To BEgin or not to BEgin? A cosmology question.

Nicker on 10/4/2013 at 21:35

So this should be a short thread unless we want to engage in the debate that has sparked this question (is the universe a self-generated phenomenon (natural / mechanistic) or was it created by a deity).

And yes I have done an extensive search but it is hard to find a definitive answer from a reliable source.

So my question to the astronomically minded here is, which of these statements is more accurate:

The Big Bang was the beginning / creation of the Universe.

or

The Big Bang was the observable universe changing its state.

or

[ your even better explanatory phrase here ]

My understanding is the second statement is more accurate and that the first one is sort of a lazy, short-hand description given to laymen by physicists, so they don't have to explain a whole bunch of other stuff as well.

But to call the Big Bang the beginning of THE Universe is inaccurate because it presumes that The Universe As We Know It (TUAWKI) is all that there was, is and will ever be - and we don't know that, one way or another.

Thanks in advance and my apologies if this devolves into something more than a primer on the Big Bang.

Vivian on 10/4/2013 at 21:41

I guess the second? I mean I have no idea. But matter/energy out of nothing gives me brain trouble.

Queue on 10/4/2013 at 21:45

God farted. Then came Adam and Eve (not Steve). And now, we have Taco Bells.

That's all you need to know, really.

Azaran on 10/4/2013 at 21:49

The second. The universe cannot have arisen out of nothing so there must have been a preexisting universe before the Big Bang, and maybe even another more ancient Big Bang before that, etc. ad infinitum

gnartsch on 10/4/2013 at 22:05

Glad you are here in order to meet the experts. :joke:

Well, #1 surely sounds lazy and it is hard to understand that the universe came out of nothing.
#2 on the other hand would mean that the universe was always there. Hard to imagine as well. Why would it have been there if no one/nothing created it ? I am not aware of any serious party supporting this position.

#1 at least is propagated by both scientists and the church - but with different arguments.
Scientists state that the Universe (3D-space + time) got created out of 'virtually nothing', but off course energy obviously was there. Energy CAN NOT be created nor destroyed.
The church says that god created it while he was bored with himself.

So, I would go with option 3 for the moment : the universe is the result of gods balls going off for no specific reason :wot:
And he was never seen again since then, because he feels ashamed. :cheeky:

demagogue on 10/4/2013 at 22:08

You gotta step back and get into what science actually is.

Science is the organization of observed data through theory. Especially modern science brackets the "truth" from what's observable, so what we know is only as deep as the phenomenology (the set of everything we've observed, which changes over time as we have more & better experiments). That doesn't mean that there isn't further truth beneath what we can observe, but if it's really unobservable, the trend is to say there's no fact of the matter to it or no validity to any physical questions you could ask about it. You don't have any data about it you can get, so it's not science anymore.

At most you can get into the debate if the "law of excluded middle" still applies. That law says an answer to any well formed question is either "A XOR not-A". But the logic of something like string theory is more like topos logic, which preserves the law of non-contradiction, you cannot have "A AND not-A", but it tosses the excluded middle law, so actually you can't say it's A XOR Not-A for some feature you can't get data on. That's effectively saying there's either no fact of the matter, or at any rate it's actually false to conclude A, and it's false to conclude Not-A; both answers would be false because observation doesn't support them. So you'll see that debate a lot on the logic of cosmology discussions. AFAIK it's still an open question. This is a much different universe than the classic one of Newton & the Enlightenment, where there's a single unified truth, even if we don't or can't know what it is. Apparently a lot of theoretical physicists don't think like that anymore.

Edit: To take one example, it may be that some fundamental truths are maellable. For example, Susskind uses the example, in one model you can see how magnetic monopoles are made out of electrons, but in another model electrons are made out of magnetic monopoles (well the actual example is more complicated, substitute "more fundamental" than "made out of"; but the gist works like that.). Which is right? He says there's no fact of the matter, or they're both right at the same time. So there is no "fundamental truth" to it; there are no true fundamental particles. You just have these set of processes that can change the forms of physical things according to certain rules, and in one perspective A is fundamental, from another perspective B is fundamental. Edit2: Then you have something like the holographic principle which suggests all you have is the transformations of basically pure information at the root of physics anyway, at least as far as the process of observing and "knowing" it goes.

What's interesting is that some theoretical models are giving answers in the theory for things beyond the Big Bang... String Theory suggests there's a multiverse, and the Big Bang was a collision of d-branes (big sheets that carry all the particles of a universe), feeding a load of energy into one and basically becoming the big bang on one of the sheets. So then you'd have the whole multiverse dynamics to talk about way above the scale of our little universe in it. Other theories (like LQG) predict things like a Big Bounce, where if you run time backwards from the Big Bang it starts expanding again, implying a previous universe that shrunk down and bounced when it reached singularity.

Lee Smolin had a crackpot theory that massive blackholes are seeds to new universes (he probably got the idea from the LQG model just mentioned, now that I think about it), but the parameters of the new baby universe's standard model physics are changed a bit. So then there's a natural selection; the wrong parameters will have no blackholes, so will seed no baby universes, but right parameters will lead to more & more blackholes, they'll seed ever more new universes. So after a while most universes will have the parameters good for blackholes, which also happen to be good for stable stars & thus life... It's interesting, but I think the logic is flawed for basically the same logic as the anthropological argument. We're not in a position to talk about a dynamic process when we only have one data point that happens to--randomly for all we know--be high on a particular scale (i.e., standard model parameters good for life).

Azaran on 10/4/2013 at 22:08

The cosmos itself must of necessity be indestructible and uncreated. Indestructible because, suppose it destroyed: the only possibility is to make one better than this or worse or the same or a chaos. If worse, the power which out of the better makes the worse must be bad. If better, the maker who did not make the better at first must be imperfect in power. If the same, there will be no use in making it; if a chaos... it is impious even to hear such a thing suggested. These reasons would suffice to show that the world is also uncreated: for if not destroyed, neither is it created. Everything that is created is subject to destruction. And further, since the cosmos exists by the goodness of god, if follows that god must always be good and the world exist. Just as light coexists with the sun and with fire, and shadow coexists with a body.

- Sallustius, On the Gods and the World

faetal on 10/4/2013 at 22:43

Quote Posted by Azaran

The universe cannot have arisen out of nothing

This is begging the question.

demagogue on 10/4/2013 at 22:45

I wouldn't put it that way (not just because it would upset ZB's lexical sensibilities).
But it's a testable hypothesis, has been tested, and is false.
Empty space has vacuum energy which has quantum fluctuations that can create particles from "nothing".

Azaran on 10/4/2013 at 22:52

Quote Posted by demagogue

Empty space has vacuum energy which has quantum fluctuations that can create particles from "nothing".

My point exactly. Even empty space is composed of something, i.e. energy