Here's an explanation of the Big Bang i read recently. I thought it was pretty good so maybe someone that doesn't understand it will understand this:
Why is there a universe at all? How could everything we see around us have been created out of nothing?
When you begin to think about how the universe began, you naturally wonder what was here before it began. The obvious answer is "nothing". But what, exactly, is "nothing"? The best way to characterize current thinking on this question is to say that "nothing" just ain't what it used to be. For most of recorded history, people have had a problem thinking about nothingness, or the vacuum - indeed, recognition of the very existence of such a state is fairly recent. The reason for this difficulty isn't hard to find. Have you ever tried to picture nothing? I can't do it. I can picture empty space surrounding something (two basketballs, for example), but i can't picture the absence of everything. And this shortcoming of human imagination has influenced our thoughts about nature - scientists accepted the existence of the vacuum only when the results of repeated experiments drove them to do so.
But that acceptance didn't last long. With the advent of quantum mechanis, our picture of nothing changed again. Instead of a passive, inert absense of matter, quantum theory tells you that a vacuum is both active and dynamic. According to the laws of quantum mechanis a bit of matter can appear spontaneously ouf of nothing, provided that (1) a corresponding bit of antimatter appears at the same time and that (2) the matter and antimatter come together and annihilate each other (disappear back into the vacuum) in a time so short that their presence cannot be directly measured. This process is called the creation of a "virtual" pair of particles, one of matter and one of antimatter.
Think of the vacuum as a level field and the creation of a virtual pair as like digging a hole and piling the dirt up. Then you have a particle (the pile of dirt) and an antiparticle (the hole), but when you put all the dirt back in the hole, you're back to the level fied again.
So the modern vacuum is a little like popcorn popping, except that this popcorn can "unpop" as well. A virtual pair pops up here and unpops, then another pops up there, and so on. And lest you think this is all a fairy tale, I should point out that occasionally a particle traveling through space, such as an electron, comes near one of these virtual pairs and is very subtly altereds by the encounter.That subtle alteration can be detected, so the concept of the quantum mechanical vacuum is backed up by more than just imagination!.
So the "nothing" from which the universe sprang was not just the absense of everything but a nothing with virtual pairs of very energetic particles popping up and disappearing all over the place. .. Let me talk about my favorite type of theory to give you a sense of how these theories operate.
Think of the fabric of space as being something like the membrane of a very special kind of ballon. The presence of any matter, even virtual pairs of particles, causes the fabris to bulge, and this drains energy from the gravitation field to make matter. If the bending is severe enough the ballon starts to expand. In this scheme, if the virtual pairs pop for a long enough time, eventually enough of them will pop in the same place at the same time to bend the fabric enough to start the expansion going. This is the event we usually refer to as the Big Bang.
There it is. I hope some people are more clear on the subject. All i ask is that the people that belive in (i'll say alternative) explanations for the creation of the universe, to not post them here since i'd like the discussion purely based on scientific theory.
Why is there a universe at all? How could everything we see around us have been created out of nothing?
When you begin to think about how the universe began, you naturally wonder what was here before it began. The obvious answer is "nothing". But what, exactly, is "nothing"? The best way to characterize current thinking on this question is to say that "nothing" just ain't what it used to be. For most of recorded history, people have had a problem thinking about nothingness, or the vacuum - indeed, recognition of the very existence of such a state is fairly recent. The reason for this difficulty isn't hard to find. Have you ever tried to picture nothing? I can't do it. I can picture empty space surrounding something (two basketballs, for example), but i can't picture the absence of everything. And this shortcoming of human imagination has influenced our thoughts about nature - scientists accepted the existence of the vacuum only when the results of repeated experiments drove them to do so.
But that acceptance didn't last long. With the advent of quantum mechanis, our picture of nothing changed again. Instead of a passive, inert absense of matter, quantum theory tells you that a vacuum is both active and dynamic. According to the laws of quantum mechanis a bit of matter can appear spontaneously ouf of nothing, provided that (1) a corresponding bit of antimatter appears at the same time and that (2) the matter and antimatter come together and annihilate each other (disappear back into the vacuum) in a time so short that their presence cannot be directly measured. This process is called the creation of a "virtual" pair of particles, one of matter and one of antimatter.
Think of the vacuum as a level field and the creation of a virtual pair as like digging a hole and piling the dirt up. Then you have a particle (the pile of dirt) and an antiparticle (the hole), but when you put all the dirt back in the hole, you're back to the level fied again.
So the modern vacuum is a little like popcorn popping, except that this popcorn can "unpop" as well. A virtual pair pops up here and unpops, then another pops up there, and so on. And lest you think this is all a fairy tale, I should point out that occasionally a particle traveling through space, such as an electron, comes near one of these virtual pairs and is very subtly altereds by the encounter.That subtle alteration can be detected, so the concept of the quantum mechanical vacuum is backed up by more than just imagination!.
So the "nothing" from which the universe sprang was not just the absense of everything but a nothing with virtual pairs of very energetic particles popping up and disappearing all over the place. .. Let me talk about my favorite type of theory to give you a sense of how these theories operate.
Think of the fabric of space as being something like the membrane of a very special kind of ballon. The presence of any matter, even virtual pairs of particles, causes the fabris to bulge, and this drains energy from the gravitation field to make matter. If the bending is severe enough the ballon starts to expand. In this scheme, if the virtual pairs pop for a long enough time, eventually enough of them will pop in the same place at the same time to bend the fabric enough to start the expansion going. This is the event we usually refer to as the Big Bang.
There it is. I hope some people are more clear on the subject. All i ask is that the people that belive in (i'll say alternative) explanations for the creation of the universe, to not post them here since i'd like the discussion purely based on scientific theory.
