Begaining of the universe.

Factual Questions
1

So, what is the most commonly accepted scientific theory’s to these questions of mine, concerning the beginning of the universe ?

  1. Since I last heard, the big bang theory, even though debatable, is still the accepted theory for how the universe began, what existed before it? Was it just the hydrogen that exploded, or other things as well ?
  2. If only hydrogen existed, did everything that exists now come from that? In other words, over the years, did it change into all the elements that exist today, or did all of the elements responsible for making up all the matter of the universe exist too ?
  3. Where did the hydrogen and, if they existed, the other molecules come from? Did they just always exist, or did they come from nothing?
    And Finally
  4. Some say that time was created along with the universe, does that mean that before the beginning of the universe, it’s impossible to say how long the hydrogen existed before it exploded because there was no time to count? Of course, then, wouldn’t that mean that everything happened instantaneously, that the universe came out of nothing? Of course, energy can’t be created or destroyed, so it had to always exist right?
    Ok, I’m babbling now so I’ll stop. Anyway, sorry for so many complicated questions, but I know that there are plenty of people here smart enough to answer one or all of them. Thanks.
2

A disclaimer first: IANACosmologist, so I may mess something up. But I think I at least have a reasonable grasp of the basics.

To start with, it seems to me like you’ve got a misconception of the Big Bang. The idea behind it isn’t a physical explosion, but rather that space-time was once compressed into a singularity and then the thing expanded. Think about it sort of like inflating a balloon; nothing is exploding, it’s just that the surface of the balloon is stretching. The same general sort of thing happened to space and time, according to Big Bang theory.

“Before the Big Bang” is pretty much meaningless, in standard theory; it’s the beginning, and there is no before. But once the Big Bang happened, the universe started expanding, and things get more interesting. We’ll leave inflation aside for a moment, because it’s a bit more tenuous, although it’s certainly an attractive hypothesis, and doesn’t much effect the main thrust of the argument. In any event, at this very early stage, there wasn’t any hydrogen; it was too hot for electrons to be bound to nuclei, and it was actually too hot for quarks to be bound into protons and protons and neutrons to be bound too each other. Basically, you’ve got exceedingly hot glop.

So the universe goes merrily expanding along, and cooling as it goes, and eventually cools down far enough that we can make protons and neutrons, and then cools further down and we can make atoms; most of it was hydrogen (if memory serves, 75% by mass), and almost all of the rest was helium. The rest of the elements are theorized to come from something called “stellar nucleosynthesis,” which means, broadly speaking, that they’re products of the nuclear reactions which power stars (someone correct me if I’m wrong on this one; I don’t off the top of my head see where the elements much heavier than Fe[sup]56[/sup] would come from).

Of course, when you’ve got lots of atoms running around, eventually you’re bound to get molecules (mainly really simple ones in space, obviously, because the atoms are quite far apart).

With luck, we’ll get a genuine cosmologist or astrophysicist to show up and provide more details and correct any errors here. But hopefully this’ll be a decent starting point.

3

Thank you for the info so far.
But where did the elements that make up the universe come from? If there is no before, then everything just appeared out of nowhere. How is that possible?
I’m no expert, but I’ve read that time is concidered to a result of the big bang just like the universe, and so before the big bang cause and effect don’t apply, but surely there must be some theorys as to how the singularity came into being.
Since time was created, then the singularity couldn’t have existed forever, but how is it possible to get something from nothing?
Oh, perhaps I’m asking impossible to answer. :confused:

4

Oops, I mean, perhaps I’m asking a question that’s impossible to answer.

5

I’m not a cosmologist either, but that never stopped me from babbling happily about these subjects, about which I know little.
According to one of the variations of the inflationary theory, “before” the Big Bang there was (and is) something called the false vacuum. False vacuum has some extremely strange properties, one of which is that it expands, geometrically and continually. In this particular scenario, “bubble” universes, of which our Universe is one, are condensing out of the false vacuum all the- er- time. But since the other bubbles are beyond the edge of our Universe, we can’t see them. So the stuff that makes up the Universe didn’t precisely exist forever, at least not in any form we could recognize.

g8rguy, in response to your question about where elements heavier than iron come from, I think the prevailing hypothesis is that they are manufactured exclusively in supernova explosions. That’s an interesting thing to ponder while looking at your wedding ring.

6

A new variation of the cyclic universe was proposed recently and discussed here, but I’m too lazy to track down a link. Being new, you’ll have to wait a few years to see if it holds up to scrutiny.

