space itself. Imagine we all live on the surface of a balloon while that balloon is being blown up. We would notice that every place on the balloon was moving away from every other place at a speed directly related to its distance (i.e. the farther away it is, the faster it appears to be moving). This is similar to the big bang. Much like there is no 'center of the explosion' on the balloon, there is no 'center of the explosion' in space.

[HydrogenBond]

Say we started with a neutron star, whose center is at (0,0,0). Next, say we could reverse GR and cause space-time to expand and allow the particles in the neutron star to expand with space-time. The original center will remain stationary even if the rest of the matter is expanding due to expanding space-time.

Ask yourself this question, what direction does the original dead center go if the expansion has symmetry? Is it left, right, up or down. Symmetry causes the original center to stay in place.

[pgrmdave]

I don't think there is a center, though.

As I understand it (and keep in mind I am by no means a physicist) the 'big bang' encompasses all of the universe. It is not that matter is spreading outward, but that the very fabric of reality is expanding. Here's the basic proof:

All distant galaxies redshift proportional to their distance, regardless of where you are in the universe.
From this, we can assume that it is not that the galaxies are 'moving', but that the distance between them is growing.

There is no physical center of the universe - or everywhere is the center of the universe.

It's kinda surreal when you think about it.

[Little Bang]

If the BB started from a single point wouldn't the location of that point still be in the same place? If the BB was not quarks or energy please explain how matter got here.

[Pluto]

G'day from the land of ozzzzzzzz

Would a cyclic process explain the ongoing of the universe rather than a start at varies points at the same time throughout the universe.

The BBT does not state how and what was before the BB. Its expalantion is on the ongoing process.

[Little Bang]

How could the BBT explain anything pre-BB? We have access to post BB phenomena and that info is ~ 13.5 billion years old. The BB released energy equivalent to all the energy contained in the universe and that energy was some how turned into all the protons and electrons that make up our universe. Any delving into pre-BB events requires an extraordinary trip of imagination. One could logically assume that a collision or event in a dimension that we can never visit did occur.

[Pyrotex]

Originally Posted by Little Bang

If the BB started from a single point wouldn't the location of that point still be in the same place? If the BB was not quarks or energy please explain how matter got here.

Hello Little Bang.

Did you ever see the movie, "The Wrath of Kahn" -- one of the Star Trek movies? Remember the scene where the Enterprise and Kahn's ship are lost in that nebula? Spock notes that even though Kahn is a genius, he has a potential flaw: he thinks in two dimensions. So Kirk moves the Enterprise in the third dimension, and gets behind Kahn and wins the battle.

Understanding the Big Bang is gonna be real difficult for most people because they can only think in three dimensions.

You say, "assume the BB started at a point...".

Okay. But where is that point? You have to have a volume to move around in to specify a point. And there wasn't any volume. There were no "points" to specify. You're thinking in three dimensions (the assumed "volume") and it didn't exist.

Everything was INSIDE that initial BB. Everything. ALL the points in our visible Universe started INSIDE that initial BB. And then they spread apart. But they didn't spread apart as ordinary points spreading within an ordinary volume of our three dimensions. Because there WAS NO volume. Volume implies an existing space-time fabric to "spread into" -- and there wasn't any.

EVERY point started in the BB, so EVERY point, no matter how far it spread can be considered to have been the "center" of the BB. There is NO unique point that did NOT "spread". All points in the BB spread equally, and if we want to be really technical, they all spread the SAME "DISTANCE". Consider again PgrmDave's example of the dots on the surface of a balloon. The balloon exists in 3 dimensions, but the SURFACE has only 2 dimensions (you have to pretend that we live in a 2-D Universe to understand this). As the balloon inflates, every dot spreads apart from every other dot equally. There is NO dot that "doesn't move". There is NO dot that "stays at the center", because the "center" is NOT ON THE SURFACE OF THE BALLOON.

Since there was NOTHING outside the BB (everything was in it), any expansion must have taken place in some OTHER dimension than the three we know and love. Maybe this OTHER dimension was similar to X, Y and Z, and maybe it wasn't. Maybe it was time-like or maybe not. But as the expansion occurred, our familiar X, Y and Z (and T) was created INSIDE the BB and expanded WITH IT.

There was NO expansion in the normal sense of our common experience, for we experience ONLY normal X, Y and Z (and T). If the BB expanded "into" anything, it was something "else" that we do not understand and can only speculate about.

[Pluto]

G'day from the land of oz

Sometime we have to remind ouselves that the BBT is just a theory. As to its reality, thats another isssue.

I have heard the BBT being told in 101 different versions.

Modest explains it well.

[freeztar]

Originally Posted by Pyrotex

Hello Little Bang.

Did you ever see the movie, "The Wrath of Kahn" -- one of the Star Trek movies? Remember the scene where the Enterprise and Kahn's ship are lost in that nebula? Spock notes that even though Kahn is a genius, he has a potential flaw: he thinks in two dimensions. So Kirk moves the Enterprise in the third dimension, and gets behind Kahn and wins the battle.

Understanding the Big Bang is gonna be real difficult for most people because they can only think in three dimensions.

You say, "assume the BB started at a point...".

Okay. But where is that point? You have to have a volume to move around in to specify a point. And there wasn't any volume. There were no "points" to specify. You're thinking in three dimensions (the assumed "volume") and it didn't exist.

Everything was INSIDE that initial BB. Everything. ALL the points in our visible Universe started INSIDE that initial BB. And then they spread apart. But they didn't spread apart as ordinary points spreading within an ordinary volume of our three dimensions. Because there WAS NO volume. Volume implies an existing space-time fabric to "spread into" -- and there wasn't any.

EVERY point started in the BB, so EVERY point, no matter how far it spread can be considered to have been the "center" of the BB. There is NO unique point that did NOT "spread". All points in the BB spread equally, and if we want to be really technical, they all spread the SAME "DISTANCE". Consider again PgrmDave's example of the dots on the surface of a balloon. The balloon exists in 3 dimensions, but the SURFACE has only 2 dimensions (you have to pretend that we live in a 2-D Universe to understand this). As the balloon inflates, every dot spreads apart from every other dot equally. There is NO dot that "doesn't move". There is NO dot that "stays at the center", because the "center" is NOT ON THE SURFACE OF THE BALLOON.

Since there was NOTHING outside the BB (everything was in it), any expansion must have taken place in some OTHER dimension than the three we know and love. Maybe this OTHER dimension was similar to X, Y and Z, and maybe it wasn't. Maybe it was time-like or maybe not. But as the expansion occurred, our familiar X, Y and Z (and T) was created INSIDE the BB and expanded WITH IT.

There was NO expansion in the normal sense of our common experience, for we experience ONLY normal X, Y and Z (and T). If the BB expanded "into" anything, it was something "else" that we do not understand and can only speculate about.

This is the best explanation of this that I've ever read!

It's really, really difficult for me to try to explain this to other people (friends mainly). I almost always get the question, "So what about the edge of the universe? Surely that is not the center of the BB". It's really difficult to answer this. I've typically said something like, "It's not useful to think of an 'edge' or border of the universe. The universe includes everything and an 'outside' is not really possible". This is usually very unsatisfying for people and also myself, because I didn't know any better way to explain it. So thanks for the speaking lines, Pyro.

It's often tempting to explain the universe as a spacetime Möbius strip, but that is equally difficult for most everyone to fathom and also, unfortunately, seems to support a SSU in some people's minds.