Little Bang Posted September 23, 2008 Report Posted September 23, 2008 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? Quote
pgrmdave Posted September 23, 2008 Report Posted September 23, 2008 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. Quote
HydrogenBond Posted September 23, 2008 Report Posted September 23, 2008 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. Quote
pgrmdave Posted September 23, 2008 Report Posted September 23, 2008 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. Quote
Little Bang Posted September 24, 2008 Author Report Posted September 24, 2008 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. Quote
Pluto Posted September 24, 2008 Report Posted September 24, 2008 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. Quote
Little Bang Posted September 24, 2008 Author Report Posted September 24, 2008 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. Quote
Pyrotex Posted September 24, 2008 Report Posted September 24, 2008 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. Quote
Pluto Posted September 24, 2008 Report Posted September 24, 2008 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. Quote
freeztar Posted September 25, 2008 Report Posted September 25, 2008 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. :hihi: 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. :hihi: 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. Quote
Little Bang Posted September 25, 2008 Author Report Posted September 25, 2008 If the universe originated from a single point then the where of the point is at the center of the universe, assuming the universe expanded like a balloon blowing up. Quote
freeztar Posted September 25, 2008 Report Posted September 25, 2008 If the universe originated from a single point then the where of the point is at the center of the universe, assuming the universe expanded like a balloon blowing up. The balloon analogy is not meant for the big bang, but rather, it is used as a conceptual tool for understanding spacetime expansion. The where is everywhere. :) Pyrotex's post explains it well. We (or at least me) have trouble envisioning time as a fourth dimension. Envisioning a fifth dimension is virtually impossible in my experience. If we think of the universe as a balloon being inflated, we miss this dimensional tidbit. Quote
Erasmus00 Posted September 25, 2008 Report Posted September 25, 2008 If the universe originated from a single point then the where of the point is at the center of the universe, assuming the universe expanded like a balloon blowing up. In the balloon analogy, the universe is the surface, not the volume, of the balloon. If you start a balloon at a point, and blow it up, every point on the surface can claim to have been the center of the expansion. -Will Quote
Pluto Posted September 25, 2008 Report Posted September 25, 2008 G'day from the land of ozzzz Ok, everywhere is everywhere from varies points. How on earth did it all go bang at the same time, lets say "A" point 26 billion light years from "B" point, not to mention all the other billions of points in between? Quote
lawcat Posted September 25, 2008 Report Posted September 25, 2008 The Big Bang is an effect theory--not the ultimate cause theory. If something exploded, the big bang does not answer why or how something exploded and why that something was there in the first place. What screws up everything is time. Did time exist before big bang? Was time affected by or how did time effect big bang? To answer all that, we must answer what is time. Right now we don't know, nor do we know how to use it. But, we have some guidelines from Einstein and Curie. Quote
Pluto Posted September 25, 2008 Report Posted September 25, 2008 G'day Lawcat Time is a measure of motion of either matter or void. Time is not matter or any phase of energy. Time cannot be changed either forward or back. Lawcat said The Big Bang is an effect theory--not the ultimate cause theory. If something exploded, the big bang does not answer why or how something exploded and why that something was there in the first place. Please explain the BBT in your words. Quote
Little Bang Posted September 25, 2008 Author Report Posted September 25, 2008 Freeze, I didn't start this thread to determine where the BB came from nor the location of the point from which it originated. That information is in a place that we can go to only in our imagination. I was hoping to get some idea of what the BB was composed. Most physicist I've seen on documentaries say it was pure energy and I would like to get the members ideas of what is this pure energy. Quote
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