If It Was A " Big Bang" That Started The Universe And Us, What Went " Bang"?

[annieigma]

I doubt if anyone can give a definite answer, but why do scientists think it was the start of the universe? could it be the aftermath of an enormous exploding star that they are seeing? I realise that many scientists seem to have the same opinion about the big bang, but why?

[bibblebub]

it's a mistake to think of the big bang as an enormous exploding star because it was a completely different type of event

[jim360]

The "Big Bang" was a name given to the theory by someone who didn't like it much, namely Fred Hoyle. It's a bad name but has somehow stuck. I don't understand most of it myself but even so it's not really a "Bang", but more of an expansion. Space and time were all gathered at a single point, and just grew outwards. Lots and lots of energy released, and crazy stuff went on, the full details of which are still a mystery to us all.

But the reason the theory holds is because this event left behind a lot of traces: an expanding universe, lots of background energy that shows up as microwaves, and other things I'm not aware of, all of which fit the theory well. There are still gaps, and holes, and things to be sorted out, but the overall picture is very convincing and as a result the general gist of the theory is almost universally accepted these days.

[DaisyNonna]

So science is not based on fact?

[LazyGun]

What?

[Noth43]

Start a new thread in R&S Daisy.

[Arksided]

I believe the Universe has been breathing in and out Infinitely (Its always existed) as a point of origin to explain what I mean Big bang, Universe expands as we know it today, slows down then contracts on itself (the Big crunch) until it becomes a singularity all that energy and mass has to go somewhere E=mc2 bang the cycle repeats itself again.

As no-one can prove what did happen before the big bang... it's good as any theory.

[jim360]

I'd always thought that to be "just as good" a theory as the Big Bang, since indeed a Big Bang would probably wipe out traces of the past. On the other hand this would make the infinite cycle theory untestable, so it's not really a scientific theory. Also apparently many models of infinite cycles have difficulty in evading the Second Law of Thermodynamics (Entropy never decreasing). Jury is still out, but either way it seems to be a good thing for the Universe to have been around for a finite amount of time.

[DaisyNonna]

Why?

[jim360]

Why what?

[Arksided]

I think Daisy was asking Noth43

[i] Start a new thread in R&S Daisy. [i]

[Khandro]

jim; What I like about your explanations are that they are informative, elegant, and yet always leave room for further speculation.

[Old_Geezer]

It would have been the newly created universe from nothing that went bang; or at least it may have done so were there something for sound waves to travel in at the time, which of course there wasn't.

By definition you don't get things like stars, enormous or otherwise, until there is a universe in which to create them.

The "Big Bang" implies a belief in a start to the universe. It is it's birth.

The big crunch/big bang cycle is a decent enough theory but as I understand it we see no evidence that the present universe will crunch, so it seems an outsider bet.

Daisy's first question seems to come out of the blue and unrelated to what occurred before, it so no wonder folk wonder why, and think it may be a dig at science or something.

[jake-the-peg]

Big bang is an analogy and not always a good one

It's not an explosion like a star exploding

What actually happened wasn't an explosion filling empty space with matter - it was the creation of space itself than space expands carrying matter and everything with it

Sounds crazy because we're not used to it in every day life but here's how we know:

When Edwin Hubble first measured the distance of galaxies 80 years ago he found that the most distant galaxies were travelling the fastest the further the galaxy the faster it was going


Imagine a stick of dynamite in a bowling ball - all the shards will travel out at about the same speed

Now imagine currents in bread left to rise - as the dough expands the currents on the outside move away fastest because there's more dough expanding between them.

This is why 'big bang' isn't a great metaphor. - it's more like a drop of that expanding foam inflating like mad carrying everything with it

[chakka35]

I think that what noth43 means, Daisy, is that your query is so vague and all-encompassing that it is better suited to R&S, where vagueness and a distrust of science is par for the course. It is too unspecific for the Science
site.

[Khandro]

jake; instead of //What actually happened// I think "The theory is," would perhaps be more apt.

[jim360]

Somewhere between the two positions is probably the right thing. "The theory is..." always seems to imply to most people that it's guesswork but of course there is more confidence than that . "What actually happened" doesn't allow for any doubt at all, and who knows, something drastic could change about our view of the world.

My preferred way of phrasing it would be closer to "What almost certainly actually happened...". There is no significant reason to doubt the theory of a Big Bang 13.82 billion years ago (plus or minus about 50 million or so), based on current understanding, as it has passed all of the tests asked of any scientific theory with flying colours (albeit with a few tweaks too).

[SSSid]

We will never know.

[jim360]

That depends on what you mean by "know"> If by "know" you mean 100% certainty beyond any doubt whatsoever and never listening to any criticism or changing anything, then no we will never know. If, on the other hand, by "know" you mean have a high confidence level (about 95-99% or better) beyond reasonable doubt, continually refining the model to fit new data and devising new experimental tests, then we already "know" about the early universe and that the Big Bang Theory as it stands is a good one.

[jake-the-peg]

No we know a certain amount

You hear a bang, see shards flying away - I think that there was an explosion would stand up in court as being beyond reasonable doubt


Maybe we won't know the fine detail but that doesn't mean the fundamentals are somehow unknowable.

[jake-the-peg]

If you want something that we'll never know - try the origin of life on Earth.

The evidence that would tell us how that happened has almost certainly been destroyed - even if we could artificially create life that would still only tell you how it might have happened.

To my mind that is an unknowable