7

It is suggested that time started with the Big Bang itself, so it makes no sense to refer to ‘before’ the Big Bang since there was no time before.

This proably sounds like a very weird and counter-intuitive idea, and it is. If you find it hard to comprehend, you’re not alone.

What might help is to realise that time is a dimension, it’s something along which you can place or measure things. To see what I mean, let’s start with something you’re familiar with. You have a room with a canary in it. There are three basic dimensions along which you can measure the position of the canary: left to right, front to back, up and down. Given a number on a scale for each of these three dimensions, in other words a set of co-ordinates, you can state exactly where the canary is. (Example: it’s 3 feet from the left wall, 4 feet from the back wall, and 2 feet off the floor).

Now suppose you have two sets of co-ordinates. Our innate understanding of identity is sich that we don’t conceive of one object being in two places. So logically, you must have either (a) two canaries, with one set of co-ordinates for each canary or (b) one canary, but the two sets of co-ordinates were taken at different times.

Think about this for a second, and you will see time is a function of our innate understanding of identity, of our sense that one item cannot be in two places. So, really, each set of co-ordinates really requires four measurements, like this: ‘3 feet from the left wall, 2 feet from the back wall, 4 feet from the floor, at 10am’.

Now, take away the three spatial dimensions, and there is nothing that the time dimension can tell us. Think about it! With no spatial dimensions, what information could the concept of time give us? None.

The Big Bang theory suggests that in the beginning all matter consisted of a singularity, which is equivalent to no spatial dimensions, and hence no ‘time’ either.

8

The universe was 10-43 old when the Big Bang occured. :smiley:

9

Particle Physics and Cosmology collide at the question of the origin of the elements. When you ask, where did all the Hydrogen (~75%) and Helium (~25%) initially come from, the answer is that they came from the stuff they’re made out of. That’s basically electrons and nuclei. They were all at one time in equilibrium with each other and weren’t necessarily together in the atoms we know and love today. There was enough energy to keep nuclei and electrons ionized. The next question is, where did the nuclei and electrons come from? Well, primordial nucleosynthesis is one of the beautiful confirmations of the Big Bang model (and to some extent, inflation) as we know it today. Basically, if you work out the theoretical calculations of what we expect from a Big Bang universe, we should get the right amount of Hydrogen, Helium, Deuterium, Lithium initially. The primal cosmic abundance is something that can be checked observationally and amazingly it works out to be the same! So, the generation of the first few elements is one of the things that the Big Bang theory gets right. BTW, the other elements are created in fusion processes in stars, but I’ll let you look that up for itself.

So where’d all these nuclei and electrons come from? Well, with the standard model right now, we think we know enough to answer that there was some point when matter/antimatter existed in the universe in equal quantities. Then they annhilated and created the Cosmic Microwave Background Radiation (the most dramatic confirmation of the Big Bang and why you should believe it is true). The little bit left over was a violation of matter/antimatter symmetry (for every particle, an antiparticle exists). Beyond that, you can ask further where’d all the matter and antimatter come from? Now you’re almost to the limits of what the standard model can do. We know that quarks exist and that they make up our nuclei friends and we can postulate the existence of a quark soup. I’m pretty confident the evidence is there that such a quark/lepton soup existed, but before that we’re really at a loss. Since there is no Superconducting Supercollider (those particle physics are still in a major depression over that one), we really don’t have the energy levels available to answer the questions on what exactly makes up these particles. Supersymmetry theories abound and probably provide the answer in some fashion, but right now that’s as far as we can go.

Before that, well, we don’t have enough data.

As for the creation of the initial singularity, all we have right now is speculation. Clever, speculation, but just speculation. We really can’t get beyond the Planck Time (ten to the minus forty-three seconds) and attempts to put General Relativity and Quantum Mechanics together have failed miserable (not too long ago by a whoppping 101 orders of magnitude… with supersymmetry it may only be something around 60… still preposterously huge errors). We just really don’t know where things came from before this.

The bubble universe, self-referential creation universe, etc, all are brilliant speculations by brilliant scientists and mathematicians but they remain speculations with absolutely no observations to back them up.

10

What we accept as true is that everything had to come from something else. Everything that we have had to have been made from something else. So this is my dilema: Where did all of the stuff that other stuff originally came from (i.e., the matter in the universe) originate? It has been said that it was all compressed into a tiny point of incredible denseness, but where did this come from? The only answer that I can fathom is that it was always there. But this goes against another paradigm of ours: Everything had to start sometime. Time had to start somewhere. The very concept of it always being there for all eternity is inconceivable. When did eternity start? When did time itself start. Something “always being there” is a concept I can’t seem to grasp. How can something just be there forever? I had trouble phrasing that :confused: , but I think you can understand what I mean. :slight_smile:

11

ianzin, I can completely understand the concept of the beginning of time. What I can’t understand is how it’s possible for anything to exist. It’s like everything came from nothing.

