Iwannaplato wrote: ↑Tue Dec 05, 2023 12:48 am
Immanuel Can wrote: ↑Mon Dec 04, 2023 11:46 pm
There's no such thing as "Big Crunch". That theory isn't just old, but now completely debunked.
Its not debunked...
Yeah, it is. There simply isn't anything close to the mass-to-space ratio in the present universe for any known force to induce a "Big Crunch," and that's by orders of vast magnitude. Furthermore, because of the red shift effect, we know for certain that the universe is expanding even further, not contracting. The mass in the universe is well beyond escape velocity. It's never coming back.
Or that this running down universe is part of something vaster and more infinite.
No, that's a misunderstanding of the word "universe." The "universe," by definition, includes all the matter and energy that exists. So proponents of "alternate universes" are actually positing the existence of things that depend on ideas like "folded time" or "alternate levels of reality," which by definition do not contact this one -- because if they did, they'd be part of THIS universe, not of some other.
Nope, you're ruling things out that cosmologists have not ruled out.
There are people willing to speculate
. There will always be speculators
. But science requires more: it requires evidence
. And those who speculate are doing so not in order to respond to the evidence, but only to escape the evidence. That's not scientific.
So there's no "science" in those theories at all, because they're pure speculations about the existence of levels of reality to which we have, and by definition can have, no scientific access at all. So we don't know if/how any such could even exist.
It's pure speculation to say that there was nothing before the Big Bang.
That's why nobody says that.
Everybody who believes in the BB recognizes that there had to be something prior to that to explode. But from where did that hydrogen, oxygen, quark gluon plasma or whatever else one postulates come from?
And again, if there can suddenly be the present of a universe of matter in low entropy and we don't know how this happened, then there is no reason to rule out cycles of this.
Yes, there is. "Low entropy" isn't the answer. If the entropic rate were a million times slower than it actually is, it would still give us exactly the same problem. All it would do is extend the time span.
Yes, we do. The belief in the universe being eternal died with Edwin Hubble and the Red Shift discovery. As cosmologist Alexander Vilenkin has summarized the situation, “All the evidence we have says that the universe had a beginning.” (quoted in New Scientist)
Which is quite different from ruling out other possiblities. The standard model took some serious recent hits.
And great you quoted one scientist from New Scientist. I can do that too...
https://www.newscientist.com/article/mg ... -universe/
But as I said, nobody says the BB was the beginning of the universe. So that's not a relevant observation.
Now you've got it! An infinite chain cannot ever start.
But that doesn't mean it isn't the case.
Actually, it does. If something "cannot" happen, then by definition, it "didn't" happen, too.
Of course it wouldn't have a start, that's by definition.
No, by maths and logic. You can do the experiment yourself. It's very easy.
A causal chain is made up of no less than two items: a cause, and an effect, right? It can be longer, but it cannot be shorter, or either the cause or the effect is missing. Is that not obvious?
And by definition, the cause must happen before the effect. Otherwise, it's not the cause. That, too, has to be perfectly obvious.
So now, run the test. Assign a number to an effect. Let's give it the designation "1". That makes the cause "O," which is numerically just before "1".
So now we can count the sequence: cause "0"...then "1" the effect. Our sequence is 0-1. And if 1 becomes the cause of anything, we can have a 2...a 3...a 4...and so on.
With me so far?
But before "0", there has to be a "-1": because our "0" is a physical cause of something, and itself has to have a cause. So let's label that earlier cause as "-1".
But before "-1", there has to have been a "-2"...and before that, a "-3", and a "-4" and so on.
But that backward sequence cannot be infinite. And why not? Because if I make you locate the number prior to every other number, you will recede back into an infinite regress...and you will never, ever find the starting point for the sequence.
In other words, in any causal chain...of which we have billions, of course...if we guess that there was not original starting point, then the sequence itself never got going. It never began. Nothing happened. And nothing ever could. Because the absolute prerequisite is never reached.
Get it now? So we know for certain, mathematically, that no causal chain is ever infinite. All must have a starting point. And that starting point cannot itself be something that has been caused by something else, or once again, we fall down the infinite-regress hole, and nothing ever happens.
But something HAS happened. A universe has appeared. That means there was an uncaused Cause at the beginning of that grand effect. And though we can't say for sure what it was, we can say for certain that there was one.
But you are assuming that everything must have a start, even though you have a central belief in something that does not have one.
Not quite. I'm pointing out that whatever started the causal chain was uncaused. It's only the Atheists, Materialists, Physicalists and Naturalist types who have to believe that everything has to have a cause...but if they were right, the universe would not exist.
But it does
exist. We're in it. So you can be absolutely sure they're wrong.
There is always another prerequisite that has to happen before the chain can commence! So all the causal chains you see around you are known to be finite ones, because infinite ones lack a starting point.
I have no way of knowing if the causal chains around me have a start.
Yes, you do. Mathematics. Logic. You cannot, yourself, reproduce any causal chain that has an infinite set of prerequisite conditions. If you can't start your sequence at "-1,236,754," or whatever other point you choose, you cannot produce any numerical sequence at all. Ever.
There's your proof.