12

Well, you’ve got to drop the concept of “nothing”. Think more in terms of “everything came from ‘other’”. We just have no idea what ‘other’ is.

13

Either matter in some form has allways existed, or it appeared. Either way, how is that possible?

14

I once met this totally stunning, gorgeous and very sexy woman in LA and, given that she was surrounded by eager male admirers, I felt sure she wouldn’t want to go out with me. But she did. After our first year together, it seemed impossible that it had happened, but it had. Same thing here. Just because we don’t understand something doesn’t mean it can’t and didn’t happen.

By the way, that might not seem much of an answer. But I promise you, you can spend the next ten years of your life wondering about this and it’s about as good an answer as you’re going to find. If you’re interested, and just in the case you haven’t heard about it, there’s a branch of philosophy which deals with what we can and cannot know. It’s called epistemology, and you can read up on it. It’s kinda fascinating if you like booky stuff.

15

I just posted a quote from Stephen Hawking in the thread Practical application of imaginary numbers which addresses the beginning of the universe.

Public Lectures - The Beginning of Time

His “no boundary” hypothesis proposes a second dimension of imaginary time which eliminates the need to explain what came “before”.

He also explains the origin of matter as borrowing energy from the gravitational field as the universe expanded.

16

ianzin, I’m not saying that I don’t believe that the universe happened. Obviously it did or else we wouldn’t be having this conversation. All I’m asking…well, all I’m asking is the impossible. How is it possible that anything exists? For example, if matter, or substance, or whatever you want to call it, has always existed…I can imagine it, but, how do you explain it? Or, if matter just came into being, again, I can imagine it happening, but, how?
Oh, I know, that’s a question that can probably never be answered. It just seems to me that nothing should exist. But it does, and I believe it.
Anyway, my question has already been answered. Nobody knows where the first substance/matter/molecules, or whatever you want to call it, comes from or how they got there.
This isn’t something I constantly dwell on, I just think about it from time to time, and recently, when I thought about it, I thought, hey, I’ll ask the brilliant people here :slight_smile: , at least one of them is bound to have a theory.
Anyway, though, like I said, my question has been answered. Thanks.

17

Remember, you can always play the, “What came before?” game. Even if you wish to ascribe the Universe to God you can ask where God came from. Sooner or later you’re going to end up with an “It’s always been there” answer.

If you buy into String Theory everything came from dimensions 1-4 splitting apart from dimensions 5-10. This split would have released a tremendous amount of energy and would have been the Big Bang event. Energy=matter=energy=matter (E=MC[sup]2[/sup]) such that as the Universe cooled some of the energy converted into matter. Dimensions 5-10 snapped down into a teeny-tiny ball (that happens to touch all points in our Universe).

What caused that split? That’s anybody’s guess. What was before that split? That’s meaningless for us to ask as we can never know and it can have no impact in any way shape or fashion on our Universe. Is String Theory correct? No one knows for sure yet since it has a long way to go and is by no means universally accepted so my explanation must be taken with a large grain of salt.

All the other atoms beyond hydrogen and helium, as others have mentioned, were formed in supernovae explosions. It is literally true that you and I are made of star stuff (at some point in the distant past the atoms in your body…many of them at least…were inside a star). I think our star is a third generation star. That is it and the planets that orbit it have been through two stars since the Big Bang. That’s a vague recollection though so someone correct me if I’m wrong.

18

What really happened at the big bang was that nothing came from nothing. When you get right down to it everything is some sort of manifestation of energy, and the energy of the universe is exactly zero.

All the energy contained in matter and radiation is exactly offset by a negative gravitational potential energy.

19

Also remember that there is no time under ~infinite gravitation. In a black hole, time does not pass, just as it would not in the original singularity. So there was no 'before. The damn thing was so small that it was subject to quantum uncertainty, too, and was capable of zero to infinite energy. I suspect that one of these critters ‘cooked off’ at a high enough energy, lost contact with its virtual partner and triggered a rip in space time. As I understand the false vacuum, its energy density is always constant, no matter the size, so when it blew, fantastic amounts of energy came with it, a small fraction of which precipitated out as matter.

I sure wish I knew what that other dark shit is, though.

20

Ring, do you have a cite for this?